Electrocardiographic differentiation of occlusion of the left circumflex versus the right coronary artery as a cause of inferior acute myocardial infarction

Bairey, C N; Shah, Prediman K.; Lew, Allan S.; Hulse, Sharon

doi:10.1016/0002-9149(87)90285-2

Cited by 109 publications

(39 citation statements)

References 6 publications

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“…For this reason, the ST segment may be elevated to a greater extent in lead II than in lead III and may be isoelectric or elevated in leads 1 and aVL. 28 When a dominant RCA is occluded proximally, left posterolateral and right ventricular wall involvement will be present, and the posteriorly directed ST-segment vector associated with this involvement may cancel the ST-segment elevation in lead V 1 anticipated by right ventricular involvement and vice versa.…”

Section: Recommendationsmentioning

confidence: 99%

AHA/ACCF/HRS Recommendations for the Standardization and Interpretation of the Electrocardiogram

Wagner¹,

Macfarlane²,

Wellens³

et al. 2009

Circulation

170

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his is the sixth and final section of the project to update electrocardiography (ECG) standards and interpretation. The project was initiated by the Council on Clinical Cardiology of the American Heart Association (AHA). The rationale for the project and the process for its implementation were described in a previous publication. 1 The ECG is considered the single most important initial clinical test for diagnosing myocardial ischemia and infarction. Its correct interpretation, particularly in the emergency department, is usually the basis for immediate therapeutic interventions and/or subsequent diagnostic tests. The ECG changes that occur in association with acute ischemia and infarction include peaking of the T waves, referred to as hyperacute T-wave changes, ST-segment elevation and/or depression, changes in the QRS complex, and inverted T waves.The ST-segment changes are produced by the flow of currents, referred to as "injury currents," that are generated by the voltage gradients across the boundary between the ischemic and nonischemic myocardium during the resting and plateau phases of the ventricular action potential, which correspond to the TQ and ST segments of the ECG. 2,3 Current guidelines suggest that when these ST-segment shifts reach Other members of the Standardization and Interpretation of the Electrocardiogram Writing Group include

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Section: Recommendationsmentioning

confidence: 99%

AHA/ACCF/HRS Recommendations for the Standardization and Interpretation of the Electrocardiogram

Wagner¹,

Macfarlane²,

Wellens³

et al. 2009

Circulation

170

View full text Add to dashboard Cite

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“…8 Conversely, IWMI due to LCx occlusion produces an ST-segment vector directed toward the left (lead II). In this case, ST-segment elevation in lead III is not greater than that in lead II, and there is an isoelectric or elevated ST segment in lead aVL 9,10 ( Figure 3). Associated STsegment depression in leads V 1 and V 2 in a case of IWMI suggests concomitant posterior wall MI, which is usually caused by LCx occlusion but may also be seen in dominant RCA occlusion.…”

Section: = Left Ventricle Electrocardiographic Localization Of Infmentioning

confidence: 86%

Electrocardiographic localization of infarct related coronary artery in acute ST elevation myocardial infarction

