Digital intravenous ventriculography (DIV) has become increasingly recognized as a useful and reliable approach for evaluating left ventricular (LV) performance. While it might be assumed that the hemodynamic changes caused by intravenous injection of contrast media are less than those caused by direct LV injection, these responses have not actually been compared. Accordingly, the hemodynamic effects of IV and direct LV contrast injections were compared in eight anesthetized dogs instrumented with two pairs of ultrasonic dimension crystals, one to measure LV endocardial segment length and one to measure LV internal dimension, and a LV high-fidelity pressure catheter.
The alterations in LV dimension and pressure were similar using both injection techniques, though they were less marked with IV injection. Both routes of injection caused a significant decline in LV pressure (P < 0.05) which was greatest at 30 seconds after injection, and a significant (P < 0.05) increase in end-diastolic dimension (which was greatest between 10-30 seconds) and extent of change in LV diameter (P < 0.01). The afterload reducing effects of the contrast media increased the rate of LV segment length shortening slightly after LV injection but not with IV injection.
These data demonstrate no important differences in the hemodynamic response to IV and LV injection of contrast media. The induced hemodynamic changes after IV administration were relatively small in magnitude and transient in duration and probably not sufficient to obviate quantitative analysis of LV dimensions and function by digital intravenous angiography.
© Lippincott-Raven Publishers.