Slow Ventricular Tachycardia in Implantable Cardioverter-Defibrillator Recipients - Slow Ventricular Tachycardia in Implantable Cardioverter-Defibrillator Recipients

Aug 15, 2005
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Date Published:
01/01/2005
Date Updated:
08/15/2005
Original Posted Date:
08/15/2005
References

Description:

The goal of the trial was to evaluate the incidence and clinical relevance of slow ventricular tachycardia (VT) and the safety and efficacy of antitachycardia pacing (ATP) therapy in slow VT among patients previously implanted with a dual chamber ICD.

Study Design

Study Design:

Patients Enrolled: 374
Mean Follow Up: Mean 11 months
Mean Patient Age: Mean age 64 years
Female: 13
Mean Ejection Fraction: Mean 39%

Patient Populations:

Patients implanted with a dual-chamber implantable cardioverter-defibrillator without prior history of slow VT (<148 bpm).

Drug/Procedures Used:

Patients previously implanted with a dual chamber ICD had a detection configuration into three groups: slow VT zone (101-148 bpm), conventional VT zone (>148 bpm) and a ventricular zone. Patients were randomized to antitachycardia pacing (ATP) with or without cardioversion activated in the slow VT zone (n=183) or a monitoring group with no activation in the slow VT zone (n=191).

Principal Findings:

Underlying heart disease was coronary artery disease in the majority of patients (73%) followed by dilated cardiomyopathy (15%). ICD indication was spontaneous VT in 70% of patients, spontaneous VF in 19%, and induced VT/VF in 11%.

There were 10 deaths in the monitoring group and 13 deaths in the therapy group (p=NS). In the monitoring group, 181 slow VT occurred in 54 patients compared with 250 slow VTs in 60 patients in the treatment group. Mean duration was 15 minutes, and three patients required hospital re-admission. Of the 250 slow VTs in the treatment group, 245 were treated and 5 resolved spontaneously. The success rate of the 245 treated was 89.8%. Quality of life score improved from baseline to 12 months in both treatment groups (p=0.002 in the monitoring group and p=0.0007 in the treatment group), with no difference between groups.

Interpretation:

Among patients previously implanted with a dual chamber ICD and without a history of slow VT, slow VT occurred in 30% of patients during one year follow-up, and were treated in 90% of episodes among patients with antitachycardia pacing. Despite the high resolution with antitachycardia pacing, clinical events did not differ between the monitoring and the treatment group, with only 3 hospital admissions required. Additionally, quality of life improved in both groups from baseline, with no difference between groups.

References:

Sadoul N, et al. Incidence and Clinical Relevance of Slow Ventricular Tachycardia in Implantable Cardioverter-Defibrillator Recipients. Circulation. 2005;112:946-953.

Keywords: Coronary Artery Disease, Tachycardia, Ventricular, Follow-Up Studies, Quality of Life, Accelerated Idioventricular Rhythm, Electric Countershock, Heart Ventricles, Defibrillators, Implantable, Cardiomyopathy, Dilated


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