Implantable Cardioverter-Defibrillator Discharge in a Patient with Dilated Cardiomyopathy: What Is the Mechanism?

The response to antitachycardia pacing can sometimes reveal clues about tachycardia mechanisms. This article discusses a case in which the diagnosis of typical atrioventricular nodal reciprocating tachycardia could be firmly established from the implantable cardioverter-defibrillator interrogation alone.

Implantable Cardioverter-Defibrillator Shock Caused by Uncommon Variety of Nonreentrant Atrioventricular Nodal Tachycardia.

This article reports a typical case of incessant double-fire tachycardia resulting in implantable cardioverter-defibrillator discharge caused by the device's misdiagnosis of ventricular tachycardia. At electrophysiology study, the presence of double-fire physiology was confirmed, and modification of the slow pathway resulted in elimination of repetitive double fires. Although this is an unusual entity, it is important to recognize, because it may be misdiagnosed as atrial fibrillation, resulting in inappropriate anticoagulation and/or antiarrhythmic therapy.

Use of the Surface Electrocardiogram to Define the Nature of Challenging Arrhythmias.

Despite unprecedented advances in technology, the electrocardiogram (ECG) remains essential to the practice of modern electrophysiology. Since its emergence at the turn of the nineteenth century, the form of the ECG has changed little. What has changed is our ability to understand the complex mechanisms that underlie various arrhythmias.

His overdrive pacing during supraventricular tachycardia: a novel maneuver for distinguishing atrioventricular nodal reentrant tachycardia from atrioventricular reciprocating tachycardia.

Background: Because the His bundle is intrinsic to the circuit in orthodromic reciprocating tachycardia and remote from that of atrioventricular nodal reentrant tachycardia (AVNRT), pacing the His bundle during supraventricular tachycardia (SVT) may be useful to distinguish these arrhythmias.

Objective: The purpose of this study was to test the hypothesis that His overdrive pacing (HOP) would affect SVT immediately for orthodromic reciprocating tachycardia and in a delayed manner for AVNRT.

Methods: Once SVT was induced, HOP was performed by pacing the His bundle 10-30 ms faster than the SVT cycle length.