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Background Some patients with RBBB may respond to cardiac resynchronization therapy (CRT). However, little is known regarding the electromechanical substrate for CRT and whether this is the optimal pacing strategy. Methods This was a pilot prospective double crossover randomized controlled clinical study comparing ventricular back up pacing (VVI-40), RV fusion pacing (DDD-40, RV only), and biventricular (BIV) pacing (DDD-40 BIV) in nine patients with RBBB and depressed EF. The study compared the frequency of dyssynchrony on baseline echocardiogram in patients with RBBB (n = 4), RBBB + anterior MI (RBBB with left axis deviation + left ventricular (LV) anterior wall thinning, n = 3), and RBBB + LAFB (RBBB with left axis deviation without LV anterior wall thinning n = 2). Echocardiographic assessment of LV dyssynchrony, LV size, and LV function was repeated after 6 months in each pacing mode. Results Patients with RBBB + LAFB demonstrated baseline echocardiographic dyssynchrony between the LV anterior and inferior wall. Both DDD-40 RV-only pacing and DDD-40 BIV pacing resulted in improved LV function and clinical status compared to VVI-40 back up pacing. Patients with RBBB alone and RBBB with anterior MI had no baseline dyssynchrony and CRT using either RV only or BIV pacing resulted in LV dilation, worsened left ventricular ejection fraction and worsened clinical status compared to VVI-40 back up pacing. Conclusion Patients with RBBB, left axis deviation, and no prior anterior MI may have LV dyssynchrony between the anterior and inferior walls that is correctable with CRT.

BACKGROUND: The acuteness score (based on the modified Anderson-Wilkins score) estimates the acuteness of ischemia based on ST-segment, Q-wave and T-wave measurements obtained from the electrocardiogram (ECG) in patients with ST Elevation Myocardial Infarction (STEMI). The score (range 1 (least acute) to 4 (most acute)) identifies patients with substantial myocardial salvage potential regardless of patient reported symptom duration. However, due to the complexity of the score, it is not used in clinical practice. Therefore, we aimed to develop a reliable algorithm that automatically computes the acuteness score.METHODS: We scored 50 pre-hospital ECGs from STEMI patients, manually and by the automated algorithm. We assessed the reliability test between the manual and automated algorithm by interclass correlation coefficient (ICC) and Bland-Altman plot.RESULTS: The ICC was 0.84 (95% CI 0.72-0.91), PCONCLUSION: In conclusion, we have developed an automated algorithm for measurement of the modified Anderson-Wilkins ECG acuteness score from the pre-hospital ECG in STEMI patients. This automated algorithm is highly reliable, can be applied in daily practice for research purposes and may be implemented in commercial automated ECG analysis programs to achieve practical use for decision support in the acute phase of STEMI.

Background There is a need for improved selection criteria for cardiac resynchronization therapy (CRT). High myocardial scar burden has been associated with worse outcome in CRT patients. However, it is unclear whether high scar burden prevents CRT clinical benefit or is merely predictive of prognosis in heart failure (HF) patients regardless of CRT implantation. We aimed to study the predictive value of scar burden estimated by electrocardiographic Selvester QRS scoring in determining CRT benefit in the multicenter automatic defibrillator implantation trial-cardiac resynchronization therapy (MADIT-CRT) population. Methods Selvester QRS scoring was performed on all 1820 ECGs of the MADIT-CRT population by a single observer. In both arms and in their respective LBBB subgroups, QRS score was analyzed in comparison to echocardiographic volumes and in relation to time to HF event or death using Cox proportional hazard ratios. To determine effect on CRT clinical benefit, we tested for interaction between the effects of CRT assignment and QRS score on time to HF event or death. Results In the CRT-D arm, a significant correlation was found between higher continuous QRS score and less increase of left ventricular ejection fraction (LVEF) as well as less decrease of left ventricular end-systolic volume (LVESV) (multivariate -p-values

BACKGROUND: In contrast to LBBB patients less is known about patients with RBBB+LAFB regarding LV contractile abnormalities and the potential role of CRT. This study investigated whether patients with RBBB+LAFB morphology have echocardiographic mechanical strain abnormalities between the inferior and anterior LV walls, similar to abnormalities between septal and lateral walls in LBBB.METHODS AND RESULTS: Ten healthy volunteers with no-BBB, 28 LBBB and 28 RBBB+LAFB heart failure patients were included in this retrospective study. Two-dimensional regional-strains were obtained by speckle-tracking. Scar was assessed by CMR. Response on echo was defined as normal, classical, borderline or other pattern. The number of classical patterns in LBBB was significantly higher than in RBBB+LAFB and no-BBB groups (pCONCLUSIONS: Patients with RBBB+LAFB on ECG and clinical HF demonstrate echocardiographic wall motion abnormalities between inferior and anterior LV walls, similar to abnormalities found between septal and lateral LV walls in patients with LBBB and HF. Fewer patients with RBBB+LAFB showed a classical pattern of opposing wall motion compared to LBBB. Factors that might alter strain patterns in RBBB+LAFB, including the detailed presence or absence of LV scar and coexisting block of the central fascicle, should be assessed in future studies.

Introduction Studies have shown terminal QRS distortion and resultant QRS prolongation during ischemia to be a sign of low cardiac protection and thus a faster rate of myocardial cell death. A recent study introduced a single lead method to quantify the severity of ischemia by estimating QRS prolongation. This paper introduces a 12-lead method that, in contrast to the previous method, does not require access to a prior ECG. Methods QRS duration was estimated in the lead that showed the maximal ST deviation according to a novel method. The degree of prolongation was determined by subtracting the measured QRS duration in the lead that showed the least ST deviation. Results The method is demonstrated in examples of acute occlusion in two of the major coronary arteries. Conclusion This paper presents a 12-lead method to quantify the severity of ischemia, by measuring QRS prolongation, without requiring comparison with a previous ECG.

Objectives System delay (time from first medical contact to primary percutaneous coronary intervention) is associated with heart failure and mortality in patients with ST segment elevation myocardial infarction (STEMI). We evaluated the impact of system delay on left ventricular function (LVF) according to the combination of ischemia severity (Sclarovsky–Birnbaum grades) and acuteness (Anderson–Wilkins scores) in the pre-hospital electrocardiogram (ECG). Methods In a predefined secondary analysis of a prospective study, the severity and acuteness scores were performed on the pre-hospital ECG. Patients were assessed with respect to 4 classifications which were not mutually exclusive: severe ischemia (+ SI) or non-severe ischemia (− SI) and acute ischemia (+ AI) or non-acute ischemia (− AI). LVF was assessed by global longitudinal strain (GLS) within 48 hours of admission. Adjusted linear regression investigated the association of system delay with GLS in each group. Results In total 262 patients were eligible for analysis of the ECG, which resulted in 42 (16%) with (+ SI, − AI), 110 (42%) with (− SI, − AI), 90 (34%) with (− SI, + AI), and 20 (8%) patients with (+ SI, + AI). Although system delay did not differ between groups, patients with severe and non-acute ischemia had the most impaired LVF. System delay correlated weakly with GLS in the entire population (r = 0.133, p = 0.031), and well with GLS in the (+ SI, + AI) group (r = 0.456, p = 0.04), while there was no correlation in the other groups. By adjusted analysis, system delay predicted impaired GLS only in the (+ SI, + AI) group (β = 0.578, p = 0.002). Conclusion Pre-hospital risk stratification by ECG identifies patients with acute and severe ischemia who are at increased risk for reduced ventricular function (assessed by GLS) after STEMI. Optimizing reperfusion delays in these patients can therefore be of particular benefit in improving clinical outcome after STEMI.

