Validation of pressure-volume data obtained in patients by initial transit radionuclide angiocardiography.

In order to validate the measurement of pressure-volume loops and stroke work in humans, simultaneous digital subtraction ventriculography (DSA) and first-pass radionuclide angiocardiography (RNA) coupled with high-fidelity micromanometer left ventricular pressure measurements were undertaken in 34 patients, mean age 75 +/- 9 years, with aortic stenosis. Twenty-nine patients had a repeat study after balloon valvuloplasty, for a total of 63 DSA and RNA pressure-volume loops. All data were analyzed in a systemic fashion in order to minimize intra- and interobserver error. Linear regression analysis was used to calculate the degree of agreement between the two technologies. Left ventricular ejection fraction (RNA: 0.47 +/- 0.17, DSA: 0.49 +/- 0.18) had a correlation coefficient of 0.96; left ventricular end-diastolic volume (RNA: 171 +/- 42 ml, DAS: 168 +/- 52 ml) and end-systolic volume (RNA: 95 +/- 50 ml, DSA: 89 +/- 50 ml) had correlation coefficients of 0.89 and 0.95, respectively. Left ventricular stroke volume (RNA: 75 +/- 26 ml, DSA: 75 +/- 27 ml) had a correlation coefficient of 0.92, while integrated pressure-volume loop or stroke work (RNA: 15.6 +/- 6.6 ergs 10(6), DSA: 15.9 +/- 6.3 ergs 10(6] had a correlation coefficient of 0.89. These data demonstrate that RNA measurements of left ventricular chamber dynamics concur with that obtained with DSA. With semiautomated data analysis, the portable first-pass RNA pressure-volume data are also less labor-intensive. Moreover, multiple measurements of ventricular performance during hemodynamic manipulations in the catheterization laboratory or operating room would allow for a more precise estimation of left ventricular performance.