ELECTROCARDIOGRAPHIC VOLTAGE IN PERICARDIAL-EFFUSION

The usefulness of the electrocardiographic sign of 'low voltage' in the diagnosis of pericardial effusion was investigated in 122 patients comprising three study groups. Sixty-four patients (group 1) had a pericardial effusion detected and measured by echocardiographic studies. The volume of the effusion showed no correlation with electrocardiographic voltage. A second group of 36 patients was identified as having low voltage on routine electrocardiograms. Only 13 (36 percent) had echocardiographically demonstrable pericardial effusion. Group 3 consisted of 22 patients who required pericardiocentesis. The ECGs obtained immediately after pericardiocentesis showed an increase in average voltage of 0.48 mm in the limb leads and 0.83 mm in the precordial leads for each 100 ml of fluid removed. This study demonstrates that a single ECG with 'low voltage' is not useful in the diagnosis of pericardial effusion but that a reduction in the voltage of serial ECGs may suggest the development of pericardial effusion.