Background Existing criteria recommended by ACC/ESC for identifying patients with ST elevation myocardial infarction (STEMI) from the 12-lead ECG perform with high specificity ( SP ), but low sensitivity ( SE ). In our previous studies, we found that the SE of ischemia detection can be markedly improved without any loss of SP by calculating, from the 12-lead ECG, ST deviation in 3 “optimal” vessel-specific leads (VSLs). Our original VSLs, based on ΔST body-surface potential maps (BSPMs), have been modified by using the more appropriate J-point BSPMs at peak ischemia (without subtraction of pre-occlusion distributions). The aim of the present study was to compare the performance of these new VSLs with that achieved by the STEMI criteria used in current practice. Methods Two independent datasets of 12-lead ECGs were used: the STAFF III dataset acquired during ischemic episodes caused by balloon inflation in LAD ( n = 35), RCA ( n = 47), and LCx ( n = 17) coronary arteries, and the Glasgow dataset comprising admission 12-lead ECGs of 116 patients who were hospitalized for chest pain and underwent contrast-enhanced cardiac MRI that confirmed AMI in 58 patients (50%). Results We found that, in the STAFF III dataset, the detection of ischemic state by the STEMI criteria attained SE/SP of 60/97%, whereas SE/SP values of VSLs were 72/98%. In the Glasgow dataset, STEMI criteria yielded SE/SP of 43/98%, whereas the VSLs improved SE/SP to 60/98%. The most significant increase in diagnostic performance appeared in patients with LCx coronary artery occlusion: in STAFF III data ( n = 17) SE achieved by STEMI criteria was improved by the VSLs from 35% to 71%; in Glasgow data ( n = 12) SE of 31% achieved by STEMI criteria was improved by the VSLs to 69%. Conclusion In our study population, existing ACC/ESC STEMI criteria complemented by the new VSLs yielded much improved sensitivity of ischemia detection without any detrimental effect on specificity. This finding needs to be corroborated on a larger chest-pain patient population with typical prevalence of acute ischemia presented to the emergency rooms.

Background Estimation of the infarct size from body-surface ECGs in post-myocardial infarction patients has become possible using the Selvester scoring method. Automation of this scoring has been proposed in order to speed-up the measurement of the score and improving the inter-observer variability in computing a score that requires strong expertise in electrocardiography. In this work, we evaluated the quality of the QuAReSS software for delivering correct Selvester scoring in a set of standard 12-lead ECGs. Method Standard 12-lead ECGs were recorded in 105 post-MI patients prescribed implantation of an implantable cardiodefibrillator (ICD). Amongst the 105 patients with standard clinical left bundle branch block (LBBB) patterns, 67 had a LBBB pattern meeting the strict criteria. The QuAReSS software was applied to these 67 tracings by two independent groups of cardiologists (from a clinical group and an ECG core laboratory) to measure the Selvester score semi-automatically. Using various level of agreement metrics, we compared the scores between groups and when automatically measured by the software. Results The average of the absolute difference in Selvester scores measured by the two independent groups was 1.4 ± 1.5 score points, whereas the difference between automatic method and the two manual adjudications were 1.2 ± 1.2 and 1.3 ± 1.2 points. Eighty-two percent score agreement was observed between the two independent measurements when the difference of score was within two point ranges, while 90% and 84% score agreements were reached using the automatic method compared to the two manual adjudications. Conclusion The study confirms that the QuAReSS software provides valid measurements of the Selvester score in patients with strict LBBB with minimal correction from cardiologists.

Background New-onset left bundle branch block (LBBB) is a known complication during Transcatheter Aortic Valve Replacement (TAVR). This study evaluated the influence of pre-TAVR cardiac conditions on left ventricular functions in patients with new persistent LBBB post-TAVR. Methods Only 11 patients qualified for this study because of the strict inclusion criteria. Pre-TAVR electrocardiograms were evaluated for Selvester QRS infarct score and QRS duration, and left ventricular end-systolic volume (LVESV) was used as outcome variable. Results There was a trend towards a positive correlation between QRS score and LVESV of r = 0.59 (p = 0.058) , while there was no relationship between QRS duration and LVESV (r = − 0.18 [ p = 0.59 ]). Conclusion This study showed that patients with new LBBB and higher pre-TAVR QRS infarct score may have worse post-TAVR left ventricular function, however, pre-TAVR QRS duration has no such predictive value. Because of the small sample size these results should be interpreted with caution and assessed in a larger study population.

Electrocardiographic (ECG) LV scar quantification may improve prediction of CRT response.Data were abstracted in 76 patients who underwent a first CRT implantation at 2 US centers. Selvester QRS scar quantification was performed using the LBBB modified QRS scoring method. Seven clinical variables previously associated with reverse LV remodeling (RLVR) and QRS score were included in logistic regression analysis. Survival was compared across QRS score quartiles using Kaplan-Meier curves. RLVR occurred more frequently in patients with QRS score ≤ 5 (63%) than QRS score5 (22%), (OR=5.83, 95% CI=2.11-16.07). After adjustment for clinical variables using logistic regression, QRS score5 predicted RLVR (Chi-square=20.3, P=0.005, AUC=0.782). Patients in the lowest quartile of QRS score (4) had improved survival compared to patients in the other QRS score quartiles (P=0.037).ECG quantified LV scar predicts RLVR and long-term survival in patients with LBBB undergoing CRT implantation.

About one-third of patients undergoing cardiac resynchronization therapy because of left bundle branch block (LBBB) and heart failure do not improve. Strauss et al. have developed strict criteria to more accurately define complete LBBB in this patient group. The aim of this study was to investigate the prevalence of the manual application of the Strauss criteria for LBBB (QRS ≥ 140 ms in men, ≥ 130 ms in women, along with mid-QRS notching/slurring) in consecutive patients who have been diagnosed with LBBB by the automated Glasgow criteria (QRS ≥ 120 ms).In 158 consecutive patients (78 females) diagnosed with LBBB according to the automated Glasgow criteria, the manual Strauss criteria were applied.A majority of patients (87%) diagnosed with LBBB using the Glasgow criteria were positive for the Strauss criteria. In 70% (13/20) of the cases of disagreement the reason for disagreement was short QRS duration.

