Interruption of Pacing Following Nonsustained Ventricular Tachycardia in an AAI Programmed Implantable Cardioverter Defibrillator

Abstract

Unintended consequences can occur when complex VT detection parameters interact with specific pacing modes. At times, nonconventional programming can avoid these interactions while still achieving effective AAI(R) pacing.

Postatrial pacing ventricular refractory period, RYTHMIQTM and ventricular tachycardia response: “An Algorithmic Conflict”

“…The VTR mode terminates after a tachycardia therapy delivery or when one of the two following conditions are met: (1) 5 of 10 sensed beats below the VT detection zone, or (2) a 6‐s pause 3 . In our case, condition 1 occurred after 11 s (Figure 3B).…”

“…In this setting, ventricular pacing will occur, without capturing the ventricle, avoiding unnecessary ventricular capture. However, since the voltage and pulse amplitude of the ventricular output during the VTR period can be individually programmed via the “ATP ventricular output setting,” ventricular capture could be maintained throughout the VTR period 3 …”

“…However, since the voltage and pulse amplitude of the ventricular output during the VTR period can be individually programmed via the "ATP ventricular output setting," ventricular capture could be maintained throughout the VTR period. 3 Like all algorithms for minimizing ventricular pacing, RYTH-MIQ TM is most suitable for patients with an intact atrioventricular conduction, such as in isolated sinus node dysfunction, chronotropic insufficiency and brady-tachycardia syndrome. It may be an option in patients with rare paroxysmal atrio-ventricular blocks, with caution for fast junctional rhythms that may prevent mode switching in DDD (R).…”