Heart rhythm : the official journal of the Heart Rhythm Society
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The aim of cardiac resynchronization therapy is correction of left ventricular (LV) dyssynchrony. However, little is known about the optimal timing of LV and right ventricular (RV) stimulation. ⋯ Optimal timing of the interventricular interval results in prolongation of the LV filling time, reduction of interventricular asynchrony, and an increase in stroke volume. In patients with advanced heart failure undergoing cardiac resynchronization therapy, LV hemodynamics may be further improved by optimizing LV-RV delay.
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Case Reports
Congenital atrial standstill associated with coinheritance of a novel SCN5A mutation and connexin 40 polymorphisms.
Congenital atrial standstill has been linked to SCN5A. Incomplete penetrance observed in atrial standstill has been attributed in part to the digenic inheritance of polymorphisms in the atrial-specific gap junction connexin 40 (Cx40) in conjunction with an SCN5A mutation. ⋯ These results suggest that genetic defects in SCN5A most likely underlie atrial standstill. Coinheritance of Cx40 polymorphisms is a possible genetic factor that modifies the clinical manifestation of this inherited arrhythmia.