Pacemaker Syndrome Induced by the Mode Switching Algorithm of a DDDR Pacemaker

Abstract

A patient with marked first-degree AV block and a DDDR pacemaker presented with a history of paroxysmal narrow QRS tachycardia, subsequently identified as sinus tachycardia (with a very long PR interval), causing a clinical problem similar to pacemaker syndrome because of loss of AV synchrony. The latter resulted from an excessively long postventricular atrial refractory period (PVARP) that prevented sensing of sinus P waves. The unfavorable hemodynamics caused reflex sinus tachycardia. The long PVARP was mandated by the mode switching algorithm of this particular device and was automatically set according to the selected tachycardia detection rate. The patient became asymptomatic when the mode switching function was turned off and the PVARP shortened.

Effect of Pacing for Soft Indications on Mortality and Heart Failure in the Dual Chamber and VVI Implantable Defibrillator (DAVID) Trial

“…The necessity of pacing is not disputed when it is performed for established clinical indications. But whether patients with ventricular dysfunction are more likely to be helped or harmed when paced for ostensibly justifiable but not essential reasons (“soft indications”) remains an important and as yet unanswered question 1–6 …”

Pacemaker Syndrome in the Young:

“…PS may occur in patients with ventricular pacing systems that are fixed (i.e., VVI) or rate‐responsive (i.e., VVIR), because these systems lack the ability to provide AV sequential contraction, and therefore, AV sequential filling 8 . PS may also occur with dual chamber systems with inappropriate AV delay 9,10 . Symptoms usually resolve when the pacing system is changed to a dual chamber system with appropriate paced AV delay (i.e., VDD/R, DDD/R) 8 .…”

Neonatal Lupus: Case Report

“…La incidencia real no es bien conocida, pero se estima que el 10% de los pacientes con estimulación VVI presentan síntomas graves y otro 15% síntomas leves (22) . Los síntomas se pueden corregir con la implantación de un marcapasos bicameral (DDD) (23,24) . En los marcapasos DDD el síndrome se produce por diferentes mecanismos: 1.…”