Combined prognostic utility of ST segment in lead aVR and troponin T on admission in non-ST-segment elevation acute coronary syndromes

aVR: The forgotten lead in acute coronary syndrome: A case series

Lead aVR is often considered as a neglected lead or forgotten lead owing to its reciprocal location to the lateral leads. However, it has diagnostic and prognostic importance in cases of acute coronary syndromes. We present a series of four cases of acute coronary syndrome with ST elevation (STE) in aVR and critical stenosis in coronary vessels. Patients with STE in aVR have a poor prognosis with increased morbidity not limited to increased chances of heart failure at presentation, greater hemodynamic instability, and in-hospital acute kidney injury, as well as increased mortality due to large infarction areas. Thus, early revascularization is warranted in such cases.

The prognostic effect of ST-elevation in lead aVR on coronary artery disease, and outcome in acute coronary syndrome patients: a systematic review and meta-analysis

BACKGROUND

Rapid diagnosis of coronary artery disease has an important role in saving patients. The aim of this study is to evaluate if aVR lead ST-elevation (STE) can predict LM/3VD, left main (LM) disease, and three-vessel disease (3VD), outcome in acute coronary syndrome (ACS) patients.

METHODS

In this systematic review and meta-analysis, 45 qualified studies were entered. Scopus, Pub med, Google scholar, Web of science, Cochrane library were searched on 12 November 2021.

RESULTS

This systematic review includes 52,175 participants. In patients with STE, the total odds ratios for LM, 3VD, and LM/3VD were 5.48 (95% CI 3.88, 7.76), 2.21 (95% CI 1.78, 3.27), and 6.21 (95% CI 3.49, 11,6), respectively. STE in lead aVR was linked with in-hospital death (OR = 2.99, CI 1.90, 4.72) and 90-day mortality (OR = 3.09, CI 2.17, 4.39), despite the fact that it could not predict 30-day mortality (OR = 1.11, CI 0.95, 1.31). The STE > 1 mm subgroup had the highest sensitivity for LM (0.9, 95% CI 0.82, 0.98), whereas the STE > 0.5 mm (0.76, 95% CI 0.61, 0.90) subgroup had the highest sensitivity for LM/3VD. The appropriate cut-off point with highest specificity for LM/3VD and LM was STE > 1.5 mm (0.80, 95% CI 0.75, 0.85) and STE > 0.5 mm, respectively (0.75, 95% CI 0.67, 0.84, I² = 97%).

CONCLUSION

The odds of LM and LM/3VD were higher than 3VD in ACS patients with STE in lead aVR. Also, STE > 0.5 mm was the best cut-off point to screen LM/3VD, whereas for LM diagnosis, STE > 1 mm had the highest sensitivity. Furthermore, LM/3VD had a higher overall specificity than LM.

Left Main Coronary Artery Disease: The Forgotten Lead of Electrocardiogram Is Predictive

An ST segment depression in eight or more leads along with ST segment elevation in lead aVR or V1, especially occurring during ischemic symptoms, has a very high predictive accuracy of left main or three-vessel disease, or tight proximal left anterior descending (LAD) coronary artery stenosis. We describe a classic case of a patient who presented with ST elevation in the lead aVR with diffuse ST segment depression during anginal symptoms and was found to have severe disease in the distal left main, ostial circumflex, and left anterior descending artery on an emergent coronary angiogram. 

Lead aVR predicts early revascularization but not long-term events in patients referred for stress electrocardiography

BACKGROUND

Exercise stress electrocardiography (ExECG) is recommended as a first-line tool to assess ischemia, but standard ST-analysis has limited diagnostic accuracy. ST elevation in lead aVR has been associated with left main and LAD disease in the population undergoing coronary angiography but has not been studied in the general population undergoing stress testing for the initial evaluation of CAD without coronary angiography. We sought to determine the predictive value of lead aVR elevation for ischemia, early revascularization, and subsequent cardiac events in consecutive patients undergoing ExECG.

