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Cardiac memory is the term used to describe an interesting electrocardiographic phenomenon. Whenever a QRS complex is wide and abnormal, such as during ventricular pacing, the T waves will also be abnormal and will point to the opposite direction of the wide QRS. If the QRS then normalizes, such as after cessation of ventricular pacing, the T waves will normalize as well, but at a later stage. The period of cardiac memory is the phase between the sudden normalization of the QRS and the eventual and gradual return of the T waves to their baseline morphology. Cardiac memory is assumed to be an innocent electrocardiographic curiosity. However, during cardiac memory, reduction of repolarizing potassium currents increases left ventricular repolarization gradients. Therefore, when cardiac memory occurs in patients who already have a prolonged QT interval (for whatever reason), it can lead to a frank long QT syndrome with QT-related ventricular arrhythmias (torsades de pointes). These arrhythmogenic effects of cardiac memory are not generally appreciated and are reviewed here for the first time.

AimsDuring non-selective His bundle (HB) pacing, it is clinically important to confirm His bundle capture vs. right ventricular septal (RVS) capture. The present study aimed to validate the hypothesis that during HB capture left ventricular lateral wall activation time, approximated by the V6R-wave peak time (V6RWPT), will not be longer than the corresponding activation time during native conduction.MethodsConsecutive patients with permanent HB pacing were recruited; cases with abnormal His-ventricle interval or left bundle branch block were excluded. Two corresponding intervals were compared: stimulus-V6RWPT and native HBpotential-V6RWPT. Difference between these two intervals (delta V6RWPT), diagnostic of lack of HB capture, was identified using receiver operating characteristic (ROC) curve analysis.ResultsA total of 723 ECGs (219 with native rhythm, 172 with selective HB, 215 with non-selective HB, and 117 with RVS capture) were obtained from 219 patients. The native HB-V6RWPT, non-selective-, and selective-HB paced V6RWPT were nearly equal, while RVS V6RWPT was 32.0 (±9.5) ms longer. The ROC curve analysis indicated delta V6RWPT > 12 ms as diagnostic of lack of HB capture (specificity of 99.1% and sensitivity of 100%). A blinded observer correctly diagnosed 96.7% (321/332) of ECGs using this criterion.ConclusionWe validated a novel criterion for HB capture that is based on the physiological left ventricular activation time as an individualized reference. HB capture can be diagnosed when paced V6RWPT does not exceed the value obtained during native conduction by more than 12 ms, while longer paced V6RWPT indicates RVS capture.

Aims QRS narrowing with initiation of biventricular pacing might be an acute electrocardiographic indicator of correction of left bundle branch block (LBBB)-induced depolarization delay and asynchrony. However, its impact on prognosis remains controversial, especially in non-LBBB patients. Our goal was to evaluate the impact of QRS narrowing on long-term mortality and morbidity in a large cohort of patients undergoing cardiac resynchronization therapy (CRT) with different pre-implantation QRS types: LBBB, non-LBBB, and permanent right ventricular pacing. Methods and results This study included consecutive patients who underwent CRT device implantation. Study endpoints: death from any cause or urgent heart transplantation and death from any cause/urgent heart transplantation or hospital admission for heart failure. All pre- and post-implantation electrocardiograms were analysed using digital callipers, high-amplitude augmentation, 100 mm/s paper speed, and global QRS duration measurement method. A total of 552 CRT patients entered the survival analysis. During the 9 years observation period, 232 (42.0%) and 292 (52.9%) patients met primary and secondary endpoints, respectively. QRS narrowing predicted survival in the Kaplan-Meier analysis only in patients with LBBB. Multivariate Cox regression model showed that QRS narrowing was the major determinant of both study endpoints, with hazard ratios of 0.46 and 0.43, respectively. There was a strong relationship between mortality risk and shortening/widening of the QRS, albeit only in the LBBB group. Patients with non-LBBB morphologies had unfavourable prognosis similar to that in LBBB patients without QRS narrowing. Conclusion Acute QRS narrowing in patients with LBBB might be a desirable endpoint of CRT device implantation.

The para-Hisian pacing maneuver is useful in determining whether retrograde conduction is dependent on atrioventricular (AV) nodal conduction. Loss of direct His bundle capture results in a longer route for the depolarization wave to reach the AV node and the atrium, as it has to travel through the working myocardium to engage the distal Purkinje fibers. Thus, loss of direct His bundle capture results in obligatory ventriculoatrial (VA) interval prolongation unless a nonphysiological retrograde conduction route (an accessory pathway [AP]) is present. Consequently, a stable VA interval with loss of His bundle capture is considered diagnostic of the presence of an AP. This concept has been regarded as useful, especially when concentric retrograde atrial activation is present.1 Subsequently, however, potential important pitfalls in the interpretation of this differentiating maneuver were described. These include the recognition of inadvertent atrial capture, pure His bundle capture, the presence of fasciculoventricular pathways, and the impact of retrograde dual AV nodal physiology

