Prognostic value of lead aVR in patients with a first non-ST-segment elevation acute myocardial infarction

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.

Comparing Door-To-Balloon Time between ST-Elevation Myocardial Infarction Electrocardiogram and Its Equivalents

Background: In patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary interventions (pPCI), longer door-to-balloon (DTB) time is known to be associated with an unfavorable outcome. A percentage of patients with acute coronary occlusion present with atypical electrocardiographic (ECG) findings, known as STEMI-equivalents. We investigated whether DTB time for STEMI-equivalent patients was delayed. Methods: This is a retrospective study including patients arriving at an emergency department with the acute coronary syndrome in whom emergent pPCI was performed. ECGs were classified into STEMI and STEMI-equivalent groups. We compared DTB time, with its components, between the groups. We also investigated whether STEMI-equivalent ECG was an independent predictor of DTB time delayed for more than 90 min. Results: A total of 180 patients were included in the present study, and 23 patients (12.8%) presented with STEMI-equivalent ECGs. DTB time was significantly delayed in patients with STEMI-equivalent ECGs (89 (80–122) vs. 81 (70–88) min, p = 0.001). Multivariable logistic regression analysis showed that STEMI-equivalent ECG was an independent predictor of delayed DTB time (odds ratio: 4.692; 95% confidence interval: 1.632–13.490, p = 0.004). Conclusions: DTB time was significantly delayed in patients presenting with STEMI-equivalent ECGs. Prompt recognition of STEMI-equivalent ECGs by emergency physicians and interventional cardiologists might reduce DTB time and lead to a better clinical outcome.

Predictive value of ST-segment deviation in aVR in patients suffering from acute coronary syndrome: A retrospective cohort study

Changes in the ST-segment in aVR of electrocardiogram have been used to predict the morbidity of left main and/or 3-vessel disease (LM/3-VD) in patients with acute coronary syndrome (ACS). However, the association with patient prognosis has rarely been reported. A total of 274 patients diagnosed with ACS were retrospectively evaluated following allocation into 1 of 3 groups: the ST-segment elevation (STE) group ≥ 0.05 mV, ST-segment depression (STD) group ≥ 0.05 mV, and the Isoelectric group in aVR. A comparison of clinical characteristics, coronary angiography results, major adverse cardiovascular events (MACE), and GRACE risk score was made. Patients in the STE and STD groups were older and had a lower LVEF, a greater number of MACE and higher GRACE risk score, compared with patients in the isoelectric group. Patients in the STE group had significantly greater morbidity due to LM/3-VD than did the non-STE groups. In addition, as the amplitude of STE in aVR increased, the number of MACE, GRACE risk score, and the incidence of LM/3-VD increased. Furthermore, after adjusting for other clinical factors, multivariate statistical results indicated that STE ≥ 0.05 mV in aVR was the only predictor of LM/3-VD, whereas STD ≥ 0.05 mV was not. It was found that STE or STD ≥ 0.05 mV in aVR was an independent predictor of MACE. STE ≥ 0.05 mV in aVR is associated with LM/3-VD. Furthermore, ST-segment deviation in aVR may have prognostic value of MACE and associated with higher GRACE risk scores in patients with ACS.

Clinical and electrocardiographic characteristics in patients with fulminant myocarditis

Background

The purpose of this study was to evaluate clinical and electrocardiographic characteristics in patients with fulminant myocarditis.

Methods

A total of 72 patients were divided into three groups: pericarditis (control: n = 25), acute myocarditis (n = 27), and fulminant myocarditis (n = 20). Patients' characteristics and electrocardiograms on admission were retrospectively analyzed in the three groups.

Results

BNP levels in the fulminant group were significantly higher than those in the other two groups. ST elevation was observed at lead aVR in the fulminant myocarditis group, whereas ST depression was observed at lead aVR in the other groups (p = .001). The maximum degree of ST elevation among the three groups was similar. However, the number of ST‐elevation leads in the fulminant myocarditis group was significantly lower than that in the other groups (p = .004). The voltage of R wave in lead V5 in the fulminant myocarditis group was significantly lower than that in the other groups (p = .005). Moreover, in the Cabrera sequence, the prevalence of ST elevation in the inferior leads, aVR, and V3–V6 in the fulminant myocarditis group was significantly or nearly significantly lower than that in the other groups.

