Isochronal map of chest wall vibration with cardiokymography.

Mapping analysis of cardiokymography is helpful in clarifying the relationship between vibratory pattern and recording sites, but needs a highly stable recording technique. We have therefore studied the stability of recording cardiokymograms, and present here a new method for creating stable maps which enables diagnosis of chest-wall vibration abnormalities. Cardiokymograms were recorded on 16 points of the chest wall located at regular intervals horizontally and vertically. The time interval between a R-wave peak of the electrocardiograms and an E-point of the cardiokymograms were measured for all the 16 records. Isochronal maps in 23 healthy subjects were classified into four types. The map of a patient with myocardial infarction was quite different from any one of the four normal patterns and seemed to show a paradoxical movement of the chest wall.