METHODS AND RESULTS

The study cohort included 641 subjects referred for ExECG who were dichotomized by presence or absence of aVR elevation ≥1mm and compared for prevalence and predictors of ischemia and a composite of cardiac death, nonfatal myocardial infarction, and late revascularization. The cohort had a median age of 57 and 57% were male. The prevalence of aVR elevation was 11.5%. The prevalence of significant ischemia on patients who received imaging was significantly higher with aVR elevation (14.3% vs 2.3%, p<0.001). Early revascularization occurred in 10.9% with vs 0.2% without aVR elevation, p<0.001. No subjects without aVR elevation or ST-depression underwent early revascularization. However, cardiac event rates were similar over a median 4.0 years of follow-up with and without aVR elevation (2.8% vs. 2.6%, p = 0.80). aVR elevation did not predict long-term cardiac events by Kaplan-Meier survival analysis (p = 0.94) or Cox proportional hazards modeling (p = 0.35).

CONCLUSIONS

aVR elevation during ExECG predicts ischemia on imaging and early revascularization but not long-term outcomes and could serve as a useful adjunct to standard ST-analysis and potentially reduce the need for concurrent imaging.

Prognostic implications of ST-segment elevation in lead aVR in patients with acute coronary syndrome: A meta-analysis

BACKGROUND

ST-segment elevation (STE) in lead aVR is a useful tool in recognizing patients with left main or left anterior descending coronary obstruction during acute coronary syndrome (ACS). The prognostic implication of STE in lead aVR on outcomes has not been established.

METHODS

We performed a systematic search for clinical studies about STE in lead aVR in four databases including PubMed, EMBASE, Cochrane Library, and Web of Science. Primary outcome was in-hospital mortality. Secondary outcomes included in-hospital (re)infarction, in-hospital heart failure, and 90-day mortality.

RESULTS

We included 7 studies with a total of 7,700 patients. The all-cause in-hospital mortality of patients with STE in lead aVR during ACS was significantly higher than that of patients without STE (OR: 4.37, 95% CI 1.63 to 11.68, p = .003). Patients with greater STE (>0.1 mV) in lead aVR had a higher in-hospital mortality when compared to lower STE (0.05-0.1 mV) (OR: 2.00, 95% CI 1.11-3.60, p = .02), However, STE in aVR was not independently associated with in-hospital mortality in ACS patients (OR: 2.72, 95% CI 0.85-8.63, p = .09). The incidence of in-hospital myocardial (re)infarction (OR: 2.77, 95% CI 1.30-5.94, p = .009), in-hospital heart failure (OR: 2.62, 95% CI 1.06-6.50, p = .04), and 90-day mortality (OR: 10.19, 95% CI 5.27-19.71, p < .00001) was also noted to be higher in patients STE in lead aVR.

CONCLUSIONS

This contemporary meta-analysis shows STE in lead aVR is a poor prognostic marker in patients with ACS with higher in-hospital mortality, reinfarction, heart failure and 90-day mortality. Greater magnitude of STE portends worse prognosis. Further studies are needed to establish an independent predictive role of STE in aVR for these adverse outcomes.

Is isolated ST segment elevation in Lead aVR associated with high grade coronary artery disease?

BACKGROUND

The diagnostic accuracy of lead aVR ST-segment elevation for left main or triple vessel disease (LM/3VD) has not been universally accepted. In the present analysis we sought to evaluate the diagnostic accuracy of STEaVR in patients presenting with an acute coronary syndrome (ACS).

METHODS

Pooled sensitivity, specificity, positive, and negative likelihood ratios were calculated using a random effects model (DerSimonian-Laird Method) for computing summary estimates and receiver operator curve (ROC) analysis for evaluating overall diagnostic accuracy.

RESULTS

This meta-analysis included 14 studies. The pooled sensitivity of STEaVR for LM/3VD was 0.40 (95% CI; 0.38 0.43, p < 0.001), specificity 0.82 (95% CI; 0.81-0.83, p < 0.001). Pooled positive likelihood ratio 2.49 (95% CI; 1.62-3.81, p < 0.001) and negative likelihood 0.54 (95% CI; 0.39-0.76, p < 0.001). The pooled sensitivity of STEaVR for LM was 0.39 (95% CI; 0.34-0.45, p < 0.001) specificity was 0.86 (95% CI; 0.85-0.87, p < 0.001) with an AUC of 0.79. The pooled positive likelihood ratio (LR) for LM was 2.78 (95% CI, 2.28-3.39, p < 0.001) negative likelihood ratio 0.51 (95% CI, 0.33-0.78, p < 0.001).

