ST segment elevation and the prediction of hospital life-threatening complications: the role of right ventricular and posterior leads

Significance of ST-Segment elevation in V4R lead in patients with anterior myocardial infarction

Background

There is some evidence of the association between ST‐segment elevation in the V4R chest lead and the likelihood of anterior wall myocardial infarction; however, the link of this phenomenon with the location and the severity of the coronary involvements in such patients remains uncertain. We aimed to investigate the ST‐segment elevation in V4R leads in patients with anterior myocardial infarction and also its effect on prognosis as well as the detection and prediction of the location of arterial stenosis in coronary angiography.

Methods

Data collection was performed by reviewing the hospital recorded files of 195 patients’ suspicion of acute myocardial infarction who have been referred within 2 h of the onset of cardiac symptoms. The patients were then categorized into two groups with and without ST elevation in the V4R chest lead.

Results

Comparing two groups showed a significantly higher rate of concurrent ST‐segment elevation in V₁ lead in those with ST‐segment elevation in V4R. Echocardiography on the day after anterior myocardial infarction showed LVEF <40% in 74% and 35.2% of patients with and without ST‐segment elevation in V4R, respectively, indicating a significant difference. The lesions on proximal LAD were more common in the group with ST‐segment elevation in V4R.

Conclusion

Our study emphasized a high likelihood of ST‐segment elevation in V4R lead concurrently with ST‐elevation in V₁ lead. Also, the appearance of ST‐segment elevation in V4R lead can be accompanied with a lower LVEF, myocardial infarct size, involvement of proximal part of LAD, and Wrap around LAD.

Comparison of myocardial tissue reperfusion of inferior wall and a right ventricle among patients after primary angioplasty for an inferior myocardial infarction with right ventricular infarction

BACKGROUND

Impaired myocardial tissue reperfusion affects prognosis of patients with ST-segment elevation myocardial infarction (STEMI) treated with percutaneous coronary intervention (PCI) and can be identified by ST-segment analysis. To date, evaluation of the myocardial tissue reperfusion of the right ventricle (RV) among the patients treated with PCI for inferior STEMI with right ventricular infarction (RVI) has not been made yet.

METHODS

Patients with inferior STEMI were screened for RVI. Tissue reperfusion was evaluated by maximal residual ST-segment deviation post PCI, independently for the RV and for inferior wall. Myocardial injury was assessed by the peak creatine kinase-mb (CK-MB) value.

RESULTS

Among 456 patients with inferior STEMI, concomitant RVI occurred in 153 (33.5%) subjects (59.86±10.35 years old, 71.9% females). Tissue reperfusion of LV was present in 75 (49%), whereas 55 (35.9%) had both successful LV and RV reperfusion. Among 97 (63.4%) with successful tissue reperfusion of RV, 55 (56.7%) had associated successful tissue reperfusion of inferior wall. Adequate LV reperfusion was accompanied by RV in over 73.3% of patients (P=0.006). Mean peak CK-MB was lower in the group with adequate versus impaired RV tissue-perfusion (197±143 vs. 305±199 U/L, P=0.021 respectively).

CONCLUSIONS

Impaired reperfusion of RV is observed in more than one third of inferior STEMIs with RVI and is not strictly associated with impaired reperfusion of inferior wall and clinical or angiographic variables, therefore ST-segment analysis for RV is mandatory.

V3R/V7 Index: A Novel Electrocardiographic Criterion for Differentiating Left From Right Ventricular Outflow Tract Arrhythmias Origins

BACKGROUND

Several algorithms have been proposed to predict the origin of outflow tract (OT) ventricular arrhythmias (VAs) using standard 12-lead ECG. However, the additive value of right precordial and posterior leads is unknown.

METHODS

Standard 12-lead ECG, right precordial leads ECG (V₃R, V₄R, V₅R) and posterior leads ECG (V₇, V₈, V₉) were recorded and analyzed in a development cohort of consecutive patients undergoing OT-VAs ablation at a single center. These findings informed the development of a novel algorithm incorporating right precordial and posterior leads to discriminate between left ventricular OT (LVOT) and right ventricular OT (RVOT) foci. The performance of this novel algorithm which includes the V₃R/V₇ index was prospectively tested in a validation cohort of consecutive patients undergoing OT-VA ablation at 4 centers and compared with published algorithms. The location of the foci was determined by the successful ablation site.

