From Left Ventricular Dysfunction to Heart Failure in the Elderly Patient.
The pathophysiology of the syndrome of congestive heart failure (CHF) is different in elderly patients compared to middle-aged subjects. When the syndrome of CHF predominantly results from left ventricular (LV) systolic dysfunction, peripheral mechanisms in elderly patients are less apt to compensate for the decline in LV performance due to deconditioning of the skeletal muscles, decreased vasodilatory response to exercise, and reduced capacity to excrete sodium. These all develop with age. LV diastolic dysfunction, i.e., LV filling impairment, appears to be a more frequent cause of CHF in elderly patients than in middle-aged subjects. Hypertrophy of the cardiac myocyte is associated with a prolongation of the calcium transient which, in turn, results from a decreased concentration of the enzyme responsible for reuptake of calcium in the sarcoplasmic reticulum. Cardiac myocyte hypertrophy results from a steady loss of myocytes and a progressive rise in arterial impedance which are both observed with aging. Notwithstanding subendocardial myocardial ischemia which is frequently associated with LV wall hypertrophy, prolongation of the calcium transient leads to impaired LV wall relaxation and the syndrome of LV diastolic dysfunction. The goals of therapy are also different in elderly patients compared to middle-aged patients. In elderly patients, one is less concerned about restoring a near normal exercise capacity, and aims at preventing acute episodes of decompensation which frequently accompany excessive sodium intake. Therefore, strict adherence to diet and careful titration of the dosages of medication to renal function are important considerations when treating CHF in elderly patients. In particular, cardiac glycosides, which should be avoided with CHF due to LV diastolic dysfunction, should be carefully titrated to creatinine clearance and body weight when treating elderly patients with LV systolic dysfunction in sinus rhythm. Similarly, the dosages of most angiotensin-converting enzyme inhibitors should be reduced in elderly patients.
Bijou
Rachel
R
Department of Medicine, Division of Cardiology, Albert Einstein College of Medicine, Bronx, NY.
Le Jemtel
Thierry
T
Sonnenblick
Edmund H.
EH