SIGNAL-AVERAGED ELECTROCARDIOGRAPHY, QT-DISPERSION, AND DOPPLER-ECHOCARDIOGRAPHY IN THE EVALUATION OF MYOCARDIAL INVOLVEMENT IN PROGRESSIVESYSTEMIC-SCLEROSIS

To assess the myocardial involvement in Progressive Systemic Sclerosis (PSS), we evaluated the presence of late potentials (LP) by signal-av eraged electrocardiography (SAECG), QT-dispersion (QTD) by standard EG G, and the ventricular function by echocardiography. Fifteen outpatien ts, 7 with diffuse PSS (dPSS) and 8 with CREST syndrome variant, witho ut clinical and electrocardiographic evidence of cardiac disease, were studied and compared with 18 normal subjects. LP in PSS occurred in 5 out of 15 patients (33%) vs 1 out of 18 controls (5.5%) with signific ant difference (p < 0.05). LP were present in 5 of 7 patients with dPS S (71.4%, p < 0.001 vs controls). By contrast none of patients with CR EST syndrome showed LP. The QTD duration in all PSS patients was highe r than in control subjects (34.01 +/- 14.87 vs 26.61 +/- 10.29), and i n the dPSS patients was found a significant increased QTD duration (42 .0 +/- 17.87; p < 0.001 vs controls). Abnormalities of left ventricula r filling dynamic were found in 9 PSS patients (5 with dPSS and 4 with CREST; p < 0.001), and dPSS subgroup showed lower values of E/A, E in tegral/A integral and EF slope and higher values of IVRT in comparison with the CREST subgroup. We found that the more altered left ventricu lar diastolic function was frequently found in patients with dPSS than in CREST patients. Besides, the presence of LP and higher duration of QTD in dPSS subgroup could be a marker of increased arrhythmic risk r elated to a more advanced myocardial fibrosis.