Right ventricular subendocardial infarction in a patient with pulmonary hypertension,right ventricular hypertrophy,and normal coronary arteries

Right ventricular infarction is usually associated with coronary artery disease and concomitant left ventricular infarction. Isolated right ventricular subendocardial necrosis was discovered at autopsy in a 52-year-old woman with pulmonary hypertension, right ventricular hypertrophy, and normal coronary arteries, who died with septicemia 41 days after mitral valve replacement. This represents the first well-documented report of isolated right ventricular subendocardial infarction associated with normal coronary arteries.     

Isolated Right Ventricular Myocardial Infarction

Abstract Isolated right ventricular infarction is uncommon. A 73-year-old man without previous cardial complaints was admitted pulseless to hospital. An infarct of the left ventricle was suspected. Autopsy showed a fresh thrombus located in a small branch artery of the right coronary artery accompanied by a fresh infarction of the anterior free wall of the right ventricle. Only 8 cases of isolated right ventricular infarction located in the anterior free wall were found in a review of the literature of right ventricular infarction. The diagnosis, treatment and prognosis of right ventricular infarction are discussed.     

Acute massive pulmonary embolism mimicking non-ST-elevation acute coronary syndrome

Non-ST-elevation acute coronary syndrome frequently presents with negative T-wave inversion. In acute pulmonary embolism precordial T-wave inversion occurs due to right ventricular strain. We herein report a case of a 48-year-old woman presenting with syncope secondary to massive main pulmonary artery embolism which was initially diagnosed as acute coronary syndrome due to negative anterior T-wave inversion and raised troponin. In addition, her room air saturation was normal and electrocardiogram showed T-wave inversion in inferior wall leads as well. We present this case of massive pulmonary embolism with varied presentation which was initially misdiagnosed as acute coronary syndrome.     

Extracardiac left to right shunt in a patient with biventricular postinfarction rupture and pseudoaneurysm

A 68 year old man had a diaphragmatic myocardial infarction and 9 months later was admitted with severe congestive heart failure (functional class IV). Cardiac catheterization demonstrated a postinfarction pseudoaneurysm. Because of a massive left to right shunt (pulmonary to systemic flow ratio = 2.7), concomitant rupture of the ventricular septum was suspected. At surgery the pseudoaneurysm communicated with the right ventricle through two different orifices and with the left ventricle through another ostium. The ventricular septum was intact. Therefore, the shunt was extracardiac through the pseudoaneurysm (left ventricle----pseudoaneurysm----right ventricle). The unique combination of lesions allowed the patient to survive. The false aneurysm was excised and primary repair was performed in the orifices of the right and left ventricular walls. The postoperative course was uneventful and 10 months later the patient was in functional class I.     

Combined right and left ventricular infarction: Pathogenesis and clinicopathologic correlations

An autopsy examination was made in 102 consecutive cases of fatal myocardial infarction that occurred in a coronary care unit. Thirty-five of the patients (34 percent) were found to have right ventricular infarction. All of the right ventricular infarcts were associated with transmural infarction of the posterior left ventricle or the interventricular septum, or both. The group with right ventricular infarction was compared with that without right ventricular infarction. Both groups had a predominant pattern of coronary arterial atherosclerosis consisting of severe stenosis of the proximal left anterior descending and proximal right coronary arteries with variable involvement of the left circumflex and left main coronary arteries. There was no significant difference between the two groups in severity or distribution of coronary arterial atherosclerosis. However, the group with right ventricular infarction had twice as many recent coronary arterial occlusions as did the group with left ventricular infarction and at least one recent coronary arterial lesion was present in 86 percent of those with right ventricular infarction, compared with only 30 percent of the group with left ventricular infarction. The majority of the acute coronary arterial lesions in both groups were thrombotic, but many intramural hemorrhages within atherosclerotic plaques were also found. In both groups the greatest number of recent coronary arterial occlusions was in the proximal right coronary artery, but the acute lesions were distributed throughout the coronary arterial tree.     

