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[Left ventricular contraction reserve in coronary heart disease. Evaluation, quantification and prognostic value
Insights
Left ventricular contraction reserve is higher in coronary heart disease patients. Postextrasystolic beats offer a superior method for assessing this reserve compared to nitroglycerin tests.
Area of Science:
- Cardiology
- Cardiovascular Physiology
Context:
- Assessing left ventricular (LV) function is crucial in coronary heart disease (CHD).
- Quantifying LV contraction reserve helps understand myocardial viability and response to ischemia.
- Evaluating the efficacy of interventions like aorto-coronary bypass surgery.
Purpose:
- To compare the efficacy of postextrasystolic potentiation (PEP) and nitroglycerin for assessing LV contraction reserve.
- To evaluate regional and overall LV contraction reserve in patients with CHD and healthy controls.
- To assess changes in LV function after aorto-coronary bypass surgery.
Summary:
- This study investigated left ventricular (LV) contraction reserve in 14 CHD patients, 5 healthy subjects, and 4 patients pre- and post-bypass surgery.
- Quantification used ventricular volumes, ejection fraction, hemiaxis method, and ventricular score.
- Postextrasystolic beats were found to be superior to nitroglycerin for assessing contraction reserve due to cost-effectiveness and better differentiation of contractile areas.
- LV contraction reserve was significantly higher in CHD patients, particularly those with angina and ischemic reactions.
- Improvement in contraction was more pronounced in the anterior wall than the posterior wall.
- Post-bypass surgery, overall and regional ventricular function did not fully recover in normal beats, with differences attributed to ischemia and scarring.
Impact:
- Recommends the ventricular score for routine quantification and the hemiaxis method for research.
- Highlights postextrasystolic beats as a preferred method for contraction reserve analysis.
- Demonstrates that LV contraction reserve is elevated in CHD patients.
- Reveals differential regional improvements in contraction post-intervention.
- Indicates incomplete functional recovery after bypass surgery, emphasizing the role of ischemia and scarring.
Abstract:
Regional and overall left ventricular contraction reserve was studied in 14 patients with coronary heart disease, in 5 healthy subjects and in 4 patients before and after aorto-coronary bypass surgery. Quantification of overall contraction was based on ventricular volumes and ejection fraction. Regional contraction reserve was calculated with the hemiaxis method and a ventricular score. Contraction reserve under nitroglycerin and in postextrasystolic beats was compared. For routine quantification of contraction reserve the ventricular score is recommended. For research purposes the hemiaxis method is to be preferred. Postextrasystolic beats are better suited for analysis of contraction reserve than are angiograms following administration of nitroglycerin. This is due to the minor expense of the procedure, furthermore, postextrasystolic beats allow better differentiation between contracting and non-contracting areas. Left ventricular contraction reserve is larger in patients with coronary heart disease, angina pectoris and ischemic reactions in the exercise ECG than in control patients. These findings are based on overall and on regional volume parameters. A quantitatively greater improvement in contraction could be provoked in the anterior wall than in the posterior wall. Regional contraction improved significantly in most cases either in the anterior wall or in the posterior wall; rarely it improved simultaneously in both left ventricular regions. In a few cases contraction deteriorated in one area with a simultaneous improvement in the opposite area. Overall and regional ventricular function, as assessed preoperatively by contraction reserve determinations could not be completely regained in normal beats after successful bypass surgery. Differences in the regional contraction reserve seemed to be mainly due to varying degrees of ischemia and scarring.