Cardiovascular

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12503/21619

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    Sinus Node Dysfunction in a Young Female Without Identifiable Risk Factors
    (2019-03-05) Reynolds, Conner MS; Thompson, Kevin MS; Tierney, Nancy PhD, RN, ACNP; DeVille, Heather MS
    Background: Sinoatrial Node Dysfunction (SND) is a multifactorial disorder leading to symptomatic bradycardia and asystolic pauses. Epidemiological studies estimate the SND annual incidence at 0.8 per 1,000 person-years, with the majority of cases occurring over 75 years old. Case Presentation: A 32-year-old Caucasian female presented to the emergency department with sharp, episodic chest pain, radiating to the mid-back and jaw. Her episodes were associated with dizziness, diminished vision, and syncope, lasting approximately 5 minutes before resolving spontaneously. She had a history of PVCs, uncomplicated C-section, & LARC placement, but not for tobacco use, DVT/PE, CAD, immobilization, or cancer. Laboratory studies revealed prolonged PT (12.7), but troponin series, PTT, TSH, BNP, CBC, magnesium, I-STAT 6, and urine hCG were within normal limits. ECG showed sinus bradycardia. She was discharged home to follow up with electrophysiology. Two days later, episodes began occurring with higher frequency and shorter latency, necessitating admission to the cardiac intensive care unit. On admission, she appeared lethargic with a HR of 41bpm, BP of 108/60, and O2 saturation of 98%. Secondary assessment revealed normal heart sounds with no rubs, gallops, or murmurs. Laboratory assessment revealed prolonged PT and isolated lymphopenia (22.9%), but troponin series was within normal limits. ECG showed no ST-changes or T-wave inversions. Echocardiogram showed no evidence of valvular or structural heart disease. On Day 2, CBC revealed leukopenia (4,900mc/L) and CMP revealed low AST (10), calcium (7.6), albumin (3.1), and total protein (5.3), as well as high BUN/Cr (21.7). On Day 3, Lyme, Lupus Anticoagulant, and Rheumatoid Factor titers were within normal limits. BUN/Cr levels had also returned to 11.7. Coronary artery angiogram showed no evidence of aneurysm or pathologic vessel narrowing. Continuous telemetry showed an average heart rate of 50bpm while awake and 30bpm while asleep. Upon ambulation she achieved 66bpm, but was so fatigued afterwards that she had to return to bed. Given the degree of bradycardia and intolerance to ambulation, the decision was made to proceed with dual-chamber pacemaker implantation. The device was successfully placed without intraoperative complications. Conclusions: This case illustrates a unique presentation of SND in a highly atypical age group without contributory medical history or identifiable risk factors.
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    Stiff Left Atrial Syndrome Masquerading as Mitral Stenosis
    (2019-03-05) Khan, Ahsan; Jipescu, Daniel; Chandraprakasam, Satish; Thambidorai, Senthil; Patel, Aman
    Background Stiff left atrial syndrome first described in 1988 by Pilote et al. and co in JACC is an uncommon condition that could have similar presentation to congestive heart failure with preserved EF and often missed if not considered as differential diagnosis of patient with heart failure symptoms especially in setting of past history radiofrequency ablation (RFA) for atrial fibrillation (Afib). We present a case of stiff left atrial syndrome that masqueraded as bioprosthetic mitral valve (MV) dysfunction and required multimodality imaging to diagnose this disease (1). Case Description The patient is a 79-year-old female with a past medical history of permanent Afib, paroxysmal atrial flutter, bioprosthetic MVR along with 1 vessel coronary artery bypass graft surgery. 2 years ago, she underwent a pulmonary vein isolation (PVI) radiofrequency ablation (RF) with roof line, posterior inferior line and cavotricuspid isthmus ablation. Recently, she developed progressive dyspnea on exertion (NYHA class III). A transthoracic echocardiogram appeared to show increased mitral valve gradient. She was brought to our institution for left and right heart catheterization followed by transesophageal echocardiogram (TEE).During cardiac catheterization, simultaneous recording of left ventricular pressure and pulmonary capillary wedge pressure (PCWP) demonstrated an elevated transmitral mean gradient of 13.15 mmHg and a calculated effective orifice area of 0.64 cm2. The PCWP was elevated at 25 mmHg, the mean pulmonary artery pressure was elevated at 31 mmHg and the left ventricular end diastolic pressure (LVEDP) and pulmonary vascular resistance were normal. Conversely, a TEE showed a normally functioning MV with no hemodynamically significant stenosis (mean gradient 4 mm Hg). Computed tomography angiography did not show evidence of iatrogenic pulmonary vein stenosis to explain these discordant findings but confirmed an enlarged left atrium (LA). Due to her history of mitral valve replacement and RF ablation, we determined that Stiff Left Atrial Syndrome was the likely cause of the patient’s symptoms. Discussion Stiff left atrium syndrome is a condition that is caused by scarring and fibrosis of the LA leading to decreased compliance. It clinically manifests as pulmonary edema and dyspnea on exertion and is often difficult to discern from diastolic heart failure of other common etiologies. Pulmonary hypertension may develop from this condition as well (1,3). It was initially described in relation to mitral valve replacement surgery and maze procedure, but now being recognized to be caused by radiofrequency ablation for atrial fibrillation. Hemodynamically, there is often elevated pulmonary artery pressures, elevated PCWP and normal LVEDP. A large v wave may be seen in PCWP tracings. In our patient, the elevated PCWP to LVEDP gradient and inaccurate effective orifice area were likely due to elevated LA pressure caused by extensive scarring and noncompliance rather than a problem with the MVR. Pulmonary vein stenosis and mitral valve stenosis must be ruled out, as it was with our patient (1). There are no proven therapies for Stiff Left Atrial Syndrome, but diuretics are primarily used. Creation of an atrial septal defect to relieve LA pressure has been tried experimentally (1,2).
