De Lorenzo Andrea, Foerster James, Sciammarella Maria G, Suey Cathy, Hayes Sean W, Friedman John D, Berman Daniel S
Department of Imaging (Division of Nuclear Medicine), Cedars-Sinai Medical Center, Los Angeles, Calif 90048, USA.
J Nucl Cardiol. 2003 Jan-Feb;10(1):51-5. doi: 10.1067/mnc.2003.23.
Failure to reach 85% of maximal predicted heart rate (MPHR) during exercise may render a myocardial perfusion single photon emission computed tomography (MPS) study nondiagnostic for ischemia detection. Although commonly used to increase heart rate (HR) during dobutamine stress, the administration of atropine for patients failing to achieve 85% of MPHR during exercise performed for MPS is still infrequent.
Patients undergoing dual-isotope MPS were considered candidates for the study when, during exercise treadmill testing, they had less than 85% of MPHR and were unable to continue because of fatigue, without an ischemic response. Forty-seven patients (aged 65.3 +/- 12.5 years, 78.7% men) received atropine (0.6-1.2 mg). Maximal HR achieved before and after atropine was 118.0 +/- 14.8 beats/min (76.3% +/- 6.2% of MPHR) and 146.4 +/- 12.6 beats/min (94.4% +/- 8.1% of MPHR), respectively (P < .001). Of patients, 44 (93.6%) reached at least 85% of MPHR after atropine and had diagnostic MPS studies. After atropine, arrhythmias occurred in 14 patients (29.8%) and other minor side effects in 1 (2.1%).
Atropine allows patients initially failing to achieve 85% of MPHR during exercise to increase HR and have a diagnostic MPS study, without major complications. It may provide an alternative to pharmacologic stress for patients with a blunted HR response to exercise.
运动期间未能达到最大预测心率（MPHR）的85%可能会使心肌灌注单光子发射计算机断层扫描（MPS）研究无法用于检测缺血。虽然多巴酚丁胺负荷试验期间常用阿托品来提高心率（HR），但在为进行MPS而进行的运动中未能达到MPHR的85%的患者使用阿托品的情况仍然很少见。
在运动平板试验期间，双同位素MPS患者若MPHR低于85%且因疲劳无法继续运动且无缺血反应，则被视为该研究的候选对象。47例患者（年龄65.3±12.5岁，78.7%为男性）接受了阿托品（0.6 - 1.2毫克）治疗。阿托品使用前后达到的最大心率分别为118.0±14.8次/分钟（MPHR的76.3%±6.2%）和146.4±12.6次/分钟（MPHR的94.4%±8.1%）（P <.001）。其中，44例患者（93.6%）在使用阿托品后达到了至少MPHR的85%，并进行了诊断性MPS研究。使用阿托品后，14例患者（29.8%）出现心律失常，1例患者（2.1%）出现其他轻微副作用。
阿托品可使最初在运动期间未能达到MPHR的85%的患者提高心率并进行诊断性MPS研究，且无重大并发症。对于运动时心率反应迟钝的患者，它可能是药物负荷试验的一种替代方法。
