Evaluation of myocardial involvement in systemic lupus erythematosus by signal-averaged electrocardiography and echocardiography

Abstract OBJECTIVE: The myocardial involvement in systemic lupus erythematosus (SLE) patients, frequently found at autopsy or at endomyocardial biopsy, is less easily detected clinically. The myocardial lesions are characterized by an increase in interstitial connective tissue and myocardial scarring. Signal-averaged electrocardiography (ECG-SA) is currently used for recording ventricular late potentials which are the expression of slowed and disorganized conduction through zones of myocardial scarring. M-mode, two-dimensional and Doppler echocardiography (ECHO) represent relatively simple methods for evaluating the left ventricular function. This study was aimed to evaluate by ECG-SA and ECHO the myocardial involvement of SLE patients without clinical and electrocardiographic evidence of cardiac disease. METHODS AND RESULTS: Twenty outpatients with SLE were studied and compared with 18 normal controls. Late potentials were recorded in 20% of SLE patients and in 5.5% of controls. A significant increase of abnormal left ventricular diastolic filling was found in the SLE patients, characterized by reduced E/A (p = 0.018), a lower deceleration rate of early diastolic flow velocity (p = 0.048) and a prolonged isovolumic relaxation time (p = 0.001). SLE patients had diastolic dysfunction of various degrees although the depolarization abnormalities detected by ECG-SA were found only in a few subjects. CONCLUSIONS: The depolarization abnormalities, revealed by ECG-SA, probably reflect a longer extent of myocardial fibrosis in SLE patients with ECHO evidence of abnormal left ventricular filling. The simultaneous occurrence of ECHO and ECG-SA alterations could be a marker of subclinical myocardial involvement.