The left ventricle and hemodynamic patterns in essential hypertension.

摘要

Hemodynamic patterns in hypertensive patients by radionuclide techniques and tomographic gamma camera were evaluated. In younger hypertensive patients, the hyperkinetic state reflected an increase in heart rate and, consequently, an increased cardiac index and left ventricular ejection fraction (LVEF). Older hypertensive patients, however, showed a different hemodynamic pattern, with reduced systolic and diastolic function at rest compared with normotensive elderly people, and marked depression of cardiac systolic and diastolic reserve during exercise. They also showed strikingly higher hyperresistance and reduced peripheral perfusion. These hemodynamic differences need to be taken into account when considering antihypertensive treatment. In a study in 106 elderly hypertensive patients, treatment with four different antihypertensive drugs produced a significant decrease in total peripheral resistance and blood pressure, together with a reduction in left ventricular (LV) afterload and an increase in cardiac output and LVEF (tending towards normal values). The LV peak filling rate was also increased and evaluation of systolic and diastolic cardiac reserve during exercise showed positive changes in cardiac performance. Left ventricular hyperthropy (LVH) is a powerful predictor of cardiac events. Long-term increases in BP predispose to LVH, impaired diastolic relaxation and, ultimately, ventricular dysfunction. A reduction in LVH produces a number of different beneficial effects. Coronary flow reserve was evaluated in hypertensive patients. Coronary flow reserve was highly impaired in comparison with normotensive controls, and increases in arteriolar wall thickness, collagen content and diastolic dysfunction were also noted. A marked improvement in coronary flow reserve in patients who received antihypertensive therapy was confirmed.