急性下壁心梗右冠不同闭塞节段心电图差异

目的回顾性分析急性下壁心肌梗死(IAMI)患者右冠状动脉(RCA)不同闭塞节段的心电图(ECG)差异,评估其应用价值,期望发现新的ECG预测标准。方法收集本院6年间符合标准的IAMI患者,对不同RCA闭塞节段的ECG特征进行比较分析。结果 58例患者,男性51例,女性7例,平均年龄65.00±13.61岁。ST_(V1)抬高≥0.5mm对提示RCA近段闭塞有显著的统计学意义(p=0.001)。ST_(V3)压低/ST_(Ⅲ)抬高比率0.5、ST_(V4R)抬高在RCA近段组的出现率明显高于中远段组(80.95%vs.50.00%,p=0.058、91.67%vs.60.00%,p=0.191),但差异无统计学意义。结论 ST_(V1)抬高与否对判断急性下壁心肌梗死RCA闭塞节段具有良好的预测价值,若能联合STV3抬高/ST_(Ⅲ)压低比率以及ST_(V4R)抬高与否做共同分析,将进一步提高诊断的灵敏度和特异性。     

Inferior wall myocardial infarction caused by anomalous right coronary artery

A 50-year-old man without previous coronary disease presented with an inferior myocardial infarction following exercise. He was initially treated with thrombolytic therapy and nitroglycerin. Subsequent coronary angiography and cardiac computed tomography demonstrated an anomalous right coronary artery originating from the left coronary sinus and passing between the aorta and main pulmonary artery. The coronary arteries were otherwise patent. The patient later underwent transaortic unroofing of the anomalous right coronary artery and was discharged in good condition.     

急性下壁心肌梗死患者右心室功能变化的探讨

目的 应用组织多普勒(TDI)结合M型超声技术评价急性下壁心肌梗死(心梗)患者右心室功能变化. 方法 急性下壁心梗患者50例,男34例、女16例;正常对照组50例,男30例,女20例.急性心梗第4～7天行超声心动图检查,采用M型超声记录三尖瓣环右心室游离壁处运动曲线,测量收缩期、舒张早期和舒张晚期运动幅度(SD、DED和DAD)及DED/DAD比值;并应用TDI技术,记录该处速度曲线,测量右室收缩期、舒张早期和晚期最大运动速度Sm、Em和Am及Em/Am比值. 结果 急性下壁心梗患者三尖瓣环右室游离壁处SD、DED运动幅度、DED/DAD比值均较对照组显著降低[分别为(18.7±5.5)mm和(24.9±2.8)mm、(10.9±3.4)mm和(16.6±3.4)mm、1.5±0.6和2.3±0.9,t值分别为18.711、19.055、6.068,均P＜0.01]Sm、Em和Em/Am明显下降[分别为(12.9±2.8)cm/s和(15.9±2.7)cm/s、(12.3±3.4)cm/s和(16.7±4.7)cm/s、0.9±0.4和1.1±0.3,t值分别为11.851、14.781、2.127,P＜0.01或P＜0.05]. 结论 急性下壁心梗损害右室舒缩功能,表现为既有运动幅度下降又有最大运动速度下降,舒张功能降低以舒张早期性能下降为主.     

急性下壁心肌梗死心电图对右冠状动脉病变的诊断价值

目的探讨心电图在ST段抬高型急性下壁心肌梗死(IWAMI)时右冠状动脉(RCA)病变位置的诊断价值。方法对109例经冠状动脉造影证实右冠状动脉为梗死相关动脉患者的18导联心电图进行回顾性分析。结果心电图STV1抬高≥2mm、STV4R抬高≥1mm、STV3压低/STⅢ抬高<0.5对右冠状动脉近段闭塞的判断有较大的价值,其阳性率与右冠状动脉远段闭塞组有显著性差异,其诊断的特异性、敏感性均较高。结论ST段抬高型急性下壁心肌梗死时体表心电图与右冠状动脉闭塞位置有明显相关性。     

Myocardial bridging of the left anterior descending coronary artery in acute inferior wall myocardial infarction

