Quantitation of papillary muscle function with tissue and strain Doppler echocardiography measures papillary muscle contractile functions.

Abstract

It is well known that papillary muscle dysfunction may cause mitral regurgitation, however, there is not a standard technique to measure the papillary muscle function. The aim of this study is to investigate papillary muscle function by using tissue and strain rate Doppler echocardiography. A study group (SG) of 42 patients (12 females, 30 males, mean age: 53.8 +/- 10.9 years) with coronary artery disease who have segmental left ventricular dysfunction and mitral regurgitation, and as a control group (CG) 20 patients (6 females, 14 males, mean age 52.5 +/- 10.2 years) who have no coronary artery disease and mitral regurgitation were studied. A subgroup 20 patients (7 females, 13 males, mean age 42.5 +/- 7.5 years) who have rheumatic mitral regurgitation was included to the study. The patients who have left ventricular and mitral annular dilatation were not included into the study. Longitudinal wall motion of mid-inferior segment (one point) and posterior papillary muscle (two point) of the left ventricle was assessed by tissue and strain rate Doppler echocardiography from the apical two-chamber view. Systolic tissue velocity (Sm), strain rate (SR), and strain (S) were measured from the two points in all patients. Comparing the one point values Sm, SR, and S were found less in SG than CG (respectively 4.2 +/- 1.4 vs 11.3 +/- 1.9 cm/sec, -1.0 +/- 0.4 vs -1.7 +/- 0.3 s-1, -13.5 +/- 5.0 vs -18.1 +/- 3.9%; P < 0.001 for all). Comparing the two point values Sm, SR and S were found less in SG than CG (respectively 2.8 +/- 1.2 vs 3.7 +/- 2.0 cm/sec, -0.8 +/- 0.4 vs -1.6 +/- 0.3 s-1, -9.7 +/- 4.6 vs -15.8 +/- 3.7%; P < 0.001 for all). Systolic mitral annulus, left ventricular systolic and diastolic dimensions were similar in two groups. Comparing the CG and subgroup, there were no significant differences with respect to Sm, SR, and S measured from the two points. Papillary muscle function may be assessed quantitatively by using tissue and strain rate Doppler echocardiography. Tissue velocity, strain rate, and strain values were found decreased in dysfunctional papillary muscle.