Lima Ronaldo S L, De Lorenzo Andrea, Soares Adriana J
Hospital Universitário Clementino Fraga Filho-UFRJ, Universidade Estácio de Sá and Cintilab, Rio de Janeiro, Brazil.
Am J Cardiol. 2006 May 15;97(10):1452-4. doi: 10.1016/j.amjcard.2005.11.078. Epub 2006 Mar 29.
Abnormal heart rate recovery (HRR) after exercise has been associated with increased cardiac mortality. The ability of gated myocardial perfusion single-photon emission computed tomography (SPECT) to evaluate myocardial perfusion and function simultaneously might make it helpful in determining possible mechanisms that are involved in this finding. This study investigated the association between abnormal HRR and other indicators of risk for cardiovascular events. Patients (n = 1,296, 784 men; 57 +/- 11 years of age) who underwent exercise/technetium-99m sestamibi gated myocardial perfusion SPECT at rest were prospectively enrolled. Exercise treadmill testing was performed according to a symptom-limited Bruce's protocol. HRR was obtained from the subtraction of heart rate in the first minute of recovery after exercise treadmill testing from maximal heart rate during exercise. Myocardial perfusion SPECT was semi-quantitatively analyzed using a 17-segment left ventricular model. Left ventricular ejection fraction was automatically calculated using quantitative gated SPECT software. In our study, patients with abnormal HRR were older, more frequently diabetic, and hypertensive and had previous myocardial infarction and myocardial revascularization, higher heart rate at rest and perfusion defect quantification scores, lower left ventricular ejection fraction, and larger left ventricular volumes than did patients with normal HRR. In multivariable analysis, age (p <0.0001), heart rate at rest (p <0.0001), left ventricular ejection fraction (p <0.0001), and perfusion defect extent and severity at rest (p = 0.038) were independent predictors of abnormal HRR. In conclusion, abnormal HRR was significantly associated with lower left ventricular ejection fraction and with perfusion defect extent and severity at rest, but not with gated SPECT markers of myocardial ischemia. Therefore, abnormal HRR may reflect myocardial damage.
运动后异常的心率恢复（HRR）与心脏死亡率增加有关。门控心肌灌注单光子发射计算机断层扫描（SPECT）同时评估心肌灌注和功能的能力可能有助于确定这一发现所涉及的潜在机制。本研究调查了异常HRR与心血管事件其他风险指标之间的关联。前瞻性纳入了1296例患者（784例男性；年龄57±11岁），这些患者在静息状态下接受了运动/锝-99m甲氧基异丁基异腈门控心肌灌注SPECT检查。根据症状限制的布鲁斯方案进行运动平板试验。HRR通过运动平板试验后恢复第一分钟的心率减去运动时的最大心率获得。使用17节段左心室模型对心肌灌注SPECT进行半定量分析。使用定量门控SPECT软件自动计算左心室射血分数。在我们的研究中，与HRR正常的患者相比，HRR异常的患者年龄更大，糖尿病、高血压患病率更高，既往有心肌梗死和心肌血运重建史，静息心率更高，灌注缺损定量评分更高，左心室射血分数更低，左心室容积更大。在多变量分析中，年龄（p<0.0001）、静息心率（p<0.0001）、左心室射血分数（p<0.0001）以及静息时灌注缺损的范围和严重程度（p=0.038）是异常HRR的独立预测因素。总之，异常HRR与较低的左心室射血分数以及静息时灌注缺损的范围和严重程度显著相关，但与心肌缺血的门控SPECT标志物无关。因此，异常HRR可能反映心肌损伤。
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