The effect of prolonged cardioplegic arrest on long-term ventricular function

Area of Science:

• Cardiology
• Cardiac Surgery
• Cardiovascular Physiology

Background:

• Prolonged cardioplegic arrest is a concern in cardiac surgery.
• Assessing the impact of extended ischemic times on long-term ventricular function is crucial.

Purpose of the Study:

• To investigate the correlation between prolonged cardioplegic arrest (>120 minutes) and late postoperative ventricular functional deterioration.
• To evaluate the utility of early postoperative tests in predicting long-term outcomes.

Main Methods:

• Studied 25 patients (15 coronary revascularizations, 10 valve replacements) with ischemic arrest times >120 minutes.
• Utilized serial enzyme analysis, EKG, and technetium pyrophosphate (PYP) scans post-operation.
• Assessed ejection fraction (EF) changes from pre-operation to 7-27 months post-operation via scintigraphy.

Main Results:

• Only 1 coronary bypass patient (6.7%) and 1 valve replacement patient (10%) experienced perioperative myocardial infarction.
• No patients developed recurrent angina, infarction, or congestive heart failure during follow-up (mean 17.9-19.9 months).
• Ejection fraction changes were minimal; mean EF remained stable pre- and post-operatively for both groups.

Conclusions:

• Prolongation of cardioplegic arrest beyond 2 hours is well-tolerated in the majority of cardiac surgery patients.
• Early postoperative tests were not reliable predictors of late functional deterioration in patients without perioperative infarction.
• Depressed ventricular function in some cases may be linked to myocardial fibrosis rather than perioperative events.