The role of electrocardiography (ECG) in prognosticating pulmonary embolism (PE) is increasingly recognized. ECG is quickly interpretable, noninvasive, inexpensive, and available in remote areas. We hypothesized that ECG can provide useful information about PE prognostication. We searched MEDLINE, EMBASE, Google Scholar, Web of Science, abstracts, conference proceedings, and reference lists through February 2017. Eligible studies used ECG to prognosticate for the main outcomes of death and clinical deterioration or escalation of therapy. Two authors independently selected studies; disagreement was resolved by consensus. Ad hoc piloted forms were used to extract data and assess risk of bias. We used a random‐effects model to pool relevant data in meta‐analysis with odds ratios (ORs) and 95% confidence intervals (CIs); all other data were synthesized qualitatively. Statistical heterogeneity was assessed using the I (2) value. We included 39 studies (9198 patients) in the systematic review. There was agreement in study selection (κ: 0.91, 95% CI: 0.86‐0.96). Most studies were retrospective; some did not appropriately control for confounders. ECG signs that were good predictors of a negative outcome included S1Q3T3 (OR: 3.38, 95% CI: 2.46‐4.66, P < 0.001), complete right bundle branch block (OR: 3.90, 95% CI: 2.46‐6.20, P < 0.001), T‐wave inversion (OR: 1.62, 95% CI: 1.19‐2.21, P = 0.002), right axis deviation (OR: 3.24, 95% CI: 1.86‐5.64, P < 0.001), and atrial fibrillation (OR: 1.96, 95% CI: 1.45‐2.67, P < 0.001) for in‐hospital mortality. Several ischemic patterns also were significantly predictive. Our conclusion is that ECG is potentially valuable in prognostication of acute PE.

Introduction Radiofrequency ablation (RFA) of outflow tract ventricular arrhythmia (VA) that originates from the aortic cusps can be challenging. Data on long‑ term efficacy and safety as well as optimal technique after aortic cusp ablation have not previously been reported. Objectives This aim of the study was to determine the short- and long‑ term outcomes after RFA of aortic cusp VA, and to evaluate aortic valve injuries according to echocardiographic screening. Patients and methods This was a prospective multicenter registry (AVATAR, Aortic Cusp Ventricular Arrhythmias: Long Term Safety and Outcome from a Multicenter Prospective Ablation Registry) study. A total of 103 patients at a mean age of 56 years (34-64) from the "Electra" Registry (2005-2017) undergoing RFA of aortic cusps VA were enrolled. The following 3 ablation techniques were used: zero‑fluoroscopy (ZF; electroanatomical mapping [EAM] without fluoroscopy), EAM with fluoroscopy, and conventional fluoroscopy‑ based RFA. Data on clinical history, complications after RFA, echocardiography, and 24‑ hour Holter monitoring were collected. The follow up was 12 months or longer. Results There were no major acute cardiac complications after RFA. In one case, a vascular access complication required surgery. The median (interquartile range [IQR]) procedure time was 75 minutes (IQR, 58-95), median follow‑ up, 32 months (IQR, 12-70). Acute and long term procedural success rates were 93% and 86%, respectively. The long‑ term RFA outcomes were observed in ZF technique (88%), EAM with fluoroscopy (86%), and conventional RFA (82%), without differences. During long‑ term follow‑up, no abnormalities were found within the aortic root. Conclusions Ablation of VA within the aortic cusps is safe and effective in long‑ term follow up. The ZF approach is feasible, although it requires greater expertise and more imaging modalities.

AimsPermanent His bundle (HB) pacing is usually accompanied by simultaneous capture of the adjacent right ventricular (RV) myocardium - this is described as a non-selective (ns)-HB pacing. Our aim was to identify ECG criteria for loss of HB capture during ns-HB pacing.MethodsConsecutive patients with permanent HB pacing were recruited. Surface 12-lead ECGs during ns-HB pacing and loss of HB capture (RV-only capture) were obtained. ECG criteria for loss/presence of HB capture were identified. In the validation phase these criteria and the “HB ECG algorithm” were tested by two blinded observers using a separate, sizable set of ECGs.ResultsA total of 353 ECG (226 ns-HB and 128 RV-only) were obtained from 226 patients with permanent HB pacing devices. QRS notch/slur in left ventricular leads and R-wave peak time in lead V6 were identified as the best features for differentiation. The 2-step HB ECG algorithm based on these features correctly classified 87.1% of cases with sensitivity and specificity of 93.2% and 83.9%, respectively. Moreover, the proposed criteria for definitive diagnosis of ns-HB capture (no QRS slur/notch in leads I, V1, V4-V6 and the R-wave peak time in V6 ≤ 100 ms) presented 100% specificity.ConclusionA novel ECG algorithm for the diagnosis of loss of HB capture and novel criteria for definitive confirmation of HB capture were formulated and validated. Practical application of these criteria during implant and follow-up of patients with HB pacing devices is feasible.Condensed AbstractThe 2-step ECG algorithm for loss of His bundle capture based on surface ECG analysis is proposed and validated. This method correctly classified 87.1% of cases with a sensitivity and specificity of 93.2% and 83.9%, respectively.What’s NewThis is the first study that analyzes QRS characteristics during non-selective His bundle pacing in a sizable cohort of patients.Precise criteria and a novel algorithm for electrocardiographic diagnosis of loss of HB capture during presumed non-selective HB pacing were validated.QRS notch/slur in left ventricular leads was identified as a simple and reproducible feature indicating loss of HB capture or lack/loss of correction of intraventricular conduction disturbances.Assessment of R-wave peak time in lead V6 rather than QRS duration for diagnosis of ns-HB pacing was validated.