Introduction Left bundle branch block (LBBB) is a known complication of transcatheter aortic valve replacement (TAVR) and has been shown to predict worsened outcomes in TAVR patients. A regional longitudinal strain pattern, termed the “classic” pattern of left ventricular (LV) dyssynchrony, which is thought to be due to LBBB, is highly predictive of response to cardiac resynchronization therapy. Whether LBBB causes this “classic” pattern is not known. Methods We retrospectively studied patients undergoing TAVR who also underwent pre- and post-TAVR strain analysis to determine if the “classic” pattern arose in those who developed TAVR-induced true LBBB. After removing patients with baseline conduction abnormalities or insufficient studies 9 patients had sufficient data for analysis. Six patients developed LBBB after TAVR and 3 patients did not develop LBBB after TAVR. ECGs were analyzed for the new onset of LBBB after TAVR. Global longitudinal strain (GLS) and regional longitudinal strain patterns were analyzed for changes between pre- and immediately post-TAVR examinations. Results Patients who did not develop LBBB showed no significant changes in their regional longitudinal strain pattern. Those patients who did develop LBBB showed significant increase in their difference of time-to-onset of contraction between the septal and lateral walls post-TAVR (22 ± 14 ms vs 111 ± 49 ms; p = 0.003) and in their difference of time-to-peak contraction between the septal and lateral walls post-TAVR (63 ± 56 ms vs 133 ± 46 ms; p = 0.002). Early lateral wall pre-stretch and delayed lateral wall peak contraction emerged in all patients with LBBB but early septal peak contraction meeting the established criteria was present in only one patient. Discussion The onset of LBBB led to acute, measurable changes in the regional longitudinal strain pattern consisting of early lateral wall pre-stretch and delayed lateral wall peak contraction. These represent 2 of the 3 findings in the “classic” pattern of LV dyssynchrony. Early termination of septal wall contraction meeting established criteria was not routinely found. Time and/or other factors may be required to develop the full “classic” pattern.

Progressive heart failure leading to transplantation or death is common in pediatric dilated cardiomyopathy (DCM), and treatment options are limited. Select children with DCM have improved after cardiac resynchronization therapy (CRT), but predicting response is challenging. Nonetheless, considering the frequency of death or transplantation in this population, identifying any candidate would be valuable. Classic-pattern dyssynchrony (CPD) identifies mechanical dyssynchrony patterns consistent with underlying electrical activation delays and strongly predicts CRT response in adult DCM but has not been evaluated in pediatric DCM. The aim of this study was to test the hypothesis that CPD is present in a subgroup of patients with pediatric DCM and is associated with activation delays.Fifty-nine subjects with pediatric DCM (left ventricular end-diastolic diameter Z score2 and left ventricular ejection fraction40%) who underwent echocardiography with a functional protocol with apical images optimized for two-dimensional speckle-tracking strain analysis (EchoPAC) were retrospectively analyzed for CPD. Electrocardiograms were evaluated for activation delays (prolonged QRS duration and strict criteria for left bundle branch block [LBBB]). Forty control subjects with no cardiac disease and good imaging widows were also analyzed.The mean age was 5.4 years (range, 1 day to 20 years); idiopathic DCM was most common (57%). Severe cardiomyopathy was present in 75% (end-diastolic diameter Z score4.6 and left ventricular ejection fraction32%). CPD was identified in seven subjects (12%), and prolonged QRS durations were present in 13 (22%), but only two subjects met strict criteria for LBBB. Six of seven subjects in the CPD group had prolonged QRS durations, and two of seven had LBBB. No control subjects had CPD. The CPD analysis was highly feasible and reproducible.In this severely affected cohort, the small CPD subgroup is potentially important because their progressive disease may respond to CRT. CPD is associated with activation delays, although not necessarily strict LBBB. This has important potential implications for prospective evaluation of CRT in this disease.

BACKGROUND: In STEMI, grade-3 ischemia (G3) on admission ECG predicts larger infarct size (IS) than grade-2 (G2). We evaluated whether pre-hospital G3 and its temporal behavior are associated with IS and salvage after pPCI.METHODS: In 401 STEMI patients, pre-hospital and pre-PCI ECGs were classified as G3 or G2. IS was assessed by single-photon emission computed tomography (SPECT) at 30days. In 245 patients, pre-PCI SPECT was available to determine myocardium at risk (MaR).RESULTS: G3 criteria were met by 88, and G2 by 313 patients. G3 was independently associated with IS (p=0.006). With ST resolution (STR) group as a reference, G2->G2, G2->G3 and G3->G3 were associated with larger IS (B=4.4, p=0.004; B=5.4, p=0.01; B=10.2, pG2 was not. Salvage was similar between G3 and G2 on pre-hospital ECG if treated early, however lower for G3 when treated later (>2.5h); 48% (35-78) vs 62% (40-87); p=0.04.CONCLUSION: Development or persistence of G3 is associated with larger IS and less salvage, but decreasing grade G3->G2 was not.

The extent and rate at which necrosis develops in experimental acute myocardial infarction in the dog heart is presented together with an analysis of the role played by protective mechanisms in myocyte death. Preconditioning with ischemia delays but does not prevent myocyte death. Arterial collateral flows exceeding 30% of control flow essentially prevent myocyte death, while lesser amounts of collateral flow delay myocyte death to a variable extent. Flows of

OBJECTIVES: The purpose of this study is to present a new and improved method for translating the electrocardiographic changes of acute myocardial ischemia into a display which reflects the location and extent of the ischemic area and the associated culprit coronary artery. This method could be automated to present a graphic image of the ischemic area in a manner understandable by all levels of caregivers; from emergency transport personnel to the consulting cardiologist.BACKGROUND: Current methods for the ECG diagnosis of ST elevated myocardial infarction (STEMI) are criteria driven, and complex, and beyond the interpretive capability of many caregivers. New methods are needed to accurately diagnose the presence of acute transmural myocardial ischemia in order to accelerate a patient's clinical "door to balloon time." The proposed new method could potentially provide the information needed to accomplish this objective.METHODS: The new method improves the precision of diagnosis and quantification of ischemia by normalizing the ST segment inputs from the standard 12 lead ECG, transforming these into a three dimensional vector representation of the ischemia at the electrical center of the heart. The myocardial areas likely to be involved in this ischemia are separately analyzed to assess the probability that they contributed to this event. The source of the ischemia is revealed as a specific region of the heart, and the likely location of the associated culprit coronary artery. Seventy 12 lead ECGs from subjects with known single artery occlusion in one of the three main coronary arteries were selected to test this new method. Graphic plots of the distribution of ischemia as indicated by the method are consistent with the known occlusion. The analysis of the distribution of ischemic areas in the myocardium reveals that the relationships between leads with either ST elevation or ST depression, provide critical information improving the current method.

We aimed to study the prevalence of acute cardiac disorders in patients with suspected ST-segment elevation myocardial infarction (STEMI) and non-significant coronary artery disease (CAD).From January to October 2012 we consecutively included patients admitted with suspected STEMI and non-significant CAD (coronary artery stenosis diameter50%). Patients were diagnosed with acute cardiac disorder in the presence of elevated cardiac biomarkers (troponin T50ng/l or creatine kinase MB4μg/l) or dynamic ECG changes (ST-segment changes or T-wave inversion).Of the 871 patients admitted with suspected STEMI, 11% (n=95) had non-significant CAD. Of these, 67% (n=64) had elevated cardiac biomarkers or dynamic ECG changes and were accordingly diagnosed with acute cardiac disorders. In the remaining 33% (n=31) of patients, cardiac biomarkers were normal and ECG changes remained stationary.Acute cardiac disorders were diagnosed in two thirds of patients with suspected STEMI and non-significant CAD.