RESULTS

One hundred ninety-one patients were recruited, of which 94 formed the validation cohort (mean age of 45.7±15.6, 39% male, 79% RVOT foci). During OT-VAs, a QS pattern in lead V₃R and an S wave in lead V₇ were exclusively recorded in RVOT and LVOT foci, respectively. The V₃R/V₇ index of LVOT origin was significantly greater than that of RVOT (1.05±0.83 versus 0.28±0.23, P<0.001). The V₃R/V₇ index ≥0.85 predicted an LVOT origin with 87% sensitivity and 96% specificity. In the prospective evaluation, when the V₃R/V₇ index ≥0.85, an RVOT origin could be excluded with 98.6% accuracy. The area under the curve of V₃R/V₇ index (0.954) was larger than that of previously reported ECG criteria, including V₂S/V₃R (0.896), V₂ transition ratio (0.792), and transition zone index (0.666). This novel index was also accurate in both patients without obvious LVOT or RVOT origins and subgroups with cardiac rotation or lead V₃ R/S transition.

CONCLUSIONS

The V₃R/V₇ index is a novel and accurate ECG criterion that predicts OT-VAs origin.

The Importance of the 15-lead Versus 12-lead ECG Recordings in the Diagnosis and Treatment of Right Ventricle and Left Ventricle Posterior and Lateral Wall Acute Myocardial Infarctions

Introduction

The 12-lead ECG at admission of patients suffering from acute myocardial infarction (AMI) is mandatory for accurate diagnosis and prompt therapeutic measures, mainly reperfusion. It has been shown that recording additional ECG leads may improve the diagnostic accuracy and therefore, the prognosis of selected cases.

Aim

The aim of the study was to assess the usefulness of the 15-lead ECG (12 classic plus 3 posterior leads) in the management of chest pain patients, especially when 12-lead ECG is not diagnostic of AMI.

Methods

Total amount of 186 consecutive patients (127 men, 59 women, mean age 69.7±13.8 years) were admitted with an acute coronary syndrome. The initial ECG recorded the 12 classic leads, and subsequently, the 3 additional posterior leads. Demographic and clinical data, including ECG alterations and selected treatment strategy, were also studied. The cumulative impact of the 15-lead ECG on the diagnosis and management of AMI were, overall, evaluated.

Results

The 12-lead ECG was diagnostic of ST-elevation AMI (STEMI) in 158 patients (Group A-84.5%) who were promptly reperfused. On the other hand, the interpretation of the posterior leads was required in 28 patients (Group B-15.1%) to establish the STEMI diagnosis warranting reperfusion therapy. Multivariate analysis illustrated that the 15-lead ECG was the only factor associated with achieving the STEMI diagnosis in non-conclusive 12-lead ECG cases (OR=2.43-p=0.04).

Conclusion

The use of the 15-lead ECG contributes to a faster and more accurate diagnosis of STEMI, particularly in the Emergency Department, facilitating the prompt reperfusion therapy.

The association of right coronary artery conus branch size and course with ST segment elevation of right precordial leads and clinical outcome of acute anterior myocardial infarction

Introduction: Coronary artery disease is the leading cause of death worldwide and electrocardiogram (ECG) is a reliable diagnostic tool to determine a myocardial infarction. The present study tried to compare the relationship between the ECG findings and angiographic findings in patients with acute anterior myocardial infarction. Methods: Seventy-four patients with acute anterior ST elevation myocardial infarction (Ant- STEMI) presenting to the emergency room in the first 12 hours after the onset of symptoms were studied. Upon admission, a full 14-lead ECG (including leads V3R and V4R) were performed. Angiographic and ECG findings, as well as clinical outcome were compared between two groups. The statistical tests including Chi-square and independent t-test were used for data analysis. Results: Small conus branch was seen in 52 (70.3%) and large conus in 22 ( 29.7%) patients. STE in right-sided leads and heart failure were significantly higher in small conus branch group versus large conus branch (88.6% vs 11.4%, P < 0.001 and 34.6% vs 9.1%, P = 0.02 respectively). There was no significant difference in mortality rate between the two groups (5.8% in small conous group vs 0% in large conus group, P = 0.55). There was a significant difference in major adverse cardiac events (MACE) between the two groups (51.9% in small conous group vs 18.2% in large conus group, P = 0.01). Conclusion: In patients with anterior MI, small conus branch was associated with higher rate of major adverse cardiac events mostly because of increased rate of acute heart failure.

