Incidence and clinical relevance of slow ventricular tachycardia in implantable cardioverter-defibrillator recipients: an international multicenter prospective study.
BACKGROUND
This study aims to assess the incidence and clinical relevance of slow ventricular tachycardia (VT) and the effectiveness and/or deleterious effects of antitachycardia pacing in slow VT in implantable cardioverter-defibrillator recipients.


RESULTS
This multicenter prospective randomized study included 374 patients (326 men) without prior history of slow VT (<148 bpm) implanted with a dual-chamber implantable cardioverter-defibrillator. Patients had a 3-zone detection configuration: a slow VT zone (101 to 148 bpm), a conventional VT zone (>148 bpm), and a ventricular fibrillation zone. Patients were randomized to a treatment group (n=183) with therapy activated in the slow VT zone or a monitoring group (n=191) with no therapy in the slow VT zone. During follow-up (11 months), 449 slow VTs occurred in 114 patients (30.5% slow VT incidence); 181 VTs (54 patients) occurred in the monitoring group; 3 were readmitted to the hospital; and lightheadedness and palpitations occurred in 4 and 250 (60 patients) in the treatment group treated by antitachycardia pacing (89.8% success rate) and shock delivery (n=2). There were 10 crossovers from the monitoring to treatment group and 3 crossovers from the treatment to monitoring group (P=0.09). Quality of life scores were not different between groups.


CONCLUSIONS
Slow VT incidence (<150 bpm) is high (30%) in implantable cardioverter-defibrillator recipients without prior history of slow VT, has limited clinical relevance, and is efficiently and safely terminated by antitachycardia pacing.
Sadoul
Nicolas
N
Département de Cardiologie, CHU Nancy Brabois, Rue du Morvan, 54500 Vandoeuvre les Nancy, France. n.sadoul@chu-nancy.fr
Mletzko
Ralph
R
Anselme
Frédéric
F
Bowes
Robert
R
Schöls
Wolfgang
W
Kouakam
Claude
C
Casteigneau
Gaëlle
G
Luise
Raffaele
R
Iscolo
Nicolas
N
Aliot
Etienne
E
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D018592:Cross-Over Studies; D017147:Defibrillators, Implantable / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results; D016019:Survival Analysis; D017180:Tachycardia, Ventricular / Q000401:mortality / Q000628:therapy*; D016896:Treatment Outcome
D000889:Anti-Arrhythmia Agents