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    Variant of Left Vertebral Artery Origin and Transverse Foramina Entry
    (2019-03-05) Ames, Kyle; Fisher, Cara Ph.D; Blackwood, Taylor
    Background: Variations in the origin, course, and transverse foramina entry of the left vertebral artery(LVA) are well documented in literature. The LVA usually originates from the left subclavian artery and courses through the neck to enter at the C6 transverse foramina. While variants of the LVA are not known to cause pathological problems, knowledge of the common variants is of great use to diagnostic radiologists, interventional radiologists, and cardiologists. Case Information: During routine dissection of a 67 year-old white female cadaver, a variant left vertebral artery was discovered. This variant was found to branch off the arch of the aorta between the left common carotid and left subclavian artery, instead of its typical origin from the left subclavian artery. Additionally, we noted that the LVA entered at the transverse foramina of the C4 vertebrae instead of its usual entry point at C6. Although a complete medical history was unable to be obtained, no other significant arterial variants were noted. However, the cadaver did possess extensive right lower extremity varicose veins, which we suspect are unrelated. The cause of death was noted to be metastatic pancreatic cancer. Conclusions: This study serves to add to the expanding body of knowledge surrounding anatomical variations of the vertebral artery including its origins and transverse foramina entry point locations. The left vertebral artery originating from the aortic arch occurs in approximately 6% of the population, but these variations are not recognized to cause problems for those individuals, assuming there is no hypertrophy or atrophy of the arterial wall. The transverse foramina entry point in this cadaver was noted to be C4, higher than the normal C6 entry point. Komiyama et al. found an incidence of dissection of 1.7% for vertebral arteries arising from the aortic arch, as opposed to .9% in the general population for those with the appropriated normal anatomy. While the exact reason has yet to be elucidated, it is hypothesized that this is due to the association of vertebral arteries off the aortic arch traveling farther in the neck to C3 and C4, thus predisposing individuals to increased stress on the vasculature allowing for dissection. For these reasons diagnostic radiologists, interventional radiologists, and cardiologists should be acutely aware of the common variants to improve diagnosis, treatment, and reduce potential complications.
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    Beyond Magnetic Resonance Angiography in Anomalous Aortic Origin of the Coronary Arteries: Additive Value of Late Gadolinium Enhancement
    (2019-03-05) Muyskens, Steve; Hamby, Tyler; Nguyen, Andrew
    Purpose: Anomalous aortic origin of the coronary arteries (AAOCA) is a common cause of sudden cardiac death (SCD) in young athletes. The prevalence, pathophysiology, and optimal method of risk stratifying AAOCA are unknown. Coronary magnetic resonance angiography (MRA) has been shown to reliably define anatomical features. However, studies evaluating current methods of detecting inducible or chronic ischemia in patients with AAOCA are lacking. We present our institutional experience utilizing late gadolinium enhancement (LGE) as an adjunct to exertional symptoms, exercise stress testing (EST), and single-photon emission computed tomography (SPECT) for risk stratifying high-risk AAOCA. Methods: A retrospective review was conducted of all patients referred for evaluation of possible AAOCA by cardiac magnetic resonance imaging (CMR) between January 2011 and December 2017. Patients with high-risk coronary anatomy were included; patients with complex congenital heart disease were excluded. High-risk AAOCA was defined as the presence of interarterial or intramural features. We assessed the utility of risk stratifying high-risk AAOCA by LGE, SPECT and exertional symptoms. Validity of SPECT in detecting affected coronary vascular territories was also examined. Chi-square test of independence was used for statistical analysis. Results: There were 74 patients evaluated for possible AAOCA (median age 14.3 years; 69% male); 40 met high-risk inclusion criteria (34 right, 6 left). SPECT was performed in 33 patients, and EST in 36 patients. Exertional symptoms were present in 11 patients. One patient with aborted SCD had subepicardial LGE, most consistent with myocarditis. No additional patients had baseline ventricular dysfunction or LGE findings on CMR. Risk stratification by exertional symptoms or coronary variant revealed no significant correlation to any markers of ischemia. Furthermore, SPECT was predominantly negative (70%), and 3 of 10 positive results did not correlate with the affected coronary vascular territory. Conclusions: Our study demonstrates the difficulties in utilizing common techniques for risk stratification in patients with AAOCA. While coronary MRA has been shown to reliably assess coronary anatomy, CMR-derived LGE had no additive value in this cohort, and SPECT had a high false positive rate. A larger multicenter study including the utility of stress CMR would be beneficial in this patient population.
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    Relationship between Sleep Duration and Hypertension in US Adults using Age- and BMI-Stratified Models
    (2019-03-05) Okunowo, Oluwatimilehin; Njesada, Ndolembai; Solomon, Ambe; Bakre, Sulaimon; Orimoloye, Helen
    Relationship between Sleep Duration and Hypertension in US Adults using Age- and BMI-Stratified Models ABSTRACT Background: Hypertension is a strong risk factor for cardiovascular disease and mortality. Previous research has confirmed the relationship between sleep duration and hypertension. However, there are unanswered questions on how this relationship is affected by age and body mass index (BMI). Purpose: To examine the association between sleep duration and hypertension in US adults and investigate interaction by age and BMI. Methods: Data from the National Health Interview Survey (NHIS) between 2014 and 2017 was analyzed for adults aged 18 years or older (n=130,139). Sleep duration was categorized as short (hours) or long ([greater than] 9 hours). Multivariable logistic regression estimated the likelihood of hypertension associated with short or long sleep duration relative to the National Sleep Foundation’s recommended 7-9 hours. Results: After adjusting for potential confounders, short sleep was associated with higher odds of hypertension (OR: 1.68, 95% CI: 1.35-2.02). Although not statistically significant, long sleep was also associated with higher odds of hypertension (OR: 1.19, 95% CI: 0.71-1.67). A significant sleep x age and sleep x BMI interaction was noted (p Conclusions: Short sleep duration is a significant risk factor for hypertension in the United States. This relationship is mediated by age and BMI and is especially notable in middle-aged and underweight adults.
