Atrial natriuretic peptide response to ionic and nonionic contrast left ventriculography

Area of Science:

• Cardiology
• Medical Imaging
• Biochemistry

Background:

• Ionic contrast agents can increase left ventricular end-diastolic pressure (LVEDP), while nonionic agents have a lesser effect.
• Atrial natriuretic peptide (ANP) levels are known to increase secondary to elevated LVEDP (atrial pressure).

Purpose of the Study:

• To compare the effects of ionic (diatrizoate) and nonionic (iopamidol) contrast agents on ANP levels during left ventriculography.
• To investigate the relationship between ANP response, LVEDP, heart rate, and left ventricular systolic pressure (LVSP).

Main Methods:

• 38 patients undergoing left heart catheterization were divided into two groups (19 each) receiving either diatrizoate or iopamidol.
• ANP levels, heart rate, LVEDP, and LVSP were measured in the left ventricle before and at 1 and 5 minutes after contrast injection.

Main Results:

• LVEDP significantly increased at 1 minute post-injection for both agents, with no further changes at 5 minutes.
• Heart rate increased significantly with diatrizoate at 1 minute, returning to baseline by 5 minutes.
• ANP levels and LVSP remained unchanged at 1 minute but increased significantly at 5 minutes only in the diatrizoate group.

Conclusions:

• The observed ANP response to contrast ventriculography is not correlated with LVEDP.
• The ANP response may be influenced by changes in heart rate and/or LVSP, particularly with ionic contrast agents.