Ballistocardiographic response to hyperthermia
The body temperature of five normal subjects was raised to levels above 100.0°F through the use of a rubberized anti-exposure suit. The induced hyperkinetic cardiovascular state was studied on an ultra-low-frequency force ballistocardiogram. The ejection deflection (HI wave) consistently increased in amplitude and became more vertical during the hyperthermic state. The time duration from the onset of ventricular ejection to the J wave peak generally was shortened. These changes were interpreted in terms of the known cardiovascular response to the hyperkinetic state. Diminished peripheral resistance and its sequelae seemed to play a major role in the ballistocardiographic changes seen with hyperthermia. Submitted on November 23, 1959