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    Preliminary Findings on Sex Differences in Response to Various Acute Stressors in Male and Female Mice
    (2019-03-05) Cross, Sissy; Wang, Lei; Mifflin, Steve; Nguyen, Dianna
    Purpose: Studies in both humans and animals have shown that pre-menopausal females are protected against the hypertensive and sympatho-excitatory effects of stress. Our goal was to identify whether sex difference exists between male and female mice in response to various acute stressors. Methods: Adult male (n=4) and female (n=4) C57BL/6J mice underwent telemetry implantation (HD-X10, DSI) surgery and allowed 1-week recovery. Each day the mice were exposed to 1 of 5 acute stressors (acute restraint, hypoxia, new cage, cold, or forced swim). Mice were allowed 1-2 days of recovery between stressors. Acute restraint: placing the mouse in a conical tube for 30 min; hypoxia: exposing the mouse to 20 min of 8% O2; new cage: placing the mouse in an empty cage with no bedding for 30 min; cold: exposing the mouse to 1-4C for 30 min; forced swim: placing the mouse in a water-filled beaker for 10 min. Mean arterial pressure (MAP), heart rate (HR), and activity were recorded and data analysis (2-way repeated measures ANOVA followed by Holm-Sidak) was performed. Results: Acute restraint: male mice responded with peak MAP of 135±4, peak HR of 768±21, and peak activity of 0.00±0.0; whereas female mice responded with peak MAP of 131±2, peak HR of 749±21, and peak activity of 0±0.0. Hypoxia: male mice responded with peak MAP of 122±4, peak HR of 780±6, and peak activity of 0.50±0.3; whereas female mice responded with peak MAP of 131±1, peak HR of 784±18, and peak activity of 0.50±0.3. New cage: male mice responded with peak MAP of 137±7, peak HR of 789±8, and peak activity of 1.75±0.5; whereas female mice responded with peak MAP of 137±4, peak HR of 790±3, and peak activity of 1.50±0.3. Cold: male mice responded with peak MAP of 133±4, peak HR of 800±9, and peak activity of 1.00±0.4; whereas female mice responded with peak MAP of 137±7, peak HR of 797±14, and peak activity of 1.50±0.3. Forced swim: male mice responded with peak MAP of 136±5, peak HR of 729±30, and peak activity of 1.50±0.3; whereas female mice responded with peak MAP of 134±5, peak HR of 694±7, and peak activity of 1.25±0.5. Conclusions: In this preliminary study, no significant sex difference was observed in male and female mice in response to the various acute stressors, however there was a trend for sex difference in MAP during acute restraint stress. This study needs to be repeated to increase sample size before further conclusions can be made.
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    Are Spontaneous Low Frequency Oscillations in Arterial Pressure and Cerebral Blood Flow Associated with the Protection of Cerebral Tissue Oxygenation during Simulated Hemorrhage?
    (2019-03-05) Rosenberg, Alexander; Kay, Victoria; Sprick, Justin; Rickards, Caroline; Anderson, Garen K.
    Introduction: Prior studies have independently demonstrated that subjects with higher tolerance to simulated hemorrhage elicited by lower body negative pressure (LBNP) exhibit maintenance of cerebral tissue oxygenation, and higher amplitude in spontaneously generated low frequency (~0.1 Hz) oscillations in arterial pressure and cerebral blood flow. We hypothesized that these two independent observations are related, wherein subjects with higher tolerance to LBNP would exhibit increased low frequency power in arterial pressure and cerebral blood flow, which may contribute to the protection of cerebral tissue oxygenation. Methods: Healthy male (n=19, 25±1 y) and female (n=13, 28±1 y) subjects participated in a stepwise LBNP protocol to pre-syncope. Mean arterial pressure (MAP), middle cerebral artery velocity (MCAv), cerebral tissue oxygen saturation (ScO2), and end tidal CO2 (etCO2) were measured continuously. Subjects were classified as high tolerant if they completed the -60 mmHg step of LBNP. Low frequency oscillations in MAP and MCAv were assessed in the 0.04-0.15 Hz range. Both time and frequency domain data were analyzed using a linear mixed model analysis of variance with Tukey post hoc tests. Comparisons were made at baseline across LBNP stages (-15, -30, -45, and -60 mmHg). Results: Of the 32 subjects tested, 20 were classified as high tolerant and 12 as low tolerant. No differences were observed between high and low tolerant subjects in MAP (P=0.28), low frequency power of MAP (P=0.13), or low frequency power of MCAv (P=0.24) during LBNP. However, high tolerant subjects exhibited greater protection against reductions in ScO2 (P2(P Conclusion: Contrary to our hypothesis, low frequency oscillations in MAP and MCAv did not account for the observed protection in ScO2 for high tolerant subjects. Rather, maintenance of oxygen delivery (indexed via MCAv) appeared to account for the protection in cerebral oxygenation in this cohort of young, healthy subjects.
