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Cardiac resynchronization therapy is a well-established treatment of heart failure with reduced left ventricular ejection fraction and a wide QRS complex. Cardiac contractility modulation therapy is an emerging electrical treatment indicated for use in patients with symptomatic heart failure caused by moderate-to-severe systolic left ventricular dysfunction (left ventricular ejection fraction ranging from 25% to 45%), with no indication for cardiac resynchronization therapy. Cardiac contractility modulation therapy improves functional status, exercise capacity, quality of life, and possibly prevents hospital admissions in indicated patients. An algorithm for patient selection for these two forms of electrical therapy for heart failure is presented.

The lecture is devoted to the pressing problem of clinical cardiology – the diagnosis and treatment of wide QRS complex tachycardia, requiring an individualized approach to patients` management. The basic principles of determination of wide QRS complex tachycardias and their electrophysiological mechanisms are reviewed. The etiology of wide QRS complex tachicardias, their clinical picture and ECG criteria for differential diagnosis, particularly between ventricular tachycardia and supraventricular tachycardia with aberrant ventricular conduction, are outlined. The basic principles of wide QRS complex tachycardias diagnosis are discussed, and the ECG signs of the certain «wide» are presented. The results of the studies, aimed at the development of the diagnostic criteria and algorithms for differential diagnosis of wide QRS complex tachycardias, are analyzed. The acute treatment of narrow and wide QRS complex tachycardias are presented. The antiarrhythmic drugs and their use are given, and the principles of catheter treatment of tachycardia are stated., Лекция посвящена серьезной проблеме в клинической практике – диагностике и лечению тахикардий с «широкими» комплексами QRS, требующими индивидуального подхода. Рассмотрены основные принципы определения тахикардий с широкими комплексами QRS и их электрофизиологические механизмы. Приведены причины «широких» тахикардий, клинические и ЭКГ-критерии дифференциальной диагностики между желудочковой тахикардией и суправентрикулярной тахикардией с аберрацией проведения. Обсуждены основные положения диагностики тахикардий с широкими комплексами QRS, приведены примеры некоторых «широких» тахикардий с демонстрацией ЭКГ. Анализируются результаты исследований, направленных на определение критериев и алгоритмов дифференциальной диагностики тахикардии с широкими комплексами QRS. Рассмотрена неотложная помощь при тахикардиях с узкими и широкими комплексами QRS, приведены антиаритмические препараты, показания к их применению, изложены общие принципы катетерного лечения тахиаритмий., Лекція присвячена серйозній проблемі у клінічній практиці – діагностиці та лікуванню тахікардій з широкими комплексами QRS, які потребують індивідуального підходу. Розглянуто основні принципи визначення тахікардій із широкими комплексами QRS та їхні електрофізіологічні механізми. Наведено причини виникнення «широких» тахікардій, клінічні та ЕКГ-критерії диференційної діагностики між шлуночковою тахікардією та суправентрикулярною тахікардією з аберацією проведення. Обговорено основні положення діагностики тахікардій із широкими комплексами QRS, наведено приклади деяких «широких» тахікардій із демонстрацією ЕКГ. Аналізуються результати досліджень, спрямованих на визначення критеріїв та алгоритмів диференційної діагностики тахікардій із широкими комплексами QRS. Розглянуто невідкладну допомогу при тахікардіях з вузькими та широкими комплексами QRS, наведено антиаритмічні препарати, показання до їх застосування, викладено загальні принципи катетерного лікування тахіаритмій.

