The role of tissue Doppler echocardiography in the evaluation of functional capacity of patients with heart failure

OBJECTIVES
We investigated correlations between the New York Heart Association (NYHA) functional classification system, which is commonly used to asses functional capacity, and conventional echocardiographic and tissue Doppler echocardiographic (TDE) parameters in patients with heart failure (HF).

STUDY DESIGN
The study included 122 patients (31 females, 91 males; mean age 59±11 years) with HF, whose left ventricular (LV) ejection fraction (EF) was less than 50%. The patients were evaluated in two groups based on the NYHA class I-II (n=79; mean age 58 years) and class III-IV (n=43; mean age 61 years). Correlations were sought between the functional status and standard two-dimensional echocardiographic and TDE parameters.

RESULTS
The NYHA class showed significant inverse correlations with LV EF, LV stroke volume, mitral deceleration time of early filling, and flow propagation velocity (Vp), and significant positive correlations with end-systolic and end-diastolic diameters and volumes, pulmonary artery pressure (PAP), and the E/Vp ratio. Mitral early (E) and late (A) diastolic peak velocities and the E/A ratio were not correlated. Concerning TDE parameters, the NYHA class was in significant inverse correlation with systolic (Sm), early (Em) and late (Am) diastolic myocardial velocities, and in positive correlation with the E/Em ratio, whereas no correlation was found with the Em/Am ratio. Linear regression analysis showed that Sm, EF, and PAP were independent variables of functional capacity (=-0.33, p<0.005; =-0.26, p<0.05; =0.23, p<0.05, respectively).

CONCLUSION
There is significant relationship between myocardial velocities and functional capacity, and Sm, in particular, has the strongest association compared to conventional echocardiographic and other TDE parameters.