Anterior ST-segment elevation with right coronary artery occlusion: a unique case of isolated right ventricular infarction

Anterior ST-segment elevation is the classic electrocardiographic feature of anterior left ventricular myocardial infarction due to occlusion of the left anterior descending artery. However, anterior ST-segment elevation has also been described in patients with right coronary artery occlusion, in whom concomitant inferior ST-segment elevation is also typically present. A case of proximal right coronary artery occlusion resulting in anterior ST-segment elevation without inferior ST-segment elevation is reported in this article. It is hypothesized that the inferior left ventricular wall was protected by left-to-right collaterals, as seen on coronary angiography, with resultant isolated right ventricular infarction upon proximal right coronary artery occlusion. In conclusion, this report presents a unique case of an isolated right ventricular infarction resulting in an electrocardiographic pattern mimicking anterior-wall left ventricular infarction.     

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。     

Concomittant ST elevation in inferior and anterior leads in acute myocardial infarction. Clinical and anatomical significance

Various instances of acute myocardial infarction that may cause concomittant ST-segment elevation in inferior and anterior leads are presented. Among the situations that produce this phenomenon are: (1) multivessel coronary artery disease or isolated disease of a dominant left anterior descending artery causing combined inferior and anterior myocardial infarction; and (2) isolated disease of a right coronary artery causing combined infarction, or isolated right ventricular myocardial infarction. The mechanisms responsible for the electrocardiographic patterns in each instance are discussed.     

急性前壁心肌梗塞下壁导联ST段压低的临床意义

对44例急性前壁心肌梗塞患者,将冠脉造影结果与体表心电图ST段改变进行比较分析.结果发现急性前壁心肌梗塞患者38.6%有下壁导联ST段压低,这些导联ST段压低与多支血管病变无关,而与前降支近端病变有关,可能反映高侧壁导联心肌缺血时心电图对应性改变.     

A common electrocardiographic finding in an uncommon presentation

Anterior ST-segment elevation is the hallmark electrocardiographic finding of acute anterior left ventricular infarction that is caused by occlusion in one of the branches of the left coronary artery. We report a case of marked ST-segment elevation in the precordial leads, with concomitant inferior ST-segment elevation that was caused by acute occlusion of the marginal branches of the right coronary artery (RCA) causing an isolated right ventricular myocardial infarction (RVMI) during coronary angioplasty. Isolated occlusion of the marginal branches of the RCA appears to be extremely rare. In the case presented, this was caused by an iatrogenic spiral dissection with subsequent stenting of the RCA. This case illustrates that diffuse ST-segment elevation in the precordial leads may occur due to the occlusion of the RCA or its branches. It is important to recognize this scenario, since the treatment of left ventricular myocardial infarction differs from that of RVMI, where maintaining adequate preload and avoiding vasodilators to preserve right ventricular stroke volume is crucial.     

Risk factors, echocardiographic patterns, and outcomes in patients with acute ventricular septal rupture during myocardial infarction

Ventricular septal rupture (VSR), which can complicate an acute myocardial infarction (MI), carries a high mortality rate. Because precordial and transesophageal echocardiography can identify the type of rupture and assess right ventricular (RV) function at the patient's bedside, we examined the prognostic significance of echocardiographic patterns in postinfarct VSR by postulating that complex rupture and RV involvement carry a worse prognosis. Seventeen patients (10 men; mean age 66 years) who had confirmed postinfarct VSR underwent precordial and transesophageal echocardiography followed by coronary angiography. Serial 12-lead and right precordial leads were also available. Type of septal rupture was classified as simple or complex based on autopsy-proved echocardiographic criteria. Three patients had inferior wall MI and 14 had anterior wall MI. ST-segment elevation persisted >72 hours in all 3 patients who had inferior wall MI and in 12 who had anterior wall MI. Segmental wall motion abnormalities helped in detecting the left ventricular entry site, and use of unconventional views superimposed with color flow Doppler provided the RV exit site. RV function was better appreciated with transesophageal echocardiography. Two patients who had inferior wall MI and 7 who had anterior wall MI had complex ruptures. All 3 patients who had inferior wall MI and 7 who had anterior wall MI had electrocardiographic and echocardiographic evidence of RV involvement. Mortality rate was higher in patients who had complex rupture (78% vs 38%, p <0.001) and in those who had RV extension (71% vs 29%, p <0.001). In conclusion, persistent ST elevation is a common finding in patients who have postinfarct VSR. Complex VSR and RV involvement are significant determinants of clinical outcome.     