BACKGROUND: We observed marked myocardial bridging of the left anterior descending coronary artery (LAD) in the acute stages of inferior wall myocardial infarction (MI) in a group of patients who developed shock despite successful reperfusion of the infarct-related lesion (IRL). HYPOTHESIS: The purpose of this study was to elucidate the clinical significance of myocardial bridging in patients with inferior wall MI and shock. METHODS: The study group consisted of 53 patients with single-vessel disease of the right coronary artery, who underwent coronary angiography for acute inferior wall MI. Clinical characteristics, coronary angiographic findings, and left ventricular function during the chronic phase were compared between the patients who developed shock (the shock group) and those who did not (the non-shock group). In addition, a multiple logistic analysis was performed to identify independent predictors of shock in patients with acute inferior wall MI. RESULTS: Reperfusion of the IRL was obtained in all 53 patients. The incidence of myocardial bridging of the LAD, the incidence of right ventricular MI, the peak creatine phosphokinase (CPK-MB). the pulmonary capillary wedge pressure, and the prevalence of pulmonary congestion seen on chest roentgenogram were significantly higher in the shock group than in the non-shock group. Myocardial bridging (p = 0.0018), right ventricular MI (p = 0.0374), and peak CPK-MB (p = 0.0189) were identified as independent predictors of shock in acute inferior wall MI. CONCLUSION: This study suggests that myocardial bridging plays a role in left ventricular function in the acute stage of inferior wall MI.     

急性下壁梗死伴或不伴右心室心肌梗死患者临床特征的比较

目的：比较急性下壁心肌梗死（IWMI）伴或不伴右心室心肌梗死（RVMI）患者的临床特征差异。方法纳入2006年10月~2012年12月总参保健处发病12 h内入院的急性下壁心肌梗死（IWMI）患者256例,根据冠状动脉造影（CAG）结果将患者分为IWMI不合并RVMI组（n=167）和IWMI合并RVMI组（n=89）,比较两组患者冠心病发病主要危险因素（包括吸烟、高血压、糖尿病、高脂血症、冠心病家族史）、临床表现、并发症和治疗用药的差异。结果两组患者冠心病主要危险因素无差异（P＞0.05）。IWMI合并RVMI患者出现低血压（80.0% vs.19.8%,P＜0.05）、颈静脉怒张（50.6%vs.1.8%）和Kussmaul征（51.7%vs.1.2%）的比例明显增加（P均＜0.01）,需要更多地应用正性肌力药物（60.7%vs.16.2%）来维持血压,且病死率较高（77.9%vs.0.6%,P＜0.05）。结论在IWMI基础上伴RVMI多合并右心功能障碍,可导致预后不良。     

急性下壁心肌梗死的房室传导阻滞及其罪犯血管

房室传导阻滞是急性下壁心肌梗死的常见并发症,而左、右冠状动脉病变均可导致下壁心肌梗死。由于心脏冠状动脉供血至心肌的部位及范围不同,因此其病变导致的心肌梗死的程度与范围也不尽相同,相应地可产生不同的心电图表现。丰富的临床经验和心电图知识有助于判断冠状动脉罪犯血管并确定其闭塞部位（近端、中端或远端）,也有助于制定合理的紧急再灌注治疗方案,挽救患者生命。     

Right ventricular echocardiographic parameters for prediction of proximal right coronary artery lesion in patients with inferior wall myocardial infarction

Background

Classifying the location of an occlusion in the culprit artery during ST-elevation myocardial infarction is important for risk stratification to optimize treatment.

Objectives

To compare the validity of echocardiographic parameters assessing right ventricular (RV) function for the prediction of proximal right coronary artery (RCA) lesion in patients with inferior wall myocardial infarction.

Methods

The study included 76 patients after their first episode of acute inferior myocardial infarction with significant RCA lesion (43 patients with proximal RCA stenosis and 33 patients with distal RCA stenosis). Full echocardiographic examination was done before revascularization, including RV dimension, tricuspid annular plane systolic excursion, and tissue Doppler imaging of RV free wall at the level of the tricuspid annulus and recording the following variables: peak systolic velocity (Sm), peak early diastolic velocity, peak late diastolic velocity, ejection time (ET), isovolumetric relaxation time (IVRT), isovolumetric contraction time (IVCT), and myocardial performance index (MPI), which was calculated as (MPI = IVRT + IVCT/ET).