Isolated right ventricular infarction followed by posterior left ventricular infarction after a few days

This report presents a rare case of isolated right ventricular infarction complicated by bilateral occlusive pulmonary embolism apparently due to right ventricular mural thrombus. Only 2 to 3 weeks later an infarct of the posterior wall of the left ventricle finally occurred. The clinical, pathological and electrocardiographic features of the case are discussed. This case shows that right ventricular infarct can occur without a preceding or simultaneous infarct of the left ventricle.     

兔的冠状动脉解剖学

从兔的心外膜下直接观察到的血管均系冠状静脉,非冠状动脉。兔的冠状动脉分为左、右两支,除去最近段0.2～0.7cm长外,一般均位于心肌肉。左冠状动脉主干长0.2～0.5cm,前降支非常细小,出现率仅86%,供应范围很小且表浅,左室支粗大,实为左冠状动脉主干的延续,斜向心脏钝缘,系左心室包括空间隔的主要供应血管。如以结扎冠状动脉的方法来造成心肌梗塞,应选左室支而不是前降支。     

Elevated troponin level is not synonymous with myocardial infarction

BACKGROUND: Elevated troponin I in the absence of angiographically visible coronary lesions is seen in up to 10-15% of those undergoing angiography for suspected coronary artery disease. This study aims to elucidate the etiology of elevated cardiac troponin I in patients with normal coronary arteries on angiography. METHODS: We identified 1551 (8.6%) patients with normal coronary arteries from our catheterization database of 17,950 patients from Jan 2000 to Jun 2004. Elevated troponin I levels were found in 217 (14%) of 1551 patients with normal coronary arteries. Of these 217 patients, 73 surgical patients were excluded, and the remaining 144 patients formed the study population. The study population was compared with age and gender matched patients with myocardial infarction and coronary artery disease (Group II). RESULTS: The patients with elevated cardiac troponin I (cTnI) with normal coronary arteries had significantly lower prevalence of atherosclerotic risk factors and significantly higher left ventricular ejection fractions. The cTnI in patients with normal coronary arteries was elevated due to a number of causes including tachycardia, myocarditis, pericarditis, severe aortic stenosis, gastrointestinal bleeding, sepsis, left ventricular hypertrophy, severe congestive heart failure, cerebrovascular accident, electrical trauma, myocardial contusion, hypertensive emergency, myocardial bridging, pulmonary embolism, diabetic ketoacidosis, chronic obstructive pulmonary disease exacerbation and coronary spasm. CONCLUSIONS: Cardiac troponin I could be elevated in a number of conditions, apart from acute myocardial infarction, and could reflect myonecrosis. Acute myocardial infarction is a clinical diagnosis as the laboratory is an aide to, not a replacement for, informed decision making.     

Right ventricular infarction: role of the moderator band artery in determining infarct size

We studied 19 patients with proximal right coronary artery occlusions associated with acute myocardial infarcts less than 30 days old. Right ventricular infarct size, determined as a percentage of right ventricular surface area, ranged from 0% to 29%. Correlation of 24 variables measuring infarct size, chamber size and coronary artery disease failed to demonstrate a significant correlation with the extent of right ventricular infarction. However, estimates of the degree of obstruction to potential collateral flow into the right coronary arterial system from the left anterior descending coronary artery, especially through the moderator band artery, showed a significant positive correlation with infarct size (p less than 0.02). Among the five patients with massive (greater than 25%) right ventricular infarction, four had significant (greater than 75%) obstruction of the left anterior descending system, resulting in potentially impaired collateral blood flow; the other patient had normal coronary arteries and embolic occlusion of the proximal right coronary artery with contraction band necrosis. The study suggests that collateral flow to the right ventricular myocardium, especially through the moderator band artery, protects against massive infarction in the presence of proximal right coronary artery occlusion.     