Acute Posterior-inferior Myocardial Infarction Caused by Total Occlusion Distal to the Apex of the Hyperdominant Left Anterior Descending Artery

A 77-year-old woman was admitted to our hospital with severe ongoing chest pain. Electrocardiography showed ST-segment elevation in the inferior leads and tall R waves in leads V1-2. Posterior-inferior myocardial infarction was diagnosed. Emergent coronary angiography (CAG) revealed the wrap-around left anterior descending artery (LAD) with total occlusion distal to the cardiac apex. She underwent percutaneous coronary intervention (PCI). Despite difficulty navigating the long and tortuous LAD, we successfully performed reperfusion of the wrap-around LAD. CAG post-PCI showed the posterior descending artery arising from the LAD, described as hyperdominant LAD.     

Comparison of diagnostic accuracy, time dependency, and prognostic impact of abnormal Q waves, combined electrocardiographic criteria, and ST segment abnormalities in right ventricular infarction.

OBJECTIVE--To determine the diagnostic and prognostic impact of abnormal Q waves in comparison to or in combination with ST segment abnormalities in the right precordial and inferior leads as indicators of right ventricular infarction during the acute phase of inferior myocardial infarction. DESIGN--Prospective study of a consecutive series of 200 patients with acute inferior myocardial infarction with and without right ventricular infarction. SETTING--Department of internal medicine, university clinic. RESULTS--Right ventricular infarction was diagnosed in 106 (57%) out of 187 patients from the results of coronary angiography, technetium pyrophosphate scanning, and measurement of haemodynamic variables or at necropsy, or both. In the acute phase of inferior infarction ST segment elevation > or = 0.1 mV in any of the right precordial leads V4-6R was the most reliable criterion for right ventricular infarction (sensitivity, 89%; specificity, 83%). Abnormal Q waves in the right precordial leads, the most specific criterion (91%) for right ventricular infarction, were superior to ST segment elevation in patients admitted > 12 hours after the onset of symptoms. Both ST segment elevation in leads V4-6R (increase in in hospital mortality, 6.2-times; P < 0.001; major complications, 2.3-times; P < 0.01) and abnormal Q waves (2.3-times, P < 0.05; 1.8-times, P < 0.05) on admission were highly predictive of a worse outcome during the in hospital period. In the presence of inferior myocardial infarction previously proposed combined electrocardiographic criteria were not better diagnostically or prognostically than ST segment abnormalities and abnormal Q waves alone. CONCLUSIONS--During the first 24 hours of inferior myocardial infarction ST segment elevation and abnormal Q waves derived from the right precordial leads are complementary rather than competitive criteria for reliably diagnosing right ventricular infarction, both indicating a worse in hospital course for the patient. In this they are better than any other previously proposed combined electrocardiographic criteria in diagnosing right ventricular infarction. Right precordial leads should be routinely monitored in acute inferior myocardial infarction.     

Coronary Angioscopy Revealing Ruptured Plaque and Thrombus Causing Acute Anterior Myocardial Infarction With a Subsequent Acute Inferior Myocardial Infarction — A Case Report

We report a unique case that suggests that a thrombotic coronary occlusion was caused by local plaque rupture in the left anterior descending coronary artery (LAD), with subsequent thrombotic occlusion in the right coronary artery (RCA), and presented with simultaneous double coronary artery occlusions. ST-segment elevations in the precordial leads and cardiac tamponade were observed first, followed by ST-segment elevations in the inferior leads. Emergency coronary intervention for the RCA lesion resulted in further ST-segment elevation, suggesting an acute inferior infarction. A left ventricular rupture was found in the anterolateral wall, consistent with acute anterior infarction. Angioscopy one month later revealed the presence of ruptured plaque with thrombus, in both the LAD and the RCA. Yuji Okuyama and Masaya Usami, contributed equally to this report     

Proximal RCA occlusion producing anterior ST segment elevation,Q waves,and T wave inversion

An ST segment elevation myocardial infarction (STEMI) that produces anterior ST segment elevation (STE) is typically caused by acute occlusion of the left anterior descending (LAD) artery. Anterior STE, however, may also be caused by acute occlusion of either the proximal right coronary artery (RCA) or the right ventricular marginal branch (RVB). It has been thought that, in contrast to occlusions of the LAD, proximal RCA/RVB occlusion rarely causes Q waves in the right precordial leads. We present a case where a proximal RCA occlusion produced not only anterior STE, but also anterior T wave inversions and anterior Q waves.     

