Twelve-lead electrocardiography in tuberculous pericarditis
Objectives. This study is part of an ongoing initiative started in 1995 to investigate the therapeutic efficacy of adjuvant corticosteroids in the management of tuberculosis (TB) pericarditis. In this retrospective, descriptive study we describe the changes found on the 12-lead electrocardiogram (ECG) in patients with TB pericarditis, with and without cardiac tamponade. We determined the diagnostic accuracy of ECG parameters for cardiac tamponade. Methods. All patients referred to our department with echocardiographically confirmed large pericardial effusions underwent a thorough clinical assessment followed by pericardiocentesis and drainage using an indwelling pigtail catheter. The amount of drained effusion was measured, and fluid was sent for diagnostic assessment. Patients were grouped into those with or without cardiac tamponade. The following ECG parameters were assessed: rate, rhythm, microvoltage, electrical alternans, PR segment and ST segment abnormalities. Results. Of the 157 patients assessed, 88 were diagnosed with TB pericarditis. All had abnormal ECGs and 83% had changes of chronic pericarditis. Microvoltage in the extremity and/or precordial leads Correlated with the presence of large effusions (> 750 ml). None of the studied parameters correlated with the presence of cardiac tamponade. Conclusions. Twelve-lead ECG is of supportive but not diagnostic value in cardiac tamponade. The presence of microvoltage suggests the presence of a large effusion. The absence of microvoltage makes the presence of cardiac tamponade unlikely.