Pathophysiology and experimental treatment of acute pulmonary embolism

Although massive pulmonary embolism can lead to acute circulatory collapse, it is not known if the right ventricle fails because it cannot respond to further increments in filling pressure (descending limb of the Starling curve), or because coronary perfusion is inadequate to support its greatly augmented pressure work. Accordingly, the effects of mechanical reduction in right ventricular pressure work by pulmonary artery counterpulsation and elevation of coronary perfusion pressure by balloon occlusion of the abdominal aorta were assessed when cardiovascular collapse was induced in open-chest dogs by pulmonary embolism. In all seven dogs tested, failure was reversed by pulmonary artery counterpulsation. Right ventricular enddiastolic pressure fell from 6 ± 1 to 3 ± 1 mm. Hg, left ventricular systolic pressure increased from 40 ± 2 to 74 ± 6 mm. Hg, and cardiac output increased from 0.4 ± 0.1 to 1.7 ± 0.6 L. per minute (p < 0.05). In three of five dogs tested failure was similarly reversed by balloon occlusion of the descending thoracic aorta. These findings are consistent with the view that cardiovascular collapse during massive pulmonary embolism is a consequence of relative coronary insufficiency which can be reversed either by an increase in coronary perfusion pressure or by a reduction of the pressure work of the right ventricle.     

121例心肌梗塞左心室乳头肌的病理分析

本文对１２８例冠心病左心室乳头肌的病变，结合临床进行了分析和讨论。其中左心室乳头肌查见不同程度的心肌梗塞１２１例（９４．５％）、冠状动脉多支粥样硬化Ⅳ级狭窄９８例（７６．５％）；９８例中乳头肌查见单一急性心肌梗塞（ＡＭＩ）２１例（２１．４％）、ＡＭＩ＋陈旧性心肌梗塞（ＯＭＩ）６４例（６５．３％）、单一ＯＭＩ１３例（１３．３％）。这显示冠状动脉粥样硬化多支Ⅳ级狭窄中乳头肌绝大多数有陈旧性合并ＡＭＩ。冠状动脉主干在粥样硬化狭窄的基础上并发血栓形成常导致乳头肌ＡＭＩ。本组２３例心脏破裂患者中有２０例在乳头肌查见有急性贯通性心肌梗塞。２５例左心室室壁瘤中左心室乳头肌查见ＯＭＩ＋ＡＭＩ１６例（６４％）占大多数。本文对左心室乳头肌病变与二尖瓣功能损伤的关系也进行了讨论。     

An unusual presentation of massive pulmonary embolism mimicking septal acute myocardial infarction treated with tenecteplase

A 31-year-old man (175 cm, 82 kg) was referred to the emergency department 2 h after the sudden onset of acute dyspnea. Immediate ECG showed sinus tachycardia with ST elevations from V1 through V2 and a diagnosis of septal acute myocardial infarction was made. ECG on admission to the cardiology department showed the same results plus the S1–Q3–T3 pattern. Echocardiogram revealed a normally contracting left ventricle, a distended right ventricle with free wall hypokinesia and displacement of the interventricular septum towards the left ventricle. Thrombolytic therapy with tenecteplase 8000 IU and heparin 5000 IU was administered 5–10 min after hospitalisation and the patient was haemodynamically stable 30 min later. Echocardiogram performed 12 h after thrombolysis showed a normal left ventricle and a less distended right ventricle. Lung spiral computed tomography (CT) and lower abdominal CT on the fourth day showed large emboli in the inferior pulmonary arteries of the right and left lung. Rarely, massive pulmonary embolism may mimic anteroseptal acute myocardial infarction on ECG and this case demonstrates the utility of echocardiography for a differential diagnosis, as well as the efficacy of tenecteplase for thrombolytic therapy.     

