Related Experiment Videos
Determinants of prognosis in idiopathic dilated cardiomyopathy as determined by programmed electrical stimulation
Insights
In idiopathic dilated cardiomyopathy, programmed electrical stimulation frequently induced polymorphic ventricular arrhythmias but did not predict outcomes. These induced arrhythmias did not correlate with heart failure severity or Holter findings.
Area of Science:
- Cardiology
- Electrophysiology
- Heart Failure Research
Background:
- Idiopathic dilated cardiomyopathy (IDCMP) is a significant cause of heart failure.
- Ventricular arrhythmias are a major concern in IDCMP, contributing to sudden cardiac death.
- The role of programmed electrical stimulation (PES) in risk stratification for IDCMP requires further elucidation.
Purpose of the Study:
- To prospectively assess the incidence of electrically induced ventricular arrhythmias in IDCMP patients.
- To investigate the prognostic significance of these induced arrhythmias.
- To explore the relationship between induced arrhythmias, left ventricular function, and Holter monitoring findings.
Main Methods:
- Prospective study of 42 patients with IDCMP.
- 24-hour Holter monitoring and signal-averaged vectorcardiography.
- Programmed electrical stimulation with up to 2 ventricular extrastimuli to induce arrhythmias.
Main Results:
- Polymorphic ventricular arrhythmias were induced in 86% of patients.
- Sustained ventricular tachycardia or fibrillation was rare (2.4% to 4.8%).
- No association found between induced arrhythmias and left ventricular function impairment or Holter findings (Lown grade, PVCs).
- Late potentials on vectorcardiography were uncommon (1/30 patients).
Conclusions:
- Programmed electrical stimulation frequently induces polymorphic ventricular arrhythmias in IDCMP.
- Electrically induced arrhythmias in this study did not correlate with impaired left ventricular function or Holter parameters.
- The prognostic value of induced arrhythmias in IDCMP, as assessed by this method, appears limited in predicting mortality during short-term follow-up.
Abstract:
The incidence and prognostic significance of electrically induced ventricular arrhythmias were prospectively assessed in 42 patients with idiopathic dilated cardiomyopathy. All patients underwent 24-hour, long-term electrocardiographic (Holter) monitoring and 30 were analyzed by a signal-averaging vectorcardiographic procedure at entry into the study. Their response to programmed electrical stimulation during basic right ventricular pacing was investigated using 1 and 2 ventricular extrastimuli. A monomorphic tachycardia was not induced in any patient. In 36 patients (86%) polymorphic ventricular arrhythmias were initiated. Three or more induced consecutive ventricular premature complexes occurred in 9 patients (21%), nonsustained polymorphic ventricular tachycardia in 2 (4.8%) and ventricular fibrillation in 1 patient (2.4%). There was no association between electrically induced polymorphic ventricular arrhythmias and the degree of impairment of left ventricular function. Furthermore, the incidence of induced ventricular arrhythmias was not related to the Lown grade or to the total number of ventricular premature complexes during Holter monitoring. A late potential was detected by the averaged vectorcardiogram in only 1 of the 30 patients. During follow-up (mean 16 +/- 7 months) 7 patients died, 5 from chronic congestive heart failure and 2 from sudden cardiac death. No patient had an electrically induced arrhythmia of 3 or more ventricular premature complexes.(ABSTRACT TRUNCATED AT 250 WORDS)