Conclusions

In fulminant myocarditis, ST‐segment elevation was observed in lead aVR, and contrarily, the number and extent of ST‐segment elevation and R wave voltage were smaller than those in the other groups. These results suggest that the number of myocytes with maintained action potential may be reduced following progressive myocardial damage and interstitial edema due to severe inflammation.

A Silent Killer: Left Main Coronary Artery Disease in Gastrointestinal Bleed

Left main coronary artery disease (LMCAD) is defined as more than 50% angiographic arterial narrowing and has been demonstrated in nearly 5% of all patients undergoing coronary angiography. It carries an extremely high risk for cardiovascular morbidity and mortality as it impacts more than two-thirds of the left ventricle. Prediction of LMCAD in the right clinical setting is important for the selection of the proper treatment strategies. Typical ECG characteristics are ST elevation (STE) in lead augmented vector right (aVR-STE) of more than 0.5 mV accompanied by ST depression (STD) notably in leads I, II, and V4-6 or STE in aVR ≥ V₁. Furthermore, the presence of aVR-STE is associated with worse outcomes and careful evaluation and close monitoring are warranted. However, not every aVR-STE is an acute occlusion of the left main coronary artery (LMCA), as acute occlusion is a catastrophic event. aVR-STE can also be associated with severe triple-vessel disease or diffuse subendocardial ischemia.

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.

The prognostic significance of a positive or isoelectric T wave in lead aVR in patients with acute coronary syndrome and ischemic ECG changes in the presenting ECG - Long-term follow-up data of the TACOS study

BACKGROUND

A positive T wave in lead aVR (aVRT+) is an independent prognostic predictor of cardiovascular mortality in the general population as well as in cardiovascular disease.

SUBJECTS AND METHODS

We evaluated the prognostic impact of aVRT+ in an ECG recorded as close to hospital discharge as possible in acute coronary syndrome patients (n = 527). We divided the patients into three categories based on the findings in the admission ECG: ST elevation, global ischemia and other ST/T changes.

RESULTS

In the whole study population, and in all the three ECG subgroups, the 10-year all-cause mortality rate was higher in the aVRT+ group than in the aVRT- group. In Cox regression analysis, the age and gender adjusted hazard ratio (HR) for aVRT+ to predict all-cause mortality in the whole study population was 1.43 (95% confidence interval [CI] 1.12-1.83; p = 0.004). To predict cardiovascular mortality, the age and gender adjusted HR for aVRT+ was 1.54 (95% CI 1.14-2.07; p = 0.005) in the whole study population and 2.07 (95% CI 1.07-4.03; p = 0.032) in the category with other ST/T changes.

CONCLUSION

In ACS patients with or without ST elevation, but with ischemic ST/T changes in their presenting ECG, a positive or isoelectric T wave in lead aVR in an ECG recorded in the subacute in-hospital stage is associated with all-cause and cardiovascular mortality during long-term follow-up. Clinicians should pay attention to this simple ECG finding at hospital discharge.

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.

aVR ST Segment Elevation: Acute STEMI or Not? Incidence of an Acute Coronary Occlusion

BACKGROUND

Identification of ST elevation myocardial infarction (STEMI) is critical because early reperfusion can save myocardium and increase survival. ST elevation (STE) in lead augmented vector right (aVR), coexistent with multilead ST depression, was endorsed as a sign of acute occlusion of the left main or proximal left anterior descending coronary artery in the 2013 STEMI guidelines. We investigated the incidence of an acutely occluded coronary in patients presenting with STE-aVR with multilead ST depression.

METHODS

STEMI activations between January 2014 and April 2018 at the University of Arizona Medical Center were identified. All electrocardiograms (ECGs) and coronary angiograms were blindly analyzed by experienced cardiologists. Among 847 STEMI activations, 99 patients (12%) were identified with STE-aVR with multilead ST depression.

