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[Myocardial ischemia in hypertension heart disease (author's transl)]
Insights
Hypertension-induced left ventricular hypertrophy is linked to subendocardial ischemia, not coronary artery blockages. Increased left ventricular mass may impair coronary blood flow, posing a high-risk condition.
Area of Science:
- Cardiology
- Internal Medicine
- Physiology
Background:
- Hypertension is a common condition associated with cardiovascular complications.
- Left ventricular hypertrophy (LVH) is a known consequence of chronic hypertension.
- Subendocardial ischemia can occur in hypertensive patients, but its underlying mechanisms require further elucidation.
Purpose of the Study:
- To investigate the relationship between left ventricular hypertrophy and subendocardial ischemia in hypertensive patients.
- To determine the role of coronary artery anatomy and function in this patient group.
- To explore potential indicators of high-risk cardiovascular conditions.
Main Methods:
- Studied 17 hypertensive patients with electrocardiogram (EKG) evidence of LVH and subendocardial ischemia.
- Performed cine-ventriculography, coronary arteriography, ejection fraction, ventricular pressure, and left ventricular mass measurements.
- Utilized EKG stress tests, atrial stimulation, and cardiac scintigraphy with TC 99m albumin-macro-aggregates in a subset of patients.
Main Results:
- All patients exhibited positive EKG stress and atrial stimulation tests, indicating ischemia.
- 83.7% of patients had patent coronary arteries with "corkscrew" tortuosity.
- All patients showed increased left ventricular mass (119 +/- 28.5% m2 s/c); ejection fraction and diastolic pressures were normal.
- Cardiac scintigraphy revealed uniform radioisotope distribution in the right ventricle and poorer, dispersed concentration in the left ventricle.
Conclusions:
- Subendocardial ischemia in these hypertensive patients with LVH is not caused by main coronary trunk obstruction.
- A significant increase in left ventricular mass is associated with this condition.
- The findings suggest impaired coronary reserve and a potentially high-risk cardiovascular state.
Abstract:
Seventeen hypertensive patients with EKG evidence of left ventricular hypertrophy and subendocardial ischemia were studied. The following tests were performed: cine-ventriculography, coronary arteriography, ejection fraction, ventricular pressures, left ventricular mass, EKG stress test and atrial stimulation. In 10 cases cardiac scintigraphy with intracoronary injection of albumin-macro-aggregates marked with TC 99m, was obtained. EKG stress and atrial stimulation tests were positive in all cases, with ST depression greater than 1mm, or accentuation of previous ST depression. 83.7% of the patients had permeable coronary arteries, with "corkscrew' tortuosity. Left ventricular mass was increased in all cases (119 +/- 28.5% m2 s/c). Ejection fraction (74.2 +/- 8.1), and left ventricular diastolic pressures were normal. Cardiac scintigraphy showed uniform distribution of the radioisotope in the right ventricle and poor concentration with better dispersion and distribution in the left ventricle. It is concluded that subendocardial ischemia in these subjects is not produced by obstruction of the main coronary trunks and is associated to a significant increment of left ventricular mass which possibly produce a poor coronary reserve, and a potentially high risk condition.