Electrocardiographic patterns of proximal left anterior descending artery occlusion in ST-elevation myocardial infarction may be modified by 3-vessel coronary artery disease

BackgroundThe electrocardiographic (ECG) pattern of ST-segment deviation in myocardial infarction is integral to the proper assessment of the location, extent, and functional significance of the infarct but may be modified by the underlying coronary artery anatomy.MethodsWe describe the ECG findings in 2 cases of proximal left anterior descending (LAD) artery occlusion in ST-elevation myocardial infarction (STEMI) associated with 3-vessel coronary artery disease.ResultsBoth patients had atypical ECG patterns of ST-segment elevation in leads V₂, I, and aVL and ST-segment depression with positive T waves suggestive of extensive subendocardial ischemia in leads II, III, aVF, and V₃ through V₆; acute proximal LAD occlusion and concomitant 3-vessel coronary artery disease were observed angiographically.ConclusionElectrocardiographic changes in proximal LAD STEMI may be modified by the presence of significant atherosclerotic disease elsewhere in the coronary vasculature. Recognition of this ECG pattern may aid the clinician in the rapid identification of high-risk STEMI.     

Deterioration in left ventricular performance during early coronary angioplasty after thrombolysis. Evidence for myocardial salvage

To investigate the effects of controlled coronary artery reocclusion after successful thrombolysis, we studied 15 patients during early elective angioplasty of the patent infarct-related artery. Eight patients underwent left anterior descending artery dilation, and the other 7 had right coronary artery dilation. In 13 cases, ST-segment elevation developed during balloon occlusion. In all 15 cases, intravenous digital subtraction left ventriculography during balloon inflation showed that the ejection fraction decreased at least 5% (mean decrease, from 60% to 47%), despite preexisting Q waves overlying the infarct territory in 5 patients. Balloon inflation resulted in decreased apical segmental shortening in all 8 patients who underwent left anterior descending artery dilation; likewise, balloon inflation produced impairment of inferior-wall contraction in all 7 patients who had right coronary artery dilation. In this setting, a deterioration in left ventricular performance indicates that the restoration of coronary patency with thrombolysis has resulted in myocardial salvage. In patients with Q waves, such deterioration suggests that this electrocardiographic abnormality does not necessarily indicate a completed infarction.     

Multiple coronary artery thrombosis in a 41-year-old male patient presenting with ST-segment elevation myocardial infarction

Simultaneous occlusion of multiple epicardial coronary arteries is an uncommon finding in patients presenting with ST-segment elevation myocardial infarction (STEMI). We describe a 41- year-old male Asian patient who presented with inferior and anterior STEMI complicated by cardiogenic shock and frequent life-threatening ventricular arrhythmias. The patient was subsequently found to have acute occlusion of the proximal right coronary artery (RCA) and proximal left anterior descending coronary artery (LAD). The patient was treated with primary percutaneous coronary interventions for RCA and LAD, and intra-aortic balloon pump placement showed excellent results. Based on the available literature, early PCI for this very rare condition is paramount for patient survival.     

Single vessel disease of the anterior interventricular branch as a cause of combined anterior and posterior wall infarct in comparison with 2-vessel disease of the RIVA and RCA

Only few studies deal with the problem of an isolated stenosis of the left anterior descending coronary artery (LAD) leading to a combined anterior and inferior myocardial infarction in the ECG and VCG. In the present study patients with electrocardiographic signs of anterior and inferior myocardial infarction and either one-vessel disease of the LAD branch (n = 27; group I) or two-vessel disease including the LAD and the right coronary artery (RCA) (n = 29; group II) were investigated. Due to the anterior myocardial infarction present in all patients, unequivocal signs of posterior and posterolateral infarct location were missing in the ECG and VCG. There was a distinct variability with regard to Q-wave duration and amplitude in the inferior leads of the ECG and of the Q/R-relation in the scalar lead Y of the VCG (Frank-leads) in patients with isolated LAD disease when compared to those with combined LAD and RCA disease, but no reliable parameter was found in the ECG and VCG which allowed to allocate patients to one of the two groups. On the other hand, there were significant differences in hemodynamics and left ventricular function between the two groups. Group I patients showed a significantly higher left ventricular ejection fraction (mean 49 +/- 15%) than patients with two-vessel disease (group II) (mean 42 +/- 12%) (p less than 0.05). Left ventricular end-diastolic pressures at rest (13 +/- 7 mm Hg).(ABSTRACT TRUNCATED AT 250 WORDS)     

Right ventricular infarction mimicking anterior infarction: A case report

Right ventricular infarction usually occurs in association with inferior infarction, with no remarkable electrocardiographic signs in conventional leads. This report describes a patient with a previous inferior acute myocardial infarction who developed right ventricular infarction with significant anterior lead ST segment elevation (V1-V4) caused by the loss of two large right ventricular branches during a coronary angioplasty of the right coronary artery. The case is discussed and the literature is reviewed.     

