Sudden death in a young man with catecholaminergic polymorphic ventricular tachycardia and paroxysmal atrial fibrillation.

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a familial condition that presents with exercise-induced syncope or sudden death in children or young adults. In most cases the disease is caused by a mutation in the cardiac ryanodine receptor (RyR2) gene. Current evidence suggests that primary therapy for CPVT is beta blockade and implantable cardioverter defibrillator (ICD) placement. There is a recent report of a patient with CPVT who died despite appropriate ICD therapies, and we report a similar case. Our patient died after probably initially receiving inappropriate ICD shocks for atrial fibrillation. We recommend that utmost efforts should be made to prevent shocks including repeated exercise testing to confirm suppression of PVT.

Factors Associated with Low Flow in Aortic Valve Stenosis.

BACKGROUND: Low-flow low-gradient aortic stenosis (AS) is a predictor of worse outcome compared with normal-flow AS. Although depressed left ventricular ejection fraction (LVEF) is associated with low flow, there is less evidence to support the role of other indices of cardiac structure and function. METHODS: Clinical and echocardiographic data from patients with native AS and valve areas ≤ 1.0 cm(2) were retrospectively analyzed to identify characteristics that are associated with low-flow low-gradient AS. RESULTS: In total, 941 patients were included. On multivariate analysis, factors independently associated with low flow (stroke volume index < 35 mL/m(2)) included worse right ventricular systolic function, atrial fibrillation, lower LVEF, and higher left ventricular mass, with moderate or severe mitral regurgitation independently associated with low flow in the 694 patients (74%) with preserved LVEFs. CONCLUSIONS: Right ventricular dysfunction and atrial fibrillation are independently associated with low-flow low-gradient AS, while moderate or severe MR is independently associated with low flow in patients with preserved LVEF. These associations with low flow in AS are clinically important to recognize, to avoid underestimation of AS severity.

Frequency and predictors of tachycardia-induced cardiomyopathy in patients with persistent atrial flutter.

BACKGROUND: There are few data on the frequency and predictors of tachycardia-induced cardiomyopathy (TICM) in patients with persistent atrial flutter. OBJECTIVES: To examine the incidence of TICM in patients undergoing ablation for persistent atrial flutter, and to examine predictors for the development of TICM. METHODS AND RESULTS: One hundred eleven patients met the inclusion criteria for the present study. Twenty-eight of 111 (25%) patients had cardiomyopathy before ablation. Sixteen of 28 (57%) patients showed significant improvement in their left ventricular (LV) function postablation. LV function improved to normal in 12 of 16 (75%) patients. Nineteen of 28 (68%) cardiomyopathy patients had preablation LV function in the range in which they would be considered for an implantable cardioverter defibrillator for primary prevention of sudden cardiac death. In nine of 19 (47%) patients, the ejection fraction improved such that an implantable cardioverter defibrillator was no longer indicated. In multivariate analysis, average ventricular rate during atrial flutter was the only independent predictor of reversibility of cardiomyopathy (P=0.013). CONCLUSIONS: Sixteen of 28 (57%) cardiomyopathy patients with persistent atrial flutter had significantly improved LV function postablation. In 75% of these patients, LV function improved to normal.