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 stenosis of left anterior descending or right coronary artery: Relation between site of stenosis and ventricular dysfunction and therapeutic implications

Indications for coronary arterial bypass surgery in single vessel coronary artery disease are unresolved. To determine the extent of myocardium at risk with stenosis (70 percent or more) of a single coronary artery, left ventricular angiograms of 200 patients with stenosis confined to either the left anterior descending or right coronary artery and of 15 normal control subjects were assessed. Among patients without myocardial infarction, ejection fraction was unchanged (p > 0.05 versus normal values) in (1) those with stenosis of the proximal (above first septal branch, n = 19), mid (between septal and first diagonal branches, n = 14) and distal (within 2 cm distal to diagonal branch, n = 15) left anterior descending coronary artery, and (2) those with stenosis of the proximal (above acute marginal branch, n = 16) and distal (between acute marginal and posterior descending branches, n = 16) right coronary artery. In contrast, ejection fraction was depressed (p < 0.001 versus normal values) In left anterior descending arterial stenosis with anterior myocardial Infarction: proximal (38 ± 10 percent, n = 33), mid (46 ± 12 percent, n = 24; p < 0.01 versus proximal), and distal (56 ± 9 percent, n = 15; p < 0.01 versus mid). Ejection fraction was similar with proximal and distal stenosis of the right coronary artery and inferior Infarction: 54 ± 11 percent versus 55 ± 9 percent, p > 0.05; both p < 0.05 versus normal value. Shortening velocity was assessed in three anterior (I to III, base to apex) and three inferior (IV to VI, apex to base) equidistant hemichords perpendicular to the long axis, 30 ° right anterior oblique view. With anterior Infarction and left anterior descending stenosis, shortening of hemichords I to V, I to IV and II to III with proximal, mid and distal stenosis, respectively, was depressed (p < 0.05 versus normal value). Septal excursion and thickening on M mode echocardiography with proximal left anterior descending stenosis and infarction were depressed (p < 0.05 versus mid and distal stenosis with infarcts). Hemichordal shortening with Inferior infarction was similarly depressed (p > 0.05) with proximal and distal stenoses.In conclusion, stenosis of the left anterior descending coronary artery is a heterogenous disease, the extent of jeopardized myocardium is highly dependent on the site of stenosis, and the criteria for surgery cannot be applied uniformly. When the surgical goal is myocardial preservation, these data provide an objective rationale for bypass of stenosis of the proximal left anterior descending coronary artery. In stenosis confined to the right coronary artery, left ventricular preservation alone should not be considered an indication for coronary bypass grafting.     

Stress thallium-201 myocardial scintigraphy for the detection of individual coronary arterial lesions in patients with and without previous myocardial infarction

The value of stress thallium-201 scintigraphy for detecting Individual coronary arterial stenoses was analyzed in 141 patients with angio-graphically proved coronary artery disease, 101 with and 40 without a previous myocardial infarction. In patients without infarction, the sensitivity for detecting greater than 50 percent narrowing in the left anterior descending, the right and the left circumflex coronary artery was 66, 53 and 24 percent, respectively. In those with a previous infarction, the sensitivity for demonstrating disease in the artery corresponding to the site of Infarction was 100 percent for the left anterior descending, 79 percent for the right and 63 percent for the left circumflex coronary artery. In patients with a prior anterior infarction, concomitant right or left circumflex coronary arterial lesions were detected in only 1 of 12 cases, whereas in those with previous inferior or inferolateral infarction, the sensitivity for left anterior descending coronary artery disease was 69 percent. Because of the reasonably high sensitivity for detecting left anterior descending arterial disease, Irrespective of the presence and location of previous infarction, myocardial scintigraphy was useful in identifying multivessel disease in patients with a previous inferior infarction. However, because of its relative insensitivity for right or left circumflex coronary artery disease, scintigraphy proved to be a poor predictor of multivessel disease in patients with a prior anterior infarction and in patients without previous myocardial infarction.     

