Effects of nifedipine and nitroglycerin on left ventricular systolic dysfunction and impaired diastolic filling after exercise-induced ischemia in humans

Exercise echocardiography and thallium-201 single-photon emission computed tomography stress test for 5- and 10-year prognosis of mortality and specific cardiac events

Limited data suggest that stress myocardial perfusion imaging and stress echocardiography have similar prognostic value for composite cardiac events. However, it is not known whether exercise echocardiography and stress thallium are similar in their prediction of specific cardiac events, eg, death, sudden death, myocardial infarction, unstable angina, and congestive heart failure. A total of 206 patients undergoing stress echocardiography and thallium-201 single-photon emission computed tomography imaging during the same exercise test were followed-up for 5 and 10 years. Multivariate Cox regression analyses incorporating clinical, exercise stress test, echocardiographic, and nuclear imaging parameters were used to predict mortality and specific cardiac events. A moderate to large amount of ischemia (> or =4 segments on the basis of a 16-segment model) by exercise stress echocardiography was the strongest predictor of overall mortality (relative risk [RR] 6.2; P <.0001), cardiac death (RR 17.6; P =.01), congestive heart failure (RR 17.4; P =.0005) or sudden death (RR 26.8; P =.003), whereas a moderate to large fixed defect (> or =2 segments on the basis of a 6-segment model) by nuclear imaging was the strongest predictor of myocardial infarction (RR 8.1; P =.0002) or unstable angina (RR 3.0; P =.005) at 5 years. The heterogeneity in the prediction of these specific cardiac events by these 2 modalities was similarly observed at 10 years. The extent of ischemia by stress echocardiography is a better predictor of overall mortality, cardiac death, congestive heart failure, or sudden death, whereas the extent of a fixed defect by nuclear imaging is a better predictor of myocardial infarction or unstable angina.

Left ventricular diastolic function in the elderly

Previous studies using pulsed Doppler echocardiography have demonstrated a pattern of abnormal left ventricular relaxation associated with increasing age. Specifically, aging is associated with decreased peak velocity of early diastolic mitral inflow, increased peak velocity of late diastolic inflow, increased isovolumic relaxation time, and early diastolic deceleration time. Abnormal relaxation can progress to significantly elevated left atrial pressure--characterized by increased early peak velocity and shortened isovolumic relaxation time and deceleration time--as part of the disease processes. Left ventricular diastolic dysfunction is highly prevalent, occurring in one half to two thirds of elderly patients with congestive heart failure, in association with normal systolic function. Left ventricular hypertrophy, which is commonly related to systemic arterial hypertension, and ischemic heart disease are the two major causes of abnormal left ventricular diastolic function in the elderly. Recently, newer echocardiographic techniques have been described that allow more accurate evaluation of left ventricular diastolic function. Treatments for left ventricular diastolic dysfunction should focus on the underlying disease etiology as well as on the derangement in left ventricular diastolic function. Although calcium channel blockers and angiotensin-converting enzyme inhibitors have been used clinically to treat diastolic dysfunction, their effects on prognosis remain unproven.