Results

Patients with proximal RCA showed significantly lower Sm (10.44 ± 2.61 cm/s vs. 12.11 ± 2.94 cm/s, p = 0.013) and shorter ET (224.18 ± 49.96 ms vs. 280.90 ± 46.12 ms, p = 0.001). While IVRT, IVCT, and MPI were significantly higher (95.25 ± 19.22 ms vs. 68.48 ± 12.77 ms, p = 0.001; 81.62 ± 23.59 ms vs. 60.90 ± 17.38 ms, p = 0.001; and 0.82 ± 0.222 vs. 0.47 ± 0.10, p = 0.001, respectively) when compared with patients with distal RCA stenosis. Multiple regression analysis including (tricuspid annular plane systolic excursion, Sm, and MPI) showed that the most independent predictors for proximal RCA lesions were MPI (p = 0.0001). The receiver operator characteristic curve for MPI showed areas under the curve of 97% and a confidence interval of 93%. A cut-off value of 0.58 for MPI had a sensitivity of 95% and specificity of 97% for the diagnosis proximal RCA.

Conclusions

The most independent predictors for proximal RCA lesion is MPI.     

Early reperfusion therapy improves left ventricular function after acute inferior myocardial infarction associated with right coronary artery disease

Quantitative global and regional ventriculographic analysis was performed acutely and 1 week later in 46 patients undergoing reperfusion procedures within 6 hours of acute inferior myocardial infarction due to right coronary artery disease. While serial improvement in global left ventricular ejection fraction was not demonstrated for the group, infarct zone regional wall motion did improve (-2.7 +/- 0.9 vs -2.3 +/- 1.4 SD/chord, p less than 0.007). Serial improvement in global ejection fraction was demonstrated in the subgroup of patients treated within 2 hours of symptom onset (55 +/- 10 vs 62 +/- 10%; n = 5; p less than 0.03). Infarct zone regional wall motion improved serially only in the subgroup of patients treated within 3 hours of symptom onset (-2.4 +/- 1.1 vs -1.3 +/- 1.7 SD/chord; n = 11; p less than 0.007). Patients with initially patent arteries had a higher ejection fraction on follow-up catheterization than did those with initially occluded vessels (61 +/- 11 vs 55 +/- 7%; p less than 0.02), and patients with patent arteries at follow-up had a higher ejection fraction than did those whose arteries were occluded (60 +/- 9 vs 48 +/- 4%; p less than 0.0001). We conclude that significant improvement in global and regional left ventricular function in patients with inferior myocardial infarction is possible when reperfusion therapy is begun early or when arterial patency is achieved.     

Echocardiographic assessment of right ventricular function in inferior wall myocardial infarction and angiographic correlation to proximal right coronary artery stenosis

BackgroundPresence of right ventricular (RV) infarction imposes a higher risk of adverse events in inferior wall myocardial infarction (IWMI). In this study, we attempted to correlate various indices of RV function assessed by echocardiography with presence of a proximal right coronary artery (RCA) stenosis in patients with first episode of acute IWMI.MethodsIn a prospective study, patients with first episode of acute IWMI underwent echocardiographic assessment within 24 h of symptom onset and indices of RV function viz. RV fractional area change (RVFAC), tricuspid annular plane systolic excursion (TAPSE), myocardial performance index (MPI) and tissue Doppler velocities from RV free wall were measured. Patients who underwent coronary angiogram (CAG) within one month and they were classified into group 1 and group 2 based on the presence or absence, respectively, of a significant proximal RCA stenosis.ResultsThere were 90 patients with first episode of IWMI of which 67 patients underwent CAG. There was significant difference between group 1 (n = 26) and group 2 (n = 41) in TAPSE (13.5 ± 1.3 vs 21.3 ± 1.7, p < 0.001), MPI by tissue Doppler (0.87 ± 0.1 vs 0.55 ± 0.2, p < 0.001) and in tissue Doppler systolic velocity from RV free wall (S′ 9.8 ± 1.1 vs 15.0 ± 1.5, p < 0.001). There was a good interobserver correlation for TAPSE, MPI by TDI, and S′ velocity. TAPSE ≤ 16 (sensitivity 93%, specificity 100%), MPI-TDI ≥ 0.69 (sensitivity 94.7%, specificity 93.5%), S ≤ 12.3 (sensitivity 90.3%, specificity 94.3%) were useful in predicting presence of proximal RCA stenosis.ConclusionRV function indices like TAPSE, MPI-TDI and S′ velocity are useful in predicting proximal RCA stenosis in first episode of acute IWMI.     