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    Impact of left atrial appendage (LAA) morphology on Outcomes of WATCHMAN device implantation (LMOW study)
    (2019-03-05) Khan, Ahsan; Gupta, Karan; Timins, Aaron; Johnson, Douglas; Jipescu, Daniel; Aftabizadeh, Som; Wilson, Kimberley; Thambidorai, Senthil; Nair, Sanjeev; Patel, Aman
    Purpose: Left atrial appendage occlusion (LAAO) with a WATCHMAN device is approved to be used in atrial fibrillation (AF) patients who are not good candidates for long term oral anticoagulation therapy (OAT) as an alternative stroke prevention strategy. Over the years, a number of different trials have addressed the various aspects of LAAO procedure, but there is still not enough literature on the impact of LAA anatomy on procedural outcomes of WATCHMAN device implantation. Besides shape, the location and orientation of LAA is a significant determinant of the complexity and success of the procedure. Chicken wing morphology has well been described as a particularly challenging anatomy from an interventional standpoint. We would like to assess the impact of the LAA morphology, as per a prior accepted classification (Chicken Wing, Cauliflower, Wind Sock or others), on the intraprocedural outcomes including procedure success, duration, compression ratio, number of devices used and major complications in the periprocedural period. 2. Methods: A single center observational study from individual institutional registries attempting to assess the impact of LAA anatomy on outcomes after WATCHMAN device implantation. Procedural outcomes, as mentioned above, will be compared between patients with and without chicken wing LAA anatomy. 3. Results: A number of 77 patients were found in our registry between September 2015 and April 2018, out of which 31(40%) had Windsock, 31(40%) had Cauliflower and 15(19%) had Chicken wing morphology. All of them had 100% successful implantation. The mean duration was noted to be 74.8 minutes with 1.065 number of attempts (NOA) for the patients with Cauliflower, 72.3 min with 1.294 NOA for the Chicken Wing and 70.3 minutes with 1.182 NOA for the Windsock. 4. Conclusion: After a thorough analysis of 77 patients it was noted that the patients with Cauliflower morphology had the longest duration of the procedures but had the least number of attempts. The patients with Chicken wing morphology had the highest number of attempts and the patients with Windsock had the lowest duration of implantation. Although the patients with the Cauliflower morphology took the longest time to be implanted having the lowest number of attempts might decrease the risk of complications. We recommend a more extensive analysis with a larger sample of patients to be able to find a significant correlation.
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    Treating Rare mid femoral pseudoaneurysm after chronic total occlusion revascularization.
    (2019-03-05) Chou, Mark; Ali, Farhan; Malik, Hamza
    Abstract Background: Arterial pseudoaneurysms (PSAs) are rare complications of endovascular procedures.They are characterized by a defect in vessel wall layers which may result in severe pain, nerve compression or even hemodynamic instability. Treatment is dependent on the size of the lesion with larger defects at higher risk for expansion or rupture. Typical treatments include manual compression, thrombin injection or open vascular repair.Usually PSAs arise at puncture sites in the common femoral artery (CFA). In this case report, we present a unique scenario of a PSA resulting from endovascular repair of mid-superficial femoral artery (SFA) chronic total occlusion by re-entry from the sub-intimal space. This case describes use of a Viabahn covered stent to occlude a mid SFA PSA successfully. Case information: 73-year-old male with a history of severe COPD, ischemic heart disease, and 30-year history of smoking presented with severe left lower extremity claudication progressively worsening over the last year. Due to comorbidities, he was deemed too high risk for surgical bypass and instead, underwent a complex intervention requiring complete revascularization with angioplasty and stenting from a transpedal approach with contrast staining of the subintimal space. One week post-operatively, he presented back in the ER with severe mid-thigh pain. Arterial Doppler showed the patent left SFA stent, with a large PSA in the mid-left SFA at the prior location of subintimal injury during revascularization. A decision was made to attempt percutaneous covered stent placement to occlude the neck of the PSA. A Viabahn stent was deployed successfully across the PSA and within the previously placed Supera stent without complication. Post-dilation was performed with excellent final angiographic result that showed patency of the SFA with successful exclusion of the PSA. The patient had immediate improvement in pain and was back to baseline one week later. Conclusions: Although rare, PSAs found in the mid-SFA are an ideal location for correction with covered stent. Covered stents offer low risk and high reward rates, and identify a viable new treatment modality that could potentially replace the need for open surgical repair in the correct patient population. Additionally, this minimally invasive approach could be a viable treatment option for PSAs in locations not easily amenable for standard methods of repair.
