Circadian patterns in the occurrence of malignant ventricular tachyarrhythmias triggering defibrillator interventions in patients with hypertrophic cardiomyopathy.

Background: Sudden death in hypertrophic cardiomyopathy (HCM) has been reported to occur most frequently in the early morning hours, similar to the pattern observed in ischemic heart disease. However, little is known about the circadian pattern of life-threatening arrhythmias in HCM in the contemporary era of the implantable cardioverter-defibrillator (ICD).

Objective: The purpose of this study was to determine the time of day when appropriate device interventions occur for ventricular tachycardia (VT)/ventricular fibrillation (VF) in HCM patients.

Adrenergic receptor polymorphisms in patients with stress (tako-tsubo) cardiomyopathy.

Background: Stress (tako-tsubo) cardiomyopathy (SC) is a newly reported condition afflicting older women, characterized by acute left ventricular (LV) systolic dysfunction, triggered by emotionally and physically stressful events, and occurring without significant coronary obstruction. Sympathetic nervous system hyperactivity has been implicated in the pathophysiology of SC. Single nucleotide polymorphisms involving the adrenergic receptors (AR) might result in susceptibility to SC.

Implantable cardioverter-defibrillators and prevention of sudden cardiac death in hypertrophic cardiomyopathy.

Context: Recently, the implantable cardioverter-defibrillator (ICD) has been promoted for prevention of sudden death in hypertrophic cardiomyopathy (HCM). However, the effectiveness and appropriate selection of patients for this therapy is incompletely resolved.

Objective: To study the relationship between clinical risk profile and incidence and efficacy of ICD intervention in HCM.

Initial report of off-pump coronary artery bypass surgery as sole therapy for moderate ischemic mitral regurgitation: operative and intermediate-term outcome.

Background: Patients undergoing on-pump coronary artery bypass surgery (CAB) with coexistent moderate ischemic mitral regurgitation (IMR) have a significant mortality rate compared to patients without MR. The mortality rate is elevated both perioperatively (0%-12% mortality), as well as over a 1- and 2-year postoperative period (15%-25%). It is thought that some patients are best served by off-pump CAB (OPCAB); however, outcomes have not been reported for such patients with coexistent moderate IMR.

Can late survival of patients with moderate ischemic mitral regurgitation be impacted by intervention on the valve?

Background: Ischemic mitral regurgitation is known to be associated with poor long-term outcome after coronary artery bypass grafting; however, our ability to alter that outcome with intervention on the valve is unclear. The decision to address the valve is most challenging for patients with only moderate mitral regurgitation, particularly with the popularization of off-pump surgery. We therefore reviewed early and late outcomes of patients undergoing revascularization with or without mitral valve surgery.

Coronary nitric oxide production in response to exercise and endothelium-dependent agonists.

Background: Endothelium-derived nitric oxide (NO) contributes to epicardial coronary artery vasodilation during exercise. However, blockade of NO production does not impair the increase in coronary blood flow (CBF) during exercise, suggesting that NO is not obligatory for exercise-induced coronary resistance vessel dilation. In contrast, the increases in CBF produced by endothelium-dependent agonists are decreased after NO blockade.