Precordial ST-segment elevation in acute occlusion of the proximal right coronary artery

Isolated right ventricular myocardial infarction (RVMI) rarely occurs and accounts for only 3% of all myocardial infarction cases. In the literature, there are several reported isolated RVMI cases with precordial ST-segment elevation. We describe a 45-year-old man with marked ST-segment elevations in leads V1 through V4 accompanied by slight ST-segment elevations in the inferior leads (III, aVF) caused by acute occlusion of a nondominant small right coronary artery proximal to the conus branch causing isolated RVMI.     

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.     

Right Ventricular Infarction Mimicking Anterior Infarction

It is rare to observe ST elevation in anterior derivations caused by right ventricular branch occlusion. We described the case of a patient with unstable angina who developed acute right ventricular myocardial infarction with ST‐segment elevation in anterior precordial leads (V₁–V₄) shortly after coronary angiography. Coronary angiogram revealed total occlusion of the right coronary artery (RCA) proximally to the right ventricular branch. This reminds us that the presence of diffuse ST‐segment elevation in the precordial leads could be due to acute RCA occlusion. The differentiation of these two entities is important, as their therapies are quite different.     

急性下壁心肌梗死患者心电图胸前导联ST段改变的临床意义

目的探讨急性下壁心肌梗死患者心电图胸前导联ST段改变与冠状动脉造影(CAG)所见冠状动脉病变部位的关系及其临床意义。方法 187例急性下壁心肌梗死患者,按入院时18导心电图胸前导联ST段改变分为3组,ST段无变化组(47例),ST段抬高组(16例),ST段压低组(124例);所有患者均行CAG。结果急性下壁心肌梗死伴胸前导联ST段抬高时多为右冠状动脉(RCA)近段闭塞(14例,82.3%),尤其是伴圆锥支动脉闭塞,与RCA中远端闭塞(2例,5.9%)比较差异有统计学意义(P0.01),且14例(73.7%)伴有右心功能不全和血流动力学障碍。下壁心肌梗死胸前导联ST段压低者可见于RCA、回旋支(LCX)闭塞及RCA、LCX闭塞与前降支(LAD)、对角支(D)病变的不同组合,其中LCX闭塞伴RCA病变者多表现为朐前ST V_4～V_6的压低,RCA闭塞伴LAD近端病变多有胸前ST V_1～V_6的压低,RCA伴D病变胸前ST V_1～V_3压低,与对照组比较差异有统计学意义(P0.05)。结论急性下壁心肌梗死合并胸前导联ST段抬高表明为RCA近段或丌口闭塞且多伴右心室心肌梗死和心功能不全;下壁心肌梗死伴胸前导联ST段压低提示为多支病变,ST V_1～V_3压低多伴有对角支严重狭窄,STV_1～V_6压低多伴有前降支的严重狭窄。     

Pure right ventricular infarction.

A 76-year-old man with chest pain was admitted to hospital where electrocardiography (ECG) showed ST-segment elevation in leads V1-4, indicative of acute anterior myocardial infarction. ST-segment elevation was also present in the right precordial leads V4R-6R. Emergency coronary angiography revealed that the left coronary artery was dominant and did not have significant stenosis. Aortography showed ostial occlusion of the right coronary artery (RCA). Left ventriculography showed normal function and right ventriculography showed a dilated right ventricle and severe hypokinesis of the right ventricular free wall. Conservative treatment was selected because the patient's symptoms soon ameliorated and his hemodynamics was stable. 99mTc-pyrophosphate and 201Tl dual single-photon emission computed tomography showed uptake of 99mTc-pyrophosphate in only the right ventricular free wall, but no uptake of 99mTc-pyrophosphate and no perfusion defect of 201Tl in the left ventricle. The peak creatine kinase (CK) and CK-MB were 1,381 IU/L and 127 IU/L, respectively. His natural course was favorable and the chest pain disappeared under medication. Two months after the onset, the ECG showed poor R progression in leads V1-4 indicating an old anterior infarction. Coronary angiography confirmed the ostial stenosis of the hypoplastic RCA. This was a case of pure right ventricular free wall infarction because of the occlusion of the ostium of the hypoplastic RCA, but not of the right ventricular branch. Because the electrocardiographic findings resemble those of an acute anterior infarction, it is important to consider pure right ventricular infarction in the differential diagnosis.     