Ischemic preconditioning is a form of intrinsic cardioprotection where an episode of sublethal ischemia protects against subsequent episodes of ischemia. Identifying a clinical biomarker of preconditioning could have important clinical implications, and prior work has focused on the electrocardiographic ST segment. However, the electrophysiology biomarker of preconditioning is increased action potential duration (APD) shortening with subsequent ischemic episodes, and APD shortening should primarily alter the T wave, not the ST segment. We translated findings from simulations to canine to patient models of preconditioning to test the hypothesis that the combination of increased [delta (Δ)] T wave amplitude with decreased ST segment elevation characterizes preconditioning. In simulations, decreased APD caused increased T wave amplitude with minimal ST segment elevation. In contrast, decreased action potential amplitude increased ST segment elevation significantly. In a canine model of preconditioning (9 mongrel dogs undergoing 4 ischemia-reperfusion episodes), ST segment amplitude increased more than T wave amplitude during the first ischemic episode [ΔT/ΔST slope = 0.81, 95% confidence interval (CI) 0.46–1.15]; however, during subsequent ischemic episodes the T wave increased significantly more than the ST segment (ΔT/ΔST slope = 2.43, CI 2.07–2.80) ( P < 0.001 for interaction of occlusions 2 vs. 1). A similar result was observed in patients (9 patients undergoing 2 consecutive prolonged occlusions during elective percutaneous coronary intervention), with an increase in slope of ΔT/ΔST of 0.13 (CI −0.15 to 0.42) in the first occlusion to 1.02 (CI 0.31–1.73) in the second occlusion ( P = 0.02). This integrated analysis of the T wave and ST segment goes beyond the standard approach to only analyze ST elevation, and detects cellular electrophysiology changes of preconditioning.

QRS duration (QRSd) is used to diagnose left bundle branch block (LBBB) and is important to determine cardiac resynchronization therapy eligibility. The same QRSd thresholds established decades ago are used for all patients. However, significant interpatient variability of normal QRSd exists, and individualized QRSd thresholds might improve diagnosis and intervention strategies. Previous work reported left ventricular (LV) mass and papillary muscle location predicted QRSd in healthy subjects, but the relation in diseased ventricles is unknown. The aim of the present study was to determine the association between LV anatomy and QRSd in patients with cardiomyopathy. Patients referred for primary prevention implantable defibrillators (n = 166) received cardiac magnetic resonance imaging, and those with normal conduction (without bundle branch or fascicular block) and LBBB were studied. The LV mass, length, internal diameter, LV end-diastolic volume, septal and lateral wall thicknesses, and papillary muscle location were measured. In patients with normal conduction, LV length (r = 0.35, p0.001), mass (r = 0.32, p0.001), diameter (r = 0.20, p = 0.03), and septal wall thickness (r = 0.20, p = 0.03) had positive correlations with QRSd. In patients with LBBB, LV length (r = 0.32, p = 0.03), mass (r = 0.39, p = 0.01), diameter (r = 0.34, p = 0.02), and LV end-diastolic volume (r = 0.32, p = 0.04) had positive correlations with QRSd. Contrary to previous studies in healthy subjects, papillary muscle angle (location) was not associated with QRSd in cardiomyopathy patients with normal conduction or LBBB. In conclusion, increasing LV anatomical measurements were associated with increasing QRSd in patients with cardiomyopathy. Future work should investigate the use of LV anatomical measurements in developing individualized QRSd thresholds for diagnosing conduction abnormalities such as LBBB and identifying candidates for cardiac resynchronization therapy.

Background Electrocardiographic (ECG) Selvester QRS score criteria with false indication of anteroseptal scarring consistent with myocardial infarction have been found in patients with ostium secundum atrial septal defect (OS-ASD). The objective of this study was to evaluate ECGs pre and post percutaneous transcatheter OS-ASD closure to test the hypothesis that the falsely positive criteria for anteroseptal scar decline 1 day post procedure. Methods Patients (n = 34, mean age 48 ± 17 years, 79% female) that underwent OS-ASD closure and had undergone pre procedure cardiac magnetic resonance imaging showing no left ventricular (LV) scarring were included in this study. ECGs pre and 1 day post procedure were assessed according to the QRS Selvester scoring system and compared. Results Mean Selvester score in anteroseptal regions pre procedure was 6.6 (0.0–6.8) % LV scar and decreased to 4.3 (0.0–6.0) % LV scar one day after the procedure (p = 0.01). Mean Selvester score in lateral regions pre procedure was 3.7 (0.0–3.0) %LV scar and decreased to 2.8 (0.0–0.0) % LV scar one day post procedure (p = 0.25). Discussion OS-ASD patients with falsely positive anteroseptal scar criteria by the Selvester QRS score pre procedure have a significant decrease in anteroseptal Selvester score 1 day post procedure. The falsely positive anteroseptal scar criteria did not completely resolve 1 day post procedure. Further studies are needed to investigate the relationship between ECG criteria for anteroseptal scar and right ventricular volume overload in late follow up.

Background and Aim The reduction of left ventricular ejection fraction (LVEF) following ST-segment elevation myocardial infarction (STEMI) is a result of infarcted myocardium and may involve dysfunctional but viable myocardium. An index that may quantitatively determine whether LVEF is reduced beyond the expected value when considering only infarct size (IS) has previously been presented based on cardiac magnetic resonance (CMR). The purpose of this study was to introduce the index based on the electrocardiogram (ECG) and compare indices based on ECG and CMR. Method and Results In 55 patients ECG and CMR were obtained 3 months after STEMI treated with primary percutaneous coronary intervention. Significant, however moderate inverse relationships were found between measured LVEF and IS. Based on IS and LVEF an IS estimated LVEF was derived and an MI–LVEF mismatch index was calculated as the difference between measured LVEF and IS estimated LVEF. In 41 (74.5%) of the patients there was agreement between the ECG and CMR indices in regards to categorizing indices as > 10 or ≤ 10 and generally no significant difference was detected, mean difference of 1.26 percentage points (p = 0.53). Conclusion The study found an overall good agreement between MI–LVEF mismatch indices based on ECG and CMR. The MI–LVEF mismatch index may serve as a tool to identify patients with potentially reversible dysfunctional but viable myocardium, but future studies including both ECG and CMR are needed.

Prompt and accurate identification of ST-elevation myocardial infarction (STEMI) in the presence of left bundle-branch block (LBBB) remains difficult. The 2004 STEMI guideline recommended emergent reperfusion therapy to patients with suspected ischemia and new or presumably new LBBB. These recommendations have led to frequent false catheterization laboratory activation and inappropriate fibrinolytic therapy because most patients with suspected ischemia and new or presumably new LBBB do not have acute coronary artery occlusion on angiography. The new 2013 STEMI guideline makes a drastic change by removing previous recommendations. Therefore, patients with suspected ischemia and new or presumably new LBBB would no longer be treated as STEMI equivalent. The new guideline fails to recognize that some patients with suspected ischemia and LBBB do have STEMI, and denying reperfusion therapy could be fatal. The Sgarbossa electrocardiography criteria are the most validated tool to aid in the diagnosis of STEMI in the presence of LBBB. A Sgarbossa score of ≥3 has a superb specificity (98%) and positive predictive value for acute myocardial infarction and angiography-confirmed acute coronary occlusion. Thus, we propose a diagnosis and triage algorithm incorporating the Sgarbossa criteria to quickly and accurately identify, among patients presenting with chest pain and new or presumably new LBBB, those with acute coronary artery occlusion. This is a high-risk population in which reperfusion therapy would be denied by the 2013 STEMI guideline. Our algorithm will also significantly reduce false catheterization laboratory activation and inappropriate fibrinolytic therapy, the inevitable consequence of the 2004 STEMI guideline.