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    Renal cortical antioxidant enzymes are not inactivated by cardiac arrest-resuscitation in pigs
    (2019-03-05) Cherry, Brandon; Nguyen, Anh; Qureshi, Imran; McGee, Bryan; Medrano, Thomas; Yurvati, Albert; Mallet, Robert T.; Petty, Mitchell
    Purpose: Cardiac arrest interrupts renal blood flow, and cardiopulmonary resuscitation (CPR) and restoration of sinus rhythm and renal perfusion may generate reactive oxygen species (ROS) that damage the kidneys. Cardiac arrest, CPR and cardioversion inactivate ROS-sensitive enzymes in heart and brain, but intravenous sodium pyruvate (PYR) treatment preserves the enzymes and prevents heart and brain injury. The impacts of cardiac arrest-CPR and PYR on ROS-sensitive antioxidant enzymes in renal cortex is unknown. This study tested the hypothesis that cardiac arrest-CPR-recovery inactivates, while PYR preserves, these renal enzymes. Methods: Yorkshire swine (c. 30 kg) were intubated and mechanically ventilated with 1-3% isoflurane in O2. Cardiac electrical activity was monitored by lead II electrocardiography. Cardiac pacing (60 Hz) produced ventricular fibrillation, and ventilation was suspended. From 6 to 10 min cardiac arrest, precordial chest compressions were applied (100/min), and then transthoracic DC countershocks were administered to achieve cardioversion, and ventilation resumed. PYR (n=7) or NaCl (n=6) were infused iv (0.1 mmol/kg/min) from 5.5 min cardiac arrest to 60 min recovery. Non-arrested sham pigs (n=9) also were studied. At 4 h recovery, the kidneys were excised, and renal cortex biopsied and snap-frozen in liquid N2. The biopsies were pulverized and extracted in 1 mM phosphate buffer (pH 7.2). Extract activities of glutathione peroxidase (GP), glutathione reductase (GR), the anti-glycation enzyme glyoxylase-1 (GLO-1), and NADPH-generating glucose 6-phosphate dehydrogenase (G6PD) and isocitrate dehydrogenase (ICD) were assayed at 37°C by spectrophotometry and normalized to total protein. Results: Contrary to our hypothesis, neither cardiac arrest-CPR-recovery, nor PYR treatment, produced statistically significant effects (single-factor ANOVA; a=0.05) on the enzyme activities (U/mg protein: mean±SEM): GP: sham 0.18±0.03, NaCl 0.25±0.07, PYR 0.15±0.02; GR: sham 0.21±0.04, NaCl 0.22±0.05, PYR 0.17±0.01, GLO-1: sham 4.45±0.40, NaCl 4.35±0.86, PYR 3.77±0.80, G6PD: sham 0.62±0.06, NaCl 0.69±0.14, PYR 0.52±0.13; ICD: sham 0.89±0.15, NaCl 1.15±0.28, PYR 0.99±0.12). Conclusions:Ischemic and oxidative stress produced by 10 min cardiac arrest with 4 min CPR did not inflict sufficient ischemic and oxidative stress to inactivate the renal cortex’s antioxidant enzymes, leaving no deficits correctable by PYR treatment.
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    Identifying Factors That May Affect Mortality of Infants with Hypoplastic Left Heart Syndrome
    (2019-03-05) Kuo, James; Hamby, Tyler; Ogunyankin, Fadeke; Li, Tommy
    1. Purpose/BackgroundHypoplastic left heart syndrome (HLHS) is a severe congenital heart defect that is fatal without surgical intervention. The CDC states that HLHS make up approximately 3% of all congenital heart defects and occur in about 3 babies per 10,000 live births. While studies have shown that survival rates are improving (5-10 year survival rate was 50-60% in 2001, 60-80% in 2014), there are still many factors that play a role in the outcome of patients born with HLHS that needs further investigation. This study aims to determine specific risk factors that may affect mortality in HLHS patients. 2. MethodsWe conducted a retrospective cohort study of patients with HLHS who underwent Norwood surgery at Cook Children’s Medical Center between January 1, 2007 and December 31, 2017. The variables included total length of intubation time (≥7 days vs.days), degree of atrial septal defect (restricted vs. intact), timing of HLHS diagnosis (prenatal vs. postnatal), and survival to initial discharge (alive vs. dead). These groups were compared using descriptive statistics and chi-square test of independence. A p-value 3. ResultsThere were 151 patients meeting study criteria and 124 (82.1%) survived to discharge. We found that patients who were intubated ≥7 days were less likely to survive to discharge (75.6% vs. 91.8%; p=0.01). RAS/IAS and timing of diagnosis was not significantly related to survival to initial discharge. 4. ConclusionThe results suggest intubation length may play a role in patient outcome and mortality, but we cannot state that there is a direct correlation from this study alone. Further analysis must be done in order to determine whether intubation length itself contributed to mortality or if confounding variables were responsible.
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    Development of Predictive Model for Detection of Sleep Apnea in Underrepresented Minorities
    (2019-03-05) Smith, Michael; Villarreal, Marcus
    Purpose: Obstructive Sleep Apnea (OSA) is a sleep disorder that is caused by recurrent upper airway closure and is highly associated with hypertension. OSA is also known to be underdiagnosed in the general population. Previous studies have shown that individuals with OSA experience hypoxia which leads to elevated sympathetic nerve activity (SNA) and arterial pressure (AP). The elevated SNA has been shown to directly correlate to an increased pressor response through voluntary apneas. This pressor response is exaggerated in OSA despite the degree of hypoxia that subjects are exposed to prior to the apnea. The current standard for the diagnosis of OSA is through polysomnography (PSG) which relies on a sleep laboratory and can be inaccessible to some patients. In order to minimize or reduce underdiagnoses, the elevated systolic AP observed in OSA patients during voluntary apneas could serve as alternative or adjunctive measure with PSG along with other predictors such as the Epworth Sleepiness Scale (ESS). Methods: A combination of anthropometric data, STOPBANG, ESS and AP responses to voluntary apnea data were used to assess the predictive power for OSA in all populations. In order to achieve this, multiple regression analyses and estimations of specificity and sensitivity were determined from cohorts of patient data from sleep and of a previously collected data set. This data set includes participants with diagnosed OSA, Normotensive participants who do not have OSA, and undiagnosed participants. Results and Conclusions: The preliminary findings from this pilot study suggest that 1) addition of the pressor response to apnea enhances predictive power for OSA and 2) the predictive power is equally strong in underrepresented minority and Caucasian populations.
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    Contribution of K+/Cl- Cotransporters in AT1aR Dependent GABAa Inhibition in the MnPO Following Chronic Intermittent Hypoxia
    (2019-03-05) Little, Joel; Marciante, Alexandria B.; Cunningham, J. Thomas; Farmer, George Jr.
