Unmappable ventricular tachycardia after an old myocardial infarction. Long-term results of substrate modification in patients with an implantable cardioverter defibrillator.

Abstract

PURPOSE:

The frequent occurrence of ventricular tachycardia can create a serious problem in patients with an implantable cardioverter defibrillator. We assessed the long-term efficacy of catheter-based substrate modification using the voltage mapping technique of infarct-related ventricular tachycardia and recurrent device therapy.

METHODS:

The study population consisted of 27 consecutive patients (age 68 ± 8 years, 25 men, mean left ventricular ejection fraction 31 ± 9%) with an old myocardial infarction and multiple and/or hemodynamically not tolerated ventricular tachycardia necessitating repeated device therapy. A total of 31 substrate modification procedures were performed using the three-dimensional electroanatomical mapping system. Patients were followed up for a median of 23.5 (interquartile range 6.5-53.2) months before and 37.8 (interquartile range 11.7-71.8) months after ablation. Antiarrhythmic drugs were not changed after the procedure, and were stopped 6 to 9 months after the procedure in patients who did not show ventricular tachycardia recurrence.

RESULTS:

Median ventricular tachycardias were 1.6 (interquartile range 0.7-6.7) per month before and 0.2 (interquartile range 0.00-1.3) per month after ablation (P = 0.006). Nine ventricular fibrillation episodes were registered in seven patients before and two after ablation (P = 0.025). Median antitachycardia pacing decreased from 1.6 (interquartile range 0.01-5.5) per month before to 0.18 (interquartile range 0.00-1.6) per month after ablation (P = 0.069). Median number of shocks decreased from 0.19 (interquartile range 0.04-0.81) per month before to 0.00 (interquartile range 0.00-0.09) per month after ablation (P = 0.001). One patient had a transient ischemic attack during the procedure, and another developed pericarditis. Nine patients died during follow-up, eight patients due to heart failure and one patient during valve surgery.

CONCLUSION:

Catheter-based substrate modification using voltage mapping results in a long-lasting reduction of cardioverter defibrillator therapy in patients with multiple and/or hemodynamically not tolerated infarct-related ventricular tachyarrhythmia.

• Authors: B S N Alzand, C C M M Timmermans, H J J Wellens, R Dennert, S A M Philippens, P J M Portegijs, L M Rodriguez
• Journal: Journal of interventional cardiac electrophysiology : an international journal of arrhythmias and pacing (J Interv Card Electrophysiol) Vol. 31 Issue 2 Pg. 149-56 (Aug 2011) ISSN: 1572-8595 [Electronic] Netherlands
• PMID: 21340515 (Publication Type: Journal Article)

Topics

• Academic Medical Centers
• Aged
• Body Surface Potential Mapping (methods)
• Catheter Ablation (methods)
• Cohort Studies
• Combined Modality Therapy
• Defibrillators, Implantable
• Electrocardiography
• Female
• Follow-Up Studies
• Humans
• Kaplan-Meier Estimate
• Male
• Middle Aged
• Myocardial Infarction (complications, diagnosis)
• Recurrence
• Retrospective Studies
• Risk Assessment
• Statistics, Nonparametric
• Tachycardia, Ventricular (diagnosis, etiology, therapy)
• Time Factors
• Treatment Outcome