RESULTS

Emergent angiography was performed in 80% (79/99) of patients. Thirty-six patients (36%) presented with cardiac arrest, and 78% (28/36) underwent emergent angiography. Coronary occlusion, thought to be culprit, was identified in only 8 patients (10%), and none of those lesions were left main or left anterior descending occlusions. A total of 47 patients (59%) were found to have severe coronary disease, but most had intact distal flow. Thirty-two patients (40%) had mild to moderate or no significant disease. However, STE-aVR with multilead ST depression was associated with 31% in-hospital mortality compared with only 6.2% in a subgroup of 190 patients with STEMI without STE-aVR (p<0.00001).

CONCLUSIONS

STE-aVR with multilead ST depression was associated with acutely thrombotic coronary occlusion in only 10% of patients. Routine STEMI activation in STE-aVR for emergent revascularization is not warranted, although urgent, rather than emergent, catheterization appears to be important.

Differences in initial electrocardiographic findings between ST-elevation myocardial infarction due to left main trunk and left anterior descending artery lesions

Background

Early discrimination of ST-elevation myocardial infarction (STEMI) due to a left main trunk (LMT) lesion provided by straightforward electrocardiographic criteria is useful for prompt treatment. The purpose of this study is to investigate differences in electrocardiographic findings between STEMI due to lesions of LMT and those of left anterior descending artery (LAD).

Methods

Initial electrocardiogram (ECG) recordings of 435 patients with analyzable ECGs from a cohort of 940 consecutive STEMI patients were analyzed retrospectively for presence of LMT lesions (LMT, n = 39), proximal (pLAD, n = 224) and distal LAD lesions (dLAD, n = 172). ST-segment deviations in 12 leads were assessed among 3 groups without bundle branch block (n = 17 in LMT, n = 180 in pLAD, and n = 159 in dLAD).

Results

Magnitudes of ST-segment deviations showed significant differences in leads II, III, aVR aVL, aVF, and V2–V6 across the three groups. This difference suggested two possible characteristic findings in the LMT group, allowing it to be distinguished from the pLAD or dLAD group; (A) larger magnitude of ST-segment depression in lead II than that of ST-segment elevation in lead V2 (47.1% in LMT vs. 0.6% in pLAD vs. 1.3% in dLAD, P < 0.0001), and (B) ST-segment depression in lead V5 (58.8% in LMT vs. 6.7% in pLAD vs. 2.5% in dLAD, P < 0.0001). These findings exhibited superior negative predictive value over conventional ST-segment elevation in lead aVR.

Conclusions

A large reciprocal ST-segment depression in inferior leads and ST-segment depression in lead V5 are useful ECG findings allowing determination of STEMI due to an LMT lesion.

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.

Prognostic value of positive T wave in lead aVR in patients with non-ST segment myocardial infarction

BACKGROUND

Lead aVR provides prognostic information in various settings in patients with ischemia. We aim to investigate the role of a positive T wave in lead aVR in non-ST segment myocardial infarction (NSTEMI).

METHODS

In a prospective cohort study, we included 400 patients with NSTEMI. Presentation electrocardiogram (ECG) was investigated for presence of a positive T wave as well as ST segment elevation (STE) in aVR and study variables were compared. Predictors of primary outcome defined as hospital major adverse cardiovascular events (MACE) and secondary outcome, defined as three-vessel coronary disease and/or left main coronary artery stenosis (3VD/LMCA) stenosis in angiography, were determined in multivariate logistic regression analysis.

RESULTS

Patients with a positive T wave in aVR were significantly older and were more likely to be female. Left ventricular ejection fraction was significantly lower in patients of positive T group. Positive T group was more likely to have 3VD/LMCA stenosis (58.3% vs. 19.8%, p < .001). The prevalence of a positive T wave in aVR was significantly higher in MACE group (54.9 % vs. 24.8%, p < .001). However, in multivariate analysis, it was not an independent predictor of MACE (OR: 1.083 95% CI: [0.496-2.365], p: .841). Though, it was independently associated with presence of 3VD/LMCA stenosis (OR: 3.747 95% CI: [2.058-6.822], p < .001).