CONCLUSION

Our study shows that in patients presenting with an ACS, presence of STEaVR may indicate the presence of LM or 3VD. STEaVR has a high specificity for both LM and 3VD, with a high pooled LR.

Value of ST-segment change in lead aVR in diagnosing left main disease in Non-ST-elevation acute coronary syndrome-A meta-analysis

BACKGROUND

Previous researches proved that the ST-segment elevation (STE) in lead aVR had great significance on the prediction of severe left main lesion or serious multivessel lesions. The current research is to summarize the published data and evaluate the overall association of STE in lead aVR and left main coronary artery disease (LMD) in Non-ST-elevation acute coronary syndrome.

METHODS

Literature searching was performed in the online database, and a systematic review was conducted based on the searched results. Meaningful STE in lead aVR was summarized and analyzed for odds ratio (OR) and 95% confidence intervals (95% CI).

RESULTS

Twenty-seven articles were included for final data analysis. Compared with STE < 0.05, STE ≥ 0.05 mV was associated with a higher incidence rate of LMD (OR = 6.64, 95% CI: 4.80 ~ 9.17), and the degree of STE in lead aVR was significantly associated with LMD. Myocardial infarction was more likely to occur in patients with STE ≥ 0.05 mV than in patients with STE < 0.05 mV (OR = 3.12, 95% CI: 1.73 ~ 5.62).

CONCLUSIONS

The STE in lead aVR and the degree of STE are independent predictors in diagnosing LMD or myocardial infarction.

Why complicate an important task? An orderly display of the limb leads in the 12-lead electrocardiogram and its implications for recognition of acute coronary syndrome

Background

In the standard ECG display, limb leads are presented in a non-anatomical sequence: I, II, III, aVR, aVL, aVF. The Cabrera system is a display format which instead presents the limb leads in a cranial/left-to-caudal/right sequence, i.e. in an anatomically sequential order. Lead aVR is replaced in the Cabrera display by its inverted version, −aVR, which is presented in its logical place between lead I and lead II.

Main text

In this debate article possible implications of using the Cabrera display, instead of the standard, non-contiguous lead display, are presented, focusing on its use in patients with possible acute coronary syndrome. The importance of appreciating reciprocal limb-lead ECG changes and the diagnostic and prognostic value of including aVR or lead −aVR in ECG interpretation in acute coronary syndrome is covered. Illustrative cases and ECGs are presented with both the standard and contiguous limb lead display for each ECG.

A contiguous lead display is useful when diagnosing acute coronary syndrome in at least 3 ways: 1) when contiguous leads are present adjacent to each other, identification of ST elevation in two contiguous leads is simple; 2) a contiguous lead display facilitates understanding of lead relationships as well as reciprocal changes; 3) it makes the common neglect of lead aVR unlikely.

Conlusions

It is logical to display the limb leads in their sequential anatomical order and it may have advantages both in diagnostics and ECG learning.

Electrocardiographic changes in patients with acute myocardial infarction caused by left main trunk occlusion

BACKGROUND

Left main trunk (LMT) occlusion is a rare angiographic finding. The primary purpose was to investigate the ECG pattern of patients with angiographic confirmation of LMT as culprit lesion.

METHODS

Forty-eight patients (32 men; mean age 73 years) with angiographic total (21 patients; 44%) or subtotal (27 patients; 56%) occlusion of the LMT were analyzed. Twenty patients (42%) were found to have concomitant coronary lesions. Eighteen patients (38%) required intra-aortic balloon pump support.

RESULTS

A significant left axis deviation was observed in 26 cases (54%) and an intraventricular conduction delay in 32 patients (67%). The average QRS width and QTc interval were 122 and 433 ms, respectively. ST-segment elevation in lead aVR occurred in 32 patients (67%). ST-segment elevation in leads V2-5 and in leads I and aVL [classic left anterior descending (LAD) type] was frequently observed (18 cases; 35%). In six patients (13%), a partial LAD type was observed with ST-segment elevation in leads I and aVL, but not in peripheral leads. The remaining patients showed ST-segment elevation only in peripheral leads (12 cases), in inferior leads III + aVF (six cases), whereas six patients had no ST-segment elevation. Diffuse ST-segment depression only (>6 leads) was observed in 15 cases (31%). Eighteen patients (38%) died during hospitalization.

