DETECTION OF VENTRICULAR-TACHYCARDIA AND FIBRILLATION USING CORONARY SINUS BLOOD TEMPERATURE - A FEASIBILITY STUDY

This study investigated the potential of coronary sinus blood temperat ure to detect ventricular arrhythmias. A rapid-response, thermistor-ti pped catheter placed in the coronary venous system of anesthetized dog s was used to record the blood temperature during periods of induced b radycardia, tachycardia, and ventricular fibrillation. A second cathet er was used to measure blood temperature in the aortic arch during the se same episodes. A pulsatile component of venous blood temperature, t ypically 40 m-degrees-C in amplitude, was well correlated with the car diac cycle, while another, slightly larger, pulsatile component was we ll correlated with respiration. The cardiac component peaked during ve ntricular systole, and the respiratory component peaked during expirat ion. As compared with sinus rhythm, the cardiac signal diminished duri ng bradycardia and tachycardia and nearly disappeared during asystole and ventricular fibrillation. The baseline component of venous blood t emperature rose during periods of tachycardia and fibrillation, while respiration proved to be an important factor in the baseline temperatu res. The presence of small, cyclic, thermal variations in the coronary venous system was verified, and the concept of measuring metabolic ac tivity to assess ventricular function was substantiated. These studies show promise that this concept could be incorporated into medical dev ices that use these temperature signals for diagnosis of ventricular a rrhythmias.