CONCLUSION

Though positive T wave in lead aVR was more common in patients with MACE; it was not an independent predictor. Additionally, a positive T wave in aVR was an independent predictor of 3VD/LMCA stenosis in NSTEMI.

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.

Acute total occlusion of the left main coronary artery treated with percutaneous intervention and simultaneous implantation of intra-aortic balloon pump

Electrocardiographic findings at first medical contact and direct transfer to the catheterization laboratory are important in acute total occlusion of the left main coronary artery. Simultaneous emergency angioplasty and intra‐aortic balloon pump implantation might be beneficial in overcoming the patient's most critical hemodynamic instability.

Comparison of Electrocardiographic Characteristics in Men Versus Women ≤ 55 Years With Acute Myocardial Infarction (a Variation in Recovery: Role of Gender on Outcomes of Young Acute Myocardial Infarction Patients Substudy)

Young women with acute myocardial infarction (AMI) have a worse prognosis than their male counterparts. We searched for differences in the electrocardiographic presentation of men and women in a large, contemporary registry of young adults with AMI that could help explain gender differences in outcomes. The qualifying electrocardiogram was blindly assessed by a central core lab in 3,354 patients (67% women) aged 18 to 55 years included in the Variation in Recovery: Role of Gender on Outcomes of Young AMI Patients study. Compared with men, women did not have a different frequency of sinus rhythm, and they had shorter PR and QRS intervals and longer QTc intervals. Intraventricular conduction disturbances were not different among genders. Notably, women were more likely than men to have abnormal Q waves in anterior leads and a lower frequency of Q waves in other territories. ST-segment elevation myocardial infarction (STEMI) diagnosis was less frequent in women than in men (44.6% vs 55.1%, p < 0.001). Among patients with STEMI, women had less magnitude and extent of ST-segment elevation than men. In patients with non-STEMI, the frequency, magnitude, and extent of ST-segment depression were not different among genders, but women had anterior ST-segment depression less frequently and anterior negative T waves more frequently compared with men. These differences remained statistically significant after adjusting for baseline characteristics. In conclusion, there are significant gender differences in the electrocardiographic presentation of AMI among young patients. Further studies are warranted to evaluate their impact on gender-related differences in the management and outcomes of AMI.

Pitfalls in Electrocardiographic Diagnosis of Acute Coronary Syndrome in Low-Risk Chest Pain

Less than half of patients with a chest pain history indicative of acute coronary syndrome have a diagnostic electrocardiogram (ECG) on initial presentation to the emergency department. The physician must dissect the ECG for elusive, but perilous, characteristics that are often missed by machine analysis. ST depression is interpreted and often suggestive of ischemia; however, when exclusive to leads V1–V3 with concomitant tall R waves and upright T waves, a posterior infarction should first and foremost be suspected. Likewise, diffuse ST depression with elevation in aVR should raise concern for left main- or triple-vessel disease and, as with the aforementioned, these ECG findings are grounds for acute reperfusion therapy. Even in isolation, certain electrocardiographic findings can suggest danger. Such is true of the lone T-wave inversion in aVL, known to precede an inferior myocardial infarction. Similarly, something as ordinary as an upright and tall T wave or a biphasic T wave can be the only marker of ischemia. ECG abnormalities, however subtle, should give pause and merit careful inspection since misinterpretation occurs in 20–40% of misdiagnosed myocardial infarctions.

Exercise test predictors of severe coronary artery disease: Role of ST-segment elevation in lead aVR

BACKGROUND

The role of exercise stress test (EST)-induced ST-segment elevation (STE) in electrocardiographic lead aVR in predicting severe coronary artery disease (CAD) is controversial.

HYPOTHESIS

Assessment of lead aVR during EST can be helpful to identify patients with severe CAD.