Background: Left bundle branch block (LBBB) is an important qualification criterion and determinant of prognosis in cardiac resynchronisation therapy (CRT) patients. Aims: Our goal was to investigate the long-term mortality and morbidity in a sizable cohort of patients with CRT with regard to the new strict LBBB definition proposed by Perrin. Methods: We performed a longitudinal cohort study that included consecutive CRT patients. Primary endpoint (all-cause death) and secondary endpoint (all-cause death and hospitalisation for heart failure) were analysed. All preimplantation elec- trocardiograms were categorised as LBBB or non-LBBB according to the new definitions/criteria analysed. Results: The survival analysis comprised 552 patients with CRT. The Perrin criteria, CRT guidelines class I indication criteria, and Strauss criteria were fulfilled in 38.9%, 79.4%, and 62.3% of all LBBB patients, respectively. During the nine-year study period, 232 patients died and the combined endpoint was met by 292 patients. The Perrin “true LBBB” definition criteria were inferior to the Strauss “complete” LBBB definition criteria in predicting survival as reflected by Kaplan-Meier survival curves (C-statistics). Multivariate Cox regression models showed that both LBBB definitions predicted mortality, however, the Perrin definition had a higher hazard ratio (HR 0.67) compared to the Strauss definition (HR 0.51). Conclusions: It seems that the Perrin “true LBBB” criteria are not well-suited for the selection of CRT candidates. Perhaps they do not reflect the presence of a true/complete LBBB or exclude too many patients who, despite some residual conduction in the left bundle branch, responded well to CRT.

INTRODUCTION Rare cardiovascular diseases and disorders (RCDDs) constitute an important clinical problem, and their proper classification is crucial for expanding knowledge in the field of RCDDs. OBJECTIVES The aim of this paper is to provide an updated classification of rare arrhythmogenic and conduction disorders, and rare arrhythmias (RACDRAs). METHODS We performed a search for RACDRAs using the Orphanet inventory of rare diseases, which includes diseases with a prevalence of no more than 5 per 10 000 in the general population. We supplemented this with a search of PubMed and Scopus databases according to a wider definition proposed by the European Parliament and the Council of the European Union. RESULTS RACDRAs are categorized into 2 groups, primary electrical disorders of the heart and arrhythmias in specific clinical settings. The first group is further divided into subgroups of major clinical presentation: disorders predisposing to supraventricular tachyarrhythmias, ventricular tachyarrhythmias, bradyarrhythmias, and others. The second group includes iatrogenic arrhythmias or heart rhythm disturbances related to medical treatment, arrhythmias associated with metabolic disorders, and others. We provide a classification of RACDRAs and supplement them with respective RCDDs codes. CONCLUSION The clinical classification of RACDRAs may form a basis to facilitate research and progress in clinical practice, both in diagnostic and therapeutic approaches.

Background: Atrial fibrillation (AF) is the most common clinically-significant arrhythmia in the adult population, and it is a strong independent risk factor for cerebrovascular accidents. Patients with non-valvular AF are five times more likely to suffer a stroke. Despite the clear recommendations for anticoagulant therapy, many clinicians are still reluctant to provide routine oral anticoagulation to patients with AF, despite the potential clinical benefits. Aim: To compare Polish and European populations of patients with AF and the every-day practice of stroke prevention in Poland and in the rest of Europe. Methods: We analysed the baseline data from the two first cohorts of patients enrolled in the GARFIELD-AF registry (an ongo­ing prospective, multicentre, international registry of patients newly diagnosed with AF) in Poland and in the rest of Europe. Results: Polish AF patients are generally younger (median age 67 years in both cohorts vs. 73 in cohort 1 in the rest of Eu­rope and 72 in cohort 2), but they carry a burden of more concomitant diseases. There are some noticeable differences in stroke prevention between Poland and the rest of Europe. The use of vitamin K antagonists (VKAs) is generally higher in other European countries in both cohorts (in Poland 41.7% in cohort 1 and 36.9% in cohort 2 vs. 55.5% in cohort 1 and 41.9% in cohort 2 in the rest of Europe). Meanwhile, it is generally more common in Poland to treat patients with both VKAs and antiplatelets (in cohort 1 20.4% of patients in Poland received vs. 12.0% in the rest of Europe). A total of 5.6% of patients in cohort 1 in Poland receive no antithrombotic treatment (it means: no VKA, oral factor Xa or thrombin inhibitors, antiplate­lets), meanwhile in other countries it amounts to 8.5%. The usage of non-vitamin K oral anticoagulants is growing in Poland similarly to the other European countries. Conclusions: The GARFIELD-AF registry data shows how distant everyday clinical practice is from the guidelines. It shows that still in Poland, as well as in the rest of Europe, too many patients with low stroke risk are treated with anticoagulants, while too frequently patients at high stroke risk are left with no stroke prevention. Although the tendency to use non-vitamin K oral anticoagulants is growing comparably in Poland and in the rest of Europe, the proportion of patients with intermediate and high stroke risk is not growing and more patients at low stroke risk are treated with anticoagulants.

Background Acquired long QT syndrome (a-LQTS) is associated with life-threatening ventricular arrhythmias, mainly torsades de pointes (TdP). ECG parameters predicting evolving into ventricular fibrillation (VF) are ill defined. Aims To determine ECG parameters preceding and during TdP associated with higher risk of developing VF. Methods We analyzed 151 episodes of TdP, recorded in 28 patients with a-LQTS (mean QTc 638 ms ± 57). Results All 28 patients had prolonged QT interval, (mean QTc 638 ms ± 57) ranging from 502 ms to 858 ms correcting by Bazett's formula. The mean TdP heart rate was 218 bpm ± 38 (mean cycle length of TdP 274 ± 47 ms). We classified TdPs episodes into “slower”-TdP (s-TdP) 1. Macro T wave alternans was observed in 4 patients. The QT interval was not different in patients with VF(+) and VF(−) episodes, 633 ± 60 and 639 ± 57, respectively. Conclusions Some electrocardiographic parameters can be helpful in determining the risk of TdP evolving into VF. The slower ventricular rate ( 30 ms) and the short episodes < 20 beats could predict benign evolution.

