Novitzky D, Cooper D K, Swanepoel A
Department of Cardiothoracic Surgery, University of Cape Town Medical School, Republic of South Africa.
Eur J Cardiothorac Surg. 1989;3(2):140-5. doi: 10.1016/1010-7940(89)90092-4.
A significant reduction in plasma free triiodothyronine (T3) (P less than 0.0001) has been observed in patients undergoing open heart surgery. The beneficial effect of T3 would appear to be associated with increased synthesis and utilization of myocardial high energy stores. We have therefore administered T3 (4-10 micrograms iv) to 10 patients either when difficulty was being experienced in weaning from cardiopulmonary bypass (CPB) support (n = 5), or when myocardial function remained extremely poor (n = 5), despite inotropic and intraaortic balloon pump support. Mean preoperative NYHA functional class of the 10 patients was 3.2, left ventricular enddiastolic pressure (LVEDP) 20 mm Hg and ejection fraction (EF) 40%. The mean myocardial ischaemia time was 72 min (range 40-120 min). Within 1 h of T3 administration the mean plasma free T3 level had risen from 1.03 to 3.56 micrograms/ml and CPB was discontinued in all 5 cases. Balloon pump support (n = 2) was no longer essential within 3 h. At 1 h, the mean arterial pressure (MAP) had risen from 42 to 78 mm Hg, and heart rate (HR) from 90 to 104 beats/min; the left atrial pressure (LAP) had fallen from 30 to 14 mm Hg, and the central venous pressure (CVP) from 20 to 11 cm H2O. (All changes significant at P less than 0.0001.) Inotropic support had been significantly reduced or discontinued. To our knowledge, T3 has not been administered previously as an inotropic agent to patients who have undergone cardiac surgery. We believe that T3 may have an important role in the rescue of failing hearts following a period of myocardial ischaemia in patients who have undergone open heart surgery.
在接受心脏直视手术的患者中，已观察到血浆游离三碘甲状腺原氨酸（T3）显著降低（P＜0.0001）。T3的有益作用似乎与心肌高能储备的合成和利用增加有关。因此，我们对10例患者静脉注射T3（4 - 10微克），其中5例是在脱离体外循环（CPB）支持遇到困难时，另外5例是尽管使用了正性肌力药物和主动脉内球囊泵支持，但心肌功能仍然极差。这10例患者术前纽约心脏协会（NYHA）功能分级平均为3.2级，左心室舒张末期压力（LVEDP）为20 mmHg，射血分数（EF）为40%。平均心肌缺血时间为72分钟（范围40 - 120分钟）。在给予T3后1小时内，平均血浆游离T3水平从1.03微克/毫升升至3.56微克/毫升，所有5例患者均停止了CPB。2例患者在3小时内不再需要球囊泵支持。1小时时，平均动脉压（MAP）从42 mmHg升至78 mmHg，心率（HR）从90次/分钟升至104次/分钟；左心房压力（LAP）从30 mmHg降至14 mmHg，中心静脉压（CVP）从20 cmH₂O降至11 cmH₂O。（所有变化P＜0.0001，均具有显著性差异。）正性肌力支持已显著减少或停止。据我们所知，此前尚未将T3作为正性肌力药物用于接受心脏手术的患者。我们认为，T3可能在挽救心脏直视手术后经历一段时间心肌缺血的衰竭心脏方面发挥重要作用。