Clinical and arteriographic variables predictive of survival in coronary artery disease

Survival, subsequent myocardial infarction and current anginal status were determined for 90 nearly consecutive patients who underwent coronary arteriography at the Johns Hopkins Hospital between 1960 and 1967. All patients had at least one coronary arterial narrowing equal to or greater than 70 percent; 78 of 90 patients would be candidates for coronary bypass surgery by present criteria. Twenty-nine of the 78 surgically “suitable” patients died of cardiac causes; 7 of 49 survivors sustained an acute myocardial infarction (mean follow-up period 9.9 years). Patients with a 70 percent or greater narrowing proximal to the first septal branch of the left anterior descending coronary artery had a significantly greater mortality compared with patients with equivalent narrowing distal to the first septal branch or with patients without 70 percent or greater narrowing of the left anterior descending artery. The patients with a 70 percent or greater narrowing of the left anterior descending artery who died were those with a significant narrowing in at least one other major coronary artery. Multivariate stepwise discriminate function analysis of all clinical, electrocardiographic (except stress electrocardiographic) and arteriographic variables identified three independent predictors of mortality: (1) the simultaneous occurrence of a narrowing in left anterior descending and right coronary arteries, (2) prior myocardial infarction; and (3) 70 percent or greater narrowing proximal to the first anterior descending septal branch. When stress electrocardiographic findings were included, a “positive” stress electrocardiographic test was also an independent predictor of mortality.     

Nonfatal myocardial infarction in medically treated patients with coronary artery disease

The purpose of this study was to identify patient characteristics associated with nonfatal myocardial infarction as the first event after cardiac catheterization in medically treated patients with coronary artery disease. Multiple logistic risk analyste of 81 baseline characteristics in 354 patients who died or had nonfatal infarction identified 10 characteristics (5 clinical and 5 cardiac catheterization variables) as independently discriminating between the two events. Left ventricular function, specific coronary anatomy, previous myocardial infarction and age were the most important discriminators. Poor left ventricular function and left main coronary stenosis were associated with death. Subtotal left anterior descending and right coronary arterial stenosis, normal hemodynamics, absence of previous infarction and young age were associated with nonfatal infarction. Thus, in any subset of patients who have a uniform risk of ischemic events (nonfatal infarction or death), nonfatal infarction is most likely to occur in those who are young, have had no previous infarction, have subtotal left anterior descending and right coronary arterial stenosis and normal hemodynamics.     

Effect of coronary occlusion site on angiographic and clinical outcome in acute myocardial infarction patients treated with early coronary intervention

In acute myocardial infarction that is treated with thrombolysis, proximal coronary artery occlusion is associated with worse prognosis, irrespective of the infarcted artery. Primary percutaneous coronary intervention (PCI) is currently the treatment of choice for ST-segment elevation acute myocardial infarction. Therefore, we evaluated the prognostic significance of proximal versus distal coronary artery occlusion in patients with acute myocardial infarction that was treated with primary PCI. Between 1994 and 2001, patients with a first acute myocardial infarction that was treated with primary PCI were analyzed. A lesion was considered proximal if it was located proximal to the first diagonal branch in the left anterior descending coronary artery (LAD), the first marginal obtuse branch in the left circumflex coronary artery, and the first right acute marginal branch in the right coronary artery. Lesions distal of these side branches were considered distal. In total, 1,468 patients were analyzed. Left ventricular ejection fraction (LVEF) for proximal LAD lesions was lower than that for distal ones (37 +/- 11% vs 42 +/- 11%, p <0.0001). Adjusted relative risk of 3-year mortality for proximal versus distal LAD was 4.04 (95% confidence interval 1.95 to 8.38). In patients with infarcts related to the right or left circumflex coronary artery, no significant association between lesion location and LVEF or mortality was seen. No difference was seen in adjusted 3-year mortality between distal LAD and non-LAD-related infarcts (p = 0.145). In conclusion, our analysis shows that, even in patients with acute myocardial infarction that is treated with primary PCI, infarcts related to the proximal LAD have the worst 3-year survival and lowest residual LVEF compared with distal LAD or non-LAD-related infarcts.     

Exercise thallium-201 myocardial imaging in left main coronary artery disease: Sensitive but not specific