Spontaneous coronary artery dissection in an antilles man with acute inferior myocardial infarction

Spontaneous coronary artery dissection is a rare cause of myocardial infarction. It has been reported mainly in young women during or after pregnancy. The diagnosis is usually confirmed at autopsy. The management of these patients remains controversial. We report the case of a patient who presented spontaneous dissection and was with successfully treated by thrombolysis. Clinical outcome was good.     

Double vessel acute myocardial infarction showing simultaneous total occlusion of left anterior descending artery and right coronary artery

Simultaneous double vessel acute myocardial infarction (AMI) is extremely rare and usually has poor clinical outcomes. Management of this complicated condition is challenging and time-limited. The case of a 46-year-old Taiwanese man with simultaneous anterior and inferior wall AMI is reported. Rapid deterioration of clinical condition with ventricular fibrillations (VF), cardiogenic shock and asystole developed before catheterization. Coronary angiogram revealed simultaneous total occlusion of left anterior descending (LAD) and right coronary arteries (RCA). Frequent VF attack was still noted after diagnostic catheterization. After cardiopulmonary resuscitation, immediate percutaneous coronary intervention of the LAD and RCA, and intra-aortic balloon counterpulsation was inserted. Due to intractable heart failure and cardiogenic shock, extracorporeal membrane oxygenation was performed. Rabdomyolysis with acute renal failure was also noted with hemodialysis treatment. Thirty-one days after hospitalization, he was discharged with a New York Heart Association functional class III heart failure, without hemodialysis.     

急性前壁心肌梗死患者心电图下壁导联ST段改变与其冠状动脉病变的关系

目的　探讨急性前壁心肌梗死患者心电图下壁导联 ST段改变与冠状动脉病变的关系。方法　对 81例冠状动脉左前降支 (L AD)单支病变所致急性前壁心肌梗死患者 ,依其早期心电图下壁导联 ST段改变的形态将患者分为 3组 ,即压低组、抬高组、无改变组 ,并与冠状动脉造影结果进行比较和分析。结果　下壁导联 ST段压低组中73.3%患者为 L AD非优势近端病变 ;抬高组中 6 2 .5 %患者为 L AD优势远端病变 ;无改变组中 L AD优势近端病变与 L AD非优势远端病变所占比例近似。结论　急性前壁心肌梗死患者下壁导联 ST段改变与 L AD形态及病变的部位有关。     

急性下壁合并右心室心肌梗死的心电图诊断价值

目的 探讨急性下壁合并右心室心肌梗死的心电图诊断价值。方法 71例急性下壁心肌梗死患者按冠状动脉造影结果分为合并右心室心肌梗死组（观察组,31例）和未合并右心室心肌梗死组（对照组,40例）,进行12导联及右胸导联心电图检查,分析STV3R～V6R抬高≥1mm、STⅢ/STⅡ抬高≥1及两项联合对急性下壁合并右心室心肌梗死的诊断价值。结果 观察组ST段抬高3项指标阳性率均明显高于对照组（P〈0.05）,其敏感性分别为90.32%、83.87%和80.65%;特异性分别为95.00%、92.50%和97.50%。两项指标联合可获较高特异性及阳性预测值。结论 心电图STV3R～V6R抬高≥1mm及/或STⅢ/STⅡ抬高≥1有助于急性下壁合并右心室心肌梗死的临床诊断。     

Early diagnosis of right ventricular or posterior infarction associated with inferior wall left ventricular acute myocardial infarction

