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Significance of ventricular late potentials in non-ischaemic dilated cardiomyopathy

DENEREAZ, D. ; ZIMMERMANN, M. ; ADAMEC, R.

In: European Heart Journal, 1992, vol. 13, no. 7, p. 895-901

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    Titre
    • Significance of ventricular late potentials in non-ischaemic dilated cardiomyopathy
    Auteur
    • DENEREAZ, D.. Cardiology Center and Policlinic of Medicine, University Hospital, Geneva, Switzerland
    • ZIMMERMANN, M.. Cardiology Center and Policlinic of Medicine, University Hospital, Geneva, Switzerland
    • ADAMEC, R.. Cardiology Center and Policlinic of Medicine, University Hospital, Geneva, Switzerland
    Type de document
    • Postprint
    Identifiant OAI-PMH
    • oai:doc.rero.ch:293205
    Summary
    To assess the incidence and clinical significance of ventricular late potentials in non-ischaemic dilated cardiomyopathy, 51 consecutive (44 male, seven female, mean age 53± 11 years) patients with dilated cardiomyopathy were studied. Twenty-eight patients (55%) were in New York Heart Association functional class III or IV, 34 out of 51 (76%) had a left ventricular ejection fraction of less than 40%, 10 out of 51 (20%) had a history of sustained ventricular tachycardia ( VT), 24 out of 37 (65%) had runs of non-sustained ventricular tachycardia during Holier monitoring and 15 out of 51 (29%) had a left bundle branch block. A signal-averaged electrocardiogram (gain 106 x, bipolar chest leads, filters 100-300 Hz) was performed in all the patients; late potentials were considered present if the total filtered QRS duration was longer than 118 ms and the interval between the end of QRS and the voltage 40 μV was more than 40 ms in the absence of left bundle branch block (total filtered QRS duration > 140 ms and interval between the end of QRS and the voltage 40 μV>50ms in the presence of left bundle branch block). Ventricular late potentials were detected in 22 out of 51 patients (43%). Late potentials were present in 80% (eight out of 10) of patients with sustained ventricular tachycardia but in only 34% (14 of 41) without sustained ventricular tachycardia (P < 0.01). This difference remained statistically significant even when patients with a left bundle branch block were excluded from the analysis (4 out of 6 vs 4 out of 30, P<0.01). To identify patients with dilated cardiomyopathy and sustained ventricular tachycardia, signal-averaging had a sensitivity of 80%, a specificity of 66%, a positive predictive value of 36% and a negative predictive value of 93%. It is concluded that, in non-ischaemic dilated cardiomyopathy, the signal-averaged electrocardiogram allows the identification of patients with sustained ventricular tachycardia, even in the presence of a left bundle branch block