O33-5 - A case of Adriamycin Cardiomyopathy with Stress Induced Worsening of Mitral Regurgitation -Possible Underlying Mechanism Based on the Circulatory Equilibrium-

Abstract

A case of adriamycin cardiomyopathy with repeated worsening of heart failure (HF). Rest TTE showed LVDd/s and LVEF were 69/58 mm and 27% with moderate functional mitral regurgitation (MR). Exercise stress induced marked worsening of MR. Simple leg exercise increased PCWP (29 to 44 mmHg), RAP (4 to 10 mmHg) and CI (2.12 to 2.74 L/min/m2). We considered exercise induced worsening of MR is one of the major mechanisms of repeated worsening of HF and performed mitral annuloplasty. After surgery, exercise stress increased RAP (4 to 13 mmHg), PCWP (15 to 30 mmHg) and CI (2.18 to 2.68 L/min/m2). Because the intensities of the exercise were different, we standardized them by the stressed blood volume (SBV). We estimated the SBV using the equation of venous return curve previously reported (Uemura K et al, AJP 2004). Exercise increased SBV from 31.5 to 55.8 ml/kg before surgery and from 25.7 to 57.3 ml/kg after surgery. ΔPWCP/ΔSBV decreased from 0.62 to 0.48 mmHg/(ml/kg) and ΔRAP/ΔSBV increased from 0.25 to 0.29 mmHg/(ml/kg). This indicates that the presence of stress induced worsening of MR contribute to make PCWP sensitive to the change of SBV while little change in the RAP sensitivity. Mitral surgery improves not only static pump function but also dynamic response for stress induced changes in hemodynamics and may prevent flush pulmonary edema.