ObjectivesThis study sought to test the hypothesis that right bundle branch block (RBBB) patients have larger scar size than left bundle branch block (LBBB) patients do.BackgroundA proximal septal perforating branch of the left anterior descending (LAD) coronary artery most commonly perfuses the right bundle branch and left anterior fascicle, but not the left posterior fascicle. Thus, proximal LAD occlusions should cause RBBB, not LBBB.MethodsWe performed electrocardiograms and magnetic resonance imaging for scar quantification in 233 patients with left ventricular (LV) ejection fraction ≤35% who were receiving primary prevention implantable cardioverter-defibrillators (ICD cohort). Scar size and location were compared among patients with RBBB, LBBB, nonspecific LV conduction delay, and QRS

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.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).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.

The ECG is at a crossroads as to its future integration into modern medical practice. Those most interested in electrocardiography remain the old guard, whose careers evolved with this technology. They remain as enamored by the experiential mythology as by the experimental science of the ECG. Electrophysiologists, who rightly should be carrying on the torch of further ECG development, are too busy with their therapeutic invasive procedures and devices to invest much time in diagnostic decision support. Young physicians in training are too busy learning the plethora of new diagnostic modalities and treatment procedures to even become competent in ECG interpretation. Many of them only have goals to recognize an ST elevation myocardial infarction and atrial fibrillation, and to pass their board examinations. Their understanding of ST elevation myocardial infarction criteria could be easily exposed by asking them to name the contiguous pairs of standard ECG leads. A disappointing number would refer to pairs of leads that are contiguous on the ECG display such as II and III or V1 and V4, rather than the leads separated by 30° going around the surface of the heart as specified in the guidelines.1 Reimbursement provides a further counterincentive: to paraphrase George Bernard Shaw ( The Doctor’s Dilemma , 1926), “the doctor orders the test that pays the most” and that is no longer the ECG, but a panoply of imaging procedures. Examples of the experiential mythology that continue to haunt electrocardiography include the requirement for contiguous or adjacent leads instead of a single lead for fulfilling diagnostic criteria. The contiguous or adjacent lead constraint is a residual from the thick, noisy tracings from the early days of electrocardiography before high-impedance amplifiers, DC coupling, and digital processing produced the high-resolution tracings of today (Figure 1). Applying the criteria to a …

The mortality benefit of implantable cardioverter defibrillators (ICD) in patients with prior myocardial infarction (MI) and reduced left ventricular ejection fraction (LVEF) demonstrated in Multicenter Automatic Defibrillator Implantation Trial II (MADIT-II) and Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) has resulted in recommendation for broad use of these devices and dramatically increased implantation rates in recent years.1–4 The high incremental cost-effectiveness ratio and relatively low rate of appropriate ICD discharge illustrates the need for better risk-stratification techniques to identify patients for ICD implantation.5, 6 The mortality reduction in MADIT-II was due to a reduction in sudden cardiac death (SCD) with no effect on heart failure (HF) deaths.7 Prior studies have shown that as HF progresses, the relative risk of total mortality and HF death (non-SCD) increases while the relative risk of SCD decreases.8–10 This may explain the U-shaped pattern in ICD efficacy observed where ICD efficacy was greatest in patients with an intermediate risk of death, but lower in patients at highest risk for death.11 Distinguishing individuals at high risk for non-SCD from those primarily at risk for SCD may allow for identification of who will benefit most from ICDs. Analysis of the SCD-HeFT trial found that quantifying infarct size using the Selvester QRS score was predictive of ventricular tachycardia or ventricular fibrillation (VT/VF) and, when combined with LVEF, was able to separate subgroups of low, medium and high risk of VT/VF.12 Additionally, several studies have implicated infarct size as a predictor of both heart failure development and worse outcomes.13–15 The value of the QRS score in predicting SCD vs. non-SCD risk in ICD eligible subjects has not yet been examined. This study evaluated whether QRS score is useful for risk stratification of ICD eligible patients. We hypothesized that (1) subjects with moderate/large infarcts would have the highest rate of SCD; (2) as MI size increases, the rates of non-SCD would approach that of VT/VF and/or SCD; and (3) ICDs would confer the greatest mortality benefit in patients with large MIs.

Background Left bundle-branch block (LBBB) is a marker of increased delay between septal and left ventricular (LV) lateral wall electrical activation and is a predictor of which patients will benefit from cardiac resynchronization therapy. Recent analysis has suggested that one-third of patients meeting the conventional electrocardiogram criteria for LBBB are misdiagnosed, and new strict LBBB criteria have been proposed. We tested the hypothesis that patients with strict LBBB have greater LV mechanical dyssynchrony than do patients meeting the nonstrict LBBB criteria, whereas there is no difference between patients with nonstrict LBBB and LV conduction delay with a QRS duration of 110 to 119 ms. Methods Sixty-four patients referred for primary prevention implantable cardioverter-defibrillators underwent 12-lead electrocardiogram and cardiac magnetic resonance myocardial tagging. The patients were classified as strict LBBB, nonstrict LBBB, or non-LBBB (nonspecific LV conduction delay with a QRS duration of 110-119 ms). The time delay between septal and lateral LV wall peak circumferential strain (septal-to-lateral wall delay) was measured by cardiac magnetic resonance. Results Patients with strict LBBB (n = 31) had a greater septal-to-lateral wall delay compared with patients with nonstrict LBBB (n = 19) (210 ± 137 ms vs 122 ± 102 ms, P = .045). There was no significant difference between nonstrict LBBB and non-LBBB (n = 14) septal-to-lateral wall delay (122 ± 102 ms vs 100 ± 86 ms, P = .51). Conclusions Strict LBBB criteria identify patients with greater mechanical dyssynchrony compared with patients only meeting the nonstrict LBBB criteria, whereas there was no significant difference between patients with nonstrict LBBB and non-LBBB. The greater observed LV dyssynchrony may explain why patients with strict LBBB have a better response to cardiac resynchronization therapy.

