A new approach to the prevention of endless loop tachycardia in DDD and VVD pacing.
Endless loop tachycardia (ELT) is a possible complication in dual chamber pacing; it is usually prevented by programming the atrial refractory period (PVARP) longer than the retrograde ventriculoatrial (VA) conduction interval; this in some patients limits the upper rate. In 15 patients with a DDD (nine patients) or a single-pass lead VDD pacemaker (six patients) and retrograde atrial activation, telemetric recording documented a significant difference in amplitude of antegrade, and retrograde atrial potentials (VDD 1.21 +/- 0.32 mV vs 0.56 +/- 0.23 mV, P = 0.008; DDD 2.7 +/- 1 vs 1.8 +/- 1 mV, P = 0.038; Student's t-test for paired data). In 3/15 patients ELT stopped after programming of atrial sensitivity to a value greater than the retrograde P wave amplitude; in 11/15 patients this occurred at a sensing value lower than or equal to retrograde P wave amplitude with a high pass band filter operating. One patient required PVARP lengthening. Holter monitoring showed no more ELTs. In most patients with a DDD or single-pass lead VDD pacemaker with widely programmable sensing amplitude and Hi/Low bandpass filters, individual programming of atrial channel sensitivity prevents ELT without affecting the PVARP and, consequently, upper rate limit.
Rognoni
G
G
Division of Cardiology, Ospedale Maggiore, Novara, Italy.
Occhetta
E
E
Perucca
A
A
Magnani
A
A
Francalacci
G
G
Audoglio
R
R
Rossi
P
P
D000368:Aged; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects* / Q000379:methods; D015716:Electrocardiography, Ambulatory; D004567:Electrodes, Implanted; D004867:Equipment Design; D006327:Heart Block / Q000628:therapy; D006801:Humans; D008875:Middle Aged; D010138:Pacemaker, Artificial; D012804:Sick Sinus Syndrome / Q000628:therapy; D012815:Signal Processing, Computer-Assisted; D013610:Tachycardia / Q000209:etiology / Q000517:prevention & control*; D013686:Telemetry