Congenital long QT syndrome (LQTS) is a primary cardiac channelopathy. Genetic testing has not only diagnostic but also prognostic and therapeutic implications. At present, 15 genes have been associated with the disease, with most mutations located in 3 major LQTS-susceptibility genes. During a routine genetic screening for KCNQ1, KCNH2 and SCN5A genes in index cases with LQTS, seven novel variants in KCNH2 and SCN5A genes were found. Genotype-phenotype correlations were analysed in these patients and their families. An open reading frame and splice site analysis of the exons was conducted using next-generation sequencing. In novel variants, phenotypes of carriers and their affected relatives were analysed. In 39 unrelated patients, 40 pathogenic/putative pathogenic mutations were found. Thirty-three of them, predominantly missense, were reported previously: 11 were in the KCNQ, 17 in the KCNH2 and 5 in the SCN5A gene. Seven novel missense variants were found in eight families. Among them, four variants were in typical for LQTS location. Two variants in the KCNH2 gene (p.D803Y and p.D46F) and one in the SCN5A gene (G1391R) were in amino acid (AA) position which up to present has not been reported in LQTS. Phenotype analysis showed the life-threatening course of the disease in index cases with a history of sudden cardiac death in six families. Mutation carriers presented with ECG abnormalities and some of them received beta-blocker therapy. We report three novel variants (KCNQ1 p.46, KCNH2 p.D803Y, SCN5A p.G1391R) which have never been reported for this AA location in LQTS; the phenotype-genotype correlation suggests their pathogenicity.

Background Left bundle branch block (LBBB) is considered an important prognostic parameter in cardiac resynchronization therapy (CRT). We aimed to evaluate, in a sizeable cohort of patients with CRT, long-term mortality, and morbidity according to four different electrocardiographic definitions of LBBB. Methods This longitudinal cohort study included consecutive patients who underwent CRT device implantation in our institution in years 2006-2014. Two endpoints were assessed: (a) death from any cause or urgent heart transplantation, and (b) death from any cause or heart failure admission. All preimplantation ECGs were analyzed by three physicians blinded to outcome and categorized as LBBB or non-LBBB according to four definitions. Results A total of 552 CRT patients entered survival analysis. According to the conventional definition, 350 (63.4%) patients had LBBB, and the Marriott, WHO/AHA, and Strauss definitions identified LBBB in 254 (46.0%), 218 (39.5%) and 226 (40.9%) patients, respectively. During the 9 years of observation, 232 patients died, the combined endpoint was met by 292 patients. The Strauss LBBB definition was significantly better to the other definitions in predicting survival (Kaplan-Meier analysis with comparison of C-statistics). Multivariate Cox regression model showed that LBBB was the major determinant of all-cause mortality with the Strauss definition having the lowest hazard ratio (0.51) of the four studied definitions. Conclusions Criteria included in various definitions of LBBB result in a diagnosis of LBBB in divergent groups of patients. Differences in LBBB definitions have clinical consequences, as patients without 'complete/true' LBBB probably get no mortality benefit from CRT.

BACKGROUND: Despite substantial progress in the field of differentiation between ventricular tachycardia (VT) and supraventricular tachycardia (SVT) with wide QRS complexes, differentiation between VT and preexcited SVT remains largely unresolved due to significant overlap in QRS morphology. Our aim was to assess the specificities of various single ECG criteria and sets of criteria (Brugada algorithm, aVR algorithm, Steurer algorithm, and the VT score) for diagnosis of VT in a sizable cohort of patients with preexcitation. METHODS: We performed a retrospective study of consecutive accessory pathway ablation procedures to identify preexcited tachycardias. Among 670 accessory pathway ablation procedures, 329 cases with good quality ECG with either bona fide preexcited SVT (n = 30) or a surrogate preexcited SVT (fast paced atrial rhythm with full preexcitation, n = 299) were identified. ECGs were analyzed with the use of wide QRS complex algorithms/criteria to determine specificities of these methods. RESULTS: The Steurer algorithm and VT score (≥3 points), with specificities of 97.6% and 96.1%, respectively, were significantly (p

We investigated prognostic value of four recently proposed ECG markers in patients with cardiac resynchronization therapy (CRT): 1./ pathological preimplantation QRS axis, 2./ increase in QRS amplitude in V3 during biventricular pacing, 3./ negative QRS in V1/V2 during left ventricular (LV)-only pacing, 4./ longer QRS duration during LV-only pacing. A longitudinal cohort study was performed (n = 552). Results During the 9-year observation period the primary endpoint (death from any cause or urgent heart transplantation) was met in 232 patients. The secondary endpoint of survival free of heart failure hospitalization was met in 292 patients. Long LV-paced QRS and pathological axis predicted unfavorable prognosis in Kaplan-Meier analysis. In multivariable Cox model (functional class, LV ejection fraction, LV end-diastolic dimension, permanent atrial fibrillation, age, gender, heart failure etiology, creatinine level, diabetes mellitus), LV-paced QRS duration remained a significant determinant of both endpoints. The other studied ECG markers lacked independent prognostic value.

Background: Mortality and morbidity in patients with cardiac resynchronisation therapy (CRT) remain very high. Prognostic evaluation of CRT candidates might be useful for the assessment of CRT indications, directing further therapy, counselling, etc. Aim: Our goal was to assess the prognostic value of various parameters in order to construct a risk score that could predict long-term mortality and morbidity during the initial evaluation of CRT candidates. Methods: This was a retrospective, single-centre, large cohort study involving consecutive heart failure patients who underwent CRT device implantation. In order to build a prediction model, 28 parameters were analysed using uni- and multivariate Cox models and Kaplan-Meier survival curves. Results: Data from 552 patients were used for the long-term outcome assessment. During nine years of follow-up, 232 patients met the primary endpoint of death and 128 patients were hospitalised for heart failure. The strongest and clinically most relevant predictors were selected as the final model. AL-FINE is the acronym for these six predictors: Age ( > 75 years), non-Left bundle branch block morphology (according to Strauss criteria), Furosemide dose ( > 80 mg), Ischaemic aetiology, New York Heart Association class ( > III), and left ventricular Ejection fraction ( < 20%). Depending on the number of AL-FINE score points, overall mortality at seven years was in the range of 28% (0–1 points) to 74% (3–6 points). Conclusions: A novel, multiparametric CRT risk score was constructed on the basis of simple and recognised clinical, electrocardiographic, and echocardiographic parameters that show a significant add-on effect on mortality in this specific population.

