Astarita C, Nicolai E, Liguori E, Gambardella S, Rumolo S, Maresca F S
Servizio di Cardiologia, UTIC Ospedale di Sorrento Regione Campania.
G Ital Cardiol. 1998 Sep;28(9):996-1004.
Hypertensive patients with left ventricular hypertrophy can be affected with angina pectoris for significant epicardial coronary stenosis or microvascular disease with normal coronarography. Exercise-electrocardiography test is positive in both conditions. The aim of the present study was to assess the accuracy of dipyridamole-echocardiography test and thallium exercise myocardial scintigraphy in the diagnosis of epicardial coronary stenosis or microvascular disease in hypertensive patients with left ventricular hypertrophy and angina pectoris.
Forty-two hypertensive patients (22 males, age 40-76 years, mean 58.6 +/- 10.1), with left ventricular hypertrophy, typical angina pectoris, ischemia that can be induced by exercise-electrocardiography test, without previous myocardial infarction, myocardial revascularization or diabetes mellitus, underwent dipyridamole-echocardiography test, thallium exercise myocardial scintigraphy and coronarography. Dipyridamole-echocardiography test was performed with dipyridamole (0.56 mg/kg over 4 minutes, followed by 0.28 mg/kg from the 8th to the 10th minute) + atropine (1 mg from the 12th to 15th min.) and was positive for a transient dyssynergy of contraction of at least 2 myocardial segments; the left ventricle was divided into 16 segments. SPECT thallium myocardial scintigraphy was performed after bicycle exercise and then three hours later, and it was positive for reversible uptake defects of at least 2 segments with a 22-segment model. Coronarography was performed with Judkin's technique and was positive if at least one large epicardial vessel was narrowed by more than 50%.
Coronarography: normal in 25 cases (59.5%, 8 males), pathologic in 17 (40.5%, 14 males): left main coronary artery in 1 (5.9%), three vessels in 5 (29.4%), two vessels in 3 (17.7%), 1 vessel in 8 (47%). Dipyridamole-echocardiography-test: positive in 15 cases (35.7%), negative in 27 (64.3%); sensitivity 88.2%, specificity 100%, diagnostic accuracy 95.2%, positive predictive value 100%, negative predictive value 92.6%. Thallium exercise myocardial scintigraphy: positive in 30 cases (71.4%), negative in 12 (28.6%); sensitivity 100%, specificity 48%, diagnostic accuracy 69%, positive predictive value 56.7%, negative predictive value 100%.
Dipyridamole-echocardiography test has higher diagnostic accuracy and when positive, it predicts significant epicardial coronary stenosis. It can be less sensitive in one-vessel patients (2 false negatives were stenosis 75% of left anterior descending and 60% of 1st diagonal). Thallium exercise myocardial scintigraphy is complementary because when negative, it excludes epicardial coronary stenosis and confirms microvascular disease. In hypertensive patients with left ventricular hypertrophy and suspected angina pectoris, the following flow-chart may be proposed: the first test is exercise-electrocardiography test. Only those who are positive at low-to-intermediate workload then undergo dipyridamole-echocardiography test. Those who are positive in this then undergo coronarography, while the negative ones undergo thallium exercise myocardial scintigraphy. Those who are positive at thallium exercise myocardial scintigraphy perform the coronarography, while cases with negative results do not undergo further diagnostic tests since they are affected with microvascular disease.
左心室肥厚的高血压患者可能因显著的心外膜冠状动脉狭窄或冠状动脉造影正常的微血管疾病而出现心绞痛。运动心电图试验在这两种情况下均为阳性。本研究的目的是评估双嘧达莫超声心动图试验和铊运动心肌闪烁显像在诊断左心室肥厚且有心绞痛的高血压患者的心外膜冠状动脉狭窄或微血管疾病中的准确性。
42例高血压患者（男性22例，年龄40 - 76岁，平均58.6±10.1岁），有左心室肥厚、典型心绞痛、运动心电图试验可诱发的缺血，既往无心肌梗死、心肌血运重建或糖尿病，接受了双嘧达莫超声心动图试验、铊运动心肌闪烁显像和冠状动脉造影。双嘧达莫超声心动图试验采用双嘧达莫（4分钟内静脉注射0.56mg/kg，随后在第8至10分钟静脉注射0.28mg/kg）+阿托品（第12至15分钟静脉注射1mg），至少2个心肌节段出现短暂收缩不协调为阳性；左心室分为16个节段。铊运动心肌单光子发射计算机断层显像（SPECT）在自行车运动后及3小时后进行，采用22节段模型，至少2个节段出现可逆性摄取缺损为阳性。冠状动脉造影采用Judkin技术，至少1支大的心外膜血管狭窄超过50%为阳性。
冠状动脉造影：25例（59.5%，男性8例）正常，17例（40.5%，男性14例）异常：左主干冠状动脉1例（5.9%），三支血管病变5例（29.4%），两支血管病变3例（17.7%），单支血管病变8例（47%）。双嘧达莫超声心动图试验：15例（35.7%）阳性，27例（64.3%）阴性；敏感性88.2%，特异性100%，诊断准确性95.2%，阳性预测值100%，阴性预测值92.6%。铊运动心肌闪烁显像：30例（71.4%）阳性，12例（28.6%）阴性；敏感性100%，特异性48%，诊断准确性69%，阳性预测值56.7%，阴性预测值100%。
双嘧达莫超声心动图试验具有较高的诊断准确性，阳性时可预测显著的心外膜冠状动脉狭窄。在单支血管病变患者中敏感性可能较低（2例假阴性分别为左前降支狭窄75%和第一对角支狭窄60%）。铊运动心肌闪烁显像具有互补性，阴性时可排除心外膜冠状动脉狭窄并确诊微血管疾病。对于左心室肥厚且疑似心绞痛的高血压患者，可采用以下流程图：首先进行运动心电图试验。只有在低至中等负荷时阳性的患者才进行双嘧达莫超声心动图试验。该试验阳性的患者进行冠状动脉造影，阴性的患者进行铊运动心肌闪烁显像。铊运动心肌闪烁显像阳性的患者进行冠状动脉造影，阴性结果的患者因患有微血管疾病而无需进一步诊断检查。
