Tracking left ventricular performance noninvasively. Response of the peak ear pulse derivative during cardiac catheterization.

The peak derivative of the ear densitograph displacement pulse was monitored on 12 patients undergoing routine coronary angiography and left ventricular angiography. Simultaneous recording of cardiac output, heart rate, systolic time intervals, and ear densitogram were obtained throughout the progression from before angiographic injections to postcoronary angiography to after left ventricular angiography. The peak derivative of the ear densitogram (PD) consistently tracked mean systolic ejection rate, and changes in PD showed good correlation with changes in ejection rate (r=.749, p less than 0.0001). The PD of the ear densitogram appears to be a reliable noninvasive tool for tracking left ventricular function during hemodynamic and other challenges.