美托洛尔对难治性正常射血分数性急性左心衰患者心功能影响的临床研究

目的探讨高选择性β1-受体阻滞剂治疗射血分数正常的难治性急性左心室衰竭的可行性、安全性和有效性。方法①纳入50例发病在24h内,首次因端坐呼吸及呼吸困难突出者而诊断为急性左心衰竭,但超声检查射血分数（LVEF）≥45%;②经标准药物治疗无效或加重,NYHA分级达到Ⅳ级心功能的患者;③监测中心静脉压、血压、心率、血氧饱和度及血气分析、肺部罗音、呼吸次数、尿量,以及临床症状;④静脉推注美托洛尔5mg后,口服美托洛尔6.25～25mg,必要时4h重复给予美托洛尔12.5～25mg口服;④给药前后每4h测量中心静脉压1次;⑤治疗前床旁心脏彩超评价心功能变化;⑥停用正性肌力强心药物。结果①NYHA心功能改善≥1级者12例（24%）,改善2级者17例（34%）,改善3级者24例（48%）,无改善者3例（6%）,院内死亡2例（4%）;平均NYHA分级改善程度为2.24±0.89级,P〈0.01,有统计学意义;②在利尿、扩血管治疗基础上加用美托洛尔治疗后收缩压下降17.16±26.70mmHg,舒张压下降12.32±18.88mmHg,心率下降48.26±20.22次/min,中心静脉压（CVP）下降7.26±4.28cmH2O,P〈0.01,有统计学意义;③治疗后CVP为11.74±3.58cmH2O,与心功能改善程度的相关系数（r）=-0.389,P〈0.01;④美托洛尔的平均剂量为76.50±40.30mg/日,剂量与CVP下降程度相关（r=0.307,P=0.03）,与心率的下降显著相关（r=0.643,P=0.000）;⑤心率的下降程度与中心静脉压下降程度具有显著相关性（r=0.435,P=0.002）。结论传统方法治疗无效的射血分数正常心力衰竭患者,在接受利尿剂、扩血管药物治疗的基础上联合β受体阻滞剂美托洛尔可以显著降低血压、心率及中心静脉压水平,尤其通过降低心率使中心静脉压水平下降更有意义,从而改善心力衰竭的临床预后。

Clinial study of the effect of metoprolol on heart function in patients with acute refractory left ventricular heart failure with normal left ventricular ejection fraction

Objective To investigate the validity and safety of β-receptor blockers in patients with acute left ventricular heart failure with normal left ventricular ejection fraction.Methods 50 patients with acute severe heart failure（stage four,according to NYHA criteria）,first admission,whose symptoms hadn＇t been controlled and formally consented to receive the trial.The patients in the study had underwent metoprolol treatment,via 5mg of intravenous followed by from 12.5mg to 25mg of oral administration,subsequent to 12.5mg to 25mg of oral administration every 4hours interval if necessary.Before and after the therapy,patients were assessed for the severity of their heart failure（stage 1～4）,based on standard New York Heart Association（NYHA） criteria;their LVEF and left ventricular end-diastolic diameter（LVDD） measured by echocardiography;and blood pressure,heart rate,central venous pressure was assessed,too.Results 3 patients had no response to such intervention because of stubborn pneumonic infection inducing 2 patients death.Finally,47 patients had achieved favorable improvements in heart function followed by meliorative symptoms,signs and hemodynamics,compared to baseline measures.① Heart function（NYHA class） improved significantly after therapy（P〈0.01）.②An decrease systolic pressure,diastolic pressure,heart rate and CVP of 17.16±26.70mmHg,12.32±18.88mmHg,48.26±20.22 times per minute and 7.26±4.28cmH2O,P〈0.01,respectively,after undergoing metoprolol.③Compared to baseline,the improvement of heart function was correlation with CVP variables after metoprolol administration（r=-0.389,P〈0.01）.④The dosage per day of metoprolol was correlation with reduction of CVP（r=0.307,P=0.03）.⑤The decrease of heart rate was significant correlation with the reduction of CVP（r=0.435,P=0.002）.Conclusion These results demonstrate that high-selective β-receptor blocker,metoprolol,is safe and effective for the treatment of acute refractory severe heart failure with normal LVEF.The marked therapeutic effect may be attributed to improvements in blood pressure,heart rate and CVP.