Faculty Bibliography

Background Amiodarone causes less drug-induced torsade de pointes (TdP) compared to other class III antiarrhythmics. Two theories proposed for this finding include that amiodarone has less repolarization heterogeneity, and/or decreases early after depolarization (EADs). Corrected QT (QTc) dispersion as measured on a surface electrocardiogram (ECG) represents spatial heterogeneity of ventricular repolarization. Objective The purpose of this study was to analyze the difference in QT dispersion between amiodarone and other class III antiarrhythmics and to determine the etiology of TdP. Methods This was a retrospective, observational study at Montefiore Medical Center between January 2005 and January 2015. Inclusion criteria were adults >18 years on amiodarone, dofetilide, or sotalol with prolonged QT interval on 12-lead ECG. ECGs were reviewed by three blinded observers. QTc was calculated using the Bazett and Framingham formulas. QTc dispersion was calculated by subtracting the shortest from the longest QTc. Analysis of variance (ANOVA) was applied for comparison between antiarrhythmic groups with Bonferroni correction for multiple comparisons. Results A total of 447 ECGs were reviewed and 77 ECGs met inclusion criteria. The average QT dispersion for amiodarone, dofetilide, and sotalol was 0.050, 0.037, and 0.034, respectively (p=0.006) and the average QTc dispersion by Bazett was 0.053, 0.038, and 0.037 (p=0.008) and by Framingham was 0.049, 0.036, and 0.035 (p=0.009), respectively. Conclusion Our results show that given the increase in QT dispersion seen with amiodarone, heterogeneous ventricular repolarization as measured by QTc dispersion likely does not account for the lower incidence of drug-induced TdP seen with amiodarone. The ability of amiodarone to decrease EADs via sodium-channel blockade is more likely the explanation for its lower incidence of drug-induced TdP.

BACKGROUND:HIV and HCV have been linked to an increased risk of cardiovascular disease (CVD). Their impact on long-term outcomes following ST-segment myocardial infarction (STEMI) has not been previously studied. METHODS:We leveraged data from a STEMI registry (n = 1208) at an inner-city health system to assess the influence of HIV and HCV on post-STEMI outcomes. Cox regression was used to compare HIV-monoinfected (n = 22), HCV-monoinfected (n = 26) and HIV-HCV-coinfected patients (n = 8) with the neither-infected group (n = 1152) with regard to death, death or any readmission, and death or CVD readmission. RESULTS:The cohort was majority black or Hispanic. Median follow-up was 4.3 years. Compared to the neither-infected group, the HIV-monoinfected group showed near-significantly higher risks of death or any readmission (HR = 1.62, 95% CI = 0.96, 2.74) and death or CVD readmission (HR = 1.82, 95% CI = 0.98, 3.39) after full adjustment. On similar comparison, the HCV-monoinfected group exhibited significantly higher risks of death (HR = 2.09, 95% CI = 1.05, 4.15) and death or any readmission (HR = 1.68, 95% CI = 1.07, 2.65), whereas the HIV-HCV-coinfected group showed higher risk of death (HR = 6.51, 95% CI = 2.28, 18.61). CONCLUSIONS:In this cohort composed mostly of race-ethnic minorities, HIV monoinfection tended to be associated with 1.6-to-1.8-fold higher risk of death or readmission for any cause or CVD over long-term follow-up compared to neither infection, whereas HCV monoinfection was associated with 1.7-to-2.1-fold higher risk of death and death or any readmission, and HIV-HCV coinfection with 6.5-fold higher risk of death. These associations require further study in larger populations, but highlight the importance of identifying and treating HIV and HCV in patients presenting with STEMI.

Left ventricular outflow tract obstruction is a serious complication of mitral valve surgery (repair and replacement) and transcatheter mitral valve replacement. An appreciation of the various mechanisms which cause outflow obstruction in these settings is critical to avoiding this complication and to initiating appropriate treatment. This article discusses the mechanisms, pathophysiology, and imaging of left ventricular outflow tract obstruction which can arise following insertion of a variety of mitral valve prosthetics.

Left ventricular outflow tract obstruction resulting from strut impingement upon the interventricular septum is a rare complication of bioprosthetic mitral valve insertion. Obstruction is more likely to develop when a small, high profile prosthetic valve is inserted into a patient with a small outflow tract. The likelihood of this complication may be reduced by appropriate modification of surgical technique.

Unstable angina is a clinical diagnosis that may present with or without electrocardiographic changes. The "giant R wave" on electrocardiogram has been reported as a manifestation of acute ischemia; however, it is a rare finding in current clinical practice. We describe a case of a patient with unstable angina and a transient "giant R wave" pattern with a culprit lesion in the right coronary artery.

Takotsubo cardiomyopathy (TCM) is a variant of stress-induced cardiomyopathy, characterized by transient left ventricular dysfunction that may be associated with emotional or physical triggers. We present the case of a 51-year-old Caucasian female with severe chronic obstructive pulmonary disease (COPD) who presented with syncope and was found to have her second lifetime episode of stress-induced cardiomyopathy. Eight months prior, she had been admitted with a COPD exacerbation and was found to have left ventricular (LV) dysfunction with ejection fraction (EF) of 22% attributed to TCM with subsequent normalization of her left ventricular function. Recurrence of stress-induced cardiomyopathy associated with COPD is a rare phenomenon and its presentation raises the possibility of a common underlying mechanism.

BACKGROUND: The benefit of </=6-month compared with 12-month dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) with drug-eluting stent (DES) placement remains controversial. We performed a meta-analysis and meta-regression of 40 was identified, effects were obtained with random models. RESULTS: Nine RCTs were included with total n = 19,224 patients. No significant differences were observed between