    Purpose: Chronic intermittent hypoxia (CIH) is an animal model that simulates the hypoxemia seen in obstructive sleep apnea (OSA). Rats exposed to CIH exhibit an increase in blood pressure during periods of normoxia, similar to that observed in OSA. The median preoptic nucleus (MnPO) exhibits increases in Angiotensin type 1a receptor (AT1aR) mRNA following CIH and blocking this increase in AT1aR mRNA prevents the sustained increase in blood pressure. Here we investigate the role of AT1aR in the MnPO and the contribution of the K+/Cl- cotransporters KCC2 and NKCC1 on excitatory/inhibitory balance in rats subjected to CIH. Methods: Under isoflurane (2-3%) anesthesia, male Sprague-Dawley rats (250-350g) received microinfusions (0.4 µL) of recombinant AAV construct containing GFP reporter and shRNA against AT1aR (AT1aKD) or an AAV containing the GFP reporter and a shRNA scramble (Scr) targeted to the MnPO. After recovery, rats were subjected to 7 days of CIH (0800-1600 hrs). The CIH protocol consisted of 6 min cycles (3 min 21% O2, 3 min 10% O2) repeated 10x/hr for 8 consecutive hrs (during the normal inactive/sleep phase) on 7 consecutive days. After 7 days CIH, the rats were anesthetized with isoflurane (2-3%) and coronal slices (300 µm) containing the MnPO were cut using standard in vitro slice procedures. Loose patch recordings were obtained from GFP labeled neurons using glass micropipettes containing aCSF as the internal solution (1-3 MΩ). Spontaneous action potentials (APs) were recorded in response to muscimol (100uM, 30s). Results: The GABAa agonist muscimol decreased AP activity of neurons from normoxic/Scr rats. GABAa inhibition was blunted in neurons from CIH/Scr and normoxic/AT1aKD rats. However, GABAa activation from neurons in the CIH/AT1aKD group produced an increase in spontaneous activity. KCC2 block reduced GABAa mediated excitation in CIH/AT1aKD but had no effect GABAa mediated inhibition in CIH/Scr. NKCC1 block reduced GABAa mediated excitation in CIH/AT1aKD and facilitated GABAa mediated inhibition in CIH/Scr. Conclusion: The current study shows AT1aKD mediated reduction in GABAa inhibition is exacerbated such that GABAa activation is excitatory following CIH. KCC2 and NKCC1 contribute to GABAa mediated excitability in CIH/AT1aKD but only NKCC1 contributes to attenuated GABAa function in CIH/Scr. Future studies will address the influence of reduced AT1a signaling and reduced GABAa mediated inhibition on downstream targets of the MnPO.
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    Risk Factors Associated with Stroke in Pediatric Patients Undergoing Fontan Palliation
    (2019-03-05) Duncan, Jay; Hamby, Tyler; Javed, Mahnoor
    Risk Factors Associated with Stroke in Pediatric Patients Undergoing Fontan Palliation Puprose: Congenital heart disease is the leading known cause for stroke in childhood. The Fontan operation is performed as the third palliative procedure in patients who have complex single ventricle physiology. Patients undergoing Fontan Palliation are at risk for 3 types of strokes: watershed, embolic, or hemorrhagic. Stroke following Fontan Palliation can result in significant deterioration of functional ability. The incidence of this complication seemed higher at Cook Children’s Medical Center (CCMC) as compared to a previous study done at Children’s Hospital in Boston (2.6%). Therefore, the aim of our study is to identify variables contributing to the development of stroke and the risk factors associated with it. The hypothesis is that there are identifiable and potentially modifiable intra-operative and post-operative risk factors that are present in Fontan patients who have radiographic and clinical evidence of stroke. Methods: This was a retrospective chart review of 149 pediatric patients who underwent Fontan Palliation at CCMC between 2007 and 2017. Exclusion factors were any patient undergoing revision of prior Fontan or death within 72 hours of the operation. Covariates included AV valve regurgitation, ventricular function, SVC pressure (pre and post op), and intraoperative change in hematocrit. A Fisher’s exact test was used and p Results: Overall 11% post-Fontan patients had a stroke, all of which were watershed infarcts. Stroke was statistically significantly associated with pre- and post-operative AV valve regurgitation, and depressed ventricular function. Cardiac bypass time, mean arterial pressure, SVC pressure (pre- and post-operative) and intraoperative changes in hematocrit were not significantly associated with stroke. Though the relationship wasn’t significant, all stroke patients had a vasoactive infusion score greater than 5. Conclusion: Pre-Fontan physiology is the single most important factor when determining the risk of developing a watershed infarct with Fontan procedure. AV valve regurgitation and depressed pre-operative single ventricular function are potentially the most significant risk factors for perioperative stroke. This information may be helpful in counseling families about potential post-operative complications.
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    Does Physical Health Differ by Weight Status in Females Ages 55-79 with Coronary Heart Disease (CHD)?
    (2019-03-05) Pryor, Madison; Ho, Brittany; Rudder, Bryanne; Hartos, Jessica; Brown, Emily
    Purpose: There is a higher prevalence of poor physical health and obesity in older adult populations and females, but there is limited research of this relationship. The purpose of this study is to assess the relationship between physical health and weight status in females ages 55 to 79 with coronary heart disease (CHD) in the general population. Methods: This study is a cross-sectional analysis using data from the 2016 Behavioral Risk Factor Surveillance System (BRFSS) for 958 females ages 55-79 years old with CHD from the states of Alabama, Georgia, Kentucky, Louisiana and Oklahoma. Ordered logistic regression using combined state data examined the relationship between physical health and weight status, while controlling for the health conditions, mental health, physical activity, smoking status, age, race, education, employment status, and state. Results: The results showed about half of the participants reported poor physical health (40-50%), and the majority reported a BMI classified as obese (45-60%) or overweight (33-40%). Adjusted results indicated that there is an inverse relationship between weight status and physical health. In addition, number of health conditions, mental health, physical activity, and smoking status were all related to physical health in the target population. Conclusion: The results showed that weight status was moderately related to physical health in older females with CHD. These results may generalize to primary care for women 55-79 years old with CHD. In practice, clinicians may expect a moderate proportion of patients in this target population to report poor physical health, and overweight or obese BMI. Because of moderate relations between them, providers should screen for both if presented with symptoms of either. Given the small proportion and relationship between physical health and smoking, clinicians should continue to screen for smoking in this population. In addition, clinicians can expect moderate proportions of good mental health and physical activity. Since these are highly related to physical health, providers should screen for all if presented symptoms of one. Given the results, clinicians should recommend weight loss, smoking cessation, improving mental health, and increasing physical activity to better physical health.