ST-Segment Elevation in the Right Precordial Leads in Patients with Acute Anterior Myocardial Infarction

BACKGROUND

Elevation of ST segment in leads V3R/ V4R, which is commonly encountered in right ventricular myocardial infarction, may also occur in patients with anterior ST elevation myocardial infarction (STEMI). However, the clinical impact of this finding in the setting of anterior myocardial infarction is not well understood.

AIMS

We aimed to investigate the prognostic value of ST segment elevation in leads V3R/V4R in patients with first acute anterior myocardial infarction.

STUDY DESIGN

Prospective cohort study.

METHODS

Right precordial leads V3R/V4R were recorded in 111 patients admitted with first time anterior myocardial infarction. Patients were allocated into two groups based on the presence or absence of ST elevation in leads V3R/V4R. Demographic, biochemical and echocardiographic data, as well as the angiographic information, were recorded. In-hospital and 3 month mortality, and major adverse cardiac events (MACE), death, heart failure and ventricular dysrhythmia were also compared.

RESULTS

ST elevation in lead V3R or V4R was present in 72 out of 111 patients (64.9%). Involvement of the proximal part of the left anterior descending (LAD) artery was not different in the two groups (44.4% of patients with elevation vs. 53.8% of patients without elevation, p=0.22). Post-myocardial infarction complications, mortality and major adverse cardiac events were similar in the two groups. Left ventricular ejection fraction (LVEF) was significantly lower in patients with ST elevation in V3R/V4R (35 %±8 vs. 38 %±8, p=0.02). Twenty three out of 111 patients (20.7%) developed heart failure, which was similar in the two groups [16 (22.2%) of patients with ST elevation vs. 7 (17.9%) of patients without ST elevation, p=0.39].

CONCLUSION

Although ST elevation in V3R/V4R can be present in patients with left anterior descending artery occlusion, it does not seem to predict the prognosis. Lower left ventricular ejection fraction in this group may play a role in the long-term prognosis; however, this issue needs further investigation.

The QRS morphology pattern in V5R is a novel and simple parameter for differentiating the origin of idiopathic outflow tract ventricular arrhythmias

AIMS

There are many reports on the ECG characteristics of idiopathic outflow tract ventricular arrhythmias (OT-VAs) to predict their origin. However, differentiating near regions using 12-lead ECGs is still complicated. The synthesized 18-lead ECG derived from the 12-lead ECG can provide virtual waveforms of the right-sided chest leads (V3R, V4R, and V5R) and back leads (V7, V8, and V9). The aim of this study was to develop a simple and useful parameter for differentiating OT-VA origins using the 18-lead ECG.

METHODS AND RESULTS

We studied 28 and 73 patients with idiopathic VAs in a pacemapping study and validation cohort, respectively. In the pacemapping study, several sites out of five different sites were paced in each patient: the anterior and posterior right ventricular OT (RVOT-ant and RVOT-post), right and left coronary cusps (RCC and LCC), and junction of both cusps (RLJ). The 18-lead ECGs during pacemapping among the five sites were compared for establishing a simple parameter to predict VA origins. A novel parameter using 18-lead ECGs was tested prospectively in 73 patients. In the pacemapping study, the dominant QRS morphology pattern in the synthesized V5R significantly differed among those sites (RVOT-ant:Rs, RVOT-post:rS, RCC:QS, RLJ:qR, and LCC:R). The patients in the validation cohort were divided into five groups depending on those QRS morphology patterns during VAs in the synthesized V5R. Each V5R QRS morphology pattern could predict a precise origin of the OT-VAs with an overall accuracy of 75%.

CONCLUSION

The QRS morphology pattern in V5R was a simple and useful parameter for differentiating detailed OT-VA origins.

