Detection and Clinical Significance of Ventricular Late Potentials in Patients with Pulmonary Sarcoidosis

Abstract

Early detection of cardiac involvement in sarcoidosis is difficult but important to achieve optimal treatment. Signal-averaged electrocardiography（SAECG）can detect subtle cardiac electrical abnormalities known as late potentials（LPs）and would be useful for the early diagnosis of cardiac involvement. We prospectively studied 74 patients with pulmonary sarcoidosis without overt electrocardiographic abnormalities. All participants underwent SAECG, cardiac echocardiography, and 24-hour ambulatory Holter monitoring. Serum angiotensin-converting enzyme and B-type natriuretic peptide levels were also evalusated. We followed up these patients to evaluate the incidence of cardiac events including cardiac death, arrhythmias, and heart failure requiring hospital admission. Of the studied population, 29 patients（39.2％）had detectable LP. During a mean follow-up period of 9.8 years, 8 patients with LPs had cardiovascular events, including development of complete atrioventricular block（n＝4）, ventricular tachycardia（n＝2）, and heart failure（n＝2）. Only 1 of 45 patients without LP developed cardiac event（heart failure）. Multivariate analyses revealed that LPs were associated with an increased risk of developing cardiac events（hazard ratio 9.66 ; 95％ confidence interval 1.20-78.01 ; p＝.033）whereas age, sex, serum angiotensin-converting enzyme and B-type natriuretic peptide levels, number of premature ventricular contractions on 24-hour Holter monitoring, and echocardiographic parameters were not associated with subsequent cardiac events. SAECG may be useful for the early detection of cardiac sarcoidosis and could be used as a screening test for further risk stratification.