Right ventricular (RV) or posterior infarction associated with inferior wall left ventricular acute myocardial infarction (AMI) has important therapeutic and prognostic implications. However, RV and posterior chest leads in addition to the 12-lead electrocardiogram are required for accurate detection. Body surface mapping (BSM) has greater spatial sampling and may further improve inferior wall AMI classification. Consecutive patients with chest pain lasting <12 hours were assessed to identify those with AMI and > or =0.1 mV ST elevation in > or =2 contiguous inferior leads of the 12-lead electrocardiogram (bundle branch block or left ventricular hypertrophy excluded). A 12-lead electrocardiogram, RV leads (V(2)R, V(4)R), posterior chest leads (V(7), V(9)), and a BSM were recorded. From each BSM, the 12 electrodes overlying the RV region (regional RV map) and 10 electrodes overlying the posterior wall (regional posterior map) were assessed for ST elevation. Infarct size was estimated by serial cardiac enzymes. AMI occurred in 173 of 479 patients. Of the 62 patients with inferior wall AMI, ST elevation > or =0.1 mV occurred in 26 patients (42 in V(2)R or V(4)R compared with 36 patients (58%) in > or =1 electrode on the regional RV map (p = 0.0019). ST elevation > or =0.1 mV occurred in 1 patient (2%) in V(7) or V(9) compared with 17 patients (27%) in > or =1 electrode on the regional posterior map (p = 0.00003). ST elevation > or =0.05 mV occurred in 6 patients (10%) in V(7) or V(9) compared with 22 patients (36%) in > or =1 electrode on the regional posterior map (p = 0.00003). Patients with ST elevation on regional RV and/or posterior maps had a trend toward larger infarct size (mean peak creatine kinase 1,789+/-226 vs. 1,546+/-392 mmol/L; p = NS). Thus, BSM, when compared with RV or posterior chest leads, provides improved classification of patients with inferior wall AMI and RV or posterior wall involvement.     

ST段抬高型急性下壁心肌梗死并心力衰竭患者的冠状动脉病变特征

目的:探讨ST段抬高型急性下壁心肌梗死(AIMI)并心力衰竭(HF)患者的冠状动脉病变特点及临床特征。方法:对108例行急诊冠状动脉介入治疗的ST段抬高型AIMI患者的临床资料进行分析,根据心功能分为2组,HF组32例,无HF组76例,比较2组临床特征及冠脉病变特点。结果:HF组年龄偏大(P<0.05),血清肌酐水平、恶性心律失常、心源性休克需要主动脉内球囊反搏比例(均P<0.01),三度房室传导阻滞发生率显著高于非HF组(P<0.05);罪犯血管为右冠状动脉,合并前降支血管病变,HF组显著高于非HF组(P<0.05和P<0.01)。结论:ST段抬高型AIMI罪犯血管为右冠状动脉,同时合并有前降支血管病变时,易发生心力衰竭。     

Significance of nitroglycerin-induced hypotension with inferior wall acute myocardial infarction

Up to 60% of patients with inferior wall acute myocardial infarction (AMI) develop hypotension. In many cases, profound hypotension is precipitated by the administration of nitroglycerin. To test the hypothesis that this hypotensive response to nitroglycerin may be related to right ventricular (RV) involvement, we compared 20 patients with electrocardiographic and enzyme-documented inferior wall AMI and marked hypotension (greater than 30 mm Hg decrease in systolic blood pressure, with symptoms) after nitrate administration, to 20 patients with documented inferior AMI, but without hypotension after administration of nitroglycerin. The presence of RV involvement was determined by electrocardiographic criteria of 1 mm of ST-segment elevation in at least 2 right precordial chest leads. Fifteen of the 20 patients who demonstrated a marked hypotensive response to nitroglycerin had evidence of RV involvement, while in 18 of the 20 patients without hypotension after nitrates there was no evidence of RV involvement. In a separate analysis of 28 patients with documented RV involvement in an inferior AMI, 20 developed hypotension in response to nitrates. Thus, in the setting of an inferior AMI, a marked hypotensive response to nitrates suggests the presence of RV involvement. Moreover, hypotension after nitrate administration may be anticipated in patients with known RV infarction, and in such patients, nitrates should be administered carefully.