Exercise capacity and cardiac function assessed by tissue Doppler imaging in chronic heart failure

Abstract

Objective: To examine the relation between longitudinal left ventricular function assessed by tissue Doppler imaging (TDi) and exercise capacity in heart failure. Subjects: 153 patients with chronic heart failure from left ventricular systolic dysfunction (ejection fraction , 45%) and 87 age and sex matched controls. Methods: Echocardiography was used to measure conventional indices of left ventricular systolic function. TDi was used to assess left and right ventricular longitudinal function by measuring mitral and lateral tricuspid annular velocities during the cardiac cycle. Velocities measured at each point were the systolic peak (S m ) and the diastolic troughs (E m and A m ), corresponding to passive and active (atrial) left ventricular filling. Each patient also underwent treadmill exercise testing with metabolic gas exchange measurements. P atients with chronic heart failure complain of exercise intolerance, usually because of breathlessness and fatigue.1 Incremental exercise testing with metabolic gas exchange measurements used to derive peak oxygen consumption (pVO 2 ) allows an objective assessment of symptoms and exercise capacity. Generally, resting echocardiographic variables predict exercise capacity poorly in chronic heart failure. Resting left ventricular ejection fraction (LVEF) correlates weakly with exercise capacity 3-8 and other markers of exercise capacity, such as the slope of the relation between ventilation (VE) and carbon dioxide production (VCO 2 ) (VE/VCO 2 slope). Many patients with reduced exercise capacity have similar global left ventricular function to less limited individuals. Tissue Doppler imaging (TDi) allows quantitative assessment of the motion of the myocardium and is particularly helpful in quantifying ventricular long axis function.15 TDi can be used to assess both regional and global left ventricular function. Measuring myocardial velocities gives information about regional ventricular contractility, while, as a consequence of the relative immobility of the cardiac apex, the measurement of mitral annular velocities provides information on longitudinal left ventricular function. Regardless of the site of the measurement, the normal TDi profile has a characteristic appearance, consisting of systolic and diastolic myocardial motion (fig 1). Systolic motion often has two peaks, S9 and S m . S9 reflects isovolumic contraction, while S m occurs during ejection. Diastolic velocities, seen as troughs, consist of early and late myocardial movement (E m and A m ). These correspond to passive ventricular filling and atrial contraction, as do the E and A waves of transmitral flow. Mitral annular velocities are less preload dependent than conventional Doppler indices of mitral inflow 16 although the diastolic waveforms are not entirely preload independent. 17Tricuspid annular profiles are similar to those from the mitral annulus. Right ventricular S m velocity correlates with right ventricular ejection fraction (RVEF) measured by first pass radionuclide ventriculography in chronic h...

Impaired left ventricular systolic function reserve limits cardiac output and exercise capacity in HFpEF patients due to systemic hypertension

“…This analysis is further supported by the inverse correlation we found between LA enlargement and exercise capacity. Ejection fraction, relied on by clinicians, was of no help, since it was normal as an inclusion criterion, confirming previous evidence which showed no relationship with exercise capacity [22,23]. Detailed analysis of LV myocardial function can be assessed by different Doppler ultrasound techniques such as tissue Doppler imaging (TDI) and speckle tracking echocardiography (STE).…”

Prognostic Value of Heart Rate Profiles During Cardiopulmonary Exercise Testing in Patients With Cardiac Disease

“…In general, many studies have failed to show a significant link between exercise capacity (peak VO 2 ) and LVEF in patients with chronic heart failure, 42) and it has been reported that peak VO 2 is superior to LVEF as a prognostic predictor. However, in this study population, because averaged LVEF was about 60% and several patients with preserved LVEF were included, it seemed that LVEF was the strongest prognostic parameter.…”

Exercise intolerance in chronic heart failure: mechanisms and therapies. Part I

“…Recently, the role of the heart has been emphasized, but that different indices of LV dysfunction (and not just ejection fraction) need to be monitored, for example, indices of longitudinal LV function assessed by tissue Doppler imaging [8]. Furthermore, LV asynchrony, rather than uniform depression of systolic ventricular function, may play a key role in determining the maximum exercise tolerance by prolonging the total isovolumic period within the cardiac cycle [9].…”