We evaluated the relationship between hyperkalemia and wide QRS complex in patients with pulseless electrical activity (PEA) cardiac arrest.This was a single-center, retrospective observational study of patients over the age of 18 treated for cardiac arrest at a tertiary referral hospital whose initial electrocardiogram rhythm was PEA from February 2010 to December 2019. Wide QRS PEA was defined as a QRS interval of 120 ms or more. Hyperkalemia was defined as serum potassium level 5.5 mmol/L. The primary outcome was hyperkalemia. Multivariable logistic regression analysis was used to evaluate the relationship between wide QRS and hyperkalemia.Among 617 patients, we analyzed 111 episodes in the wide QRS group and 506 episodes in the narrow QRS group. The potassium level in the wide QRS group was significantly higher than in the narrow QRS group (5.4 mmol/L, IQR 4.4-6.7 vs. 4.6 mmol/L, IQR 4.0-5.6, P 0.001). Among all patients, 49.6% (n = 55/111) in the wide QRS group had hyperkalemia, which was significantly higher than the 26.7% (n = 135/506) in the narrow QRS group (P 0.001). In multivariable logistic regression analysis, wide QRS PEA was significantly associated with hyperkalemia (odds ratio = 2.86, 95% confidence interval: 1.80-4.53, P 0.001).Wide QRS PEA as an initial cardiac rhythm was significantly associated with hyperkalemia in cardiac arrest patients.

Subcutaneous implantable cardioverter-defibrillators are a modern alternative to classic cardioverter-defibrillators. Prior to implantation of the device, qualification based on assessment of the heart's specific rhythm shape during a resting electrocardiogram examination must be performed. In the presented case, a patient with a subcutaneous implantable cardioverter-defibrillator experienced numerous discharges during exercise. An exercise test was performed, which revealed a bundle branch block that appeared during exercise. The wide QRS complex was double- or triple-counted by the device, resulting in an inaccurate heart rate estimation and multiple discharges. Optimising the sensing vectors during exercise solved this problem.

Cardiac resynchronization therapy (CRT) is an established treatment of patients with medically refractory, mild-to-severe systolic heart failure (HF), impaired left ventricular function, and wide QRS complex. The pathologic activation sequence observed in patients with abnormal QRS duration and morphology results in a dyssynchronous ventricular activation and contraction leading to cardiac remodeling, worsening systolic and diastolic function, and progressive HF. In this article, the authors aim to explore the current CRT literature, focusing their attentions on the promising innovation in this field.

El síndrome de Wolff Parkinson White ocurre por la presencia de vías accesorias que comunican anormalmente las aurículas con los ventrículos, es una de las principales causas de taquicardia paroxística supraventricular en jóvenes y adolescentes, en quienes el manejo ideal es la ablación con catéter. Este síndrome también puede presentarse en pacientes de menor edad como neonatos y lactantes, en donde las opciones terapéuticas son distintas. Presentamos el caso de una paciente de 47 días de vida que ingresó a un hospital pediátrico público de Perú presentando vómitos, a su ingreso mostró una frecuencia cardiaca de 250 latidos por minuto; se logró documentar taquicardia de complejos QRS anchos; posteriormente, en el electrocardiograma en ritmo sinusal, se evidenció signos de preexcitación

A case of wide complex tachycardia with isolated QRS complexes of different amplitude suggesting that this was ventricular tachycardia.

Symptomatic heart failure patients with ischemic heart disease may require both coronary sinus reducer (CSR) implantation due to refractory angina pectoris and cardiac resynchronization therapy (CRT). Optimal approach to CRT in these patients is unknown as CSR implantation in the distal coronary sinus could deter left ventricular lead placement and thus preclude conventional CRT with biventricular pacing. We present a 70-year-old patient with ischemic cardiomyopathy and wide QRS complex after CSR implantation in whom we achieved successful cardiac resynchronization with His bundle pacing (HBP). HBP led to acute improvement in hemodynamic parameters and exercise capacity that persisted at follow-up. This case represents the first description of successful CRT with HBP in a patient after CSR implantation. HBP could present a feasible and safe resynchronization approach in these patients.

