Determination of ventricular volume from changes in wall thickness.

A new method of measuring left ventricular volume is proposed which utilizes ventricular wall thickness at end systole and end diastole to estimate the ejection fraction. These measurements plus stroke volume allow the calculation of ventricular EDV. Although data from angiocardiographic studies have been used to validate the method it appears that the same data can be derived from ultrasound studies. The use of ultrasound methods would allow long term monitoring of ventricular volume changes during the course of a disease process. The proposed method appears to offer a more consistently accurate means of measuring EDV than previously suggested ultrasound methods. Comparison of EDV data calculated from angiographic and wall thickness measurements reveals the two methods to be statistically identical. In patients with a normal myocardium or valve lesions the correlation between the two methods is 0.97 with a standard error of 21 cc. There is a significant loss of accuracy when estimating ventricular volume in patients having diagnoses compatible with ventricular asynergy. An alternative method is suggested which may improve estimates of ventricular volume in these patients.