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[The ST-segment-dependent indices of patients with left ventricular hypertrophy and coronary failure]
Insights
Essential hypertension and left ventricular hypertrophy can cause coronary insufficiency. ST/HR parameters correlate with left ventricular mass in some patients, but not all, indicating complex influences on coronary insufficiency.
Area of Science:
- Cardiology
- Internal Medicine
- Exercise Physiology
Background:
- Essential hypertension (EH) and left ventricular hypertrophy (LVH) are common cardiovascular conditions.
- Coronary insufficiency can occur in patients with EH and LVH, even without significant coronary artery stenosis.
- Understanding the relationship between cardiac structure, function, and ischemic response is crucial for patient management.
Purpose of the Study:
- To investigate the correlation between ST/HR parameters during exercise stress testing and left ventricular mass (LVM) in patients with EH and LVH or hypertrophic cardiomyopathy (HCMP).
- To differentiate the causes of coronary insufficiency in patients with EH, LVH, HCMP, and coronary heart disease (CHD).
- To evaluate the diagnostic utility of ST/HR parameters in identifying myocardial ischemia due to atherosclerosis.
Main Methods:
- Forty male patients with EH and LVH or HCMP underwent treadmill exercise testing (Cornell protocol).
- Measurements included ST/HR slope, ST/HR index, echocardiography for LVM and asymmetry index, and coronary ventriculography.
- Patients were categorized based on the presence of CHD or relative coronary insufficiency.
Main Results:
- All patients exhibited coronary insufficiency.
- ST/HR parameters correlated with LVM and left ventricular asymmetry in patients with EH and relative coronary insufficiency without stenosis.
- In patients with EH and CHD, ST/HR parameters did not correlate with atherosclerosis extent or LVM, suggesting multifactorial influence on coronary insufficiency.
- Specific ST/HR thresholds (slope ≥ 4.5, index ≥ 2.5) indicated a higher likelihood of ischemia due to atherosclerosis (sensitivity 28%, specificity 71%).
Conclusions:
- The relationship between ST/HR parameters, LVM, and coronary insufficiency is complex and depends on the underlying pathology.
- ST/HR parameters are valuable in assessing cardiac strain in EH with LVH but have limited correlation with atherosclerosis in EH with CHD.
- Exercise stress testing parameters can aid in differentiating causes of myocardial ischemia in hypertensive patients.
Abstract:
As many as 40 men suffering from essential hypertension (EH) and left ventricular hypertrophy (LVH) or hypertrophic cardiomyopathy (HCMP) were examined. All the patients exercised on a treadmill according to the Cornell protocol taking into consideration the ST/HR slope and the ST/HR index, underwent echocardiography with measurements of the left ventricular mass (LVM), and coronary ventriculography. Coronary insufficiency was revealed in all the patients. Of these, 11 patients suffered from it due to associated EH and coronary heart disease (CHD), 31 had relative coronary insufficiency in the presence of associated EH and LVH phenomena with no stenosis of coronary vessels, and 7 patients showed up relative coronary insufficiency in the presence of HCMP. The ST/HR slope and the ST/HR index correlated well with the LVM and the asymmetry index of the left ventricle but in patients with associated relative coronary insufficiency and EH. In patients with associated EH and CHD, the ST-dependent parameters correlated well neither with the degree of atherosclerosis spreading nor with the LVM. This may indicate that both factors influence the gravity of coronary insufficiency at a time. In case a patient suffering from associated EH and coronary insufficiency phenomena has the ST/HR slope greater than or equal to greater than or equal to 4.5 microV/stroke/min and/or the ST/HR index greater than or equal to greater than or equal to 2.5 microV/stroke/min, it is more likely that myocardial ischemia is provoked by concomitant atherosclerosis of coronary arteries (sensitivity 28%, specificity 71%).