Background Many graphical methods for displaying ST-segment deviation in the ECG have been tried for enhancing decision-making in patients with suspected acute coronary syndromes. Computed electrocardiographic imaging (CEI), based on a mathematical inverse solution, has been recently applied to transform ST-J point measurements made in conventional 12-lead ECG into a display of epicardial potentials in bull’s-eye format. The purpose of this study is to assess utility of CEI in the clinical setting. Methods In 99 patients with stable coronary disease, 12-lead ECGs were recorded during elective percutaneous coronary intervention (PCI), first before balloon-catheter insertion and then when an intracoronary balloon blocked blood supply to a region of myocardium for more than 4 minutes (typically 5 minutes). Four groups of patients were additionally studied, namely those with preexcitation, pericarditis, early repolarization syndrome (ERS), and left ventricular hypertrophy (LVH) with strain. Comparisons between performances of published criteria for ST-elevation myocardial infarction (STEMI) and quantitative as well as visual assessment of CEI images were based on sensitivities and specificities. Results Visual assessment of CEI outperformed STEMI criteria. This was especially evident for the capability of detecting LCx occlusion with sensitivities for STEMI criteria = 35% and for visual assessment of CEI by 2 physicians = 71%, i. e. twice as many patients were correctly identified by CEI. False positive rates for CEI were low in patients with LVH with strain as well as with preexcitation for both methods. For pericarditis and ERS, visual as well as quantitative assessment of CEI performed better than STEMI criteria. Conclusion Visual assessment of CEI is a promising method for increasing the accuracy of ECG-based triage to PCI or conservative care.

Background and purpose Identification of prognostic markers can be used to stratify patients in the acute phase of ST-elevated myocardial infarction (STEMI) according to their potential to retain viable myocardium after reperfusion. The percentage of the myocardial area at risk (MaR) that is ischemic at admission, defined as the Acute Ischemia Index, is potentially salvageable. The percentage of the MaR viable at 3 months post-reperfusion, by salvage and healing, was defined as the Chronic Salvage Index. A positive relationship between the Acute Ischemia Index and the Chronic Salvage Index was hypothesized. Methods Both indices were assessed by using the ECG indices Aldrich ST and Selvester QRS scores estimating the ischemic and infarcted myocardium. The study population comprised inferior STEMI patients. (N = 59). Results A correlation of 0.253 (P = 0.053) was found. Conclusions These results are relevant and suggest evidence of a trend in the association between these indices.

Background/Objectives Timely identification of cardiac ischemia is critical in patients with acute coronary syndrome (ACS). The first test is often the standard, resting 12-lead ECG. Given its limitations, signal analysis enhancements have been proposed. We summarize the published evidence for commercially available ECG-based signal analysis technologies. Methods This is a systematic review of the English-language published literature. Results Published evidence meeting inclusion criteria was available for two devices: PRIME ECG and LP 3000. Meta-analysis of eight studies estimated a 68.4% sensitivity (95% CI, 35.1%–89.7%) and 91.4% specificity (CI, 83.6%–95.7%) for the PRIME ECG, compared with 40.5% sensitivity (CI, 19.6%–65.5%) and 95.0% specificity (CI, 87.9%–98.0%) for the standard 12-lead ECG. Conclusions Existing evidence is insufficient to confidently inform the appropriate use of ECG-based signal analysis technologies for detecting ischemia or infarct in ACS. Further research is needed to determine in what circumstances, if any, these devices might precede, replace, or add to the standard ECG in test strategies for detecting ischemia or infarct in ACS.

Both myocardial necrosis and ischemia can decrease the left ventricular ejection fraction (LVEF). An accurate estimate of the relative contributions of these irreversible and potentially reversible factors could lead to better decisions regarding the risk and benefit of coronary artery bypass grafting (CABG). The value of an Ischemia Index calculated by subtracting the ECG estimated infarction dependent LVEF from the measured LVEF to predict post-operative improvement of LVEF was studied in 55 patients with LVEF40% before CABG. Patients were grouped according to absence or presence of other coexisting ECG confounders.No significant (p=0.083) relationship was found between the Ischemia Index and the improvement in LVEF after CABG in the overall population, but a strong trend was present in the patients with ECGs without confounding QRS changes (p=0.056).These results suggest a positive relationship between the Ischemia Index and improvement of LVEF after CABG in patients without electrocardiographic confounders, but a prospective study using a larger sample is needed.

Background Elevated levels of N-terminal pro brain natriuretic peptide (NT-proBNP) are associated with adverse cardiovascular outcome after ST elevation myocardial infarction (STEMI). We hypothesized that decreasing acuteness-score (based on the electrocardiographic score by Anderson-Wilkins acuteness score of myocardial ischemia) is associated with increasing NT-proBNP levels and the impact of decreasing acuteness-score on NT-proBNP levels is substantial in STEMI patients with severe ischemia. Methods In 186 STEMI patients treated with primary percutaneous coronary intervention (pPCI), the severity of ischemia (according to Sclarovsky-Birnbaum severity grades of ischemia) and the acuteness-score were obtained from prehospital ECG. Patients were classified according to the presence of severe ischemia or non-severe ischemia and acute ischemia or non-acute ischemia. Plasma NT-proBNP (pmol/L) was obtained after pPCI within 24 hours of admission and was correlated with the acuteness-score. Results NT-proBNP levels were median (25th–75th interquartile) 112 (51–219) pmol/L in patients with non-severe ischemia (71.5%) and 145 (79–339) in patients with severe ischemia (28.5%) (p = 0.074). NT-proBNP levels were highest in patients with severe and non-acute ischemia compared to those with severe and acute ischemia (182 (98–339) pmol/L vs 105 (28–324) pmol/L, p = 0.012). There was a negative correlation between acuteness-score and log(NT-proBNP) in patients with severe ischemia (r = 0.395, p = 0.003), which remained significant in multilinear regression analysis (β = −0.155, p = 0.007). No correlation was observed between the acuteness-score and log(NT-proBNP) in patients with non-severe ischemia (p = 0.529) or in the entire population (p = 0.187). Conclusion In STEMI patients with severe ischemia, neurohormonal activation is inversely associated with ECG patterns of acute myocardial ischemia.

His Bundle pacing (HBP) restores electrical synchronization in left bundle branch block (LBBB); however, the underlying mechanisms are poorly understood. We examined the relation between native QRS axis in LBBB, a potential indicator of the site of block, and QRS normalization in patients with LBBB. Data from patients (n= 41) undergoing HBP at 3 sites were studied (68 ± 13years, 13 women). Study criteria included strictly defined complete LBBB and successful implantation of a permanent HBP lead. Preprocedure and postprocedure electrocardiograms were reviewed independently by 2 blinded readers. QRS axis and duration were measured to the nearest 10° and 10ms, respectively. QRS narrowing or normalization was the primary end point. Of 29 patients meeting study criteria, 9 had frontal plane QRS axes between-60° and-80°, 10 from-40° to 0°, and 10 from+1° to+90°. QRS narrowing occurred in 24 patients (83%, 44 ± 34ms, p

The scientific STAFF and MALT meetings were created around the turn of the century for scientists engaged in enhancing the role of the 12-lead ECG for detection and quantification of involved myocardium in patients with acute coronary syndrome. These meetings were initially focused on computer processing of data from two single-center databases. The STAFF database was collected in the mid-nineties on patients with prolonged total coronary occlusion; high-resolution 12-lead ECGs were collected before, during, and after 5 minutes of occlusion. The MALT database was created in the early years of this century on consecutive patients with chest pain admitted to a large teaching hospital. Delayed enhancement magnetic resonance imaging and electrocardiograms were recorded in these acutely ill patients. The paper highlights the first 2 decades of the STAFF and MALT meetings and details the meeting format.