Background Andersen–Tawil Syndrome (ATS) is a channelopathy caused by mutations in KCNJ2 gene. It is characterized by symptoms of ventricular arrhythmias, periodic paralysis or muscle weakness, and dysmorphic features. ATS can present with the triad of symptoms, any combination or none of them. Risk factors for dangerous arrhythmias are unknown. The study assessed the impact of K897T polymorphism in hERG1 gene and H558R polymorphism in SCN5A gene coexisting with R218Q mutation in KCNJ2 in one family on clinical manifestation. Methods Family members underwent clinical assessment, ECG and genotyping. Holter monitoring was performed in mutation carriers and additionally in one family member with no mutation, but with K897T polymorphism. Results Proband with ATS mutation, K897T and H558R polymorphisms and proband's sister with ATS mutation and K897T polymorphism presented following symptoms: loss of consciousness, bidirectional and polymorphic ventricular tachycardia and about 5000 ventricular extrasystoles. Symptoms presented by the member with only the ATS mutation and by member with ATS mutation and H558R polymorphism were not as severe. U wave appeared in all examined family members regardless of the mutation presence. Studied individuals with ATS mutation had the T-peak–U-peak interval longer than 200 ms. In all ATS mutation carriers it was longer than in family members with no mutation. T-peak–T-end interval was the longest (>120 ms) in members with coexisting mutation and K897T polymorphism. Conclusion ATS severity possibly depends on other genes’ polymorphisms. In the presented family, it could depend on the presence of K897T polymorphism in hERG1.

Electrocardiographic (ECG) abnormalities in the setting of acute pulmonary embolism (PE) are being increasingly characterized and mounting evidence suggests that ECG plays a valuable role in prognostication for PE. We review the historical 21-point ECG prognostic score for the severity of PE and examine the updated evidence surrounding the utility of ECG abnormalities in prognostication for severity of acute PE. We performed a literature search of MEDLINE, EMBASE, and PubMed up to February 2015. Article titles and abstracts were screened, and articles were included if they were observational studies that used a surface 12-lead ECG as the instrument for measurement, a diagnosis of PE was confirmed by imaging, arteriography or autopsy, and analysis of prognostic outcomes was performed. Thirty-six articles met our inclusion criteria. We review the prognostic value of ECG abnormalities included in the 21-point ECG score, including new evidence that has arisen since the time of its publication. We also discuss the potential prognostic value of several ECG abnormalities with newly identified prognostic value in the setting of acute PE.

Atrial fibrillation (AF) can induce a hypercoagulable state in both the left and right atria. Thrombus in the right side of the heart (RHT) may lead to acute pulmonary embolism (APE). The aim of the study was to determine the prevalence of RHT and AF and to assess their impact on outcomes in patients with APE. The retrospective cohort included 1,006 patients (598 female), with a mean age of 66 ± 15 years. The primary end point was all-cause mortality. The secondary end point was incidence of complications (death, cardiogenic shock, cardiac arrest, vasopressor/inotrope treatment, or ventilatory support). Atrial fibrillation was detected in 231 patients (24%). RHT was observed in 50 patients (5%). The combination of AF and RHT was observed in 16 patients (2%). The overall mortality rate was significantly higher in patients with RHT compared with those without (32% vs 14%, respectively, odds ratio [OR] 3.0, 95% confidence interval [CI] 1.6 to 5.6, p = 0.001). The rate of complications was significantly higher in patients with RHT in comparison to those without (40% vs 22%, respectively, OR 2.4, 95% CI 1.3 to 4.4, p = 0.004). The mortality rate in patients with both AF and RHT was significantly higher in comparison to those with AF but without RHT (50% vs 20%, respectively, OR 3.86, 95% CI 1.3 to 11.2, p = 0.01). In multivariate analysis, RHT (p = 0.03) was an independent predictor of death. In conclusion, AF is a frequent co-morbidity in patients with APE, and the presence of RHT is not uncommon. Among patients with APE, the presence of RHT increases the mortality approximately threefold regardless of the presence of known AF.

Hypocalcemia is mainly the consequence of hypoalbuminemia, advanced renal impairment, cirrhosis, malnutrition, or sepsis. The most common ECG manifestation of hypocalcemia is QT prolongation as a result of ST segment lengthening. Very occasionally, hypocalcemia can manifest with ST segment elevation forcing the differential diagnosis with ST elevation MI. We described a case of severe hypocalcemia manifesting in electrocardiogram with a J point elevation, absent of ST segment and with associated short QT interval mimicking acute myocardial infarction.