Incremental benefit of 80-lead electrocardiogram body surface mapping over the 12-lead electrocardiogram in the detection of acute coronary syndromes in patients without ST-elevation myocardial infarction: Results from the Optimal Cardiovascular Diagnostic Evaluation Enabling Faster Treatment of Myocardial Infarction (OCCULT MI) trial

BACKGROUND

The initial 12-lead (12L) electrocardiogram (ECG) has low sensitivity to detect myocardial infarction (MI) and acute coronary syndromes (ACS) in the emergency department (ED). Yet, early therapies in these patients have been shown to improve outcomes.

OBJECTIVES

The Optimal Cardiovascular Diagnostic Evaluation Enabling Faster Treatment of Myocardial Infarction (OCCULT-MI) trial was a multicenter trial comparing a novel 80-lead mapping system (80L) to standard 12L ECG in patients with chest pain and presumed ACS. This secondary analysis analyzed the incremental value of the 80L over the 12L in the detection of high-risk ECG abnormalities (ST-segment elevation or ST depression) in patients with MI and ACS, after eliminating all patients diagnosed with ST-elevation MI (STEMI) by 12L ECG.

METHODS

Chest pain patients presenting to one of 12 academic EDs were diagnosed and treated according to the standard care of that site and its clinicians; the clinicians were blinded to 80L results. MI was defined by discharge diagnosis of non-ST-elevation MI (NSTEMI) or unstable angina (UA) with an elevated troponin. ACS was defined as discharge diagnosis of NSTEMI or UA with at least one positive test result (troponin, stress test, angiogram) or revascularization procedure.

RESULTS

  Of the 1,830 patients enrolled in the trial, 91 patients with physician-diagnosed STEMI and 225 patients with missing 80L or 12L data were eliminated from the analysis; no discharge diagnosis was available for one additional patient. Of the remaining 1,513 patients, 408 had ACS, 206 had MI, and one had missing status. The sensitivity of the 80L was significantly higher than that of the 12L for detecting MI (19.4% vs. 10.4%, p = 0.0014) and ACS (12.3% vs. 7.1%, p = 0.0025). Specificities remained high for both tests, but were somewhat lower for 80L than for 12L for detecting both MI and ACS. Negative and positive likelihood ratios (LR) were not statistically different between groups. In patients with severe disease (defined by stenosis > 70% at catheterization, percutaneous coronary intervention, coronary artery bypass graft, or death from any cause), the 80L had significantly higher sensitivity for detecting MI (with equivalent specificity), but not ACS.

CONCLUSIONS

Among patients without ST elevation on the 12L ECG, the 80L body surface mapping technology detects more patients with MI or ACS than the 12L, while maintaining a high degree of specificity.

Recommendations for the standardization and interpretation of the electrocardiogram: part I: the electrocardiogram and its technology a scientific statement from the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society endorsed by the International Society for Computerized Electrocardiology

This statement examines the relation of the resting ECG to its technology. Its purpose is to foster understanding of how the modern ECG is derived and displayed and to establish standards that will improve the accuracy and usefulness of the ECG in practice. Derivation of representative waveforms and measurements based on global intervals are described. Special emphasis is placed on digital signal acquisition and computer-based signal processing, which provide automated measurements that lead to computer-generated diagnostic statements. Lead placement, recording methods, and waveform presentation are reviewed. Throughout the statement, recommendations for ECG standards are placed in context of the clinical implications of evolving ECG technology.

Recommendations for the Standardization and Interpretation of the Electrocardiogram

This statement examines the relation of the resting ECG to its technology. Its purpose is to foster understanding of how the modern ECG is derived and displayed and to establish standards that will improve the accuracy and usefulness of the ECG in practice. Derivation of representative waveforms and measurements based on global intervals are described. Special emphasis is placed on digital signal acquisition and computer-based signal processing, which provide automated measurements that lead to computer-generated diagnostic statements. Lead placement, recording methods, and waveform presentation are reviewed. Throughout the statement, recommendations for ECG standards are placed in context of the clinical implications of evolving ECG technology.

