Study objective: The purpose of this study was to evaluate the diagnostic value of low voltage with PR-segment and ST-T wave changes in determining the amount of clinically silent pericardial effusion detected in a routine echocardiography.
Design: Consecutive case series analysis.
Setting: Noninvasive cardiology department of a university hospital.
Patients: Among 8,041 consecutive patients referred to our echocardiography laboratory, 121 asymptomatic patients with pericardial effusion free of heart disease were studied.
Interventions: Echocardiography and ECG.
Measurements and results: The amount (small or moderate/large) of pericardial effusion was correlated with ECG. Among 121 patients with pericardial effusion, low voltage was detected in 32 patients (26%), while widespread PR-segment depression was observed in 32 patients (26%) and widespread ST-segment elevation in 8 patients (7%). Although there was a significantly higher incidence of low voltage in patients with moderate/large pericardial effusion compared to that of small pericardial effusion, 13 of 32 patients (41%) with low voltage had a small pericardial effusion. In patients with a small pericardial effusion, 7 of 13 patients (54%) with low voltage had PR-segment depression, while 15 of 85 patients (18%) without low voltage had PR-segment depression; the difference was significant (p = 0.011). In patients with moderate/large pericardial effusions, there was no significant difference in the incidence of PR-segment depression between patients with and without low voltage (47% vs 25%, respectively; p = 0.791).
Conclusions: In the presence of PR-segment depression, even a small pericardial effusion may cause low voltage in the surface ECG.