Atrial natriuretic peptide response to ionic and nonionic contrast left ventriculography

Abstract

Summary:Atrial natriuretic peptide (ANP) levels were measured prior to and at 1 and 5 minutes postcontrast left ventriculography with an ionic contrast agent (diatrizoate), and a nonionic agent (iopamidol) and the results were compared. Since ionic contrast agents have been found to cause an increase in left ventricular end-diastolic pressure (LVEDP) and nonionic agents have been found to have less of an effect on LVEDP, we investigated the response of ANP levels, which have been found to increase secondary to increased LVEDP (atrial pressure), with both agents. A group of 38 patients who were scheduled for left heart catheterization for suspected coronary artery disease was included (19 in each group) and blood samples for ANP levels were drawn from the left ventricle. At the same time, heart rate, LVEDP, and left ventricular systolic pressure (LVSP) were also measured. It was found that the LVEDP increased significantly for both agents at 1 minute postventriculography, but no further change occurred at 5 min. Heart rate increased significantly in the diatrizoate group at 1 minute with a return of heart rate to preventriculography levels at 5 min, while the ANP level and LVSP remained unchanged at 1 minute postventriculography with both agents but increased significantly at 5 min in the diatrizoate group only. This difference in ANP response is not correlated with the LVEDP. The response of ANP may be related to heart rate and/or LVSP.

Systemic and Pulmonary Haemodynamic Effects of Intravenous Infusion of Non-Ionic Isoosmolar Dimeric Contrast Media

“…MPAOP reflects left atrial pressure as well as left ventricular end diastolic pressure which has been shown to increase after left ventriculography with high and low osmolar CM (12,32). These haemodynamic changes correspond well with expansion of the intravascular volume and dilatation of the peripheral resistance vessels, thus increasing the pre-load.…”

“…ANP is a circulating hormone deeply involved in the haemodynamic response to acute and chronic volume expansion (32,38). The hormone is mainly stored in the myocytes in the wall of the right atrium.…”