Wander G S, Pasricha S, Aslam N, Avasthi G, Mahajan R, Khurana S B
Department of Medicine, Dayanand Medical College and Hospital, Ludhiana.
Indian Heart J. 1997 Sep-Oct;49(5):503-6.
In most patients of myocardial infarction, beta-blockers are used for secondary prophylaxis and a treadmill test is required for risk stratification. To study the effect of oral beta-blockers on interpretation of treadmill test, 54 consecutive patients were subjected to treadmill test four to six weeks after myocardial infarction. Fourteen patients with strongly positive treadmill test were referred for coronary angiography. Treadmill test was repeated in 37 patients 72 hours after withdrawal of beta-blockers. The peak exercise heart rate was significantly different while off and on beta-blockers (148 +/- 13 bpm vs 124 +/- 14 bpm, respectively; p < 0.01). The test was negative on both the occasions in 17 patients. On stopping beta-blockers, the negative test became mildly positive in five and strongly positive in six patients. The mildly positive test became strongly positive in four patients and remained almost unchanged in five. In 10 patients there was conversion of negative or mildly positive treadmill test into strongly positive result after withdrawal of beta-blockers. Thus the risk stratification changed significantly in 27 percent patients. It is suggested that beta-blockers can and should be withdrawn in post-MI patients before doing treadmill test.
在大多数心肌梗死患者中，β受体阻滞剂用于二级预防，且需要进行运动平板试验以进行危险分层。为研究口服β受体阻滞剂对运动平板试验结果判读的影响，对54例连续的心肌梗死患者在心肌梗死后4至6周进行运动平板试验。14例运动平板试验强阳性的患者被转诊进行冠状动脉造影。37例患者在停用β受体阻滞剂72小时后重复进行运动平板试验。停用和使用β受体阻滞剂时的运动高峰心率有显著差异（分别为148±13次/分和124±14次/分；p<0.01）。17例患者两次试验结果均为阴性。停用β受体阻滞剂后，5例患者阴性试验变为轻度阳性，6例变为强阳性。轻度阳性试验的4例患者变为强阳性，5例几乎无变化。10例患者在停用β受体阻滞剂后运动平板试验由阴性或轻度阳性转为强阳性。因此，27%的患者危险分层发生了显著变化。建议在对心肌梗死后患者进行运动平板试验前停用β受体阻滞剂。