CONCLUSION

ST-segment elevation in lead aVR or a LAD-type pattern can be associated with LMT disease. Other relevant aspects are the presence of cardiogenic shock at admission, the left axis deviation and marked prolongation of QTc interval and QRS width.

Prognostic Value of Avr Lead and the Well-Known Risk Factors in Acute St-Segment Elevated Myocardial Infarction

Objective

The present study was designed to analyse the effect of ST segment changes in aVR lead and the well-known risk factors in ST-segment elevated myocardial infarction (STEMI) patients.

Materials and Methods

A total of 250 patients who were admitted between 2009 and 2010 with STEMI and ≥1 mm ST-segment elevation in aVR lead were enrolled in the study. The patients were followed for life-threatening events like acute pulmonary oedema, atrial fibrillation, AV block, ventricular tachycardia, length of stay in hospital and death.

Results

Among the enrolled patients, 222 were discharged and 28 died. Pulmonary oedema and mortality rates were significantly higher in patients with ST-segment elevation in aVR lead (both p=0.001).

Conclusions

There is a correlation of ST-segment elevation in aVR lead with poor outcome in STEMI. Therefore aVR lead must be analysed as well as the other leads and well-known risk factors while it estimates the prognosis.

Left main coronary artery disease: A review of the spectrum of noninvasive diagnostic modalities

Medically managed significant left main (LM) stem disease has been considered a determinant of increased cardiac mortality approaching 50% at 3-year follow-up. Despite the clinical significance of LM disease, studies comparing the various diagnostic modalities, especially noninvasive, are sparse. Clinicians, particularly imagers, should be aware of the strengths and weaknesses of existing modalities to diagnose LM disease as integrating many clues (history, symptoms, electrocardiogram, and stress hemodynamics are essential to suspect this diagnosis and proceed to the next step). Here we review the existing data on the current role of electrocardiography, nuclear myocardial perfusion imaging (single photon emission computed tomography and positron emission tomography), stress echocardiography, cardiac computed tomography, and cardiac magnetic resonance imaging in diagnostic evaluation of LM disease. Wherever applicable we have extended our discussion to multivessel coronary artery disease encompassing scenarios where LMS can present as LM equivalent with or without extensive multivessel coronary artery disease.

Prevalence and Associated Clinical Characteristics of Exercise-Induced ST-Segment Elevation in Lead aVR

Background

Exercise-induced ST-segment elevation (STE) in lead aVR may be an important indicator of prognostically important coronary artery disease (CAD). However, the prevalence and associated clinical features of exercise-induced STE in lead aVR among consecutive patients referred for exercise stress electrocardiography (ExECG) is unknown.

Methods

All consecutive patients receiving a Bruce protocol ExECG for the diagnosis of CAD at a tertiary care academic center were included over a two-year period. Clinical characteristics, including results of coronary angiography, were compared between patients with and without exercise-induced STE in lead aVR.

Results

Among 2227 patients undergoing ExECG, exercise-induced STE ≥1.0mm in lead aVR occurred in 3.4% of patients. Patients with STE in lead aVR had significantly lower Duke Treadmill Scores (DTS) (-0.5 vs. 7.0, p<0.01) and a higher frequency of positive test results (60.2% vs. 7.3%, p<0.01). Furthermore, patients with STE in lead aVR were more likely to undergo subsequent cardiac catheterization than those without STE in lead aVR (p<0.01, odds ratio = 4.2).

Conclusions

Among patients referred for ExECG for suspected CAD, exercise-induced STE in lead aVR was associated with a higher risk DTS, an increased likelihood of a positive ExECG, and referral for subsequent coronary angiography. These results suggest that exercise-induced STE in lead aVR may represent a useful ECG feature among patients undergoing ExECG in the risk stratification of patients.