To determine the usefulness of thallium-201 scintigraphy for identifying left main coronary artery disease, the results of scintigraphy at rest and during exercise were compared in 24 patients with 50 percent or greater narrowing of the left main coronary artery and 80 patients with 50 percent or greater narrowing of one or more of the major coronary arteries but without left main coronary involvement. By segmental analysis of the scintigrams, perfusion defects were assigned to the left anterior descending, left circumflex or right coronary artery, singly or in combination, and the pattern of simultaneous left anterior descending and circumflex arterial defects was used to identify left main coronary artery disease. Of the 24 patients with left main coronary artery disease, 22 (92 percent) had abnormal exercise scintigrams. Despite this high sensitivity, the pattern of perfusion defects was not specific; the “left main pattern” was found in 3 patients (13 percent) with left main coronary artery disease but also in 3 (33 percent) of 9 patients with combined left anterior descending and left circumflex arterial disease, 4 (19 percent) of 21 patients with three vessel disease and 3 (6 percent) of 50 patients with one or two vessel disease but excluding the group with left anterior descending plus left circumflex arterial disease.The pattern of perfusion defects in the patients with left main coronary artery disease was determined by the location and severity of narrowings in the coronary arteries downstream from the left main arterial lesion. Concomitant lesions in other arteries were found in all patients with left main coronary disease (one vessel in 1 patient, two vessels in 7 patients and three vessels in 16). For this reason, it is unlikely that even with improvements in radiopharmaceutical agents and imaging techniques, myocardial perfusion scintigraphy will be sufficiently specific for definitive identification of left main coronary artery disease.     

Natural history of severe proximal coronary artery disease as documented by coronary cineangiography

Studying the natural history of patients with severe proximal coronary arterial lesions may assist evaluation of coronary revascularization surgery. We reviewed the mortality statistics of 469 patients with 80 to 100 percent occlusive lesions in the proximal coronary tree as diagnosed by selective angiography. Only patients with normal or moderately impaired left ventricular function were included in the study; patients with severe cardiomegaly, congestive heart failure or severe left ventricular impairment by left ventriculography were excluded. Follow-up periods ranged from 6 to 11 years for 178 patients with single vessel disease, 177 with double vessel disease and 114 with triple vessel disease. Patients with isolated disease of the left anterior descending artery had a 4 percent average yearly attrition rate or a 6 year mortality rate of 25.5 percent (17 of 69). Those with isolated disease of the right coronary artery demonstrated only a 2.3 percent yearly attrition rate or a 14 percent mortality rate in 6 years (11 of 77). Patients with double and triple vessel disease had, respectively, 41.5 and 63 percent 6 year mortality rates.Survival was related to the number of vessels involved. Patients with single vessel disease of the left anterior descending artery had a significant annual mortality rate. The prognosis improved when good angiographic collateralization was present, particularly in single vessel disease with total occlusion. Functional disability, classified according to the New York Heart Association criteria, was related to mortality rates and proved a useful indicator in large patient groups. Prior myocardial infarction, location of the lesion above or below the major septal perforator in left anterior descending artery disease, and left main trunk lesions did not alter the prognosis significantly.     

Transient prominent anterior QRS forces in the setting ST segment elevation coronary syndrome: Left septal fascicular block

Numerous successive publications have shown that transient prominent anterior QRS forces (PAF) in the setting of acute coronary syndrome (ACS) is suggestive of critical proximal obstruction of left anterior descending coronary artery (LAD) before its first septal perforator branch (S₁). Transient ischemia of the left septal fascicle resulting in left septal fascicular block has been proposed as the causative mechanism. We present a case of acute inferior ST-elevation myocardial infarction caused by acute proximal occlusion of the right coronary artery associated with proximal critical obstruction of the left anterior descending coronary artery.     

Myocardial infarction caused by electric injury. Value of coronarography

The authors report the case of a 54 year old surgeon who received an electric shock from his diathermy equipment. The shock caused an anteroseptal myocardial infarction complicated by an apical aneurysm. The clinical course was followed up by myocardial and cavitary scintigraphy. Coronary arteriography was carried out after convalescence and showed proximal occlusion of the left anterior descending artery and an apical aneurysm on ventriculography. Myocardial infarction after electrical injury is a rare event and its pathogenesis remains controversial. Although electrical currents can damage the walls of the coronary arteries, they may also have a direct thrombogenic effect. This would appear to be the most probable mechanism in the case reported in which the myocardial lesions corresponded to acute occlusion of the left anterior descending artery, perhaps favoured by the presence of an atheromatous plaque. Coronary arteriography was the most helpful investigation in assessing the physiopathology of this rare event.     

Transient right axis deviation with left posterior hemiblock and junctional rhythm during acute myocardial infarction

One of the most common causes of hemiblocks is coronary artery disease, and there is a particularly frequent association between anteroseptal myocardial infarction and left anterior hemiblock. Changing Axis Deviation has been reported during acute myocardial infarction also associated with atrial fibrillation. Isolated left posterior hemiblock is a very rare finding but the evidence of transient right axis deviation with a left posterior hemiblock pattern has been reported during acute anterior myocardial infarction as related with significant right coronary artery obstruction and collateral circulation between the left coronary system and the posterior descending artery. We present a case of transient changing axis deviation, transient right axis deviation, transient left posterior hemiblock pattern and transient junctional rhythm too in a 61-year-old Italian man with acute myocardial infarction and a significant left anterior descending coronary artery stenosis.     

