Figure 1
From: Applications of minimally invasive cardiac output monitors
Esophageal Doppler has the ability to measure flow time and peak velocity. The flow time is the time from the beginning of aortic pulse waveform upstroke to its return to baseline. A. Peak velocity is a good indicator of myocardial contractibility (normal). B. The left ventricular ejection time (or flow-time) corrected for heart rate provides an index of preload (hypovolemia). C. Left ventricular failure. Note that during hypovolemia and heart failure the stroke distance is decreased.