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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.

Autonomic nervous system (ANS) is governed by complex interactions arising from feedback loops of nonlinear systems that operate over a wide range of temporal and spatial scales, enabling the organism to adapt to stress, metabolic changes and diseases. This study is aimed to assess multifractal and nonlinear characteristics of the ANS during ischemic events provoked by a prolonged percutaneous coronary intervention (PCI) procedure. Eighty-seven patients from the STAFF III database were used. Patients were classified into 2 groups: (1) with prior myocardial infarction (MI) and (2) without MI (noMI). R–R signals during three 3-min stages of the procedures were analyzed using multifractal and surrogate data techniques. Multifractal indices increased significantly from the pre-inflation stage to the post-deflation stage. These variations were more marked for the noMI group. Multifractal changes significantly correlated with both the decreased parasympathetic and the increased sympathetic modulations accounted by classical linear indices. Multifractal measures resulted to be a more powerful indicator than linear HRV indices in quantifying the ischemia-induced changes. Right coronary artery (RCA) occlusions provoke greater multifractal reactions throughout the PCI procedure. Our findings suggest reduced complex multifractal and nonlinear reactions of ANS activity in patients with prior MI in comparison to the noMI group, possibly due to degradation in the complexity of control mechanism of heart rate generation.

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.

Here we report a simple Mn coordination complex with utility as a redox-sensitive MR probe. The HBET ligand stabilizes both the Mn(2+) and Mn(3+) oxidation states. In the presence of glutathione (GSH), low relaxivity Mn(III)-HBET is converted to high relaxivity Mn(II)-HBET with a 3-fold increase in relaxivity, and concomitant increase in MR signal. Alternately, hydrogen peroxide can convert Mn(II)-HBET to Mn(III)-HBET with a reduction in MR signal.

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.

To minimize maintenance immunosuppression in upper-extremity transplantation to favor the risk-benefit balance of this procedure.Despite favorable outcomes, broad clinical application of reconstructive transplantation is limited by the risks and side effects of multidrug immunosuppression. We present our experience with upper-extremity transplantation under a novel, donor bone marrow (BM) cell-based treatment protocol ("Pittsburgh protocol").Between March 2009 and September 2010, 5 patients received a bilateral hand (n = 2), a bilateral hand/forearm (n = 1), or a unilateral (n = 2) hand transplant. Patients were treated with alemtuzumab and methylprednisolone for induction, followed by tacrolimus monotherapy. On day 14, patients received an infusion of donor BM cells isolated from 9 vertebral bodies. Comprehensive follow-up included functional evaluation, imaging, and immunomonitoring.All patients are maintained on tacrolimus monotherapy with trough levels ranging between 4 and 12 ng/mL. Skin rejections were infrequent and reversible. Patients demonstrated sustained improvements in motor function and sensory return correlating with time after transplantation and level of amputation. Side effects included transient increase in serum creatinine, hyperglycemia managed with oral hypoglycemics, minor wound infection, and hyperuricemia but no infections. Immunomonitoring revealed transient moderate levels of donor-specific antibodies, adequate immunocompetence, and no peripheral blood chimerism. Imaging demonstrated patent vessels with only mild luminal narrowing/occlusion in 1 case. Protocol skin biopsies showed absent or minimal perivascular cellular infiltrates.Our data suggest that this BM cell-based treatment protocol is safe, is well tolerated, and allows upper-extremity transplantation using low-dose tacrolimus monotherapy.

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.

Here we report a generalizable solid/solution phase strategy for the synthesis of discrete bimodal fibrin-targeted imaging probes. A fibrin-specific peptide was conjugated with two distinct imaging reporters at the C- and N-terminus. In vitro studies demonstrated retention of fibrin affinity and specificity. Imaging studies showed that these probes could detect fibrin over a wide range of probe concentrations by optical, magnetic resonance, and positron emission tomography imaging.

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.

In patients with pulmonary arterial hypertension (PAH), right ventricular mass (RVM) correlates linearly with pulmonary artery pressure, and decreases with successful treatment. Accurate measurement of RVM currently requires cardiovascular magnetic resonance (CMR) imaging. We therefore tested the relationship between RVM and a simple, 12 lead ECG-derived value, the Butler-Leggett (BL) score. This has previously been validated in patients with RV hypertrophy (RVH) due to mitral stenosis. We also tested the diagnostic accuracy of the BL score in detecting RVH. The Scottish Pulmonary Vascular Unit database was reviewed retrospectively. Twenty-eight patients with PAH were identified, in whom CMR and ECG data had been recorded no more than 28 days apart. All had completed a comprehensive clinical assessment, including right heart catheterization. CMR-derived absolute RVM and RV mass index (RVMI=RV mass/LV mass) were correlated against BL score. The ability of this score to detect RVH was tested using 2 x 2 contingency tables. RVM and RVMI correlated with BL score (r=0.77, P0.7 mV proved a highly specific but insensitive indicator of RVH, based on either absolute RVM (sensitivity 74%, specificity 100%) or a high RVMI (sensitivity 61%, specificity 100%). The BL score, which can be defined using a standard 12-lead ECG, correlates with RVM and RVMI in patients with PAH. A score >0.7 mV was a highly specific but insensitive indicator of RVH in these patients.