Recommendations for the standardization and interpretation of the electrocardiogram. Part I: The electrocardiogram and its technology. A scientific statement from the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society

This statement examines the relation of the resting ECG to its technology. Its purpose is to foster understanding of how the modern ECG is derived and displayed and to establish standards that will improve the accuracy and usefulness of the ECG in practice. Derivation of representative waveforms and measurements based on global intervals are described. Special emphasis is placed on digital signal acquisition and computer-based signal processing, which provide automated measurements that lead to computer-generated diagnostic statements. Lead placement, recording methods, and waveform presentation are reviewed. Throughout the statement, recommendations for ECG standards are placed in context of the clinical implications of evolving ECG technology.

ECG Techniques and Technologies

The electrocardiogram (ECG) continues to be a critical component of the evaluation of patients who have signs and symptoms of emergency cardiac conditions. This tool is now approximately 100 years old and has been a standard in clinical practice for more than half a century. Application of new signal processing techniques and an expansion in the use of additional leads allows clinicians to extract more and more information from the cardiac electrical activity. An understanding of the technology inherent in the recording of ECGs allows one to more fully understand the benefits and limitation of electrocardiography.

Additional electrocardiographic leads in the ED chest pain patient: right ventricular and posterior leads

In the evaluation of the patient with chest pain, the 12-lead electro cardiogram is a less-than-(ECG) perfect indicator of acute myocardial infarction (AMI), particularly when used early in the course of the acute ischemic event; this relative insensitivity for AMI results from many different issues, including a less-than-optimal imaging of certain areas of the heart. It has been suggested that the sensitivity of the 12-lead ECG can be improved if 3 additional body surface leads are used in selected individuals. Acute posterior (PMI) and right ventricular myocardial infarctions are likely to be underdiagnosed, because the standard lead placement of the 12-lead ECG does not allow these areas to be assessed directly. Additional leads frequently used include leads V(8) and V(9), which image the posterior wall of the left ventricle, and lead V(4R), which reflects the status of the right ventricle. The standard ECG coupled with these additional leads constitutes the 15-lead ECG, the most frequently used additional lead ECG in clinical practice. The use of the additional leads might not only confirm the presence of AMI, but also provide a more accurate reflection of the true extent of myocardial damage.

Early diagnosis of right ventricular or posterior infarction associated with inferior wall left ventricular acute myocardial infarction

Right ventricular (RV) or posterior infarction associated with inferior wall left ventricular acute myocardial infarction (AMI) has important therapeutic and prognostic implications. However, RV and posterior chest leads in addition to the 12-lead electrocardiogram are required for accurate detection. Body surface mapping (BSM) has greater spatial sampling and may further improve inferior wall AMI classification. Consecutive patients with chest pain lasting <12 hours were assessed to identify those with AMI and > or =0.1 mV ST elevation in > or =2 contiguous inferior leads of the 12-lead electrocardiogram (bundle branch block or left ventricular hypertrophy excluded). A 12-lead electrocardiogram, RV leads (V(2)R, V(4)R), posterior chest leads (V(7), V(9)), and a BSM were recorded. From each BSM, the 12 electrodes overlying the RV region (regional RV map) and 10 electrodes overlying the posterior wall (regional posterior map) were assessed for ST elevation. Infarct size was estimated by serial cardiac enzymes. AMI occurred in 173 of 479 patients. Of the 62 patients with inferior wall AMI, ST elevation > or =0.1 mV occurred in 26 patients (42 in V(2)R or V(4)R compared with 36 patients (58%) in > or =1 electrode on the regional RV map (p = 0.0019). ST elevation > or =0.1 mV occurred in 1 patient (2%) in V(7) or V(9) compared with 17 patients (27%) in > or =1 electrode on the regional posterior map (p = 0.00003). ST elevation > or =0.05 mV occurred in 6 patients (10%) in V(7) or V(9) compared with 22 patients (36%) in > or =1 electrode on the regional posterior map (p = 0.00003). Patients with ST elevation on regional RV and/or posterior maps had a trend toward larger infarct size (mean peak creatine kinase 1,789+/-226 vs. 1,546+/-392 mmol/L; p = NS). Thus, BSM, when compared with RV or posterior chest leads, provides improved classification of patients with inferior wall AMI and RV or posterior wall involvement.