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Updated: Aug 8, 2026
Postconditioning with Lactate-enriched Blood for Cardioprotection in ST-segment Elevation Myocardial Infarction
Published on: May 28, 2019
Adaptation to ischemia during percutaneous transluminal coronary angioplasty. Clinical, hemodynamic, and metabolic
E Deutsch1, M Berger, W G Kussmaul
1Department of Medicine, University of Pennsylvania, School of Medicine, Philadelphia.
Insights
Second coronary artery occlusions during angioplasty show reduced ischemia. This suggests the heart adapts to brief periods of reduced blood flow, a phenomenon known as ischemic preconditioning.
Area of Science:
- Cardiology
- Physiology
Background:
- Percutaneous transluminal coronary angioplasty (PTCA) involves temporary coronary artery occlusion.
- Understanding the heart's response to repeated ischemia is crucial for patient outcomes.
Purpose of the Study:
- To investigate the clinical, electrocardiographic, and hemodynamic responses to sequential coronary artery occlusions during PTCA.
- To examine myocardial lactate metabolism during repeated occlusions.
Main Methods:
- 12 patients undergoing PTCA had sequential 90-second occlusions of the left anterior descending coronary artery.
- Myocardial lactate metabolism was assessed in a separate group of 7 patients.
Main Results:
- The second occlusion caused less anginal discomfort, ST segment shift, and lower pulmonary artery pressure compared to the first.
- Cardiac vein flow and myocardial lactate production were significantly reduced during the second occlusion.
- These findings indicate a protective adaptation to ischemia.
Conclusions:
- Reduced evidence of myocardial ischemia during the second occlusion supports the concept of ischemic preconditioning.
- Ischemic preconditioning may offer a protective mechanism during interventional procedures like PTCA.
Abstract:
The clinical, electrocardiographic, and coronary hemodynamic responses to sequential 90-second occlusions of the left anterior descending coronary artery in 12 patients undergoing elective percutaneous transluminal coronary angioplasty were examined. Transmyocardial lactate metabolism was examined in an additional group of seven patients with clinical and hemodynamic features similar to the first group. We noted that in comparison with the initial balloon occlusion the second occlusion was characterized by less subjective anginal discomfort, less ST segment shift (0.44 +/- 0.13 versus 0.21 +/- 0.07 mV, p = 0.01), and lower mean pulmonary artery pressure (25 +/- 1.0 versus 20 +/- 1.7 mm Hg, p = 0.005). In addition, for the same heart rate-blood pressure product, cardiac vein flow during the second inflation was significantly lower than that recorded during the first inflation (96 +/- 1.4 versus 83 +/- 2.4 ml/min, p = 0.005). Finally, there was significantly less myocardial lactate production during the second inflation (lactate extraction ratio: first inflation, -0.11 +/- 0.03; second inflation, -0.03 +/- 0.02; p = 0.04). We conclude that the lessened clinical, electrocardiographic, hemodynamic, and metabolic evidence of myocardial ischemia during the second of two periods of coronary artery occlusion during percutaneous transluminal coronary angioplasty supports the concept of adaptation to myocardial ischemia (ischemic preconditioning).
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