Assessment of regional left ventricular function during exercise test with pulsed tissue Doppler imaging

Area of Science:

• Cardiology
• Diagnostic Imaging
• Physiology

Background:

• Assessing left-ventricular (LV) function post-myocardial infarction (MI) is crucial for patient management.
• Traditional methods may have limitations in evaluating regional LV function during stress.
• Tissue Doppler imaging (TDI) offers a potential non-invasive method for assessing myocardial mechanics.

Purpose of the Study:

• To determine if mitral annular velocity, measured by TDI, can quantitatively evaluate global and regional LV function during exercise in patients with prior MI.
• To correlate TDI-derived mitral annular velocities with left-ventricular ejection fraction and identify regional wall motion abnormalities.

Main Methods:

• Exercise echocardiography with TDI was performed on 29 patients with previous MI and 12 healthy controls.
• TDI sample volumes were placed on mitral annuli corresponding to different LV walls.
• Coronary arteriography was conducted within 10 days of the stress echocardiography.

Main Results:

• A significant correlation was found between left-ventricular ejection fraction and mean systolic (S) mitral annular velocities (r = 0.83, p < 0.01).
• Mean S values at infarct regions were significantly lower in MI patients compared to controls (5.5 vs. 11 cm/sec, p < 0.001).
• After stress, S values in remote regions of patients with multivessel disease were also significantly lower than in controls (p < 0.01).

Conclusions:

• Pulsed TDI-derived mitral annular velocities accurately reflect LV asynergy in infarct regions.
• TDI parameters can identify reversible regional dysfunction following exercise in patients with prior MI.
• TDI provides a feasible quantitative evaluation of regional LV function during stress testing.