The classical versus the Cabrera presentation system for resting electrocardiography: Impact on recognition and understanding of clinically important electrocardiographic changes

The classical system for presentation of the 12-lead electrocardiogram (ECG) reflects the electrical activity of the heart as viewed in the transverse plane by 6 leads with a single anatomically ordered sequence, V1-V6; but in the frontal plane by 6 leads with dual sequences, I, II, and III, and aVR, aVL, and aVF. However, there is also a single anatomically ordered sequence of leads, called the Cabrera display that presents the six frontal plane leads in their anatomically ordered sequence of: aVL, I, -aVR, II, aVF, and III. Although it has been recognized that the Cabrera system has clinical diagnostic advantages compared to the classical display, it is currently only used in Sweden. The primary explanation of why the Cabrera system has not been adopted internationally has been that analog ECG recorders had technical limitations. Currently, however, the classical system is most often seen as a historical remnant that prevails because of conservatism within the cardiology community.

Significance of lead aVR in acute coronary syndrome

The 12-lead electrocardiogram (ECG) is a crucial tool in the diagnosis and risk stratification of acute coronary syndrome (ACS). Unlike other 11 leads, lead aVR has been long neglected until recent years. However, recent investigations have shown that an analysis of ST-segment shift in lead aVR provides useful information on the coronary angiographic anatomy and risk stratification in ACS. ST-segment elevation in lead aVR can be caused by (1) transmural ischemia in the basal part of the interventricular septum caused by impaired coronary blood flow of the first major branch originating from the left anterior descending coronary artery; (2) transmural ischemia in the right ventricular outflow tract caused by impaired coronary blood flow of the large conal branch originating from the right coronary artery; and (3) reciprocal changes opposite to ischemic or non-ischemic ST-segment depression in the lateral limb and precordial leads. On the other hand, ST-segment depression in lead aVR can be caused by transmural ischemia in the inferolateral and apical regions. It has been recently shown that an analysis of T wave in lead aVR also provides useful prognostic information in the general population and patients with prior myocardial infarction. Cardiologists should pay more attention to the tracing of lead aVR when interpreting the 12-lead ECG in clinical practice.

The forgotten lead: does aVR ST-deviation add insight into the outcomes of ST-elevation myocardial infarction patients?

BACKGROUND

Lead aVR ST-segment deviation has been associated with increased mortality in ST-elevation myocardial infarction patients treated with fibrinolysis. However, its prognostic value in a contemporaneous population undergoing primary percutaneous coronary intervention is unknown.

METHODS AND RESULTS

A core laboratory examined the 12-lead baseline electrocardiogram in 5,683 patients presenting within 6 hours of symptom onset in the APEX-AMI trial, and readers were blinded to study treatment and clinical outcomes. aVR ST-deviation was significantly associated with 90-day death when compared with patients with no aVR ST-deviation (aVR ST-depression [ST-D] 5%, aVR ST-elevation [ST-E] 10.2%, no ST-deviation [N] aVR 3.8%, P < .001). After multivariable adjustment, aVR ST-E was strongly associated with 90-day death in inferior myocardial infarction (MI) (adjusted hazard ratio [HR] 5.87, 95% CI 2.09-16.5), whereas aVR ST-D was associated with excess mortality in noninferior MI (1.53, 1.06-2.22; P [interaction] < .001). aVR ST-E was also significantly associated with the presence of left main coronary (N aVR 1.8%, aVR ST-E 7.7%, P ≤ .001) and multivessel coronary disease (N aVR 41.3%, aVR ST-E 53.3%, P ≤ .001).

CONCLUSIONS

Lead aVR ST-deviation is common, occurring in one-third of all ST-elevation myocardial infarction patients and independently associated with increased 90-day death. Myocardial infarction location modulates the prognostic significance of aVR ST-deviation such that lead aVR ST-E in inferior MI and ST-D in noninferior MI represent 2 high-risk groups. There was also more frequent advanced coronary disease in patients with aVR ST-E.

A Case of Acute Myocardial Infarction With ST-Segment Elevation in a Lead Augmented Right Vector Caused by a Left Main Coronary Artery Vasospasm

Diagnosing and selecting an appropriate treatment strategy for left main coronary artery (LMCA) obstruction is very important. Although this disease is not frequently encountered, it can cause severe hemodynamic deterioration resulting in a less favorable prognosis without a suitable management approach. Another aspect of LMCA that we must not overlook is coronary artery spasm, which can be an infrequent but important cause of acute coronary syndrome. Although it is rare, LMCA can cause critical complications. In this study, we report the case of a 35-year-old female who was admitted to the hospital with a diagnosis of acute myocardial infarction with ST-segment elevation in the aVR lead caused by a left main coronary spasm that was examined on intravascular ultrasound.

