慢性腎不全患者の心予備能に関する研究 ： 等尺性運動負荷試験による検討

Abstract

The hemodynamic responses to isometric handgrip (IHG) exercise were studied in 33 patients with chronic renal failure in comparison with 15 normal subjects (Group N). The patients were classified by serum creatinine (Scr) level : Group F₁ ; 18 cases with Scr 2.0-4.9 mg/dl, Group F₂ ; 15 cases with Scr 5.0 mg/dl and more. Studies were conducted at rest and immediately, 1 and 5 minutes after IHG exercise at 50% of maximum voluntary contraction for one minute, and consisted of simultaneous recording of mechanocardiogram and echocardiogram. The relations between clinical data and hemodynamic indices in 33 patients with chronic renal failure were analyzed. (1) At rest, stroke index (SI) was increased and left ventricular ejection fraction (EF) and mean velocity of circumferential fiber shortening (mVcf) tended to increase in Group F₁ as compared with Group N. While in Group F₂, corrected pre-ejction period (PEPc) increased and ET/PEP decreased as compared with Group N ; besides, EF and mVcf tended to decrease as compared with Group F₁. These findings suggest that myocardial contractility decreases with aggravation of renal failure. (2) Hemodynamic indices in 33 patients with chronic renal failure were closely related to mean blood pressure (MBP) and Scr. (3) IHG exercise resulted in a significant rise in heart rate, MBP, cardiac index, EF, mVcf and ET/PEP and a significant shortening of PEPc in Group F₁ and F₂, which showed left ventricular reserve. In Group F₂, IHG exercise resulted in an insignificant rise in SI and changes in PEPc and ET/PEP were less than in Group F₁. Thus, augmentation of myocardial contractility induced by IHG exercise tends to decrease with aggravation of renal failure.