Impact of baseline PR interval on cardiac resynchronization therapy outcomes in patients with narrow QRS complexes: an analysis of the ReThinQ Trial.

Purpose: Heart failure (HF) is a major cause of morbidity and mortality, and ventricular dyssynchrony is an important contributor. The ReThinQ trial reported no improvement with cardiac resynchronization therapy (CRT) in HF patients with left ventricular ejection fraction (LVEF) <35%, narrow QRS (<130 ms), New York Heart Association (NYHA) class III, and echocardiographically detected dyssynchrony, in spite of echocardiographic optimization. We investigated whether a subset of narrow QRS patients might derive benefit from CRT, based on baseline PR interval.

Electrophysiologic characteristics of anger-triggered arrhythmias.

Background: Anger can precipitate ventricular arrhythmias in patients with implantable cardioverter-defibrillators (ICDs). Determining electrophysiologic characteristics of anger-triggered arrhythmias may help elucidate the mechanisms that link emotion and arrhythmia.

Objectives: We sought to compare the morphology and initiation pattern between ventricular arrhythmias that are triggered by anger and those that are not.