Doppler Echo Cardiac Output Calculator

What Is Doppler Echocardiography Cardiac Output?

Doppler echocardiography estimates cardiac output from left ventricular outflow tract (LVOT) measurements without invasive catheterization. The method combines LVOT cross-sectional area (CSA), velocity-time integral (VTI), and heart rate to derive stroke volume and cardiac output. See also the Cardiac Output Calculator and Cardiac Index Calculator for related hemodynamic estimates.

Calculation Steps

LVOT CSA equals π multiplied by the squared radius (diameter divided by 2). Stroke volume (SV) equals CSA multiplied by LVOT VTI in centimeters, yielding milliliters. Cardiac output (CO) equals SV times heart rate divided by 1000, giving liters per minute. Cardiac index (CI) equals CO divided by body surface area (BSA) from height and weight.

Normal Values and Clinical Use

Normal cardiac output is roughly 4 to 8 L/min in adults at rest. Cardiac index typically ranges from 2.5 to 4.0 L/min/m². Low CI may indicate heart failure, hypovolemia, or cardiogenic shock. Elevated CI can occur with sepsis, anemia, or hyperthyroidism. LVOT diameter should be measured carefully in systole for accurate CSA.