Acute myocardial infarction with significant left main coronary artery stenosis, significant 3-vessel coronary artery disease and elevated troponin-I at admission

Exercise-induced ST-segment elevation in lead aVR accompanied by ST-segment elevation in lead V1 might be a specific finding of left main coronary artery (LMCA) stenosis. Lead aVR and lead v1 ST segment elevation has been reported, during an attack of chest pain, in patients with LMCA disease with ST segment depression in leads V3, V4 and V5 (with maximal depression in V4). ST-segment elevation in lead aVR in patients with angina at rest can be related to transmural ischemia of the basal part of the interventricular septum, frequently due to LMCA or multivessel coronary disease too. 3-vessel coronary artery disease (CAD) and LMCA disease show a frequent combination of leads with abnormal ST segments during chest pain with ST-segment depression in leads I II V4-V6, and ST-segment elevation in lead aVR. When ST-segment status in lead aVR combines with troponin T, ST-segment elevation in lead aVR and positive troponin T on admission are useful predictors of LMCA or 3-vessel CAD. We present a case of acute myocardial infarction with significant left main coronary artery stenosis, significant 3-vessel coronary artery disease and elevated troponin I at admission in an 83-year-old Italian woman. Also this case focuses attention on the importance of the recognition of the patterns suspected for LMCA and/or 3-vessel coronary disease.

ST-segment deviation in lead aVR on admission is not associated with left ventricular function at predischarge in first anterior wall ST-segment elevation acute myocardial infarction

Previous studies have shown that the analysis of ST-segment deviation in lead aVR on admission provides useful information on angiographic coronary anatomy and risk stratification in acute coronary syndromes. However, the association between ST-segment deviation in lead aVR on admission and left ventricular (LV) function has not been fully investigated in anterior wall acute ST-segment elevation myocardial infarction. In this study, 237 patients with first anterior wall acute ST-segment elevation myocardial infarction were examined. The patients were divided into the following 3 groups according to ST-segment deviation in lead aVR on admission: 85 with ST-segment elevation ≥0.5 mm (group A), 106 without ST-segment deviation (group B), and 46 with ST-segment depression ≥0.5 mm (group C). LV ejection fractions at predischarge were compared among the 3 groups. Among the 3 groups, there were significant differences in the prevalences of proximal left anterior descending coronary artery (LAD) occlusion (group A 75.3%, group B 56.6%, group C 45.7%, p = 0.002), long LAD (group A 27.1%, group B 31.1%, group C 56.5%, p = 0.002), and good collaterals to the LAD (group A 40.0%, group B 25.4%, group C 17.4%, p = 0.01). LV ejection fractions at predischarge did not differ among the 3 groups (group A 56.4 ± 12.5%, group B 56.9 ± 12.7%, group C 53.3 ± 12.2%, p = 0.26). On a multiple regression analysis, establishment of Thrombolysis In Myocardial Infarction grade 3 flow, proximal LAD occlusion, and long LAD were associated with the LV ejection fraction at predischarge. In conclusion, ST-segment deviation in lead aVR on admission is not associated with LV function at predischarge in first anterior wall acute ST-segment elevation myocardial infarction.

Short- and long-term prognostic significance of ST-segment elevation in lead aVR in patients with non-ST-segment elevation acute coronary syndrome