WOS: 000418210700016, PubMed ID: 28336205, Background: Andersen-Tawil syndrome (ATS) is rare channelopathy caused by KCNJ2 mutation and probably KCNJ5. It is characterized by arrhythmias, neurological symptoms, and dysmorphic features. The present study retrospectively examined the characteristics of 11 unrelated families with ATS. Methods: This study consisted of 11 probands positive for KCNJ2 variants and 33 family members (mean age 30.0 +/- 17.3 years, female n=31). Additional genetic screening of 3 LQTS genes (KCNQ1, KCNH2, SCN5A) was performed in 9 families. Predictors of arrhythmias [premature ventricular beats>2000/24h, biventricular and polymorphic ventricular tachycardia (VT)], syncope, and/or cardiac arrest (CA) were evaluated. Results: In KCNJ2 mutation carriers vs non-carriers (n=25 vs n=19) significant differences were observed in U-wave manifestations in V2-V4, T-peak-T-end duration, QTUc duration (p2000/24h was higher (p=0.005). Conclusion: A higher risk of arrhythmia, syncope, and/or CA is associated with the presence of micrognathia, periodic paralysis, and prolonged T-peak-T-end time. Our findings suggest that K897T may contribute to the occurrence of syncope. (C) 2017 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved., NHLBI of the NIHUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH National Heart Lung & Blood Institute (NHLBI) [HL47678], The Turkish part of the research was supported by NHLBI of the NIH (HL47678, CA).

We report three patients with intermittent loss of the preexcitation pattern in the ECG that had undergone an electrophysiological study. Despite apparently poorly conducting accessory pathway (AP), in each case a fast anterograde conduction, either during spontaneous atrial fibrillation or during incremental atrial pacing (on isoproterenol) was documented; shortest preexcited RR intervals of 200–240 ms were observed. We review the literature and conclude that intermittent preexcitation observed on resting 12-lead ECG lacks sufficient specificity for the diagnosis of an AP with long refractory period and cannot be considered a substitute for electrophysiological study in patients with this electrocardiographical phenomenon.

Philosophy, merits and limitations of a novel method for wide QRS complex tachycardia differentiation, based on a scoring system and called the ventricular tachycardia (VT) score, were explained. The following criteria were assigned one point: initial dominant R wave in V1; initial r>40 ms in V1 or V2; notched S in V1; initial R wave in aVR; lead II RWPT≥50 ms; and absence of an RS in leads V1-V6. Atrioventricular dissociation (including fusion/capture beats and partial dissociation) was assigned two points. We recommend ≥3 VT score points for a firm diagnosis of VT. A cut-off ≥1 point can be used for diagnosis of VT when highest overall accuracy rather than error-free diagnosis is desired. However, in case of VT score of 0-2 (i.e., not fully diagnostic ECG), we recommend using other options (electrophysiological study, clinical data, previous and following ECGs, etc.) for confirming the diagnosis.

Background An accurate and universal method for diagnosis of biventricular (BiV) capture using a standard 12-lead electrocardiogram (ECG) would be useful for assessment of cardiac resynchronization therapy (CRT) patients. Our objective was to develop and validate such an ECG method for BiV capture diagnosis that would be independent of pacing lead positions—a major confounder that significantly influences the morphologies of paced QRS complexes. Methods On the basis of an evaluation of 789 ECGs of 443 patients with heart failure and various right ventricular (RV) and left ventricular (LV) lead positions, the following algorithm was constructed and validated. BiV capture was diagnosed if the QRS in lead I was predominantly negative and either V1 QRS was predominantly positive or V6 QRS was of negative onset and predominantly negative (step 1), or if QRS complex duration was

We report a case of 82-year-old female with total masquerading bundle branch block. We discuss the problems with ECG analysis.

We described 2 patients (28-year-old and 69-year-old females) with hypercalcemia (4.47 mmol/L and 4.8 mmol/L), chest painand electrocardiogram with ST-T segment changes mimicking acute coronary syndrome. One patient presented ST segment elevation in right precordial leads V1-V3 max. 4 mm, the second one presented negative T waves in V1-V6 leads. Troponin level was normal in both cases. Additionally, corrected QT apex was shortened in both cases, 250 ms and 206 ms respectively and T wave humps in lateral leads was observed.

Atypical form of tako-tsubo cardiomyopathy (TTC) is associated with regional wall motion abnormalities in basal and/or middle segments or only middle segments with sparing of apical segments or apical and basal segments. We described a case of47-year-old female with atypical form of TTC due to fast atrial fibrillation that converted into ventricular fibrillation in WPW syndrome. The echocardiogram made after direct current cardioversion revealed decreased left ventricular ejection fraction (LVEF 35%) with akinesis of inferior and posterior walls and anterior part of interventricular septum in the middle and the basal segments with hyperkinesis of apical segments. The biochemistry blood samples revealed elevated both troponin T- 0.35 ng/mL and NT-proBNP - 3550 pg/mL plasma level. The ECG showed sinus rhythm 62 bpm, shortened PQ interval 100 ms, widened QRS duration - 115 ms with delta wave, prolonged QT interval - 520 ms, QS in leads: II, III, aVF. NegativeT waves in leads: I, aVL and positive, symmetrical T waves in leads V1-V6. The coronarography revealed normal coronaryarteries. The control echocardiography after 10 days showed normal LVEF 70%, without any wall motion abnormalities. TTC was recognised based on: history of sudden stress situation before, ischaemic ECG changes, positive markers of myocardial injury, transient segmental wall motion abnormalities and normal coronary arteries. The ablation of right postero-septal accessory pathway was successfully performed.

We present a case of broad QRS complex tachycardia and atrioventricular (AV) dissociation that was documented during electrophysiological study to be a supraventricular rather than a ventricular tachycardia. Ablation of AV nodal slow pathway eliminated the arrhythmia confirming the diagnosis of atypical AV nodal reentrant tachycardia.

