Lampert M B, Weinert L, Hibbard J, Korcarz C, Lindheimer M, Lang R M
Department of Medicine, University of Chicago Medical Center, IL 60637, USA.
Am J Obstet Gynecol. 1997 Jan;176(1 Pt 1):189-95. doi: 10.1016/s0002-9378(97)80034-8.
Peripartum cardiomyopathy is a rare complication of pregnancy. Thirty percent of patients with this disorder are reported to recover baseline ventricular function within 6 months of delivery, but the ability of these ventricles to respond to hemodynamic stress is unknown. The aim of this investigation was to quantitatively assess the contractile reserve of patients with a history of peripartum cardiomyopathy and recovered left ventricular function.
Baseline left ventricular contractility was assessed by use of the load and heart rate-independent relationship between end-systolic stress and rate-corrected velocity of fiber shortening. Data were acquired from "recovered" patients (10.5 +/- 11.6 months after delivery) and compared with data from matched nonpregnant controls with use of two-dimensionally targeted M-mode echocardiography and calibrated subclavian pulse tracings that were recorded over a wide range of afterloads (end-systolic stress) generated by methoxamine (1 mg/min) infusion. Contractile reserve was assessed by a dobutamine challenge (5 micrograms/kg/min) and quantified as the vertical deviation of the dobutamine end-systolic stress minus the corrected velocity of fiber shortening data point from the baseline contractility line.
Patients with peripartum cardiomyopathy and matched controls had normal baseline heart rates, blood pressures, ventricular dimensions, and left ventricular function. Contractile reserve, however, was reduced in patients with recovered peripartum cardiomyopathy (0.30 +/- 0.12 vs 0.17 +/- 0.04 circ/sec, p < 0.03).
Women with a history of peripartum cardiomyopathy who have regained normal resting left ventricular size and performance have decreased contractile reserve revealed by the use of a dobutamine challenge test. Ventricles of these women may respond suboptimally to hemodynamic stress in spite of evidence of recovery by routine echocardiographic evaluation.
围产期心肌病是妊娠罕见的并发症。据报道，30%患有这种疾病的患者在分娩后6个月内恢复到基线心室功能，但这些心室对血流动力学应激的反应能力尚不清楚。本研究的目的是定量评估有围产期心肌病病史且左心室功能已恢复的患者的收缩储备。
通过使用收缩末期应力与纤维缩短率校正速度之间的负荷和心率无关关系来评估基线左心室收缩性。数据来自“恢复”患者（分娩后10.5±11.6个月），并使用二维靶向M型超声心动图和校准的锁骨下脉搏描记图与匹配的非妊娠对照的数据进行比较，这些描记图是在甲氧明（1mg/min）输注产生的广泛后负荷（收缩末期应力）范围内记录的。通过多巴酚丁胺激发试验（5μg/kg/min）评估收缩储备，并将其量化为多巴酚丁胺收缩末期应力减去纤维缩短校正速度数据点与基线收缩性线的垂直偏差。
围产期心肌病患者和匹配的对照组在基线心率、血压、心室大小和左心室功能方面均正常。然而，围产期心肌病恢复患者的收缩储备降低（0.30±0.12对0.17±0.04次/秒，p<0.03）。
有围产期心肌病病史且静息左心室大小和功能已恢复正常的女性，通过多巴酚丁胺激发试验显示其收缩储备降低。尽管常规超声心动图评估显示恢复，但这些女性的心室对血流动力学应激的反应可能欠佳。