Isolated right ventricular infarction resulting from thrombotic occlusion of a hypoplastic right coronary artery

Three cases of isolated right ventricular infarction resulting from thrombotic occlusion of a hypoplastic right coronary artery were found in 4,000 consecutive autopsies performed at Tokyo Metropolitan Geriatric Hospital. The incidence of isolated right ventricular infarction was 0.08%. The clinical profile of the first case was characterized by shock, pulmonary congestion, pleural effusion, decreased V1R and V2R on ECG, a small elevation of CPK and transaminase, elevation of fibrin degenerative products and decreased platelet count. The patient responded to volume expansion, heparin and catecholamines. One year later she died from cerebral bleeding. In the second case, mild aortic regurgitation and atrial fibrillation were present. He died suddenly during an episode of pneumonia. In the third case, there was chronic obstructive lung disease, atrial fibrillation and lung cancer. He died of respiratory failure. On autopsy, the coronary arteries revealed a marked left dominant and right hypoplastic pattern in all cases. The right coronary artery perfused only the free wall of the right ventricle. Complete occlusion of the hypoplastic right coronary artery resulted in isolated right ventricular infarction. In addition, chronic pulmonary disease and arrhythmia may be contributory.     

Isolated right ventricular infarction presenting as anterior wall myocardial infarction on electrocardiography

Isolated right ventricle infarction is extremely rare, and its electrocardiographic (ECG) signs may be misinterpreted or even missed, especially when a typical clinical picture is lacking. This paper describes a case of isolated right ventricle infarction, recognized only by echocardiography. The patient presented with ST-segment elevation in left precordial leads together with minimal ST-segment elevation in inferior leads on a 12-lead ECG. Angiography revealed the culprit right coronary artery, which was small and non-dominant. No significant obstructions were found in the left anterior descending artery. This case demonstrates that the ECG appearance of isolated right ventricle infarction may mimic anterior wall infarction and can be easily missed if not suspected.     

Scintigraphic evidence that the right ventricular myocardium tolerates ischaemia better than the left ventricular myocardium

To study the incidence of right ventricular infarction and theeffect of intracoronary thrombolysis on the ischaemic rightventricular myocardium, we performed intracoronary myocardialthallium scintigraphy in 18 patients with complete occlusionof the right coronary artery who underwent intracoronary thrombolysis.In 15 of these patients, intracoronary thallium-201 and technetium-99m pyrophosphate scintigrams were performed simultaneously. All18 patients had a right ventricular thallium defect before thrombolysis,and all had new thallium uptake after thrombolysis. 17 out of18 patients had a left ventricular thallium defect before thrombolysis,but only 10 of them showed new thallium uptake after thrombolysis.14 out of 15 patients had a left ventricular technetium-99 mpyrophosphate spot after thrombolysis and some diffuse pyrophosphateaccumulation in the area of the right ventricle. In one patientpyrophosphate accumulation was found only in the area of theright ventricle. Thus, right ventricular thallium defects weredetected by intracoronary thallium scintigraphy in the majorityof patients with inferior acute myocardial infarction due toright coronary artery occlusion. Right ventricular thalliumdefects were always reversible in contrast to left ventricularthallium defects in the same patients, suggesting that rightventricular myocardium tolerates ischaemia better than leftventricular myocardium.     

Clinical-Echocardiographic Correlation of Myocardial Infarction with Extension to Right Chambers

In order to determine the transesophageal echocardiographic characteristics in patients with acute myocardial infarction of right ventricle and establish the relationship between these findings, the clinical condition, and their prognostic value, 38 patients consecutively admitted to the Instituto Nacional de Cardiología with a diagnosis of acute left ventricular myocardial infarction with extension to right ventricle and/or atrium were retrospectively studied. Of the left ventricular infarctions, 37 were posteroinferior and one anterior. Significant elevations of CPK and DHL were found in 35. In 30 patients (78%) electrocardiographic evidence of extension of infarction to the right ventricle was found, and in 3, evidence of right atrial infarction. Twenty-one patients presented clinical data compatible with right ventricular infarction. In 19, cardiac rhythm and atrioventricular conduction disturbances were documented. Coronary angiograms practiced on 34 patients demonstrated single-vessel (right coronary) disease in 12, affection of two vessels in 14, and lesions in three or more in 6. Coronary arteries presented no significant lesions in two cases. With TEE, alterations of right ventricular segmental mobility were demonstrated in all patients, and in 6, alterations of right atrial mobility as well. As respects the ventricular wall movement index, 68.5% had total scores (RV + LV) of <5. The other 31.5% had scores >/= 5. In 26%, the right ventricular wall movement index was >/=4. The RVDD/LVDD ratio was 1 or less in 30 patients (78%) and >1 in only 8 (22%). The conclusions from these findings are that: (1) TEE is an excellent diagnostic means of identifying right ventricular and/or atrial infarction; and (2) a relationship exists between the magnitude of right ventricular damage and a wall movement index of 5 or more or an RV/LV diastolic diameter ratio > 1:postinfarction hemodynamic deterioration is significantly greater and the incidence of intrahospitalary complications higher.     