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    “Posterior STEMI- The solar eclipse of EKG”. How to uncode and not miss it
    (2019-03-05) Chou, Mark; Jipescu, Daniel; Patel, Aman
    Background/Abstract: The clinical presentation of posterior myocardial infarction (PMI) is not always easy, not even for the cardiologist. True posterior myocardial infarction is difficult to recognise because the leads of the standard 12-lead electrocardiogram are not a direct representation of the area involved. Only with indirect changes in the precordial leads as such the diagnosis can be suspected. It is suggested to be one of the most commonly missed types of acute myocardial infarction (MI) electrocardiographic patterns. Case Report: A 47-years-old caucasian former 22 pack per year smoker with no significant PMHx presented with complaint of upper back pain radiating to both shoulders that started during a business meeting. He went home had some beers and rested. He slept and woke up at 11:30PM with severe pain in b/w shoulders: sharp, 10/10, constant with no aggravating or alleviating factors. The pain progressed to involve his both arms and chest and he got worried, therefore, decided to go to the ED where EKG changes and troponin elevation were noted. He reported nausea, palpitations. Denied SOB, diaphoresis, fever, cough, chills, physical exertion, trauma. His father had an MI at 53 yo. EKG was noted with: ST/T depression in inferolateral leads with loss of T wave balance in V1 and R wave in V2 taller than V3. Troponin elevation to 2.25 . The patient was taken emergently to cardiac cath and he was noted to have: patent Left main artery, patent left anterior descending artery, mild disease in the mid right coronary artery, and 100% occlusion of the Left Circumflex coronary artery. A drug eluting stent was placed. Discussion/Conclusion: True isolated posterior STEMI is rare and comprises of 3% of total STEMI and missed frequently in ER as well as in patient setting. Posterior STEMI associated with inferior or lateral MI is very common and comprises of 20% of the STEMI cases and usually not missed due to STEMI changes in inferior or lateral leads. Missed STEMI leads to increased cardiac morbidity and mortality and thus for clinicians it is very important to read each and every EKG for the patients presenting with suspected coronary disease. Our patient had back pain and first clinical impression was aortic dissection that was ruled out with CXR and urgent TTE. With back pain, elevated troponins and Tall R wave in lead V2 in the absence of any other causes of elevated troponin, posterior STEMI was suspected leading to emergent LHC that was suggestive of total occlusion of circumflex artery that was stented with a drug eluting stent with good flow was noted after that (TIMI 3 flow). Patient did well and was discharged home on same day with maximal medical therapy.
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    Safety and Efficacy Analysis of Balloon Cryoablation vs Radiofrequency Ablation in Atrial Fibrillation: A Retrospective Analysis. (SECARA AFib TRIAL)
    (2019-03-05) Khan, Ahsan; Gupta, Karan; Wilson, Kimberly; Jipescu, Daniel; Subramanian, Anand; Thambidorai, Senthil; Johnson, Douglas; Timins, Aaron; Patel, Aman
    Background: According to the ACC/AHA/HRS guidelines, Pulmonary-Vein Isolation has become the cornerstone approach in ablation for patients with medication refractory paroxysmal atrial fibrillation. (Class 1). Radiofrequency ablation is the most frequently employed technology followed by balloon cryoablation. According to multiple, smaller studies in recent past, both procedures have similar efficacy in terms of recurrence with little difference in complication rate. The FreezeAF trial, a 5-year observational study from 2011-2016 involving 4,073 patients, showed a better safety profile with radiofrequency ablation with lower rates of phrenic-nerve injuries in comparison to those of balloon cryoablation. However, some studies have shown that the rate of perforation was higher with thermal ablation. The landmark FIRE AND ICE Trial, a multicenter randomized controlled noninferiority trial of almost 800 patients published in 2016 in NEJM by Karl Heinz et al. showed a similar result in terms of efficacy and end safety result between the two. A systematic review of 7200 patients by Yi-He Chen et al. concluded that cryoablation has fewer rates of atrial fibrillation recurrence, shorter procedural duration and similar fluoroscopy times. Similar other studies are favoring the use of balloon cryoablation due to lower rate of hospitalizations, repeat ablation, and cardioversions. Methods: Retrospective single center chart review. Results: Cryoablation ( n -139 ) vs RF ( n -507) MACE - ( OR 2.62, p: 0.045, CI: 1.1 - 6.28) Non cardiac ADEs (OR 6.47, p: 0.0029, CI 2.3098 - 18.1395) Death: ( 1 vs 2, OR 1.84, p: 0.52, CI: 0.16-20.28) Efficacy: Persistent afib at discharge: ( OR 1.69, p: 0.08, CI: 0.85-3.07 ) Mean Contrast volume: (78 cc vs 4.48 cc, p Mean LA volume: (3.94 vs 4.59) Mean Fluoroscopy time: ( 31 vs 32 mins, p: 0.86) Conclusion: In our retrospective single-center study, patients who underwent cryoablation for pAF had a statistically significant higher incidence of MACE and noncardiac ADEs. There was no significant difference in mortality rates or primary efficacy.