Лекція присвячена одній з найактуальніших проблем кардіології – пароксизмальним суправентрикулярним тахікардіям (СВТ) у клінічній практиці. Розглянуті основні принципи визначення СВТ та їхні електрофізіологічні механізми. Викладені клініка та ЕКГ-діагностика різноманітних форм тахікардій. Представлені невідкладна допомога і тривала терапія при СВТ із вузькими і широкими комплексами QRS. Згідно з оновленими рекомендаціями, показані способи лікування та алгоритми ведення пацієнтів із СВТ. Наведені антиаритмічні препарати та їхнє застосування, викладені загальні принципи катетерного лікування тахікардій., The lecture is devoted to one of the most urgent problems in cardiology – management of patients with paroxysmal supraventricular tachycardia (SVT) in clinical practice. The main principles of the diagnosis of SVT and their electrophysiological mechanisms are outlined. Clinical presentation and ECG diagnosis of different forms of tachycardia are stated. The acute care and long-term treatment of SVT with narrow and wide QRS complex are presented. The methods of treatment and algorhythms of management of patients with SVT are given according to the updated ESC guidelines. The data on antiarrhythmic drugs and their usage are presented, along with the general principles of catheter treatment of tachycardia, Лекция посвящена одной из наиболее актуальных проблем кардиологии – пароксизмальным суправентрикулярным тахикардиям (СВТ) в клинической практике. Рассмотрены основные принципы определения СВТ и их электрофизиологические механизмы. Изложена клиника и ЭКГдиагностика различных форм тахикардий. Представлены неотложная помощь и длительная терапия при СВТ с узкими и широкими комплексами QRS. Согласно обновленным рекомендациям, показаны способы лечения и алгоритмы ведения пациентов с СВТ. Приведены антиаритмические препараты и их применение, изложены общие принципы катетерного лечения тахикардий.

We describe a case of Wenckebach periodicity in the distal conduction system. Our observation strengthens the concept that Wenckebach type block in surface ECG may reflect block in infra-hissian tissues, especially if there is a wide QRS complex in the conducted beats.

We present the case of one premature infant who developed bradycardia due to hyperkalemia and hypocalcemia with continuous ECG recording showing second-degree atrioventricular block and wide QRS complex rhythm. TAKE-HOME MESSAGE: Multiple ECG changes can occur with combined hyperkalemia and hypocalcemia in newborns. If left unchecked, these electrolyte disorder can be fatal. Early recognition enables prompt appropriate treatment, preventing serious complications.

Macroreentrant atrial tachycardia within the right atrium is the dominant mechanism in patients with prior surgical repair of atrial septal defects, with dual-loop circuits much more common than single-loop circuits. This case highlights the importance of clinical history for predicting arrhythmia mechanisms. Considering prior cardiac surgery may assist in preprocedural preparations and discussions regarding potential risks and benefits of catheter ablation.

„Das sollte ich eigentlich wissen!“ So oder ahnlich ausern sich manche Arzte in der Praxis oder im Notdienst, denen ein 12-Kanal-EKG eines hamodynamisch beeintrachtigten Patienten vorgelegt wird, das eine Tachykardie mit breiten Kammerkomplexen zeigt. Trotz einer Fulle an etablierten Kriterien kann die korrekte Diagnose einer Tachykardie mit breiten Kammerkomplexen durchaus schwierig oder alleine aufgrund des 12-Kanal-EKG sogar unmoglich sein. In diesem Beitrag erhalten Sie nutzliche Tipps.

Electrocardiogram (ECG) analysis trying to understand the mechanisms of QRS widening is often problematic. During WCTs, identification of P waves and atrioventricular relationship is often difficult and increasingly so if the number of recording leads available for examination is limited. For this reason, it is necessary to use every information available in an ECG tracing. The goal of this article is to focus on the reasons for QRS variations occurring during tachycardia. Correct interpretation of these data can offer the key to understand the arrhythmia mechanism.

Atrial fibrillation (AF) may be fatal in patients that have accessory pathways (APs) with fast anterograde conduction. In some individuals, however, conduction across the AP may not be observed during sinus rhythm despite the presence of a pathway capable of rapid anterograde conduction. This unique and interesting pathway was previously reported as a latent AP.1 Here, we would like to describe a case in which preexcitation was not visible on the resting electrocardiogram (ECG) and anterograde AP conduction was manifested only during the tachycardia or rapid atrial rates and was diagnosed as at high risk for the development of ventricular fibrillation (VF).

