Clinical implications of precordial ST-segment elevation in acute inferoposterior myocardial infarction caused by proximal right coronary artery occlusion

Assessment of validity of the 'Culprit Score' for predicting the culprit lesion in patients with acute inferior wall myocardial infarction

INTRODUCTION

Many electrocardiographic criteria have been developed to determine the infarct-related artery in acute inferior wall myocardial infarction. The aim of this study was to test the commonly used criteria and devise a simplified score to further improve the diagnostic accuracy.

MATERIALS AND METHODS

From 2011 to 2013, 100 patients with acute inferior wall myocardial infarction were recruited for electrocardiographic and angiographic analyses.

RESULTS

The mean age of the patients was 65±12 years with 74% of patients being male. In our study population, significantly more ST-segment depression was seen in lead aVL and ST elevation in lead III in those with right coronary artery (RCA) occlusions. In left circumflex artery (LCX) occlusions, significantly more ST depression was seen in leads V1-3 (most significantly in lead V2) and ST elevation in lead II. In addition, more prominent ST depression was seen in lead aVL and ST elevation in V1 in proximal RCA occlusions. Based on the findings, we devised a score named Culprit Score, which was defined as [II-V2/III+V1-aVL]. The sensitivity and specificity of Culprit Score ≤0.5 to predict proximal RCA occlusions; 0.5 to ≤1.5 to predict distal RCA occlusions; and score >1.5 to predict LCX occlusions were 85% and 85%; 80% and 86%; and 80% and 94%, respectively. Similarly, the negative predictive value was more than 80%.

CONCLUSION

The Culprit Score was found to have high specificity and negative predictive value to identify the infarct-related artery in inferior wall myocardial infarction.

Proximal complete occlusion of right coronary artery presenting with precordial ST-segment elevation: A case report

BACKGROUND

It is well known that cardiologists empirically judge the culprit lesion of acute ST-segment elevation myocardial infarction (STEMI) according to the corresponding electrocardiographic leads. However, In addition to the obstruction of left anterior descending (LAD) coronary artery, rare cases with the occlusion of proximal right coronary artery (RCA) and/or isolated right ventricular (RV) branch showed the ST-segment elevation in precordial leads V1-V3 as well.

CASE SUMMARY

We reported a patient complaining of acute chest pain and suffering ventricular fibrillation (VF) on admission. The electrocardiogram (ECG) showed mild ST-segment elevation in precordial leads V1-V3 and V4R. Bedside echocardiography displayed normal left ventricular ejection fraction and slight RV dilation. Proximal occlusion of nondominant RCA was confirmed by coronary angiography and urgent percutaneous coronary intervention (PCI) to RCA successfully resolved the chest pain and ST-segment elevation.

CONCLUSION

Undoubtedly, coronary angiography is usually the definite measurement for the diagnosis of culprit lesion. However, bedside echocardiography, ST-segment features in left and right precordial leads, and heart rate will be the additional information for judging ST-segment elevation in precordial leads V1-V3 resulting from occlusion of RCA or LAD.

Precordial ST-Segment Elevation Caused by Proximal Occlusion of a Non-Dominant Right Coronary Artery

For patients with ST-segment elevation myocardial infarction, primary percutaneous coronary intervention to the culprit lesion via electrocardiographic guidance is essential. We herein report the rare case of a 49-year-old man who presented with ST-segment elevation in the precordial leads, while coronary angiography results indicated total occlusion of the proximal non-dominant right coronary artery. We evaluated its possible pathophysiologic mechanisms and thoroughly discussed isolated right ventricular infarction and its electrocardiography findings.

KEY WORDS

Coronary angiography; Myocardial infarction; Total occlusions.

