title: 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.
authors.affiliation: Hôpital Cardiologique du Haut Lévêque, Bordeaux Pessac, France.
authors.forename: P
authors.initials: P
authors.lastname: Jaïs
authors.forename: S
authors.initials: S
authors.lastname: Barold
authors.forename: D C
authors.initials: DC
authors.lastname: Shah
authors.forename: A
authors.initials: A
authors.lastname: Takahashi
authors.forename: M
authors.initials: M
authors.lastname: Hocini
authors.forename: M
authors.initials: M
authors.lastname: Haïssaguerre
authors.forename: J
authors.initials: J
authors.lastname: Clémenty
mesh_terms: D000465:Algorithms; D001283:Atrioventricular Node / Q000503:physiopathology; D005117:Cardiac Complexes, Premature / Q000209:etiology; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects*; D004562:Electrocardiography; D015716:Electrocardiography, Ambulatory; D005500:Follow-Up Studies; D006327:Heart Block / Q000628:therapy; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial / Q000009:adverse effects*; D012032:Refractory Period, Electrophysiological / Q000502:physiology; D013577:Syndrome; D013614:Tachycardia, Paroxysmal / Q000209:etiology; D013616:Tachycardia, Sinus / Q000209:etiology