Ermis C, Seutter R, Zhu AX, Benditt LC, VanHeel L, Sakaguchi S, Lurie KG, Lu F, Benditt DG. Impact of Upgrade to Cardiac Resynchronization Therapy on Ventricular Arrhythmia Frequency in Patients With Implantable Cardioverter-Defibrillators.
J Am Coll Cardiol 2005;
46:2258-63. [PMID:
16360055 DOI:
10.1016/j.jacc.2005.04.067]
[Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2005] [Revised: 04/02/2005] [Accepted: 04/13/2005] [Indexed: 11/30/2022]
Abstract
OBJECTIVES
This study compared cardiac resynchronization therapy's (CRT) impact on ventricular tachyarrhythmia susceptibility in patients who, due to worsening heart failure (HF) symptoms, underwent a replacement of a conventional implantable cardioverter-defibrillator (ICD) with a CRT-ICD.
BACKGROUND
Cardiac resynchronization therapy is an effective addition to conventional treatment of HF in many patients with left ventricular systolic dysfunction. However, whether CRT-induced improvements in HF status also reduce susceptibility to life-threatening arrhythmias is less certain.
METHODS
Clinical and ICD electrogram data were evaluated in 18 consecutive ICD patients who underwent an upgrade to CRT-ICD. Pharmacologic HF therapy was not altered during follow-up. The definition of ventricular tachycardia (VT) and ventricular fibrillation (VF) for each patient was as determined by device programming. Statistical comparisons used paired t tests.
RESULTS
Findings were recorded during two time periods: 47 +/- 21 months (range 24 to 70 months) before and 14 +/- 2 months (range 9 to 18 months) after CRT upgrade. At time of upgrade, patient age was 69 +/- 11 years and ejection fraction was 21 +/- 8%. Before CRT the frequency of VT, VF, and appropriate ICD shocks was 0.31 +/- 1.23, 0.047 +/- 0.083, and 0.048 +/- 0.085 episodes/month/patient, respectively. After CRT-ICD, VT and VF arrhythmia burdens and frequency of shocks were respectively 0.13 +/- 0.56, 0.001 +/- 0.004, and 0.003 +/- 0.016 episodes/month/patient (p = 0.59, 0.03, and 0.05 vs. pre-CRT).
CONCLUSIONS
Arrhythmia frequency and number of appropriate ICD treatments were reduced after upgrade to CRT-ICD for HF treatment. Thus, apart from hemodynamic benefits, CRT may also ameliorate ventricular tachyarrhythmia susceptibility in HF patients.
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