Changes of Mitral Inflow According to Position in Patients with Dilated Cardiomyopathy

ABSTRACT

BACKGROUND AND OBJECTIVES: Dilated cardiomyopathy(DCMP) probably is the end result of myocardial damage produced by various causes and shows various clinical manifestations. Some patients with DCMP experience more shortness of breath when change their position especially in left lateral decubitus position. We investigated whether the symptomatic changes according to position in DCMP patients were related to the changes of mitral inflow pattern. MATERIALS AND METHOD: DCMP patients with New York Heart Association functional class III or IV, who felt more shortness of breath when changed their position, were studied. The patients with atrial fibrillation or with moderate and severe valvular heart disease were excluded. Early and late atrial left ventricular filling velocities and time velocity integrals(TVI) and it's ratios of mitral inflow, heart rates, isovolumic relaxation time(IVRT), decelaration time(DT) of early mitral inflow were analysed in each decubitus position. RESULTS: 4 men and 3 women were included and their mean age was 60.3 years. 6 patients had mild mitral regurgitation and 4 patients had mild aortic regurgition. All patients felt more shortness of breath in left lateral decubitus position. Peak velocity and TVI of early mitral inflow were not changed significantly according to position. Peak velocity of late mitral inflow was increased significantly with right lateral decubitus position(Lt; 39.0+/- 14.1cm/sec, Rt; 49. 4+/-23.6cm/sec, p<0.05). TVI of late mitral inflow was increased significantly with right lateral decubitus position(Lt; 2.8+/-1.1cm, Rt; 3.8+/-1.9cm, p<0.05). Ratio of early and late mitral inflow peak velocity was decreased significantly with right lateral decubitus position(Lt; 2.13+ 0.34, Rt 1.62+/-0.57, p<0.05). Ratio of early and late mitral inflow TVI was decreased significantly with right lateral decubitus position(Lt; 3.13+/-1.49, Rt; 2.13+/-1.32, p<0.01). Heart rate, IVRT, DT were not changed significantly according to position. CONCLUSION: In DCMP patients with symptomatic relief in right lateral position, mitral inflow patterns were changed. And this finding suggests that symptomatic relief may be related to decreased left ventricular filling pressure.