Search

His-Purkinje-related ventricular arrhythmias are a subset of ventricular tachycardias that use the specialized cardiac conduction system. These arrhythmias can occur in various different forms of structural heart disease. Here, we review the basic science discoveries and their analogous clinical observations that implicate the His-Purkinje system as a crucial component of the arrhythmia circuit. While mutations serve the molecular basis for arrhythmias in the heritable cardiomyopathies, transcriptional and posttranslational changes constitute the adverse remodeling leading to arrhythmias in acquired structural heart disease. Additional studies on the electrical properties of the His-Purkinje network and its interactions with the surrounding myocardium will improve the clinical diagnosis and treatment of these arrhythmias.

Background Controversy exists regarding how atrial activation mode and heart rate affect optimal atrioventricular (AV) delay in cardiac resynchronization therapy. We studied these questions using high‐reproducibility hemodynamic and echocardiographic measurements. Methods Twenty patients were hemodynamically optimized using noninvasive beat‐to‐beat blood pressure at rest (62 ± 11 beats/min), during exercise (80 ± 6 beats/min), and at three atrially paced rates: 5, 25, and 45 beats/min above rest, denoted as Apaced,r+5, Apaced,r+25, and Apaced,r+45, respectively. Left atrial myocardial motion and transmitral flow were timed echocardiographically. Results During atrial sensing, raising heart rate shortened optimal AV delay by 25 ± 6 ms (P