https://www.internationaljournalofcardiology.com/article/S0167-5273(07)01968-7/pdf

Value of the 12-lead electrocardiogram to define the level of obstruction in acute anterior wall myocardial infarction: correlation to coronary angiography and clinical outcome in the DANAMI-2 trial

Background: Lead aVR is a neglected, however, potentially useful tool in electrocardiography. Our aim was to evaluate its value in clinical practice, by reviewing existing literature regarding its utility for identifying the culprit lesion in acute myocardial infarction (AMI). Methods: Based on a systematic search strategy, 16 studies were assessed with the intent to pool data; diagnostic test rates were calculated as key results. Results: Five studies investigated if ST-segment elevation (STE) in aVR is valuable for the diagnosis of left main stem stenosis (LMS) in non–ST-segment AMI (NSTEMI). The studies were too heterogeneous to pool, but the individual studies all showed that STE in aVR has a high negative predictive value (NPV) for LMS. Six studies evaluated if STE in aVR is valuable for distinguishing proximal from distal lesions in the left anterior descending artery (LAD) in anterior ST-segment elevation AMI (STEMI). Pooled data showed a sensitivity of 47%, a specificity of 96%, a positive predicative value (PPV) of 91% and a NPV of 69%. Five studies examined if ST-segment depression (STD) in lead aVR is valuable for discerning lesions in the circumflex artery from those in the right coronary artery in inferior STEMI. Pooled data showed a sensitivity of 37%, a specificity of 86%, a PPV of 42%, and an NPV of 83%. Conclusion: The absence of aVR STE appears to exclude LMS as the underlying cause in NSTEMI; in the context of anterior STEMI, its presence indicates a culprit lesion in the proximal segment of LAD. Ann Noninvasive Electrocardiol 2009;14(3):219–225

Utility of Lead aVR for Identifying the Culprit Lesion in Acute Myocardial Infarction

Background: Rapid identification of a proximal occlusion site of a major coronary artery is of paramount importance in the care of myocardial infarction (MI). It is increasingly recognized that routine electrocardiogram (ECG) can be used for that purpose, provided that expert interpretation is available. Computer-based signal analysis has potential to enhance early ECG interpretation but its performance must be validated against manual algorithms. We therefore set out to develop a computer-assisted model to detect proximal occlusion of the left anterior descending coronary artery (LAD) in patients with suspected acute coronary syndrome (ACS).



Methods: Based on manual anatomical interpretation of the ECG, obtained from 216 consecutive patients who were admitted due to suspected ACS, an automatic computerized ECG model to detect LAD occlusion was constructed. Agreement between manual evaluation of the ECG by two cardiologists and a computerized ECG algorithm to detect occlusion of the LAD and the site of occlusion was determined.



Results: Using an expert electrocardiographer's anatomical interpretation as the gold standard, the computer model recognized patients fulfilling ECG criteria for any occlusion of the LAD with a specificity of 99% and a sensitivity of 67% (κ= 0.71). However, proximal LAD occlusion was detected with 100% specificity and 86% sensitivity (κ= 0.72). The computer program detected a distal occlusion in the LAD with a specificity of 99% and a sensitivity of 40% (κ= 0.72).



Conclusions: Computerized anatomical interpretation of the ECG is feasible and allows detection of a proximal LAD occlusion with excellent accuracy.

/pdf/detection-of-proximal-coronary-occlusion-in-acute-coronary-3kvqymevg6.pdf

Detection of proximal coronary occlusion in acute coronary syndrome: a feasibility study using computerized electrocardiographic analysis.

