Low Voltage in the Electrocardiogram

In the course of the routine interpretation of electrocardiograms, records are frequently encountered in which the Q-R-S complexes are small. The condition is called when the greatest excursion is less than 5 mm. in amplitude in all three leads. 1 It is not uncommon. At the Presbyterian Hospital it was found thirty-one times in the last thousand records, an incidence of 3 per cent. Despite the frequency of this electrocardiographic abnormality, a review of the available literature leaves its significance uncertain. Because of the doubt covering its interpretation, the cases of low voltage at this hospital have been reviewed with the hope of gaining further insight into the occurrence and clinical significance of this deviation from the normal electrocardiogram. REVIEW OF THE LITERATURE Waves of low amplitude were first noted as a part of the electrocardiographic picture in the disturbance of intraventricular conduction formerly called arborization block. 2