Noninvasive assessment of left and right ventricular filling in myocardial infarction with a two-dimensional Doppler echocardiographic method

Inflow characteristics of left and right ventricular filling were assessed in 40 patients with myocardial infarction and in 10 normal subjects by pulsed Doppler echocardiography. Patients with myocardial infarction were subdivided into four groups, focusing on the involvement of right ventricular and septal branches of the coronary arteries. Group I consisted of 11 patients with anterior infarction who showed an obstructive lesion of the proximal left anterior descending branch involving the first septal perforator with a patent right coronary artery. Group II consisted of 10 patients with inferior infarction who showed an obstructive lesion of the proximal right coronary artery involving the right ventricular branch. Group III consisted of 12 patients with both anterior and inferior infarction who showed obstructive lesions of both the proximal left anterior descending branch and the right coronary artery involving the right ventricular branch. Group IV consisted of seven patients with lateral infarction who showed an obstructive lesion of the diagonal branch or branches of the circumflex coronary artery with a patent left anterior descending branch and right coronary artery. Three measurements were performed from the transmitral and transtricuspidal inflow velocity patterns to assess the left and right ventricular diastolic behaviors. These measurements were: acceleration half-time, deceleration half-time of early diastolic rapid inflow, and the ratio of the peak velocity of early diastolic rapid inflow to that of the late diastolic inflow due to the atrial contraction. Impaired diastolic filling of the left ventricle compensated by enhanced left atrial contraction was observed in patients with myocardial infarction from groups I, II, III and IV.(ABSTRACT TRUNCATED AT 250 WORDS)     

Reversible ischaemia of right ventricle detected by exercise thallium-201 scintigraphy.

Exercise and redistribution thallium-201 imaging is commonly used for the detection and evaluation of left ventricular ischaemia and infarction. The right ventricle is frequently visualised after stress and sometimes on redistribution images. The visualisation of the right ventricle at rest is thought to be abnormal and is suggestive of pressure or volume overload of the right ventricle, either a result of pulmonary hypertension or secondary to left ventricular dysfunction. Using stress and delayed 201Tl imaging we have shown reversible left and right ventricular ischaemia and fixed left ventricular perfusion defects in two patients with multivessel coronary artery disease and left ventricular dyskinesia caused by prior myocardial infarction. Judging by the rarity of this finding as well as taking into consideration 201Tl kinetics, it is suggested that reversible right ventricular ischaemia after exercise may only be detected in patients with coronary artery disease who have severely compromised ventricular function. This finding may have therapeutic and prognostic significance.     

Cardiac involvement in progressive systemic sclerosis.

The case of a patient with progressive systemic sclerosis (PSS) who developed electro- and vectorcardiographic patterns of myocardial necrosis without clinical picture of myocardial infarction is reported. The coronarography showed no obstruction of coronary arteries and cineventriculography a hypodynamic enlarged left ventricle. The analysis of electrocardiograms from 43 other patients affected with PSS revealed myocardial necrosis in 5 of them. The clinical syndrome of myocardial infarction was absent in all these cases. Moreover, the hemodynamic investigation in 13 cases allowed to record a dip-plateau figure on the right ventricle pressure curve in 3 of them. In PSS, the electrocardiographic aspects of "necrosis" as well as hemodynamic restrictive findings or ventricular enlargement at ventriculography could indicate myocardial disease.     

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.