Publication:

以年齡預測急性心肌梗塞病患最大運動心跳率之探討

研究背景:急性心肌梗塞是臨床常見的心臟疾病，在考量心肌梗塞後心臟復健計畫的安全性及有效性，適當的運動強度設定就顯得特別重要。傳統(220-年齡)最大心跳預估公式被廣泛運用在臨床運動測試及復健計畫之運動強度設定。心肌梗塞病患常見存在心跳節律性不足反應且控制心跳藥物(乙型交感斷劑)的使用，而沿用(220-年齡)預估公式做為復健計畫運動強度設定的適當性尚未被證實。提供可以反應趨近實際心臟負荷的替代性最大心跳預估公式，對心肌梗塞後早期臨床復健計畫實施與安全性顯得特別重要。 研究目的: (1)探討以年齡預測最大心跳公式在急性心肌梗塞病患運用的有效性；(2)服用乙型交感阻斷劑對最大心跳的影響；(3)發展新的替代性最大心跳數預估公式。 研究方法與受測者:本研究主要從2009年10月至2011年10月期間於台中某醫學中心招募急性心肌梗塞患者參與研究共214位(男性200位；女性14位)，平均年齡為56±11歲(29-84歲)。所有受測者接受心肺運動測試，評估最大運動耐受度，並將受測者最大運動表現的相關數據進行分析。 研究結果:研究顯示，傳統預估(220-年齡)最大心跳明顯高估受測者的實際最大心跳數(平均163.8±11.5比較124.3±18.7下/分鐘；P<0.001)。在性別差異及急性心肌梗塞診斷別對實際檢測最大心跳的影響均未達統計上的差異(P>0.05)。而乙型交感阻斷劑未服用者的最大心跳數表現明顯高於服用者(130±20比較119±16下/分鐘；P<0.05)。考量受測者服用乙型交感阻斷劑對最大心跳的影響，發展特定族群的最大心跳預估公式:(1)未服用乙型交感阻斷劑者: 170-0.7年齡(r2=0.17；P<0.001)，預估標準誤差為18.5下/分鐘。(2)服用乙型交感阻斷劑者: 142-0.4年齡 (r2=0.1；P=0.002)，預估標準誤差為15.3下/分鐘。 結論: 本研究結果顯示，傳統(220-年齡)預估公式明顯高估急性心肌梗塞病患的最大心跳數，也表示未能適當預估趨近心臟實際之負荷程度。本研究發展之最大心跳預估公式:(1)交感阻斷劑未使用者:(170-0.7年齡)；(2)交感阻斷劑使用者:( 142-0.4年齡)。比傳統(220-年齡)預估公式更能準確預估實際最大心跳反應，建議可做為急性心肌梗塞病患臨床復健計畫之運動強度設定的替代性參考依據。

Background: The acute myocardial infarction(AMI) is a commonly clinical heart disease.In consideration of the safety and effectiveness of cardiac rehabilitation program for post- MI. Traditional (220 - age) predicted maximum heart rate formula is is widely applied to set in clinical exercise testing and to prescribe exercise intensity in rehabilitation programs. Chronotropic Incompetence is common in patients with AMI and used control heart beat drugs (beta-blockers). Follow the (220 - age) predicted formula as rehabilitation program of exercise intensity settings appropriateness has not been confirmed. To provide alternative predicted formula can to approaching actual stress on the heart. For post- MI early clinical rehabilitation program implementation and safety of is especially important. Purpose: (1) To investigate the effectiveness of age-predicted maximum heart rate formula for use in patients with AMI. (2) Taking beta blockers affect the maximum heart rate. (3) Development of new alternative predicted maximum heart rate formula. Methods: The 214 subjects of this study from October 2009 to October 2011 were patients with AMI who entered the Taichung Veterans General Hospital. The subjects included two hundred males and fourteen females with 56 ± 11 years old (29 to 84 years). All subjects performed cardiopulmonary exercise testing. Evaluation maximal exercise tolerance and data analysis. Results: The study showed the traditional (220 - age) predicted maximum heart rate was significantly overestimate the actual maximum heart rate of the subject's (Mean 163.8 ± 11.5 vs. 124.3±18.7 beats/min；P<0.001 ).Gender differences and diagnosis classified of AMI did not affect the actual maximum heart rate due to not reach statistical difference (P> 0.05). The unused beta-blockers have actual maximum heart rate significantly greater than the taking beta-blockers (Mean 130±20 vs. 119±16 beats/min；P<0.05 ). Considerations taking beta-blockers affect the maximum heart rate. Development of a particular group estimated maximum heart rate formula: (1) Unused beta-blockers: 170-0.7age (r2=0.17；P<0.001)；estimated standard error of 18.5 beats / min. (2) taking Beta-blockers:142-0.4age (r2=0.1；P=0.002)；estimated standard error of 15.3 beats / min. Conclusion: The results of this study show that the traditional (220 - age) predicted equation significantly overestimated maximum heart rate of patients with AMI. Expressed not adequately estimate approaching actual stress on the heart. The study development of a particular formula: (1) heart rate of unused beta-blockers: 170-0.7age；(2) heart rate of taking beta-blockers:142-0.4age. Alternative formulas developed in this study than traditional (220 - age) formula more accurately estimate the actual maximum heart rate response, recommendations can be used for setting exercise intensity in rehabilitation programs.