Could inspiratory apnea disturb left ventricular volume assessment by contrast angiography?

To assess the influence of postinspiratory apnea on the measurement of the left ventricular volumes, contrast ventriculography was performed on 19 patients during spontaneous breathing and then in postinspiratory apnea. Data obtained were similar for end diastolic volumes (81 +/- 29 ml/m2 vs. 83 +/- 25; NS), end systolic volumes (35 +/- 20 ml/m2 vs. 34 +/- 19; NS), systolic index (46 +/- 13 ml/m2 vs. 49 +/- 12; NS), and ejection fraction (0.57 +/- 0.11 vs. 0.59 +/- 0.12; NS). Postinspiratory apnea suppressed the overlapping of the left ventricle with abdominal viscera in 15 of 17 patients. Diaphragmatic immobility permitted the assessment of regional left ventricular function in all 19 patients. However, pressures recorded in inspiratory apnea can no longer be compared to a transmural pressure, and, to assess ventricular compliance, intrapleural pressure must be measured simultaneously. We conclude that left ventricular volume assessment by contrast ventriculography is not disturbed by inspiratory apnea. This maneuver improves the quality of the images and allows a better evaluation of left ventricular segmental function. Spontaneous breathing can be recommended to simplify left ventricular compliance study.