METHODS

We performed maximal EST in 200 patients undergoing coronary angiography for suspect of CAD. Four angiographic findings of severe CAD were considered: (1) left main (LM) disease; (2) LM or equivalent LM (LM/EQLM) disease; (3) LM or proximal left anterior descending (LAD) artery (LM/proxLAD) disease; and (4) LM or 3-vessel (LM/3V) disease.

RESULTS

LM, LM/EQLM, LM/proxLAD, and LM/3V disease were shown in 6 (3%), 13 (6.5%), 33 (16.5%), and 27 (13.5%) patients, respectively. EST-induced STE in aVR occurred in 41 patients (20.5%). ST-segment depression (STD) in ≥5 leads was the only predictor of LM stenosis (odds ratio [OR]: 6.18, 95% confidence interval [CI]: 1.19-32.2, P = 0.03) and the most significant variable associated with LM/proxLAD stenosis (OR: 4.73, 95% CI: 2.0-11.2, P = 0.0001); maximal STD ≥3 mm was the most significant variable associated with LM/EQLM (OR: 7.58, 95% CI: 2.31-24.9, P = 0.001) and LM/3V (OR: 3.86, 95% CI: 1.47-10.1, P = 0.006) CAD. EST-induced STE in aVR was associated with LM/proxLAD disease only (OR: 3.23, 95% CI: 1.44-7.24, P = 0.004). At multivariate analysis, STD in ≥5 leads was the only independent predictor of LM/proxLAD disease (OR: 3.99, 95% CI: 1.58-10.1, P = 0.003).

CONCLUSIONS

EST-induced STE in lead aVR does not significantly increase the prediction of severe CAD compared with severity and extension of STD as assessed in the other electrocardiographic leads.

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.

Syncope on a Hot Summer Day

In a 63-year-old man, episodes of ventricular tachycardia causing syncope and myocardial infarction are the first manifestations of triple vessel coronary disease in the absence of arteriographic evidence of a fresh occlusion.

Chicken or the egg: ST elevation in lead aVR or SYNTAX score

Background:

ST-segment elevation in lead aVR (STEaVR) anticipates left main and/or three-vessel disease (LM/3VD) in patients with acute coronary syndromes. STEaVR is generally reciprocal to and accompanied by ST-segment depression (STD) in the precordial leads. SYNTAX score (SS) is an angiographic scoring system and is widely used to evaluate the severity and complexity of coronary artery disease. The purpose of our study was to assess the relationship between STEaVR and SS.

Methods:

We performed a retrospective analysis of 117 patients with non-ST-segment elevation acute coronary syndrome (NSTEACS). Electrocardiograms at presentation were reviewed, especially for ST-segment elevation of ≥ 0.05 mV in lead aVR and STD of ≥ 0.05 mV in more than two contiguous leads. All lesions causing ≥ 50% stenosis in a coronary artery with a diameter of ≥ 1.5 mm were included in the SS calculation. SS was divided into two groups: ≥ 23: high, < 23: low.

Results:

Among the 117 patients, 80 (68.4%) had STEaVR and 37 (31.6%) did not. Patients with STEaVR had a higher SS and higher rate of LM/3VD (85 vs 67.6%, p < 0.001; 86.2 vs 72.9%, p = 0.03, respectively) than those without STEaVR. On multivariate analysis, STEaVR [odds ratio (OR) 1.85; 95% confidence interval (CI): 1.20–3.97, p = 0.03] and STD in leads V₁–V₄ (OR 2.14; 95% CI: 1.46–4.23, p = 0.002) were independent predictors of a high SS.

Conclusion:

This study demonstrated that STEaVR was an independent predictor of a high SS.

Electrocardiography changes in acute aortic dissection-association with troponin leak, coronary anatomy, and prognosis

BACKGROUND

Electrocardiography (ECG) offers some information that may be used to prognosticate acute type A aortic dissection (AAOD) for short- and long-term mortality.

METHODS

We retrospectively analyzed the electrocardiograms of patients with AAOD admitted from March 2004 to March 2015. The frequency of ECG findings and their prognostic value on hospital and follow-up mortality were investigated. Findings pertaining to coronary involvement and troponin level were also examined.