Existing criteria recommended by ACC/ESC for identifying patients with ST elevation myocardial infarction (STEMI) from the 12-lead ECG perform with high specificity (SP) but low sensitivity (SE). In our previous studies, we found that the SE of acute ischemia detection can be markedly improved without any loss of SP by calculating, from the 12-lead ECG, ST deviation in 3 "optimal" vessel-specific leads (VSLs). To further validate the method, we evaluated the SP performance using a dataset with non-ischemic ST-segment changes.12-lead ECGs of 100 patients (75 males/25 females, age range 12-83years, average age 52years) were retrieved from a centralized ECG management system at Skåne University Hospital, Lund, Sweden. These ECGs were chosen to represent five subgroups with various causes of pathological ST deviation, other than acute coronary occlusion: a) ventricular preexcitation (n=12), b) acute pericarditis (n=26), c) early repolarization syndrome (ERS) (n=14), d) left ventricular hypertrophy (LVH) with "strain" (n=26), and e) left bundle branch block (LBBB) (n=22). ECGs with inadequate signal quality, heart rate exceeding 120bpm and/or atrial flutter were not selected for this study population. Both STEMI criteria and VSLs criteria with and without a new augmented LVH-specific derived lead were tested. SP, calculated for each subgroup and combined, was used as the performance measure for comparison.SP test results for the STEMI criteria vs. the VSLs method without the augmented LVH lead were 100% vs. 92%, 4% vs. 88%, 29% vs. 100%, 100% vs. 77%, and 64% vs. 68% for the five subgroups with preexcitation, pericarditis, ERS, LVH, and LBBB, respectively. For the whole group, SP was 57% for the STEMI criteria and 83% for the VSLs criteria; this improvement was statistically significant (p0.001). With the augmented LVH lead, SP for the VSLs improved from 77% to 96% for the LVH subgroup and SP for the other subgroups remained unchanged. For the whole study group, SP improved from 83% to 88%.Based on these results, we conclude that the VSLs criteria are not only more sensitive in detecting acute ischemia but also more specific in recognizing patients with non-ischemic ST deviation than the existing STEMI criteria. This finding needs to be further corroborated on a larger patient population with AMI prevalence typical of the population presenting to the emergency room.

Background Previous studies have shown that QRS prolongation is a sign of depressed collateral flow and increased rate of myocardial cell death during coronary occlusion. The aims of this study were to evaluate ischemic QRS prolongation as a biomarker of severe ischemia by establishing the relationship between prolongation and collateral flow experimentally in a dog model, and test if the same pattern of ischemic QRS prolongation occurs in man. Methods Degree of ischemic QRS prolongation was measured using a novel method in dogs (n = 23) and patients (n = 52) during coronary occlusion for 5 min. Collateral arterial flow was assessed in the dogs. Results There was a significant correlation between QRS prolongation and collateral flow in dogs (r = 0.61, p = 0.008). Magnitude and temporal evolution of prolongation during ischemia were similar for dogs and humans (p = 0.202 and p = 0.911). Conclusion Quantification of ischemic QRS prolongation could potentially be used as a biomarker for severe myocardial ischemia.

BackgroundKnowledge regarding factors that influence deviation of the QRS axis is important when seeking to differentiate between physiological and pathological changes. We hypothesised that, in contrast to those patients with an atrioventricular septal defect and common atrioventricular junction permitting only atrial shunting, those associated with ventricular shunting would show no relationship between the positions of the papillary muscles and the degree of the leftward deviation of the QRS axis.MethodsWe compared the positions of endocardial origin of the papillary muscles, and the frontal plane QRS axis, in patients with atrioventricular septal defects and common atrioventricular junction permitting exclusively atrial as opposed to atrial and ventricular shunting.ResultsWe analysed 18 patients with atrial and ventricular shunting and 23 patients with exclusively atrial shunting. The correlation coefficient between the ratio of distances of the papillary muscles from the mid-septum and the amount of leftward deviation in the frontal plane QRS axis was 0.1 (p=0.4) in those with ventricular shunting and 0.26 (p=0.01) in those with exclusively atrial shunting.ConclusionsIn contrast to patients with the so-called primum form of atrioventricular septal defect, in whom the locations of the papillary muscles correlate with the degree of QRS axis, such relationships are lacking in patients with defects permitting both atrial and ventricular shunting. It may be, therefore, that the presence of ventricular shunting and/or their younger age causes pressure overload, which negates the leftward QRS forces caused by the abnormally positioned papillary muscles.

BACKGROUND: Systems providing computer-based analysis of the resting electrocardiogram (ECG) seek to improve the quality of health care by providing accurate and timely automatic diagnosis of, for example, cardiac rhythm to clinicians. The accuracy of these diagnoses, however, remains questionable. OBJECTIVES: We tested the hypothesis that (a) 2 independent automated ECG systems have better accuracy in rhythm diagnosis than nonexpert clinicians and (b) both systems provide correct diagnostic suggestions in a large percentage of cases where the diagnosis of nonexpert clinicians is incorrect. METHODS: Five hundred ECGs were manually analyzed by 2 senior experts, 3 nonexpert clinicians, and automatically by 2 automated systems. The accuracy of the nonexpert rhythm statements was compared with the accuracy of each system statement. The proportion of rhythm statements when the clinician's diagnoses were incorrect and the systems instead provided correct diagnosis was assessed. RESULTS: A total of 420 sinus rhythms and 156 rhythm disturbances were recognized by expert reading. Significance of the difference in accuracy between nonexperts and systems was P = .45 for system A and P = .11 for system B. The percentage of correct automated diagnoses in cases when the clinician was incorrect was 28% ± 10% for system A and 25% ± 11% for system B (P = .09). CONCLUSION: The rhythm diagnoses of automated systems did not reach better average accuracy than those of nonexpert readings. The computer diagnosis of rhythm can be incorrect in cases where the clinicians fail in reaching the correct ECG diagnosis. (Less)

Background The 2009 electrocardiographic Selvester QRS score for LBBB (2009 LBSS) is prognostic in CRT-patients. Previous studies show limited diagnostic performance in detecting and quantifying left ventricular (LV) scar determined by cardiovascular magnetic resonance imaging (CMR). We aimed to develop an improved method for ECG detection of scar using a large and broadly selected dataset of patients with LBBB. Methods and results We retrospectively identified LBBB patients (n = 325) with available ECG and late gadolinium enhancement (LGE) CMR exams from four centers (142 [44%] with > 0% CMR scar). ECG metrics were measured digitally and semi-automatically, and were compared to CMR-determined scar presence and extent. The 2009 LBSS did not accurately detect or quantify CMR scar (R 2 = 0.04, Area under the Receiver operating characteristic curve [AUC]: 0.60, [95% confidence interval: 0.54–0.66]). Multivariable stepwise logistic regression applied in 44 pre-determined ECG variables resulted in an improved 6-variable ECG model to detect CMR-scar (AUC 0.72 [0.66–0.77]). Furthermore, a single ECG variable (Lead I R/S amplitude ratio) was predictive of both scar presence (AUC 0.71 [0.65–0.77]) and of LV ejection fraction 2 = 0.21) Conclusions The 2009 LBSS does not accurately detect or quantify CMR scar. Extensive comparison of ECG and CMR identified a single ECG measure (lead I R/S amplitude ratio