Background: Assessment of left ventricular (LV) capture is of paramount importance in patients with biventricular (BiV) pacing. Our goal was to identify electrocardiographic features that differentiate between BiV and right ventricular (RV)-only pacing in patients with nonapical RV leads. Methods: The study enrolled 300 consecutive patients with BiV devices and nonapical RV leads, and obtained from them 558 electrocardiograms with either BiV pacing (n = 300) or RV-only pacing (n = 258). RV pacing served as a surrogate for loss of LV capture. Electrocardiograms from the first 150 patients were used to identify BiV-specific features, and to construct an algorithm to differentiate between BiV and RV-only pacing. Electrocardiograms from the second 150 patients were used to validate the algorithm. Results: The following electrocardiographic features typical of BiV pacing were identified: QS in lead V6 (specificity = 98.7%, sensitivity = 54.7%), dominant R in lead V1 (specificity = 100%, sensitivity = 23.3%), q in lead V6 (specificity = 96%, sensitivity = 22.7%), and a QRS < 160 ms (specificity = 100%, sensitivity = 66.0%). The algorithm based on those features was found to have an overall diagnostic accuracy of 95.0%, a specificity of 96.0%, and a sensitivity of 93.5%. Conclusions: The study identified QRS features that were very specific for BiV pacing in patients with nonapical RV leads. Sequential arrangement of those features resulted in an algorithm that was very accurate for differentiating between BiV pacing and loss of LV capture. (PACE 2012; 35:1199–1208)

Background Myocardial ischemia during coronary spasm may generate malignant ventricular arrhythmias. The J-wave pattern was suggested to be a marker of a disorder associated with life-threatening arrhythmias. Results We report the case of a patient with vasospastic angina and J-wave pattern in inferior and lateral leads associated with polymorphic ventricular tachycardia which was effectively treated only with quinidine-vasodilating drugs were not able to prevent the arrhythmia although they were effective in preventing ischemic events. Conclusion The J-wave pattern in inferolateral leads may be a sign of electrical vulnerability to lethal ventricular arrhythmia in patients suffering from vasospastic angina--quinidine can effectively prevent such arrhythmias in these patients.

Aims To compare the sensitivity (SN), specificity (SP), and diagnostic accuracy (ACC) for ventricular tachycardia (VT) diagnosis of five electrocardiographic methods for wide QRS-complex tachycardia (WCT) differentiation, specifically the Brugada, Bayesian, Griffith, and aVR algorithms, and the lead II R-wave-peak-time (RWPT) criterion. Methods and results We retrospectively analysed 260 WCTs from 204 patients with proven diagnoses. The SN, SP, ACC, and likelihood ratios (LRs) were determined for the five methods. Of the 260 tracings, there were 159 VTs and 101 supraventricular tachycardias. All five methods were found to have a similar ACC although the RWPT had a lower ACC than the Brugada algorithm (68.8 vs. 77.5%, P = 0.04). The RWPT had lower (60%) SN than the Brugada (89.0%), Griffith (94.2%), and Bayesian (89%) algorithms ( P < 0.001). The Griffith algorithm showed lower (39.8%) SP than the RWPT (82.7%), Brugada (59.2%), and Bayesian (52.0%) algorithms ( P < 0.05). The positive LRs for a VT diagnosis for the RWPT criterion and the Brugada, Bayesian, aVR, and Griffith algorithms were 3.46, 2.18, 1.86, 1.67, and 1.56, respectively. Conclusion The present study is the first independent ‘head-to-head’ comparison of several WCT differentiation methods. We found that all five algorithms/criteria had rather moderate ACC, and that the newer methods were not more accurate than the classic Brugada algorithm. However, the algorithms/criteria differed significantly in terms of SN, SP, and LR, suggesting that the value of a diagnosis may differ depending on the method used.

A 72-year-old man with heart failure, left ventricular dysfunction (ejection fraction 20%), prior ischemic stroke, COPD, and exacerbation of chronic renal failure was admitted in our unit. Serum potassium was 6.1 mmol/L, calcium concentration was at the lower normal range 2.15 mmol/L, and NT-pro-BNP was 28,900 pg/mL. The surface 12-lead electrocardiogram (ECG) showed sinus rhythm at 60 bpm, PR interval 160 ms, QRS duration 115 ms, QT interval 460 ms, and left ventricular hypertrophy criteria. Negative T waves in leads I, II, aVL, and V4 -V6 were also seen. In leads V4 -V6 , negative U waves were observed in concordance with negative T waves. In all precordial leads, beat-to-beat U-wave polarity variability was observed as a polarity variation from negative to positive with associated and stable negative T waves, in a beat-to-beat alternate morphology.

We here describe a surface 12-lead electrocardiogram (ECG) of a 72-year-old female with a prior history of breast cancer and chemotherapy-induced cardiomyopathy. An echocardiogram revealed left ventricular dysfunction, ejection fraction of 23%, with mild enlarged left ventricle. The 12-lead ECG showed atrial fibrillation with a mean heart rate of about 100 bpm, QRS duration 160 ms, QT interval 400 ms, right bundle branch block (RBBB) and left anterior fascicular block (LAFB). The combination of RBBB features in the precordial leads and LAFB features in the limb leads is known as ''masquerading bundle branch block''. In most cases of RBBB and LAFB, the QRS axis deviation is located between - 80 to -120 degrees. Rarely, when predominant left ventricular forces are present, the QRS axis deviation is near about -90 degrees, turning the pattern into an atypical form. In a situation of RBBB associated with LAFB, the S wave can be absent or very small in lead I. Such a situation is the result of not only purely LAFB but also with left ventricular hypertrophy and/or focal block due to scar (extensive anterior myocardial infarction) or fibrosis (cardiomyopathy). Sometimes, this specific ECG pattern is mistaken for LBBB. RBBB with LAFB may imitate LBBB either in the limb leads (known as 'standard masquerading' - absence of S wave in lead I), or in the precordial leads (called 'precordial masquerading' - absence of S wave in leads V₅ and V₆). Our ECG showed both these types of masquerading bundle branch block - absence of S wave in lead I and in leads V₅ and V₆.

