Watanabe K, Hirokawa Y, Suzuki K, Shibata A
Division of Cardiology, Kuwana Hospital, Niigata, Japan.
Jpn Heart J. 1988 Sep;29(5):603-15. doi: 10.1536/ihj.29.603.
Xamoterol, a beta 1-partial agonist, was given to 10 patients with idiopathic dilated cardiomyopathy in NYHA functional classes II and III. The acute and chronic effects of xamoterol were assessed by changes in effort tolerance measured by multistage bicycle ergometry, echocardiography, radionuclide ventriculography and right heart catheterization. The acute effect was determined after a single intravenous injection of 0.2 mg/kg of xamoterol. Exercise heart rate decreased from 117 +/- 10 (mean +/- 1 SD) to 97 +/- 19 beats/min (p less than 0.01), but blood pressure and cardiac index were unaffected. When the drug was given orally at 200 mg/day for 3 months, exercise duration increased from 4.2 +/- 2.3 to 6.4 +/- 2.4 min (p less than 0.01), echocardiographic ventricular ejection fraction from 29 +/- 12 to 33 +/- 14% (NS) and radionuclide left ventricular ejection fraction from 37 +/- 11 to 45 +/- 14% (p less than 0.01), while pulmonary wedge pressure during exercise decreased from 40 +/- 10 to 31 +/- 10 mmHg (p less than 0.01). It may be concluded that xamoterol, by its action as a partial agonist, demonstrated both beta-agonist and antagonist effects in patients with idiopathic dilated cardiomyopathy. It thereby had beneficial effects on left ventricular function with resultant improvements in effort tolerance and subjective symptoms during long term treatment.
对10例纽约心脏协会（NYHA）心功能分级为II级和III级的特发性扩张型心肌病患者给予β1部分激动剂扎莫特罗。通过多级自行车测力计、超声心动图、放射性核素心室造影和右心导管检查测量的耐力变化来评估扎莫特罗的急性和慢性效应。单次静脉注射0.2mg/kg扎莫特罗后确定急性效应。运动心率从117±10（平均值±1标准差）降至97±19次/分钟（p＜0.01），但血压和心脏指数未受影响。当以200mg/天的剂量口服该药物3个月时，运动持续时间从4.2±2.3分钟增加至6.4±2.4分钟（p＜0.01），超声心动图心室射血分数从29±12%增加至33±14%（无显著性差异），放射性核素左心室射血分数从37±11%增加至45±14%（p＜0.01），而运动期间的肺楔压从40±10mmHg降至31±10mmHg（p＜0.01）。可以得出结论，扎莫特罗作为部分激动剂，在特发性扩张型心肌病患者中表现出β激动剂和拮抗剂的双重作用。因此，在长期治疗中，它对左心室功能具有有益作用，从而改善了耐力和主观症状。