We sought to evaluate the prognostic significance of ST-segment elevation (STE) in lead aVR in unselected patients with non-STE acute coronary syndrome (NSTE-ACS). We enrolled 1,042 consecutive patients with NSTE-ACS. Patients were divided into 5 groups according to the following electrocardiographic (ECG) patterns on admission: (1) normal electrocardiogram or no significant ST-T changes, (2) inverted T waves, (3) isolated ST deviation (ST depression [STD] without STE in lead aVR or transient STE), (4) STD plus STE in lead aVR, and (5) ECG confounders (pacing, right or left bundle branch block). The main angiographic end point was left main coronary artery (LM) disease as the culprit artery. Clinical end points were in-hospital and 1-year cardiovascular death defined as the composite of cardiac death, fatal stroke, and fatal bleeding. Prevalence of STD plus STE in lead aVR was 13.4%. Rates of culprit LM disease and in-hospital cardiovascular death were 8.1% and 3.8%, respectively. On multivariable analysis, patients with STD plus STE in lead aVR (group 4) showed an increased risk of culprit LM disease (odds ratio 4.72, 95% confidence interval [CI] 2.31 to 9.64, p <0.001) and in-hospital cardiovascular mortality (odds ratio 5.58, 95% CI 2.35 to 13.24, p <0.001) compared to patients without any ST deviation (pooled groups 1, 2, and 5), whereas patients with isolated ST deviation (group 3) did not. At 1-year follow-up 127 patients (12.2%) died from cardiovascular causes. On multivariable analysis, STD plus STE in lead aVR was a stronger independent predictor of cardiovascular death (hazard ratio 2.29, 95% CI 1.44 to 3.64, p <0.001) than isolated ST deviation (hazard ratio 1.52, 95% CI 0.98 to 2.36, p = 0.06). In conclusion, STD plus STE in lead aVR is associated with high-risk coronary lesions and predicts in-hospital and 1-year cardiovascular deaths in patients with NSTE-ACS. Therefore, this promptly available ECG pattern could be useful to improve risk stratification and management of patients with NSTE-ACS.

An early and simple predictor of severe left main and/or three-vessel disease in patients with non-ST-segment elevation acute coronary syndrome

Clopidogrel should be initiated as soon as possible in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) except those who urgently require coronary artery bypass grafting (CABG). The present study assessed the ability to predict severe left main coronary artery and/or 3-vessel disease (LM/3VD) that would most likely require urgent CABG based on only clinical factors on admission in 572 patients with NSTE-ACS undergoing coronary angiography. Severe LM/3VD was defined as ≥75% stenosis of LM and/or 3VD with ≥90% stenosis in ≥2 proximal lesions of the left anterior descending coronary artery and other major epicardial arteries. Patients were divided into the 3 groups according to angiographic findings: no LM/3VD (n = 460), LM/3VD but not severe LM/3VD (n = 57), and severe LM/3VD (n = 55). Severe LM/3VD was associated with a higher rate of urgent CABG compared to no LM/3VD and LM/3VD but not severe LM/3VD (46%, 2%, and 2%, p <0.001). On multivariate analysis, degree of ST-segment elevation in lead aVR was the strongest predictor of severe LM/3VD (odds ratio 29.1, p <0.001), followed by positive troponin T level (odds ratio 1.27, p = 0.044). ST-segment elevation ≥1.0 mm in lead aVR best identified severe LM/3VD with 80% sensitivity, 93% specificity, 56% positive predictive value, and 98% negative predictive value. In conclusion, ST-segment elevation ≥1.0 mm in lead aVR on admission electrocardiogram is highly suggestive of severe LM/3VD in patients with NSTE-ACS. Selected patients with this finding might benefit from promptly undergoing angiography, withholding clopidogrel to allow early CABG.

Significance of a prominent Q wave in lead negative aVR (-aVR) in acute anterior myocardial infarction

PURPOSE

The aim of this study was to clarify the significance of a Q wave in lead negative aVR (-aVR) in anterior wall acute myocardial infarction (AMI).

METHODS

Eighty-seven patients with a first anterior wall AMI were classified into 2 groups according to the presence (n = 17, group A) or absence (n = 70, group B) of a prominent Q wave (duration > or =20 milliseconds) in lead -aVR at predischarge. Group A had a higher prevalence of a long left anterior descending coronary artery (LAD), a lower left ventricular ejection fraction, and more reduced regional wall motion in the apical and inferior regions than group B. None of group A patients had an LAD that did not reach the apex.

CONCLUSION

A prominent Q wave in lead -aVR in anterior wall AMI is related to severe regional wall motion abnormality in the apical and inferior regions, with an LAD wrapping around the apex.

Utility of lead aVR for identifying the culprit lesion in acute myocardial infarction

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.

Determinants of ST-segment level in lead aVR in anterior wall acute myocardial infarction with ST-segment elevation

BACKGROUND

This study aimed to clarify the determinants of ST-segment level in lead aVR in anterior wall acute myocardial infarction (AAMI).