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.     

Spontandissektion der Koronararterien: Eine seltene kardiologische Diagnose

A 55-year-old woman who was admitted to hospital with acute chest pain as a case of emergency suffered from an acute anteroseptal myocardial infarction. Four weeks later coronary angiography revealed a long dissection of the left anterior descending artery (LAD) as well as a significant stenosis of the left main and the proximal circumflex. Cardiovascular surgery was done subsequently. In addition to myocardial revascularization using coronary artery bypass grafts a readaptation of the dissecting artery walls and a proximal ligation of the LAD before anastomosis were performed. Clinical data, pathogenesis, and indications for medical and surgical treatment of spontaneous artery dissection are presented.     

Reappearance of anterior QRS forces after coronary bypass surgery: An electrovectorcardiographic study

This report describes the reappearance of anterior QRS electrical forces in six patients after direct coronary arterial bypass surgery. Each patient had severe coronary artery disease including a segmental stenosis of the left anterior descending artery. Revascularization was performed by direct anastomosis of the left Internal mammary artery to the left anterior descending coronary artery and saphenous vein bypass of other stenotic coronary arteries. Preoperative electrocardiograms and vectorcardiograms showed patterns of anterior wall myocardial infarction with absent or diminutive anterior QRS forces. In each case, postoperative studies demonstrated the regeneration of anterior QRS forces within 10 days of operation. Although these patients represent a small percent of those with a preoperative pattern of infarction who undergo coronary revascularization, the findings demonstrate that electrically silent areas of myocardium may be altered and are not always synonymous with myocardial cell death. Chronic myocardial ischemia may in certain instances produce electrocardiographic and vectorcardiographic patterns of myocardial infarction that may be reversible upon reestablishment of perfusion to ischemie areas.     

Reciprocal ST depression in acute myocardial infarction.

ST segment depression in leads remote from those showing ST elevation during acute myocardial infarction has been attributed to benign electrical phenomena, distant myocardial ischaemia, or extensive myocardial damage. Eighty four consecutive survivors under 55 years of age with a first transmural myocardial infarction were studied. All patients had exercise tests six weeks after infarction and coronary angiography a mean of three months after infarction. Thirty eight (75%) of the 51 inferior and 19 (58%) of the 33 anterior infarcts showed reciprocal ST depression of greater than or equal to 1 mm during the acute phase. Ten (26%) of the 38 patients with inferior infarcts and reciprocal depression had ST depression in the same leads on exercise. There was concomitant disease of the left anterior descending artery in four (40%) of these 10 patients and in five (18%) of the 28 with inferior infarcts with reciprocal depression but without ST depression in the same leads on exercise. Five (26%) of the 19 patients with anterior infarcts with associated reciprocal depression and four of the 14 without reciprocal depression had important right coronary artery disease. In patients with inferior infarction important disease of the left anterior descending artery could not be predicted by ST depression in particular lead groups. Therefore reciprocal ST depression during acute myocardial infarction does not predict concomitant disease in the coronary artery supplying the reciprocal territory.     

Syncope in association with Prinzmetal variant angina.

A case of Prinzmetal variant angina with transient complete atrioventricular block and syncopal episodes following an anteroseptal myocardial infarction is described. The syncopal attacks were not prevented by demand cardiac pacing and were presumably caused by transient severe ischaemia of the left ventricle, with a consequent reduction in cardiac output. The left ventriculogram showed a large anterior dyskinetic area corresponding to the high grade proximal obstruction in the left anterior descending artery demonstrated by coronary angiography. All other coronary vessels appeared free of disease and it is suggested that the anginal episodes were caused by transient proximal segmental spasm of the right coronary artery. The anginal episodes were successfully prevented by a regimen of two-hourly coronary arterial vasodilator therapy.     