右室梗塞冠脉阻塞部位与血流动力学异常程度关系的探讨

为了解右室梗塞冠脉阻塞部位与血流动力学的关系，对２１例急性下壁心肌梗塞患者进行血流动力学监测和冠状动脉造影发现，血流动力学改变符合急性右室梗塞（ＲＶＭＩ）１６例，无ＲＶＭＩ５例。１６例中１５例（９３．８％）为右冠状动脉（右冠脉）近或中段阻塞，１例（６．２％）为左回旋支阻塞，无冠脉远段的阻塞。同时发现，血流动力学紊乱较重［平均右房压（ＭＲＡＰ）／肺毛细血管楔入压（ＰＣＷＰ）≥０．８］和较轻（ＭＲＡＰ／ＰＣＷＰ０．６５～＜０．８）两亚组右冠脉近、中段阻塞分别为１０例中的４例、５例、６例中的３例和３例。结果表明，下壁心肌梗塞病人中右冠脉近或中段阻塞可导致ＲＶＭＩ，并且ＲＶＭＩ时血流动力学紊乱程度与冠脉阻塞部位不一致。     

Marked ST-segment elevation in the precordial and inferior leads in right ventricular myocardial infarction: a case report

This is a report of right ventricular infarction complicated by inferior myocardial infarction in which marked ST-segment elevation was observed in the precordial and inferior leads. A 51-year-old man was admitted with chest pain of one-half hour duration. His admission ECG showed conspicuous ST-segment elevation in the precordial and inferior leads. The maximum magnitude of the ST-segment elevation in the precordial leads was 21 mm in lead V2 and 10 mm in lead II. Echocardiography showed akinesis of the right ventricular free wall and the posterior half of the left ventricle. Angiography revealed a 90% reduction in the diameter of the right coronary artery in its proximal portion, and a normal left coronary system. Recent reports have indicated that precordial ST-segment elevation may reflect right ventricular infarction. However, there has been no previous report of marked ST-segment elevation in the precordial and inferior leads. In right ventricular infarction, the currents of injury usually occur simultaneously in the right ventricular free wall and left ventricular inferior wall, and then are electrically opposed to each other. The diffuse and marked ST-segment elevation observed in this case is thus a rare phenomenon.     

Differentiation between left circumflex and right coronary artery occlusions: studies on ST-segment deviation during percutaneous transluminal coronary angioplasty

To distinguish between acute occlusion of the right coronary artery (RCA) and the left circumflex artery (LCx) by electrocardiography, we studied ST-segment deviation during balloon inflation in percutaneous transluminal angioplasty. The composite electrocardiographic criteria based on ST-segment deviations increased the diagnostic specificity: that is, the finding of inferior infarction (ST-segment elevation in leads II, III, aVF) without lateral infarction (ST-segment elevation in leads V5,6) was highly suggestive of RCA occlusion (sensitivity and specificity: 35 of 43 cases, 81.4%; and 33 of 36 cases, 91.7%), whereas ST-segment elevation in leads V5,6 (LCx: 23 of 36 cases; 63.9%, RCA: 5 of 43 cases; 11.6%) or isolated ST-segment depression in leads V2-4 (LCx: 9 of 36 cases; 25.0%, RCA: none of 43 cases) was highly suggestive of LCx occlusion. These results indicate that the composite electrocardiographic criteria were useful in predicting the artery involved in acute myocardial infarction, although any single criterion was not sensitive or specific enough to differentiate right from left circumflex coronary artery occlusion.     

Massive ST-segment elevation in precordial and inferior leads in right ventricular myocardial infarction

This report describes a case of right ventricular infarction in which massive ST-segment elevation in the precordial and inferior leads was observed. The maximum magnitude of the ST-segment elevation in the precordial leads was 21 mm in lead V2 and that in the inferior leads was 10 mm in lead II. Angiography revealed a reduction of 90% in the diameter of the right coronary artery in its proximal portion and a normal left coronary system. Recent reports have shown that precordial ST-segment elevation may reflect right ventricular infarction. However, no previously reported instance except our case has shown massive ST-segment elevation in both the precordial and inferior leads. In right ventricular infarction, the current of injury is usually simultaneously present in the right ventricular free wall and left ventricular inferior wall, electrically opposed to each other. Thus, the diffuse and massive ST-segment elevation observed in this study seems to be a rare phenomenon.     

急性下壁心肌梗死心电图胸前导联V1-3 ST段抬高的临床意义

目的 探讨急性下壁心肌梗死患者心电图胸前导联ST段抬高与冠状动脉造影所示冠状动脉病变的关系及其临床意义.方法 187例急性下壁心肌梗死患者,按入院时18导心电图胸前导联ST段改变分为2组,ST段抬高组（16例）和非ST段压低组（171例）.所有患者均行冠状动脉造影术,病变适合行经皮腔冠状动脉成型术并检测B型钠尿肽（BNP）.结果 急性下壁心肌梗死伴胸前导联ST段抬高时多为右冠状动脉近段闭塞,尤其是圆锥支闭塞（P＜0.01）,且伴有右心功能不全和血流动力学障碍,与下壁右室心梗相比BNP差异有统计学意义（P＜0.01）.结论 急性下壁心肌梗死合并胸前导联ST抬高表明为右冠状动脉近段或开口闭塞且多伴右室心肌梗死和心功能不全.     

