Accuracy of ventricular lumen volume measurement by intraventricular balloon method

To assess the accuracy of left ventricular volume measured by the intraventricular balloon method, we measured the space between the endocardium and the gradually inflated balloon in six Formalin-fixed canine left ventricles. The space was as small as 1-1.5 ml for intraballoon pressure of 100-200 mmHg and tended to increase to 2 ml with decreases in pressure to 50 mmHg.