METHODS

We analyzed ST-segment levels in all 12 leads on admission and emergency coronary angiographic findings in 261 patients with a first AAMI with ST-segment elevation. The length of the left anterior descending coronary artery (LAD) was classified as follows: short = not reaching the apex; medium = perfusing less than 25% of the inferior wall; long = perfusing 25% or more of the inferior wall.

RESULTS

The ST-segment level in lead aVR correlated significantly with the ST-segment levels in leads I, II, III, aVF, V(1), and V(3-6), especially with those in leads II and V(6) (r = -0.63, P < .001; r = -0.61, P < .001; respectively). Patients with a proximal LAD occlusion had a greater ST-segment level in lead aVR than those with a distal LAD occlusion (P < .001). Patients with a long LAD had a lower ST-segment level than those with a short or medium LAD (P < .05).

CONCLUSIONS

The ST-segment levels, especially in leads II and V(6), the site of the LAD occlusion, and the length of the LAD affect the ST-segment level in lead aVR in ST-segment elevation AAMI.

ST-segment elevation in lead augmented vector right may also be caused by diffuse left main coronary artery vasospasm without fixed stenosis

ST-segment deviation in lead augmented vector right (aVR) is useful for evaluating patients with acute coronary syndrome (ACS). The ST-segment elevation in this aVR in the patient with clinically suspected acute coronary syndrome suggests a strong possibility of left main coronary artery (LMCA) obstruction due to fixed stenosis. In this article, we report the first case, to our knowledge, of ST-segment elevation in lead aVR due to diffuse LMCA spasm.

Relationship of ST elevation in lead aVR with angiographic findings and outcome in non-ST elevation acute coronary syndromes

BACKGROUND

Limited data suggest that ST elevation (ST elevation) in aVR is associated with higher mortality and more extensive coronary artery disease in the setting of non-ST elevation acute coronary syndromes (ACS).

METHODS

In the prospective Global Registry of Acute Coronary Events (GRACE) electrocardiographic substudy, the admission electrocardiograms were analyzed by a blinded core laboratory. We performed multivariable analysis to determine (1) the independent prognostic significance of ST elevation in aVR and (2) its association with significant (> or = 50% stenosis) left main or 3-vessel disease (LM/3-vd).

RESULTS

Among 5064 patients with non-ST elevation ACS, 4696 had no ST elevation in aVR, 292 (5.8%) had minor (0.5-1 mm) ST elevation in aVR, and 76 (1.5%) had major (>1 mm) ST elevation in aVR; their in-hospital mortality rates were 4.2%, 6.2%, and 7.9%, respectively (P for trend =.03). At 6 months follow-up, the cumulative mortality rates were 7.6%, 12.7%, and 18.3%, respectively (log-rank P for trend <.001). However, minor and major ST elevation in aVR were not independent predictors of in-hospital or 6-month death after adjusting for other validated prognosticators in the GRACE risk model. Of the 2416 patients without prior coronary bypass surgery who underwent cardiac catheterization, the prevalence of LM/3-vd was 26.1%, 36.2%, and 55.9% for the groups with no, minor, and major ST elevation in aVR, respectively (P for trend <.001). After adjusting for other clinical characteristics, major ST elevation in aVR remained an independent predictor of LM/3-vd (adjusted odds ratio, 2.68; 95% confidence interval, 1.29-5.58; P = .008).

CONCLUSION

ST elevation in aVR is less prevalent than reported in previous smaller studies. Although it is associated with higher unadjusted in-hospital and 6-month mortality, it does not provide incremental prognostic value beyond comprehensive risk stratification using the validated GRACE risk model. However, ST elevation greater than 1 mm in aVR may be useful in the early identification of LM/3-vd in ACS patients with ST depression.

Electrocardiographic applications of lead aVR

Lead aVR, 1 of 12 electrocardiographic leads, is frequently ignored in clinical medicine. In fact, many clinicians refer to the 12-lead electrocardiogram (ECG) as the 11-lead ECG, noting the commonly held belief that lead aVR rarely offers clinically useful information. In this report, we discuss the findings in lead aVR, which are potentially of value, including ST-segment elevation in the patient with acute coronary syndrome suggestive of left main coronary artery occlusion, PR-segment elevation in the patient with acute pericarditis, prominent R wave in the patient with significant tricyclic antidepressant poisoning, and ST-segment elevation in narrow complex tachycardia suggestive of Wolff-Parkinson-White syndrome.