Jeopardised Inferior Myocardium (JIM) Score: An Arithmetic Electrocardiographic Score to Predict the Infarct-Related Artery in Inferior Myocardial Infarction

Introduction: A few electrocardiographic criteria have been described to identify the infarct-related artery in inferior myocardial infarction. The aim of this study was to devise an arithmetic score to further improve the diagnostic accuracy. Materials and Methods: From 2004 to 2006, 78 patients who underwent primary angioplasty for inferior myocardial infarction within 6 hours from symptom onset were recruited for electrocardiographic and angiographic analysis. Results: The mean age of patients was 65 ± 12 years with male predominance (74%). Less ST depression in lead I and aVL, and more prominent ST depression in lead V1-3 were observed in left circumflex artery (LCX) than right coronary artery (RCA) occlusions. In addition, more prominent ST depression in lead I and ST elevation in V1 were found in proximal RCA than distal RCA occlusions. Based on the findings, the Jeopardised Inferior Myocardium (JIM) score was constructed and defined as [II–V3/III+V1– I]. The sensitivity and specificity of JIM score ≤0.5 to predict proximal RCA occlusions; 0.5 <JIM score ≤1.5 to predict distal RCA occlusions; and JIM score >1.5 to predict LCX occlusions were 58% and 85%, 69% and 68%, and 79% and 94%, respectively. The accuracy of prediction is slightly better than the 2 previously reported criteria. Conclusion: By taking into account more leads, the JIM score is capable of identifying the infarct-related artery with an improved diagnostic accuracy. Key words: Coronary angiography, Electrocardiography

Acute Myocardial Infarction by Right Coronary Artery Occlusion Presenting as Precordial ST Elevation on Electrocardiography

It is rare to observe ST-segment elevation in only the anterior leads and not the inferior leads during right coronary artery occlusion. We describe a case with acute myocardial infarction (MI) by right coronary artery occlusion who developed ST-segment elevation only in the precordial leads V1 to V3.

Dominant right coronary artery occlusion entailing diffuse ST-segment elevation in the precordial leads

Right ventricular infarction (RVI) during inferior myocardial infarction (MI) is readily diagnosed when ST-segment elevation (STE) is recorded in lead V4R. RVI may also yield precordial STE and such an electrocardiographic (ECG) pattern may be misinterpreted as a sign of anterior MI. We present a case of inferior-right ventricular (RV) MI due to occlusion of a dominant right coronary artery manifesting STE in the inferior, all precordial and right chest leads. RV dilation due to acute ischemic insult facilitated STE in leads V1-V4 despite the dominant opponent inferior and posterolateral left ventricular injury current. This case illustrates that dilation of an infarcted RV should be considered when such an ECG pattern is encountered during inferior MI, specifically a dominant one. Awareness of the circumstances under which this ECG pattern develops facilitates avoidance of misinterpretation as a sign of anterior MI and proper management.

Angiographic and clinical implications of combined ST-segment elevation in anterior and inferior leads in acute myocardial infarction

BACKGROUND

The clinical and angiographic findings of patients suffered from acute myocardial infarction (MI) and presented with combined ST elevation in both anterior and inferior leads remain unclear.

HYPOTHESIS

These patients might have >/= 1 coronary arteries occluded.

METHODS

From January 2002 to December 2006, 49 consecutive patients were found to have ST elevation in both anterior and inferior leads during myocardial infarction. Patients who had left circumflex artery occlusion (acute or chronic) were excluded. These patients were divided into 4 types according to the infarct-related artery (IRA) and status of the contralateral vessel patency: left anterior descending artery (LAD) as the IRA with a patent right coronary artery (RCA) (type 1A, n = 25); LAD as IRA with an occluded RCA (type 1B, n = 1); RCA as IRA with a patent LAD (type 2A, n = 19); and RCA as IRA with an occluded LAD (type 2B, n = 4).

RESULTS

Single vessel occlusion (type A angiographic pattern) was found in 90% of patients. Type 1A patients had a larger infarct size than that of 2A. ST elevation in V(2) >/= V(3) identified RCA as the IRA with a high specificity (92%) and sensitivity (74%). Type 2B patients (2-vessel occlusion) had a larger infarct size than that of 2A; however, no electrocardiogram (ECG) criteria could reliably differentiate them.

CONCLUSION

In a real world situation, single vessel occlusion is found in the majority of cases of combined ST elevation in anterior and inferior leads. ST elevation in V(2) >/= V(3) distinguishes RCA against LAD as the IRA with high accuracy.