Aim. To evaluate standard 12-lead ECG indices for the differential diagnosis of wide QRS tachycardias with right bundle branch block (RBBB) pattern. Materials and methods. Study analyses the 244 ECG indices in 111 patients (79 males and 32 females, age 53±17 years) with RBBB tachycardias, who underwent electrophysiological studies. First step includes retrospective analysis of QRS characteristics in 20 patients with ventricular tachycardias (VT), 24 pts with aberrant supraventricular tachycardias (SVT+RBBB) and 14 pts with antidromic SVTs (WPW). ROC- and multifactorial analyses were performed to develop diagnostic ECG algorithms. The prognostic accuracy of the algorithms was subsequently evaluated on a prospective group of patients with RBBB tachycardias (n=53). Results and discussion. ECG criteria of RBBB VTs were: 1) the presence Q-wave in lead II, 2) the duration interval R(peak)-S(end) >100 ms in lead V5. ECG criteria for antidromic SVTs with RBBB were: 1) the duration of the R wave in lead I ≥80 ms, 2) the absence of split (M-sharp) R-waves in lead V2, 3) the absence notch in ascending S wave in lead aVL. The accuracy of the algorhythm for diagnostic of VTs with RBBB was 83% (sensitivity 100%, specificity 73%). The accuracy of the algorhythm for diagnostic of antidromic SVTs with RBBB was 91% (sensitivity 85%, specificity 96%). Conclusion. The proposed algorithms are based on new ECG criteria for the differential diagnosis of wide QRS complexes tachycardias with RBBB pattern, unlike the previous algorithms.

Background The differential diagnosis of regular wide QRS complex tachycardia (RWQRST) remains the subject of numerous publications, all of which aim at diagnosis during the acute phase. Although an accurate diagnosis is necessary to make long-term decisions, it often leads to invasive testing. Methods Criteria with high positive predictive values (PPVs) for diagnosis can be obtained by analyzing the electrocardiogram (ECG) data during RWQRST and comparing them with these data at baseline. By assigning points to these criteria, a scoring algorithm to accurately diagnose numerous patients can be obtained. A total of 352 consecutive patients with RWQRST were included. Two electrophysiologists blind to patient condition analyzed the 16 criteria considered as having high PPVs. Results A total of 149 (42.3%) cases were supraventricular tachycardia (SVT), and 203 (57.7%) cases were ventricular tachycardia (VT). A higher percentage of patients with VT had structural heart disease (86.7% vs 16.1%). Seven of the 16 criteria analyzed had PPVs > 95%, and each criterion was assigned a score. A final score of -1 was indicative of SVT (PPV 98%); a score of 1 was indicative of VT (PPV 98%); and a score of ≥2 was indicative of VT (PPV 100%). A score of ≠0 was obtained for 51.7% of all cases of tachycardia, making it possible to reach a highly accurate diagnosis in approximately half of all cases. No cases of VT scored -1, and no cases of SVT scored ≥2. Conclusions The current scoring system stands out for its high PPV (98%) and specificity (98%), enabling an accurate diagnosis for more than half of the patients.

Background Left ventricular (LV) lead placement at the late activation site (LAS) has been proposed as an optimal LV pacing site (ie, Q-LV interval). However, LAS may be relevant to local electrical conduction, measured as an interval from LV pacing stimulation to QRS onset (S-QRS interval). Objective The purpose of this study was to evaluate the prognostic value of S-QRS for reverse remodeling and the impact of S-QRS on pacing QRS configuration in patients undergoing cardiac resynchronization therapy (CRT). Methods Sixty consecutive heart failure patients with a wide QRS complex underwent CRT. A site with Q-LV ≥95 ms was targeted for LV lead placement. A responder was defined as one with >15% reduction in LV end-systolic volume 6 months after CRT. Results LV lead placement with Q-LV ≥95 ms was achieved in 52 of 60 patients (86.7%). Thirty-two of 52 patients (61.5%) were responders. S-QRS was significantly shorter in responders than nonresponders (P Conclusion In addition to a sufficient Q-LV, S-QRS can be a useful indicator of optimal LV lead position to achieve reverse remodeling. S-QRS contributes to the pacing QRS configuration associated with CRT response.