急性前壁心肌梗死伴不同下壁导联ST段改变的临床特点

目的探讨ST段抬高急性前壁心肌梗死(简称心梗)伴不同下壁导联ST段改变患者的梗死相关血管以及梗死面积及心功能情况。方法73例急性前壁心梗患者,根据入院时心电图下壁导联ST段改变情况将患者分为3组:A组为Ⅱ、Ⅲ、aVF中至少两个导联ST段抬高;B组为Ⅱ、Ⅲ、aVF中至少两个导联ST段压低,C组为Ⅱ、Ⅲ、aVF中少于两个导联ST段有改变。比较三组CK最大值,左室射血分数以及梗死相关血管(IRCA)。结果CK最大值3组比较A组最低(1280±531IU/Lvs2034±911,1677±630IU/L,P<0.01);左室射血分数A组最高(0.54±0.09vs0.48±0.07,0.47±0.08,P<0.01);三组IRCAA组中85.7%的患者位于“绕过心尖的左前降支(LAD)”的中远段,有14.3%的患者位于右冠状动脉(RCA)的近段;B组的患者中全部为非“绕过心尖的LAD”,其中有70.4%的患者位于非“绕过心尖的LAD”的近段;C组中有96.7%的患者为非“绕过心尖的LAD”,其中有73.3%的患者位于非“绕过心尖的LAD”的近中段,三组比较差异有显著性(P<0.01)。结论IRCA为LAD的急性前壁心梗时下壁ST段改变可能与LAD长度和病变部位有关;前壁合并下壁ST段同时抬高的患者若IRCA为“绕过心尖的LAD”,其梗死面积较小,心功能较好。     

Relation between electrocardiography and coronary angiography findings in the infarct stage

One hundred and fifty-two patients underwent cardiac catheterization and coronary arteriography within 6.3 +/- 6.0 hours from onset of acute myocardial infarction. All had a standard 12-lead electrocardiogram recorded within 1.5 hours of cardiac catheterization. The electrocardiographic abnormalities present were correlated with the infarct related artery as determined by coronary arteriography. ST segment elevation was the most common finding in patients with the left anterior descending (LAD), or right coronary artery (RCA) as the infarct related artery. ST segment depression was the most common abnormality in patients with left circumflex artery (CX) as the infarct related artery. A typical pattern of anterior acute myocardial infarction was seen in 93% of all patients with the LAD as the infarct related artery. A typical pattern of acute inferior myocardial infarction was seen in 53% of all patients with RCA or CX narrowing taken as one group. The pattern of true posterior or posterolateral wall acute myocardial infarction in the absence of typical changes in the inferior leads was highly specific and predictive of CX narrowing. In contrast, the pattern of an inferior wall myocardial infarction, in the absence of true posterior or lateral wall changes, was highly specific and predictive of right coronary artery narrowing. Fifty-six percent of patients with CX artery as the infarct related artery presented with non-classical electrocardiographic abnormalities. The electrocardiographic pattern in patients with subtotal occlusions were similar to those of patients with total occlusions. Thus the electrocardiogram obtained in the first few hours of acute myocardial infarction is reliable in localizing the LAD as the infarct related artery.(ABSTRACT TRUNCATED AT 250 WORDS)     

Implications of inferior ST-segment elevation accompanying anterior wall acute myocardial infarction for the angiographic morphology of the left anterior descending coronary artery morphology and site of occlusion.

Inferior ST-segment elevation during anterior wall acute myocardial infarction (AMI) due to left anterior descending (LAD) coronary artery occlusion is unusual and was not previously investigated. This study tested the hypothesis that inferior ST-segment elevation during anterior AMI predicts a specific angiographic morphology that satisfies 2 necessary conditions: (1) mass of ischemic anterior wall myocardium is relatively small, resulting in a weaker anterior injury current and less reciprocal inferior ST-segment depression; and (2) there is concomitant inferior wall transmural ischemia that further shifts the inferior ST segments upward. The study group consisted of 42 consecutive patients with anterior AMI undergoing angiography at 4.1 days (range 0 to 14). Coronary angiograms were examined for 3 features: (1) site of LAD artery occlusion (a distal obstruction implying a smaller mass of ischemic anterior wall myocardium), (2) LAD artery extension onto inferior wall of left ventricle (termed a "wrap around" vessel), and (3) collateral flow from LAD artery to inferior wall. The latter 2 features would be expected to contribute to inferior wall transmural ischemia. Acute inferior ST-segment elevation (sum of ST-segment deviation in leads II, III and aVF greater than or equal to 3.0 mm) was seen in 7 patients (16%). A greater number of LAD artery branches proximal to the site of occlusion was significantly correlated with less inferior ST-segment depression (r = 0.59, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)