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[Arrhythmogenic potential of cardiomyopathies. Dilated cardiomyopathies]
J P Fauchier1, P Cosnay, D Babuty
1Service de cardiologie B, hôpital Trousseau, Tours.
Insights
In non-ischemic dilated cardiomyopathy, late ventricular potentials on signal-averaged ECG correlate with lower cardiac index and higher ventricular arrhythmia risk. This aids in identifying patients needing closer monitoring for sudden cardiac events.
Area of Science:
- Cardiology
- Electrophysiology
- Heart Failure Research
Context:
- Non-ischemic dilated cardiomyopathy (DCM) presents a significant challenge in predicting adverse cardiac events.
- Identifying reliable markers for risk stratification in DCM is crucial for patient management.
Purpose:
- To investigate the diagnostic and prognostic value of signal-averaged electrocardiography (SAECG) and Holter monitoring in patients with non-ischemic DCM.
- To correlate findings from SAECG, Holter monitoring, and electrophysiological studies with cardiac function and ventricular arrhythmias.
Summary:
- Sixty-nine patients with non-ischemic DCM underwent comprehensive cardiac evaluation, including SAECG, 24-hour Holter monitoring, and electrophysiological studies.
- Late ventricular potentials (LVPs) on SAECG were detected in 25% of patients, significantly more than in controls (2%).
- LVPs were associated with a lower cardiac index (2.3 vs. 2.8 L/min/m2) and a higher incidence of ventricular arrhythmias (Grade ≥3 Lown, non-sustained VT).
- Spontaneous sustained ventricular tachycardia (VT) was present in 6 patients, all of whom had inducible VT during electrophysiological testing with similar ECG characteristics.
Impact:
- Signal-averaged ECG identifying late ventricular potentials is a valuable tool for risk stratification in non-ischemic dilated cardiomyopathy.
- Findings suggest that SAECG can help identify patients at higher risk of ventricular arrhythmias and reduced cardiac function.
- This research contributes to a better understanding of the electrophysiological substrate underlying ventricular arrhythmias in DCM, potentially guiding therapeutic strategies.
Abstract:
Sixty-nine cases of non-ischemic dilated cardiomyopathy were studied prospectively from February 1983 to February 1989 (52 men: 53 +/- 13.5 years of age). There were 6 cases of sustained ventricular tachycardia. Thirty-seven patients were in Class III or IV of the NYHA Classification. In addition to echocardiography, radionuclide studies, cardiac catheterisation and coronary angiography, they all underwent 24 hour Holter monitoring, signal-averaged electrocardiography and, in 46 cases, endocavitary electrophysiological investigations. Holter monitoring showed ventricular extrasystoles greater than or equal to Grade 3 of Lown's classification in 72% of patients (26% had nonsustained ventricular tachycardia) and these patients had a significantly lower cardiac index. Twenty five per cent of patients had late ventricular potentials (versus 2% in 50 normal subjects; p less than 0.02); this proportion rose to 32% in those patients with greater than or equal to Grade 3 ventricular extrasystoles and to 66% in the patients with spontaneous ventricular tachycardia; the cardiac index was lower in patients with late ventricular potentials (2.3 vs 2.8 l/min/m2; p less than 0.01) and they had a higher incidence of greater than or equal to Grade 3 ventricular extrasystoles (94% vs 65% in patients without late ventricular potentials, p less than 0.05). Programmed ventricular stimulation induced sustained or nonsustained monomorphic ventricular tachycardia and ventricular fibrillation in 15% of cases. The 6 cases of induced sustained ventricular tachycardia were only observed in the 6 patients with spontaneous sustained ventricular tachycardia and they had the same electrocardiographic appearances.(ABSTRACT TRUNCATED AT 250 WORDS)