RESULTS

A total of 120 men and 64 women were admitted. Acute ischemic changes were reported in 38.0%, whereas T inversion was the most common recorded abnormality, which occurred in 38.6%. Acute ST-elevation myocardial infarction was detected in 16.3%. Troponin increased in 36.6%; 21.9% of the patients underwent coronary angiography among which 70% were normal. Coronary involvement or troponin increase was not different in patients with acute ECG changes. During hospitalization, 45.7% of the patients died. In multivariate analyses, ST elevation in lead aVR was associated with higher hospital death (odds ratio, 5.30; 95% confidence interval, 1.09-25.73; P = .038), whereas QRS greater than 120 milliseconds was associated with long-term mortality (hazard ratio, 2.45; 95% confidence interval, 1.25-3.76; P = .006).

CONCLUSION

Acute ischemic ECG changes are common in AAOD, and a completely normal ECG is infrequently encountered. Acute ECG changes were not associated with the increased troponin or the presence of coronary lesions in angiography.

Classical electrocardiographic clues for left main coronary artery disease

Prediction of left main coronary artery (LMCA) or equivalent disease is important with regard to selecting the appropriate treatment strategy. The classical electrocardiographic pattern of LMCA disease includes ST elevation (STE) in lead aVR in the presence of extensive ST depression (most prominent in leads I, II, and V4–6) with the STE in aVR ≥ V1. Patients with these findings may potentially require early coronary angiography and coronary bypass surgery; therefore selected patients with these findings on exercise testing might benefit from more urgent or expedited angiography.

Acute myocardial infarction due to left main coronary artery disease in men and women: does ST-segment elevation matter?

INTRODUCTION

Gender-specific issues regarding ST-segment elevation (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI) due to unprotected left main coronary artery (ULMCA) disease were not sufficiently studied. We assessed the value of STEMI/NSTEMI initial classification on the management of men and women with acute MI due to critical stenosis or occlusion of the ULMCA.

MATERIAL AND METHODS

The study group consisted of 643 consecutive patients with acute MI with the ULMCA as the infarct-related artery. Data derive from an ongoing, nationwide, multicenter, prospective, observational registry.

RESULTS

Isolated ULMCA disease was more frequent in women and multivessel disease was more frequent in men in the NSTEMI group. The incidence of cardiogenic shock or pulmonary edema and cardiac arrest was higher in the STEMI group. Totally occluded ULMCA was more frequent in the STEMI group. Although the majority of patients underwent percutaneous coronary intervention (PCI), it was less frequently used in NSTEMI women and NSTEMI men. Although in-hospital and long-term mortality rates were higher in the STEMI group, there were no gender-related differences within groups. The initial ST-segment elevation was an independent predictor of in-hospital (OR = 2.37, 95% CI: 1.14-4.91, p = 0.02) and 12-month (OR = 1.52, 95% CI: 1.01-2.27, p = 0.045) mortality.

CONCLUSIONS

There were no gender-related differences in the management within the STEMI or NSTEMI group. Although acute myocardial infarction due to ULMCA disease is associated with high mortality in both genders, STEMI was a negative prognostic factor of in-hospital and 12-month mortality. Despite poor baseline characteristics and clinical presentation in women, female gender itself did not influence mortality.

The role of the ECG in diagnosis, risk estimation, and catheterization laboratory activation in patients with acute coronary syndromes: a consensus document

