Forte Ezequiel H, Rousse Maria G, Lowenstein Jorge A
Investigaciones Médicas, Buenos Aires, Argentina.
Cardiovasc Ultrasound. 2011 Apr 4;9:10. doi: 10.1186/1476-7120-9-10.
The determination of coronary flow reserve (CFR) is an essential concept at the moment of decision-making in ischemic heart disease. There are several direct and indirect tests to evaluate this parameter. In this sense, dobutamine stress echocardiography is one of the pharmacological method most commonly used worldwide. It has been previously demonstrated that CFR can be determined by this technique. Despite our wide experience with dobutamine stress echocardiography, we ignored the necessary heart rate to consider sufficient the test for the analysis of CFR. For this reason, our main goal was to determine the velocity of coronary flow in each stage of dobutamine stress echocardiography and the heart rate value necessary to double the baseline values of coronary flow velocity in the territory of the left anterior descending (LAD) coronary artery.
A total of 33 consecutive patients were analyzed. The patients included had low risk for coronary artery disease. All the participants underwent dobutamine stress echocardiography and coronary artery flow velocity was evaluated in the distal segment of LAD coronary artery using transthoracic color-Doppler echocardiography.
The feasibility of determining CFR in the territory of the LAD during dobutamine stress echocardiography was high: 31/33 patients (94%). Mean CFR was 2.67 at de end of dobutamine test.There was an excellent concordance between delta HR (difference between baseline HR and maximum HR) and the increase in the CFR (correlation coefficient 0.84). In this sense, we found that when HR increased by 50 beats, CFR was ≥ 2 (CI 93-99.2%). In addition, 96.4% of patients reached a CFR ≥ 2 (IC 91.1 - 99%) at 75% of their predicted maximum heart rate.
We found that the feasibility of dobutamine stress echocardiography to determine CFR in the territory of the LAD coronary artery was high. In this study, it was necessary to achieve a difference of 50 bpm from baseline HR or at least 75% of the maximum predicted heart rate to consider sufficient the test for the analysis of CFR.
在缺血性心脏病的决策过程中，冠状动脉血流储备（CFR）的测定是一个重要概念。有多种直接和间接检测方法来评估这一参数。从这个意义上说，多巴酚丁胺负荷超声心动图是全球最常用的药理学方法之一。此前已有研究表明，该技术可用于测定CFR。尽管我们在多巴酚丁胺负荷超声心动图方面经验丰富，但我们忽略了在分析CFR时认为检测充分所需的必要心率。因此，我们的主要目标是确定多巴酚丁胺负荷超声心动图各阶段的冠状动脉血流速度，以及使左前降支（LAD）冠状动脉区域内冠状动脉血流速度基线值翻倍所需的心率值。
共分析了33例连续患者。纳入的患者冠心病风险较低。所有参与者均接受了多巴酚丁胺负荷超声心动图检查，并使用经胸彩色多普勒超声心动图评估LAD冠状动脉远端节段的冠状动脉血流速度。
多巴酚丁胺负荷超声心动图期间在LAD区域测定CFR的可行性很高：33例患者中有31例（94%）。多巴酚丁胺试验结束时，平均CFR为2.67。心率变化量（基线心率与最大心率之差）与CFR增加之间存在极好的一致性（相关系数0.84）。从这个意义上说，我们发现当心率增加50次/分时，CFR≥2（可信区间93 - 99.2%）。此外，96.4%的患者在其预测最大心率的75%时达到CFR≥2（可信区间91.1 - 99%）。
我们发现多巴酚丁胺负荷超声心动图在LAD冠状动脉区域测定CFR的可行性很高。在本研究中，需要使心率较基线心率差值达到50次/分或至少达到预测最大心率的75%，才能认为检测对于分析CFR是充分的。
