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Ventricular function after atrial cardioplegia
D R Salter1, J P Goldstein, A Abd-Elfattah
1Department of Surgery, Duke University Medical Center, Durham, NC 27710.
Insights
Continuous retrograde coronary sinus cardioplegia (CSCP) preserved biventricular function, unlike atrial cardioplegia which caused significant right ventricular dysfunction. Atrial cardioplegia may lead to postoperative right ventricular issues, especially without topical cooling.
Area of Science:
- Cardiology
- Cardiac Surgery
- Cardiovascular Physiology
Background:
- Continuous retrograde coronary sinus cardioplegia (CSCP) is effective during ischemia, even with coronary lesions or hypertrophy.
- A novel atrial cardioplegia technique via the right atrium has shown clinical success.
Purpose of the Study:
- To evaluate right ventricular function following atrial cardioplegia and acute passive right ventricular distension.
- To compare CSCP with continuous and intermittent atrial cardioplegia delivery methods.
Main Methods:
- Comparison of CSCP (n=10) with continuous (n=10) and intermittent (n=8) atrial cardioplegia.
- Assessment of ventricular function using stroke work vs. end-diastolic length relationship.
- Measurement of right and left ventricular ATP levels.
Main Results:
- Profound right ventricular dysfunction (44% and 37% of control) observed in atrial cardioplegia groups after 1 hour reperfusion.
- Biventricular function fully preserved in the CSCP group.
- Left ventricular function preserved in all groups; RV ATP depressed in all, LV ATP depressed in atrial groups.
Conclusions:
- Atrial cardioplegia leads to significant right ventricular dysfunction, potentially due to inadequate myocardial cooling below 16°C.
- CSCP fully preserves biventricular function.
- Postoperative right ventricular dysfunction may be underestimated with atrial cardioplegia, particularly without topical cooling.
Abstract:
Continuous retrograde coronary sinus cardioplegia (CSCP) has previously been carefully evaluated experimentally and shown to be efficacious during ischemia, even in the presence of coronary lesions and in the hypertrophied state. A new technique of retrograde cardioplegia delivery through the right atrium, using right ventricular distension and pressures of 60 mm Hg, has recently been described with excellent clinical results. This study was designed to specifically examine right ventricular function after atrial cardioplegia and acute passive right ventricular distension. CSCP (n = 10) was compared with cardioplegia delivered through the right atrium both continuously (n = 10) and intermittently (n = 8). When ventricular function was examined with the use of the load-independent relationship of stroke work vs end-diastolic length, there was a profound deterioration of right ventricular function in both atrial cardioplegia groups (44% and 37% of control values, respectively) after 1 hr of reperfusion. In contrast, biventricular function was fully preserved in the CSCP group 1 hr after reperfusion. Left ventricular function measured at the end of reperfusion was preserved in all three groups. Right ventricular ATP levels were slightly but significantly depressed in all groups and in the atrial cardioplegia groups, this metabolic change was also seen in the left ventricle. These metabolic and hemodynamic data may reflect the inability of atrial cardioplegia to cool the myocardium below 16 degrees C. Postoperative right ventricular dysfunction may be more common than has been previously thought when atrial cardioplegia is used, particularly in the absence of topical cooling.