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    A Comparison of Protocols for Simulating Hemorrhage in Humans: Step vs. Ramp Lower Body Negative Pressure
    (2019-03-05) Kay, Victoria; Anderson, Garen; Sprick, Justin; Rickards, Caroline; Rosenberg, Alexander
    Lower body negative pressure (LBNP) elicits central hypovolemia, and has been used to characterize the cardiovascular and cerebrovascular responses to simulated hemorrhage in humans. LBNP protocols traditionally employ a progressive stepwise reduction in pressure that is maintained for specific time periods. More recently, however, continuous ramp LBNP protocols have been utilized to simulate the continuous nature of most bleeding injuries. Purpose: The aim of this study was to compare tolerance and hemodynamic responses between a step LBNP protocol and a continuous ramp LBNP protocol until the onset of presyncope. Methods: Healthy human subjects (N=20; 8F, 12M) participated in two LBNP protocols to presyncope: 1) Step Protocol, where chamber pressure decreased every 5-min to -15, -30, -45, -60, -70, -80, -90 and -100 mmHg, and, 2) Ramp Protocol, where chamber pressure decreased 3 mmHg/min. Heart rate (HR), mean arterial pressure (MAP), stroke volume (SV), middle and posterior cerebral artery velocity (MCAv and PCAv), muscle and cerebral oxygen saturation (SmO2 and ScO2), and end-tidal CO2 (etCO2) were measured continuously. Time to presyncope, the cumulative stress index (CSI; summation of chamber pressure*time at each pressure), and hemodynamic responses were compared between the two protocols. Results: Time to presyncope (Step: 1611.8 ± 80.5 s vs. Ramp: 1675.4 ± 68.3 s; P=0.17), and the ensuing magnitude of central hypovolemia (%Δ SV, Step: -54.3 ± 2.5 % vs. Ramp: -51.9 ± 2.7 %; P=0.31) were similar between protocols, despite a higher CSI for the step protocol (Step: 946.5 ± 98.4 mmHg*min vs. Ramp: 836.7 ± 81.6 mmHg*min; P=0.06). While there were no differences at presyncope between protocols for the maximum change in HR, MCAv, or SmO2 (P≥0.21), the reduction in MAP was slightly less (Step: -17.1 ± 1.8 % vs. Ramp: -20.0 ± 1.4 %; P=0.02) and the reductions in PCAv, ScO2,and etCO2 (P≤0.08) were slightly greater for the step protocol compared to the ramp protocol. Conclusion: These results suggest that step and continuous ramp LBNP protocols elicit relatively similar tolerance times, reductions in central blood volume, and subsequent reflex hemodynamic responses, despite a greater cumulative stress in young healthy adults.
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    Prevalence of Metabolic Syndrome Components and other Cardiovascular Risk factors related to Cardiovascular Disease and Cognition: A Comparison between the HABLE and UNAM cohorts.
    (2019-03-05) Reyes, Miguel; Hall, James; Johnson, Leigh; O'Bryant, Sid E.; Vintimilla, Raul
    Background: In the United States, the number two cause of death among Latinos in general, and Mexican Americans in particular is cardiovascular disease (CVD). Prevalence of major cardiovascular risk factors (CVRF) is higher among Mexican Americans than non-Hispanic Whites. Metabolic syndrome (MS) is a group of CFRF associated with greater risk of diabetes, CVD, cognitive decline, and dementia. Reports of CVRF prevalence among Mexico population and Mexican Americans living in the US have been contradictory. In general, it has been reported that the prevalence of CFRF in Mexico is within the range of what is observed in the US. A few comparative studies have demonstrated that US born and Mexico-born Mexicans Americans have higher prevalence that their Mexican counterparts. Also, some studies found that the only components of the metabolic syndrome with a higher prevalence in Mexico are total cholesterol and HDL. The purpose of this study was to compare the distribution of MS components among Mexican Americans from the Health and Aging Brain Among Latino Elders study (HABLE), with data from the National Autonomous University of Mexico (UNAM). Our goal was to gain a better insight about the similarities and differences in the prevalence of CVRF associated with metabolic syndrome in Mexicans and a cohort of Mexican Americans living in the United States (US). Methods: Data were analyzed in 290 participants (197 female), 60 years and older, from the ongoing HABLE study, and compared with data from a study done in 161 subjects (101 female), 60 years and older, at the UNAM. CVRF entered in the models included: fasting glucose, total cholesterol, HDL cholesterol, triglycerides, body mass index (BMI), abdominal circumference, and systolic and diastolic blood pressure. According to the National Cholesterol Education Program (ATP III), metabolic syndrome was defined as having 3 or more of the following: abdominal circumference ≥ 40 inches in males or ≥ 35 inches in females, triglycerides ≥ 150 mg/dl, HDL-Cholesterol Results: In both, male and female subjects, no significant difference was found for glucose and triglycerides levels among the two cohorts. . Between males, the UNAM cohort had higher levels of cholesterol (F=3.11, p=0.007), and HDL (F=1216.7, p2(1, N = 93) = 13.2, p = 0.0003 when comparing with males of the UNAM cohort. The difference in prevalence between females from both cohorts was not significant. Conclusion: In our study, with the exception of cholesterol and HDL, the prevalence of CVRF and metabolic syndrome was higher in urban dwelling Mexican Americans enrolled in the HABLE study than Mexicans enrolled in the UNAM study. Mexican Americans suffer a higher burden of CFRF and