Electrocardiographic, arteriographic and ventriculographic correlations in transmural myocardial infarction

To determine if significant interrelations exist between the electrocardiographic diagnosis of transmural myocardial infarction, sites of coronary arterial obstruction, and left ventricular asynergy, 235 patients with angiographically documented coronary artery disease were subdivided according to the electrocardiographic location of the myocardial infarction, the coronary arterial system involved and the site of ventricular asynergy. Of 82 instances of anterior myocardial infarction, the left anterior descending artery demonstrated significant disease in 79 (96 percent). Of 100 instances of inferior myocardial infarction, the right coronary artery was significantly diseased in 87 and the left circumflex in 55. When multiple infarctions were present, multivessel disease was found in 93 percent of patients. Left ventricular asynergy was present in 81 percent, including 84 percent of those with anterior infarction, 74 percent of those with inferior infarction, and 93 percent of those with multiple infarctions. The results of our study suggest that the electrocardiogram is often of value in indicating sites of coronary arterial obstruction and ventricular asynergy in patients with coronary artery disease and transmural myocardial infarction.     

Reciprocal ST depression in acute myocardial infarction

ST segment depression in leads remote from those showing ST elevation during acute myocardial infarction has been attributed to benign electrical phenomena, distant myocardial ischaemia, or extensive myocardial damage. Eighty four consecutive survivors under 55 years of age with a first transmural myocardial infarction were studied. All patients had exercise tests six weeks after infarction and coronary angiography a mean of three months after infarction. Thirty eight (75%) of the 51 inferior and 19 (58%) of the 33 anterior infarcts showed reciprocal ST depression of greater than or equal to 1 mm during the acute phase. Ten (26%) of the 38 patients with inferior infarcts and reciprocal depression had ST depression in the same leads on exercise. There was concomitant disease of the left anterior descending artery in four (40%) of these 10 patients and in five (18%) of the 28 with inferior infarcts with reciprocal depression but without ST depression in the same leads on exercise. Five (26%) of the 19 patients with anterior infarcts with associated reciprocal depression and four of the 14 without reciprocal depression had important right coronary artery disease. In patients with inferior infarction important disease of the left anterior descending artery could not be predicted by ST depression in particular lead groups. Therefore reciprocal ST depression during acute myocardial infarction does not predict concomitant disease in the coronary artery supplying the reciprocal territory.     

Inferolateral ST Elevation as a First Sign of Left Anterior Descending Artery Occlusion

Combined anterior and inferior ST elevation due to occlusion of wrapped left anterior descending artery (LAD) is well reported in the literature. However, there is rare literature mentioned about inferolateral ST elevation in this patient group. Herein, we report a case of acute proximal wrapped LAD occlusion with initial electrocardiographic sign of inferolateral ST elevation. The most likely mechanism of this electrocardiographic finding might be related to old anteroseptal myocardial infarction, combination with other coronary abnormality, such as chronic total occlusion of left circumflex artery that caused larger injury current in inferolateral than anteroseptal myocardium, and made anteroseptal leads reveal isoelectric pattern. Ann Noninvasive Electrocardiol 2010;15(1):90–93     

Electrocardiographic prediction of the site of lesion in the anterior descending artery in acute myocardial infarction

INTRODUCTION AND OBJECTIVES: The goal of this study was to analyze the value of electrocardiography in predicting the site of the lesion in the left anterior descending coronary artery, in relation to the first septal and the first diagonal branches, in patients with acute anterior myocardial infarction. METHOD: Ninety consecutive patients who were admitted to the coronary unit with acute anterior myocardial infarction from July 1998 to May 2000 were studied retrospectively. The electrocardiographic changes were analyzed and correlated with the site of the lesion in the anterior descending artery, as determined by coronary angiography. RESULTS: The most useful parameters in predicting the site of the lesion in the left anterior descending coronary artery in acute anterior myocardial infarction are: 1) For lesions proximal to the first septal branch, ST-segment elevation in aVR (p < 0.001) and the absence of Q wave in V4-V6 (p = 0.01). 2) For lesions proximal to the first diagonal branch, abnormal Q wave in aVL (p = 0.01) and ST depression in III (p = 0.05). 3) For lesions proximal to both the first septal and first diagonal branches, ST elevation in aVR (p < 0.001), abnormal Q wave in aVL (p = 0.02), and absence of Q wave in V4-V6 (p = 0.01). 4) For lesions distal to both the first septal and first diagonal branches, abnormal Q wave in V4-V6 (p = 0.001) and absence of ST depression in III (p < 0.001). CONCLUSIONS: In acute anterior myocardial infarction, electrocardiography is useful for predicting the site of the lesion in the left anterior descending coronary artery in relation to the first septal and the first diagonal branches.