The displacement cardiograph. A noninvasive technique for recording myocardial wall motion

The displacement cardiograph (DCG) is a noninvasive device employing an electromagnetic field to record tissue motion within the body. The sensing coil need not be in contact with the patient since the field penetrates air and stationary tissue without significant distortion. Disturbances in the field with result from ventricular wall motion are electronically converted to an analog output and a pattern inscribed on the paper of a physiological recorder. In an attempt to determine the reliability of the DCG in detecting regional areas of abnormal left ventricular wall motion, displacement cardiograms were obtained from 70 patients who underwent cardiac catheterization and left ventriculography. The DCG interpretations were in agreement with the ventriculographic picture of left ventricular wall motion in 67 of the 70 patients. There were two false positive and one false negative DCG diagnoses. The results indicate that the DCG can be employed as a reliable noninvasive method for repetitive assessment of the pattern of contraction of the anterior, anterolateral and posterior left ventricular wall.