Ventricular safety pacing, ventricular sense response, and ventricular tachycardia

Pacing Spikes All Over

“…Cross talk is a serious complication that might occur in dual-chamber PPMs and ICDs 3. Ventricular safety pacing is a vital pacemaker function that prevents inhibition of ventricular pacing due to oversensing of an atrial pacing impulse on the ventricular channel, yet VSP algorithm is not entirely without pitfalls 4–6…”

Resynchronization or Proarrhythmia? A Conundrum

“…In all examples, the delivery of the biventricular pacing during a ventricular‐sensed event is shortly preceded by an As event. This cannot be ventricular safety pacing because this feature is only operational following atrial‐paced events …”

“…VSR also improves hemodynamic response in heart failure patients compared with intrinsic conduction without pacing . However, proarrhythmic effects of biventricular pacing have also been described . In a retrospective series of 145 biventricular device implants in patients with a history of VT, five were proarrhythmic within 1 week with induction of monomorphic VT and required cessation of LV pacing.…”

“…In our case, the proarrhythmia resulted from a VSR‐triggered biventricular pacing critically timed to a spontaneous ventricular ectopy. A case study by Lim suggested that VSR triggered by an LV ectopy, detected late after its onset, was proarrhythmic by entering an excitable gap and contributing to reentry. In our examples, the proarrhythmia resulted when an ectopy in close proximity to the RV lead triggered a VSR causing depolarization of the LV epicardial tissue and, therefore, creating a second wave front that contributed to reentry.…”

“…This cannot be ventricular safety pacing because this feature is only operational following atrial-paced events. 3 In Medtronic biventricular devices, "ventricular sense response" is an algorithm whereby PACE, Vol. 37…”