Rajasekhar

Vanajakshamma

2013

JCSR

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Myocardium is usually supplied by three coronary arteries, although there are several variations in the number, origin, course and distribution of coronary arteries. Major contribution to left ventricular myocardial blood flow is by left anterior descending coronary artery (LAD) (50%), rest is equally contributed by right coronary artery (RCA) and left circumflex artery (LCx). In addition, most of the right ventricle is supplied by RCA. The need for a rapid reperfusion therapy is largely determined by how close the occlusion site is to the origin of the coronary artery, which corresponds to the area of ischaemic myocardium.Each artery contributes its blood supply to specific regional areas in the heart. These areas are topographically represented by the following groups of leads: 1 (Table 1). MYOCARDIAL DISTRIBUTION OF THREE MAIN CORONARY ARTERIES Left anterior descending arteryThe LAD travels along the anterior interventricular groove towards the apex of the heart. The major branches of LAD are septal and diagonal branches.The septal branches arise perpendicularly from the LAD and pass into the interventricular septum. The diagonal branches of the LAD course over the anterolateral aspect of the heart. Considerable variations exist in the number and size of the diagonal branches. In most (80%) patients, the LAD courses around the apex of the left ventricle and terminates along the diaphragmatic aspect of the left ventricle. In the remaining patients, the LAD terminates either at or before the cardiac apex. In these patients, the left ventricular apical portion is supplied by the posterior descending branch (PDA) of the RCA or LCx, which is larger and longer than usual. Left circumflex arteryThe LCx artery passes within the left atrioventricular groove toward the inferior interventricular groove. The LCx artery is the dominant vessel in 15% of patients, supplying the left PDA from the distal continuation of the LCx. In the remaining patients, the distal LCx varies in size and length, depending on the number of posterolateral branches supplied by the distal RCA. The major ABSTRACTThe electrocardiogram (ECG) remains a crucial tool in the identification and management of acute myocardial infarction (MI). A detailed analysis of patterns of ST-segment elevation may influence decisions regarding the use of reperfusion therapy. The early and accurate identification of the infarct-related artery on the ECG can help predict the amount of myocardium at risk and guide decisions regarding the urgency of revascularization. The specificity of the ECG in acute MI is limited by individual variations in coronary anatomy as well as by the presence of preexisting coronary artery disease, particularly in patients with a previous MI, collateral circulation, or previous coronary-artery bypass surgery. The ECG is also limited by its inadequate representation of the posterior, lateral, and apical walls of the left ventricle. Despite these limitations, the electrocardiogram can help in identifying proximal occlusion of the coronary arte...

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“…[6] Thus we conclude that age is the most important risk factor for atherosclerosis which can lead to various cardiovascular diseases. Various studies [12][13][14] recommend that the most important factors which contribute to the disease are hypertension followed by smoking. In this study we found that hypertension accounts for the disease in 54.6% of patients followed by smoking in 39% and dyslipidaemia in 20.7% of patients.…”

Section: Discussionmentioning

confidence: 99%

An Observational Study to Identify the Role of ECG in Locating the Occluded Vessel in Patients of Myocardial Infarction with Angiographic Correlation

Singhal¹,

Singhal²,

Singh³

2016

AIMDR

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Background: The electrocardiography (ECG) is considered as a fundamental tool in identifying the location and managing the symptoms of acute myocardial infarction. The aim of the present study is to study different ECG patterns according to the vessel involved and then it is correlated with the angiographic findings. Methods: It is a prospective and observational study conducted on 50 patients suffering from myocardial infarction with elevated ST segment in ECG who subsequently underwent coronary angiography. Based on the various ECG criteria the vessel involved was recognized and then correlated with angiographic findings. The sensitivity and specificity of individual parameters were calculated. Results: The present study demonstrated that ST depression in inferior leads >1mm had maximum sensitivity and specificity in localizing the position of occlusion proximal to S1. Presence of Q wave in aVL had maximum sensitivity and ST depression in the inferior leads showed extreme specificity in patients with occlusion proximal to D1. Presence of Q wave in V4-V6 had 95% specificity and Absence of inferior ST depression presented 89% sensitivity in patients with occlusion in distal S1. Presence of ST depression in aVL showed 98% specificity in patients with distal D1 occlusion. In patients with right coronary artery, ST elevation in LIII>ST elevation in LII and in case of left circumflex occlusion, ST ↑elevation in LII > LIII is the parameter with highest sensitivity and specificity. Conclusion: The ECG in patients with ST elevation myocardial infarction is important not only for defining which patient should receive early reperfusion treatment, but also for deciding the site and degree of acute myocardial injury.

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Electrocardiographic differentiation of occlusion of the left circumflex versus the right coronary artery as a cause of inferior acute myocardial infarction

Cited by 109 publications

References 6 publications

AHA/ACCF/HRS Recommendations for the Standardization and Interpretation of the Electrocardiogram

AHA/ACCF/HRS Recommendations for the Standardization and Interpretation of the Electrocardiogram

Electrocardiographic localization of infarct related coronary artery in acute ST elevation myocardial infarction

An Observational Study to Identify the Role of ECG in Locating the Occluded Vessel in Patients of Myocardial Infarction with Angiographic Correlation

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