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The effect of contrast media on the isolated perfused canine heart
Insights
Contrast media can affect heart function. Studies on isolated canine hearts show Renografin-76 depresses contractility, independent of saline or osmotic effects, while sucrose enhances it.
Area of Science:
- Cardiovascular Physiology
- Pharmacology
Background:
- Intravascular injection of contrast media can increase ventricular filling pressure.
- This may be due to blood volume expansion, negative inotropic effects, or decreased diastolic compliance.
Purpose of the Study:
- To investigate the effects of contrast media on myocardial function.
- To differentiate between saline, osmotic, and intrinsic effects of contrast agents.
Main Methods:
- Isolated perfused canine heart model.
- Fixed end-diastolic volume and afterload using an intraventricular balloon.
- Infusion of Renografin-76, 1% saline, and 38% sucrose into the aortic root.
Main Results:
- Renografin-76 caused a dose-related depression in left ventricular systolic pressure and peak dP/dt.
- No significant changes in left ventricular diastolic pressure or compliance were observed.
- Sucrose demonstrated a significant positive inotropic effect.
Conclusions:
- The negative inotropic effect of Renografin-76 is not solely due to saline or osmotic properties.
- Contrast media can directly impact myocardial contractility.
- Osmotic agents like sucrose can positively influence myocardial contractility.
Abstract:
The intravascular injection of contrast medium produces a rise of ventricular filling pressure which may reflect blood volume expansion, a negative inotropic effect on the myocardium, and/or a decrease in ventricular diastolic compliance. This phenomenon was studied by randomly infusing three substances, Renografin-76, 1% saline and 38% sucrose, into the aortic root of the isolated perfused canine heart. The preparation was modified by having an inflated ballon within the left ventricular cavity so that the end diastolic ventricular volume and afterload were fixed. A dose-related depression of left ventricular systolic pressure and peak dP/dt due to contrast media occurred, without a significant change in the left ventricular diastolic pressure. This decrease in ventricular contractility due to Renografin-76 could not be attributed entirely to either a saline or an osmotic effect. No significant changes were observed in left ventricular diastolic compliance. Sucrose was found to exhibit a marked positive inotropic effect.