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Aortic valve disease and the ST segment/heart rate relationship: a longitudinal study before and after aortic valve
N Bishop1, R M Boyle, D A Watson
1Department of Cardiovascular Studies, University of Leeds, U.K.
Insights
Maximal ST/HR slope indicates myocardial ischemia in aortic valve disease patients. After valve replacement, this ischemia marker significantly decreased, showing the link between aortic valve disease and cardiac ischemia.
Area of Science:
- Cardiology
- Cardiac Electrophysiology
Background:
- The ST segment/heart rate (ST/HR) relationship, or maximal ST/HR slope, is a validated index for myocardial ischemia in patients with angina pectoris.
- Aortic valve disease can lead to cardiac enlargement and potentially myocardial ischemia, even without significant coronary artery narrowing.
Purpose of the Study:
- To investigate the presence and significance of the maximal ST/HR slope in patients with aortic valve disease and cardiac enlargement but without significant coronary artery narrowing.
- To assess the impact of aortic valve replacement on the maximal ST/HR slope and associated ST segment depression.
Main Methods:
- Evaluated seven patients with aortic valve disease and cardiac enlargement, unaccompanied by angiographic coronary artery narrowing.
- Measured the maximal ST/HR slope and ST segment depression before and after aortic valve replacement.
- Assessed changes in heart size (cardiothoracic ratio) and QRS complex amplitude via electrocardiogram post-surgery.
Main Results:
- All seven patients exhibited a maximal ST/HR slope and ST segment depression (>1 mm) indicative of myocardial ischemia prior to surgery.
- Following aortic valve replacement, a statistically significant reduction in the maximal ST/HR slope was observed (abolished in two, markedly reduced in five).
- Post-surgery, ST segment depression indicative of ischemia was obtainable in only one patient, and heart size/QRS amplitude decreased.
Conclusions:
- Maximal ST/HR slope is present in patients with aortic valve disease and cardiac enlargement, even without significant coronary artery disease.
- Aortic valve replacement leads to a significant reduction or abolition of the maximal ST/HR slope, suggesting reversal of myocardial ischemia.
- The findings highlight the role of aortic valve disease as a cause of myocardial ischemia detectable by the ST/HR slope.
Abstract:
The ST segment/heart rate relationship or maximal ST/HR slope has been validated as an index of myocardial ischemia in selected populations of patients with angina pectoris. The present study involved patients selected as having aortic valve disease unaccompanied by angiographic coronary artery narrowing. In each of seven patients, so far examined, a slope value and ST segment depression of greater than 1 mm were obtained which, according to previous experience, indicated myocardial ischemia equivalent to coronary heart disease. After aortic valve replacement, there was a significant reduction in heart size as assessed using the cardiothoracic ratio, and the amplitude of QRS complex on the electrocardiogram. The slope was abolished (two patients) or markedly reduced (five patients), and the decrease in the seven patients was statistically significant. ST segment depression could be obtained in one patient. This study has shown the occurrence of maximal ST/HR slope in patients without large coronary artery disease who have aortic valve disease and cardiac enlargement.