The apexcardiogram (ACG) and cardiokymogram (CKG) (displacement cardiogram) tracings were compared in 45 patients with a variety of cardiac diseases and in 16 normal subjects. The ACG and CKG were generally comparable in waveform and timing of standard tracing intervals; however, on a case by case comparison frequent discrepancies between the ACG and CKG were observed. In 13 patients where no ACG could be recorded, an interpretable CKG tracing was obtained. However, the CKG produced frequent artifacts, mirror images, was very sensitive to probe position, and was judged to be of limited advantage over the ACG.