Cardiac function and dysfunction in hypertension
Fetnat M. Fouad, MDAddress reprint requests to F.M.F., Department of Cardiovascular Biology, FF10, The Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195.
Hypertension is the most common condition of increased left ventricular afterload that affects the cardiovascular system.OBJECTIVE
To review the effects of increased blood pressure on cardiac function.SUMMARY
In early or borderline hypertension, cardiac output increases but intravascular volume remains normal. In uncomplicated established hypertension, left ventricular systolic function is generally normal at rest; however, the left ventricular filling rate is reduced in approximately 30% of hypertensive patients without associated alterations in systolic function. In the presence of left ventricular hypertrophy, overall left ventricular systolic performance remains within normal limits; however, left hypertrophy in hypertension is associated with a high morbidity rate, possibly due t o increased collagen concentration leading to reduced left ventricular compliance, fewer adrenergic receptors, reduced responsiveness of the adenylate cyclase system, and reduced coronary flow reserve. Acute increases in blood pressure in a hypertensive patient may worsen cardiac function, particularly in the presence of medications that interfere with the adrenergic support of the heart. New, accurate, noninvasive techniques can assess cardiac structural and functional aspects of hypertension under precise circumstances.CONCLUSIONS
Assessing both systolic and diastolic function is important in the follow-up of hypertensive patients and in the choice of therapy.