The electrocardiogram (ECG) is the most widely used imaging tool helping in diagnosis and initial management of patients presenting with symptoms compatible with acute coronary syndrome. Acute ischemia affects the configuration of the QRS complexes, the ST segments and the T waves. The ECG should be read along with the clinical assessment of the patient. ST segment elevation (and ST depression in leads V1 -V3 ) in patients with active symptoms usually indicates acute occlusion of an epicardial artery with ongoing transmural ischemia. These patients should be triaged for emergent reperfusion therapy per current guidelines. However, many patients have ST segment elevation secondary to nonischemic causes. ST depression in leads other than V1 -V3 usually are indicative of subendocardial ischemia secondary to subocclusion of the epicardial artery, distal embolization to small arteries or spasm supply/demand mismatch. ST depression may also be secondary to nonischemic etiologies, such as left ventricular hypertrophy, cardiomyopathies, etc. Knowing the clinical scenario, comparison to previous ECG and subsequent ECGs (in cases that there are changes in the quality or severity of symptoms) may add in the diagnosis and interpretation in difficult cases. This review addresses the different ECG patterns, typically seen in patients with active symptoms, after resolution of symptoms and the significance of such changes when seen in asymptomatic 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.

Left Ventricular Dyssynchrony Predicts Left Main Coronary Artery Disease in Patients with Non-ST-Segment Elevation Myocardial Infarction

BACKGROUND

The purpose of our study was to examine whether left ventricular dyssynchrony predicts left main coronary artery stenosis in patients with non-ST-segment elevation myocardial infarction.

METHODS

A total of 100 consecutive patients with non-ST-segment elevation myocardial infarction underwent echocardiography and coronary artery angiography. The 3-dimensional echocardiography-derived left ventricular dyssynchrony parameter was determined by using the standard deviation of the time to the minimal systolic volume for the 16 segments. A stenosis ≥ 50% of the diameter of the left main coronary artery or a stenosis ≥ 70% in 1 or more of the major epicardial vessels or their main branches was considered significant.

RESULTS

The logistic regression analysis revealed that this parameter (odds ratio 1.2; 95% confidence interval, 1.01-1.42; p = 0.04) was the independent predictor of left main coronary artery stenosis. The receiver operating characteristic curve analysis revealed 8.86 as the optimal cutoff value to predict left main coronary artery stenosis (sensitivity, 71.4%; specificity, 89.2%).

CONCLUSIONS

The assessment of left ventricular dyssynchrony by 3-dimensional echocardiography is useful for a noninvasive diagnosis of the left main coronary artery stenosis in patients with non-ST-segment elevation myocardial infarction.

KEY WORDS

Dyssynchrony; Left main coronary artery stenosis; Non-ST-segment elevation myocardial infarction.

Predictive Value of ST-Segment Elevation in Lead aVR for Left Main and/or Three-Vessel Disease in Non-ST-Segment Elevation Myocardial Infarction

BACKGROUND

ST-segment elevation in lead aVR predicts left main and/or three-vessel disease (LM/3VD) in patients with acute coronary syndromes. ST-segment elevation in lead aVR is generally reciprocal to and accompanied by ST-segment depression in precordial leads. Previous studies have assessed the independent predictive value of ST-segment elevation in lead aVR for LM/3VD in non-ST-segment elevation acute coronary syndrome and have reported conflicting results.

METHODS

We performed a retrospective analysis of 379 patients with non-ST-segment elevation myocardial infarction (NSTEMI). Electrocardiograms on presentation were reviewed especially for ST-segment elevation ≥0.05 mV in lead aVR and ST-segment depression ≥0.05 mV in more than two contiguous leads in any other leads.

RESULTS

Among 379 patients, 97 (26%) patients had ST-segment elevation in lead aVR and 88 (23%) patients had LM/3VD. Patients with ST-segment elevation in lead aVR had a higher rate of LM/3VD (39% vs. 18%; P < 0.001) and in-hospital revascularization (73% vs. 60%; P = 0.02) driven by a higher rate of in-hospital coronary artery bypass grafting (19% vs. 7%; P < 0.001) than those without ST-segment elevation in lead aVR. On multivariate analysis, ST-segment elevation in lead aVR (odds ratio [OR] 2.05; 95% confidence interval [CI] 1.10-3.77; P = 0.02) and ST-segment depression in leads V1 -V4 (OR 2.99; 95% CI 1.46-6.15; P = 0.003) were independent predictors of LM/3VD.

CONCLUSION

This study demonstrates that ST-segment elevation in lead aVR is an independent predictor of LM/3VD in patients with NSTEMI.

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.