Precordial ST-segment elevation caused by right coronary artery occlusion

Among 57 consecutive patients undergoing percutaneous transluminal coronary angioplasty (PTCA) of the right coronary artery, eight patients showed precordial ST-segment elevation in leads V1-3 during the procedure. The mechanism of this ST elevation was investigated reviewing the coronary angiographic findings. All patients had angina pectoris, but none had evidence of myocardial infarction. The balloon inflation time was limited to 60 sec, and 12 lead electrocardiograms were recorded every 15 sec. In the eight patients who had precordial ST-segment elevation, six had the anatomically dominant right coronary artery, and two had proportioned (balanced) left and right coronary arteries. Six patients, however, had functionally dominant left coronary arteries because of good collaterals supplying the right coronary artery from the left coronary artery. Thus, functionally, six had the dominant left coronary artery, one had proportioned coronary supply, and only one had the dominant right coronary artery. In all eight patients, the most proximal portion of the right coronary artery was occluded during PTCA, obstructing both the conus branches and the right ventricular branches. This often induced precordial ST-segment elevation in cases with the functionally dominant left or proportioned coronary artery. This ST-segment elevation seemed to represent right ventricular ischemia, as the inferior wall was protected from ischemia by good collaterals. However, precordial ST-segment elevation was rare in the functionally dominant right coronary artery even when the most proximal portion of the right coronary artery was occluded. This fact seemed due to masking of electrocardiographic manifestations of right ventricular ischemia by the dominant electrical forces of inferior wall ischemia.     

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.     

Isolated right ventricular infarction--an uncommon cause of acute anterior ST segment elevation

We describe a case of isolated right ventricular myocardial infarction as the cause of anterior precordial lead ST segment elevation. This case illustrates that anterior ST segment elevation may occur with occlusion of the right coronary artery. It is important to recognize this scenario as the treatment of right ventricular myocardial infarction differs from that of left ventricular myocardial infarction.     

Unusual electrocardiographic presentation of an isolated right ventricular myocardial infarction secondary to thrombotic occlusion of a non-dominant right coronary artery--a case report and brief review of literature

Isolated right ventricular infarction is an extremely rare phenomenon. Its electrocardiographic (ECG) features may be misinterpreted or even missed if not suspected. A case of an isolated right ventricular myocardial infarction is presented, recognized by ST-segment elevation in a single precordial lead, such as V1, aided thereafter by right precordial ECG changes. Immediate coronary angiography revealed proximal occlusion of a small non-dominant right coronary artery. Coronary intervention as well as infusion of intravenous normal saline solution and pressor agent for hypotension provided symptomatic relief, and subsequent recovery from this potentially life-threatening, but rare condition. Routine 12-lead ECG done approximately 12 hours after the admission showed extension of ST segment elevation from V1 trough V3 without any ST-segment elevation in inferior leads. This case demonstrates that there might be a very unusual ECG appearance in the setting of an isolated right ventricular myocardial infarction and can be missed if not immediately suspected. Isolated right ventricular myocardial infarction may be difficult to recognize, requiring both a high index of clinical suspicion for its presence, as well as careful evaluation of unusual ECG features of the disease entity.     

ST segment elevation in leads V1 to V3 due to isolated right ventricular branch occlusion during primary right coronary angioplasty.

It is rare to observe ST elevation in anterior derivations caused by isolated right ventricular branch occlusion. We described the case with acute inferior and right ventricular myocardial infarction (MI) who developed ST segment elevation in precordial leads V(1) to V(3) due to isolated right ventricular branch occlusion during primary right coronary angioplasty.     

A totally occluded right coronary artery presenting with a normal electrocardiogram

Total occlusion of the right coronary artery (RCA) typically manifests as ST-segment elevation in the inferior leads and sometimes the lateral precordial leads of the surface electrocardiogram (ECG). We report a case of a patient with a normal electrocardiogram on presentation who, on angiography, revealed a totally occluded proximal RCA. Emergency angioplasty and stenting was successfully able to recanalize the entire RCA and restore TIMI III flow. ECGs performed post-procedure showed minimal change. The existence of a subendocardial microvascular network may have allowed this patient to escape what typically would have been a large ST-elevation inferior myocardial infarction.