The Selvester QRS score translates subtle changes in ventricular depolarization measured by the electrocardiogram into information about myocardial scar location and size. This estimated scar has been shown to have a high degree of correlation with autopsy-measured myocardial infarct size. In addition, multiple studies have demonstrated the value of the QRS score in post-myocardial infarct patients to provide prognostic information. Recent studies have demonstrated that increasing QRS score is predictive of increased implantable defibrillator shocks for ventricular tachycardia and fibrillation as well as decreased response to cardiac resynchronization therapy. Although QRS scoring has never achieved widespread clinical use, increased interest in patient selection and risk-stratification techniques for implantable defibrillators and cardiac resynchronization therapy has led to renewed interest in QRS scoring and its potential to identify which patients will benefit from device therapy. The QRS score criteria were updated in 2009 to expand their use to a broader population by accounting for the different ventricular depolarization sequences in patients with bundle-branch/fascicular blocks or ventricular hypertrophy. However, these changes also introduced additional complexity and nuance to the scoring procedure. This article provides detailed instructions and examples on how to apply the QRS score criteria in the presence of confounding conduction types to facilitate understanding and enable development and application of automated QRS scoring.

The study purpose is to determine whether numeric and/or graphic ST measurements added to the display of the 12-lead electrocardiogram (ECG) would influence cardiologists' decision to provide myocardial reperfusion therapy. Twenty ECGs with borderline ST-segment deviation during elective percutaneous coronary intervention and 10 controls before balloon inflation were included. Only 5 of the 20 ECGs during coronary balloon occlusion met the 2007 American Heart Association guidelines for ST-elevation myocardial infarction (STEMI). Fifteen cardiologists read 4 sets of these ECGs as the basis for a "yes/no" reperfusion therapy decision. Sets 1 and 4 were the same 12-lead ECGs alone. Set 2 also included numeric ST-segment measurements, and set 3 included both numeric and graphically displayed ST measurements ("ST Maps"). The mean (range) positive reperfusion decisions were 10.6 (2-15), 11.4 (1-19), 9.7 (2-14), and 10.7 (1-15) for sets 1 to 4, respectively. The accuracies of the observers for the 5 STEMI ECGs were 67%, 69%, and 77% for the standard format, the ST numeric format, and the ST graphic format, respectively. The improved detection rate (77% vs 67%) with addition of both numeric and graphic displays did achieve statistical significance (P < .025). The corresponding specificities for the 10 control ECGs were 85%, 79%, and 89%, respectively. In conclusion, a wide variation of reperfusion decisions was observed among clinical cardiologists, and their decisions were not altered by adding ST deviation measurements in numeric and/or graphic displays. Acute coronary occlusion detection rate was low for ECGs meeting STEMI criteria, and this was improved by adding ST-segment measurements in numeric and graphic forms. These results merit further study of the clinical value of this technique for improved acute coronary occlusion treatment decision support.

BACKGROUND: The time from symptom onset to reperfusion in acute myocardial infarction (MI) has been shown to be a poor predictor of patient outcome. Acute electrocardiographic (ECG) changes, however, have been shown useful for estimated acuteness of myocardial ischemia using the Anderson-Wilkins ECG ischemia acuteness score (AW-acuteness score). The aim was to study whether acute ischemic ECG changes can predict the amount of salvageable myocardium in patients with acute ST-elevation MI. METHODS: Thirty-eight patients treated with primary percutaneous coronary intervention for first-time ST-elevation MI were retrospectively enrolled. Myocardium at risk (MaR) was determined by myocardial perfusion single photon emission computed tomography acutely or by T2-weighted cardiac magnetic resonance after 1 week, at the same time when final MI size was determined by late gadolinium enhancement. Myocardial salvage was calculated as (MaR - MI size)/MaR and compared with AW-acuteness score and time from symptom onset to primary percutaneous coronary intervention. RESULTS: The AW-acuteness score correlated significantly with salvageable myocardium for right coronary artery (RCA) occlusions (r = -0.57; P = .02) but not for left anterior descending artery (LAD) occlusions (r = -0.04; P = .88). Time from symptom onset did not correlate with the amount of salvageable myocardium (LAD, r = 0.04 and P = .87; RCA, r = -0.40 and P = .13). CONCLUSIONS: There is a moderate correlation between AW-acuteness score and salvageable myocardium in patients with acute RCA occlusion but not in patients with LAD occlusion.

Materials and Methods To minimize delays in time to reperfusion in an urban-suburban North Carolina County, Guilford County Emergency Medical Services (EMS) and Moses Cone Hospital, Greensboro, NC, have collaborated to use the acquisition of 12-lead electrocardiographs and their paramedic interpretation to initiate the catheterization laboratory team and cardiologist; independent of over read by a physician. The study population of 91 patients was divided into the catheterization laboratory activation by EMS and catheterization laboratory activation by the emergency department physician (ED-MD) groups, and also by EMS and self-transported groups. Results The EMS group had shorter median time intervals from hospital door to percutaneous coronary intervention (PCI) with balloon inflation than those patients who self-transported to the hospital. Also, patients who were treated during the EMS activation of the catheterization laboratory phase had shorter median hospital door to PCI times than those who were treated during ED-MD activation of the catheterization laboratory. Conclusion The time from hospital arrival to PCI with balloon inflation was significantly shorter during the period in which EMS activated the catheterization laboratory than during the period the laboratory was activated by hospital staff. Thus, paramedics with quality electrocardiogram interpretation training and education can identify patients with acute ST-elevation myocardial infarction and properly activate the catheterization laboratory.

Objectives The aim of this study was to assess the relationship between initial ST-segment deviation and final QRS complex changes related to the posterolateral left ventricular wall in patients with acute inferior myocardial infarction receiving reperfusion therapy. The secondary aim was to determine if this relationship is stronger for patients who present early in the ischemia/infarction process in comparison with patients who present late. Methods The ST-segment depression in the leads V 1 , V2, and −V6 were measured in the electrocardiograph (ECG) just before initiation of myocardial reperfusion. These leads were chosen because they represent the posterolateral wall in the Selvester score. In addition, the Anderson-Wilkins acuteness score was calculated in the admission ECG. Selvester criteria related to the posterolateral wall were identified in the ECG performed before hospital discharge to assess final infarct size. Results Fifty-six patients were included in this study. No significant relationship was found between the sum of initial ST-segment depression in the leads V 1 , V 2 , and −V 6 , and final infarct size in the posterolateral left ventricular wall for the total study population ( r = 0.19, P = .16). Patients were subgrouped by Anderson-Wilkins acuteness score of less than 3 vs 3 or more. In those with a low acuteness score, the amount of ST-segment depression had no relationship with final infarct size ( r = −0.16, P = .41). However, the correlation was statistically significant for those with a high acuteness score ( r = 0.42, P = .04). Conclusion The initial ST-segment depression in leads V 1 , V 2 , and −V 6 can predict ECG-estimated amount of infarction in the posterolateral left ventricular wall in patients with acute inferior myocardial infarction receiving reperfusion therapy, but only in those who present early in the ischemia/infarction process.