.............................................................................................................................5 TIIVISTELMÄ (ABSTRACT IN FINNISH) ..........................................................................7 ABBREVIATIONS................................................................................................................. 12 LIST OF ORIGINAL COMMUNICATIONS ...................................................................... 13 INTRODUCTION .................................................................................................................. 14 REVIEW OF THE LITERATURE ....................................................................................... 16 1. ST-ELEVATION MYOCARDIAL INFARCTION...................................................................... 16 1.1 Definition................................................................................................................... 16 1.2 Prognosis................................................................................................................... 17 1.3 Risk stratification of patients...................................................................................... 17 1.3.1 TIMI risk score.................................................................................................. 18 2. ECG PRESENTATIONS IN ACUTE STEMI ......................................................................... 19 2.1 T wave ....................................................................................................................... 20 2.2 ST segment................................................................................................................. 20 2.3 Localization of infarction ........................................................................................... 23 2.4 Reciprocal changes.................................................................................................... 23 2.5 Attenuation phenomenon............................................................................................ 24 2.6 Grade of ischemia ...................................................................................................... 25 2.7 Dynamic ECG changes during reperfusion and infarct process.................................. 26 2.7.1 T wave .............................................................................................................. 26 2.7.2 ST segment........................................................................................................ 27 2.7.3 Q wave .............................................................................................................. 28 2.7.4 ST-T patterns..................................................................................................... 28 2.7.5 Pre-infarction syndrome .................................................................................... 29 2.7.6 Evolving myocardial infarction.......................................................................... 30 3. ANATOMICAL INTERPRETATION OF ECG IN ANTERIOR STEMI ........................................ 31 3.1 Principles................................................................................................................... 31 3.2 Site of lesion............................................................................................................... 32 4. ECG IN RISK STRATIFICATION ........................................................................................ 35 4.1 Prognostic value of infarct location............................................................................ 35 4.2 Site of culprit lesion ................................................................................................... 37 4.3 Sum of ST deviation.................................................................................................... 38 4.4 Grade of ischemia ...................................................................................................... 39 4.5 Pre-infarction syndrome and evolving myocardial infarction ..................................... 40 5. COMPUTERIZED ECG ANALYSIS IN STEMI..................................................................... 40 5.1 Accuracy of computer-interpreted ECG ..................................................................... 41 5.2 Value of selecting patients for reperfusion therapy..................................................... 42 6. TRANSMISSION OF ECG DATA ........................................................................................ 42 7. REPERFUSION THERAPY IN STEMI ................................................................................. 43 7.1 Fibrinolytic therapy ................................................................................................... 44 7.1.1 Limitations of fibrinolytic therapy ..................................................................... 45 7.1.2 Pre-hospital fibrinolysis..................................................................................... 46

Use of the 12-lead Electrocardiogram in Selecting Reperfusion Therapy for St-elevation Myocardial Infarction

Proximal occlusion of the left anterior descending coronary artery (LAD) results in a less favorable prognosis in coronary angiography. Therefore, it is important to determine whether there are significant lesions in LAD by electrocardiography (ECG) before coronary angiography. Twelve-lead ECG was compared in 130 patients with significant lesions (≥70% stenosis) confined to proximal part of the LAD (P LAD group) and 492 patients with normal coronary angiography (control group). Fifty-nine patients in the P LAD group and 18 patients in the control group had signs of anterior myocardial infarction as shown by ST elevation (≥1.0 mV) in two consecutive pericardial leads or the presence of a pathological Q wave. An inverted U wave (biphasic T wave) in leads V1 to V4 had a sensitivity of 49.3% (35/71) in P LAD patients without signs of anterior myocardial infarction (MI) and 96.6 % (57/59; specificity, 66.6%; positive predictive value, 90.9 %) in the P LAD patients with signs of anterior MI. In the P LAD patients with signs of anterior MI, T inversion in V4–V5 had a lower sensitivity (67.0% [40/59]) than an inverted U wave. ST depression in inferior leads and ST depression in V5 were not useful markers of proximal LAD occlusion. In conclusions, an inverted U wave in V1 to V4 (or in each of these leads) and T inversion in V4–V5 are the best predictors of significant proximal LAD lesion, especially in patients with ECG findings of anterior MI.

Electrocardiographic predictors of proximal left anterior descending coronary artery occlusion

The complications, therapy and prognosis are significantly determined by the exact location of occlusion site in left anterior descending (LAD) coronary artery in anterior acute myocardial infarction (AMI). This study assessed the role of Electrocardiogram (ECG) as a predictor of coronary artery occlusion site in anterior AMI. Sixty two patients of anterior AMI were divided into two groups according to the occlusion site in relation to first septal and first diagonal branches, proximal--group A and distal--group B. Their initial ECG were analyzed and interpreted. The number of patients having ST elevation in leads aVR and aVL (> or = 0.5 mm) were significantly higher in proximal group compared to distal ones (42.3% vs 2.8% and 73.1% vs 22.2%; p or = 1 mm), III (> or = 1 mm) and aVF (> or = 1 mm) were also significantly higher in proximal group (84.6% vs 22.2%, 88.5% vs 33.3% and 84.6% vs 22.2%; p or = 1 mm), III (> or = 1 mm) and aVF (> or = 1 mm) to predict the proximal lesion were 85.0%, 88.0% and 85.0% respectively, whereas specificity were 78.0%, 67.0% and 78.0% respectively. The ST elevation in a VR had 42.0% sensitivity and 97.0% specificity to predict proximal lesion. Similarly ST elevation in aVL (> or = 0.5 mm) had 73% sensitivity and 78% specificity. In anterior AMI, ST elevation in aVR, aVL and ST depression in inferior leads can predict the occlusion site in LAD proximal to first diagonal and first septal branch.

Chandeshwar Yadav

Papers

Electrocardiographic prediction of left anterior descending coronary artery occlusion site in acute anterior myocardial infarction.