多巴酚丁胺负荷超声心动图评估冠状动脉血流储备的目标心率

目的 通过记录多巴酚丁胺负荷超声心动图(DSE)每一阶段的心率,探讨DSE评价冠状动脉血流储备(CFR)的目标心率.方法 选择DSE的受检者33例作为研究对象,受检者静息状态下测量心率,并计算最大心率(HRmax),然后在DSE的每一阶段测量冠状动脉舒张期血流速度,并计算CFR,同时测量受检者的心率,用△HR表示心率的改变,对△HR与CFR以及HRmax百分比与CFR行Pearson相关分析.结果 随着多巴酚丁胺的剂量逐渐提高,受检者的冠脉血流速度与心率均逐渐升高,△HR与CFR呈正相关(r=0.84,P＜0.05).同时,当△HR≥50次/min时,97.2％的患者CFR≥2(可信区间:93.2％～99.2％,P＜0.01).HRmax百分比与CFR同样呈正相关(r=0.73,P＜0.05),并且当心率达到75％HRmax时,95.6％的患者CFR≥2(可信区间:91.1％～99.0％).结论 临床仅需要在以受检者△HR≥50次/min,或75％HRmax为目标心率进行CFR测定,不需在DSE的每一阶段均测定受检者的CFR.

Evaluation of target heart rate of coronary flow reserve by dobutamine stress echocardiography

Objective To evaluate the target heart rate of coronary flow reserve through testing the heart rate at every stage by dobutamine stress echocardiography. Methods A total of 33 subjects were analyzed. The heart rates(HR)of all subjects were detected under their resting conditions and the maximum heart rates(HRmax)were calculated. The coronary artery flow velocity and the heart rate were detected at each stage of the DSE. Then the coronary flow reserves(CFR)were calculated. The changes of heart rates were represented as △HR. Pearson correlation analyses were applied to △HR and CFR or HRmax percentage and CFR. Results The coronary artery blood flow velocity and heart rate of the subjects increased gradually with the rising dose of Dobutamine. A positive correlation was found at △HR and CFR (r=0.84,P<0.05). There were 97.2% of patients with CFR≥2(CI:93.2%~99.2%,P<0.01)when △HR≥50 bpm. A positive correlation was also found at HRmax percentage and CFR (r=0.73,P<0.05). There were 95.6% of patients with CFR ≥2 (CI:91.1%~99.0%)when the heart rate reached 75% HRmax. Conclusions It’s not necessary to measure the CFR of subjects at each stage of DSE. In this study,it is necessary that CFR detection is proceeded when △HR ≥ 50 times/min or 75% HRmax is used as target heart rate.