BACKGROUND: Andersen–Tawil Syndrome (ATS) is a channelopathy caused by mutations in KCNJ2 gene. It is characterized by symptoms of ventricular arrhythmias, periodic paralysis or muscle weakness, and dysmorphic features. ATS can present with the triad of symptoms, any combination or none of them. Risk factors for dangerous arrhythmias are unknown. The study assessed the impact of K897T polymorphism in hERG1 gene and H558R polymorphism in SCN5A gene coexisting with R218Q mutation in KCNJ2 in one family on clinical manifestation. METHODS: Family members underwent clinical assessment, ECG and genotyping. Holter monitoring was performed in mutation carriers and additionally in one family member with no mutation, but with K897T polymorphism. RESULTS: Proband with ATS mutation, K897T and H558R polymorphisms and proband's sister with ATS mutation and K897T polymorphism presented following symptoms: loss of consciousness, bidirectional and polymorphic ventricular tachycardia and about 5000 ventricular extrasystoles. Symptoms presented by the member with only the ATS mutation and by member with ATS mutation and H558R polymorphism were not as severe. U wave appeared in all examined family members regardless of the mutation presence. Studied individuals with ATS mutation had the T‐peak–U‐peak interval longer than 200 ms. In all ATS mutation carriers it was longer than in family members with no mutation. T‐peak–T‐end interval was the longest (>120 ms) in members with coexisting mutation and K897T polymorphism. CONCLUSION: ATS severity possibly depends on other genes’ polymorphisms. In the presented family, it could depend on the presence of K897T polymorphism in hERG1.

Electrocardiographic (ECG) abnormalities in the setting of acute pulmonary embolism (PE) are being increasingly characterized and mounting evidence suggests that ECG plays a valuable role in prognostication for PE. We review the historical 21‐point ECG prognostic score for the severity of PE and examine the updated evidence surrounding the utility of ECG abnormalities in prognostication for severity of acute PE. We performed a literature search of MEDLINE, EMBASE, and PubMed up to February 2015. Article titles and abstracts were screened, and articles were included if they were observational studies that used a surface 12‐lead ECG as the instrument for measurement, a diagnosis of PE was confirmed by imaging, arteriography or autopsy, and analysis of prognostic outcomes was performed. Thirty‐six articles met our inclusion criteria. We review the prognostic value of ECG abnormalities included in the 21‐point ECG score, including new evidence that has arisen since the time of its publication. We also discuss the potential prognostic value of several ECG abnormalities with newly identified prognostic value in the setting of acute PE.

We report a case of 82‐year‐old female with total masquerading bundle branch block. We discuss the problems with ECG analysis.

To establish an appropriate treatment strategy and determine if ablation is indicated for patients with narrow QRS complex supraventricular tachycardia (SVT), analysis of a standard 12-lead electrocardiogram (ECG) is required, which can differentiate between the 2 most common mechanisms underlying SVT: atrioventricular nodal reentry tachycardia (AVNRT) and orthodromic atrioventricular reentry tachycardia (OAVRT). Recently, new, highly accurate electrocardiographic criteria for the differential diagnosis of SVT in adults were proposed; however, those criteria have not yet been validated in a pediatric population. All ECGs were recorded during invasive electrophysiology study of pediatric patients (n = 212; age: 13.2 ± 3.5, range: 1–18; girls: 48%). We assessed the diagnostic value of the 2 new and 7 standard criteria for differentiating AVNRT from OAVRT in a pediatric population. Two of the standard criteria were found significantly more often in ECGs from the OAVRT group than from the AVNRT group (retrograde P waves [63% vs 11%, P

A 46-year-old male was admitted to our emergency department due to a narrow QRS tachycardia of 230 bpm with impeding hemodynamic collapse. His only remarkable medical history was mild hypertension. Adenosine administration was ineffective in stopping the tachycardia, and sinus rhythm was restored using an electrical cardioversion. A few weeks later, during an electrophysiology study an identical tachycardia was immediately induced during the introduction of diagnostic catheters into the right atrium (Fig. 1, upper panel). A rate-related right bundle branch block aberration was present for most of the time. Atrial activation was simultaneous with ventricular activation, ruling out atrioventricular reentrant tachycardia (AVRT), and suggesting atrioventricular nodal reentrant tachycardia (AVNRT) (Fig. 1, lower panel). To confirm the absence of atrial tachycardia, ventricular entrainment pacing using a cycle length shorter by 30 milliseconds than the tachycardia cycle length was performed. The atrial rate accelerated to the pacing rate (Fig. 2), and when ventricular (V) pacing was ceased, the activation sequence was the last entrained atrium (A) followed by the ventricle (V) (i.e., a V-A-V response). Such a response is considered to rule out atrial tachycardia and these findings were repeatable. Therefore, by exclusion of all other possible causes a diagnosis of AVNRT could have been considered irrefutable. However, long VA interval during entrainment and the atrial activation sequence with atrial depolarization later on His catheter than on high right atrial catheter (Fig. 1, lower panel) were not compatible with slow-fast AVNRT, either. Moreover, multiple attempts to stop the tachycardia with fast ventricular and atrial burst pacing failed. This prompted a more detailed assessment of the atrial activation sequence and an analysis of entrainment from the right atrium. Those analyses both led to an unquestionable diagnosis of a macroreentrant right atrial tachycardia with a reentrant circuit identical to that observed in a typical clockwise atrial flutter, albeit slower, which resulted in a rate below the arbitrary thresh