RESUMO
The aim of our study was to ascertain the prevalence of ventricular late potentials (VLP) in systemic sclerosis (SSc) and their correlation with the immunologic patterns and cutaneous and pulmonary involvement of the disease. Ventricular late potentials, which are low-amplitude high-frequency signals present in the terminal portion of the QRS complex, express the delayed and fragmented depolarization of ventricular myocardial fibers. Observed in myocardial interstitial fibrosis, they are characteristic of the myocardial alterations occurring in SSc. Twenty-six patients with SSc (1 man, 25 women) with a confirmed lack of cardiac involvement (negative history and normal clinical, electrocardiographic, and echocardiographic findings) underwent signal averaged high resolution electrocardiography. Pulmonary involvement was evaluated by pulmonary function tests and high resolution computed tomography. The degree of cutaneous involvement was assessed by skin score. In the patients with SSc, VLP presence with time-domain analysis was 30.8% when a 25-250 Hz pass-band filter was used and 26.9% when a 40-250 Hz pass-band filter was used whereas with frequency domain analysis it was 23.1%. Ventricular late potentials were confirmed in 7.7% of the control subjects, no matter what filter or technique was used. No significant correlations among VLP, pulmonary involvement, skin score and specific antibody patterns were found. Although this technique requires further consolidation, it seems to have the potential for use as an early index of myocardial fibrosis.