We describe a case where ventricular overdrive pacing during a wide QRS complex supraventricular tachycardia demonstrated constant fusion by narrowing the QRS complex duration and diagnosing the tachycardia mechanism.

A wide QRS-complex tachycardia with 1:1 ventriculoatrial conduction may present diagnostic difficulties, and multiple pacing maneuvers are often required for an accurate diagnosis. We report a case, in which observation of transient ventriculoatrial interval variation following atrio-His block quickly led to the diagnosis.

Background The 12-lead electrocardiogram (ECG) is an essential tool for the diagnosis and management of heart failure (HF). There are few population-based studies on the prevalence and prognostic implications of ECG abnormalities in patients with HF. There are also no robust diagnostic criteria for HF. We explored these issues in a large administrative database. Methods The National Health Service Greater Glasgow and Clyde Health Board serves a population of ∼1.1 million. We obtained de-identified administrative data, including investigations, diagnosis and prescriptions, linked to hospital admissions and deaths, for anyone with a diagnosis of vascular disease or HF or prescribed loop diuretics (LD) or neuro-endocrine antagonists between 1st January 2012 and 1st April 2018. People were classified into 5 exclusive groups: a) prevalent HF; b) incident (or latent) HF with onset during follow-up; c) people taking LDs but with no diagnosis of HF at any time; d) new prescription of LDs during follow-up but with no diagnosis of HF at any time and d) people to whom none of the above applied. ECGs were classified according to heart rhythm (sinus, AF or flutter or pacemaker/CRT/ICD) and QRS duration 130ms. Follow-up for each group started on 1st of January 2012 (prior to the onset of the classifying event for incident groups). Results During the observation period, of 316,350 people included, 158,421 had a recorded ECG (mean of 3.2 per person with an ECG), including 8,768 prevalent and 13,195 incident cases of HF. Of those who never got a diagnosis of heart failure, 11,508 were receiving and a further 14,633 were newly prescribed LD during follow-up. There were 110,317 people who did not fall into the above groups, of whom 51,089 were aged ≥60 years. A higher proportion of those who were prescribed loop diuretics without a diagnosis of heart failure were women. A similar proportion of those with heart failure and those prescribed diuretics alone had, lung disease and renal dysfunction but patients with heart failure had more ischaemic heart disease, more often had a heart rhythm other than sinus and had longer QRS duration. By three years, 8,816 people (11%) had died, of whom 2,919 (33%) had a diagnosis of heart failure and 2,694 (31%) had been prescribed LD without a diagnosis of HF, together accounting for 64% of all deaths. Patients with a rhythm other than sinus had a worse prognosis in all 5 groups of patients. QRS duration >130ms was associated with a worse prognosis in patients with HF or taking LD. Conclusions Most people with cardiovascular disease who die will first develop HF or be prescribed a LD (indicating possible undiagnosed HF). Patient characteristics of those prescribed LD suggest that many might have HF with preserved left ventricular ejection fraction (HFpEF). Baseline characteristics and HR Funding Acknowledgement Type of funding source: None

Transient Atrial-His Block during Wide QRS-Complex Tachycardia with 1:1 Ventriculoatrial Relationship: What is the Diagnosis?

Background The information on electrocardiographic features of patients with coronavirus disease 2019 (COVID-19) is limited. Our aim was to determine if baseline electrocardiographic features of hospitalized COVID-19 patients are associated with markers of myocardial injury and clinical outcomes. Methods In this retrospective, single center cohort study, we included 223 hospitalized patients with laboratory-confirmed COVID-19. Clinical, electrocardiographic and laboratory data were collected and analyzed. Primary composite endpoint of mortality, need for invasive mechanical ventilation, or admission to the intensive care unit was assessed. Results Forty patients (17.9%) reached the primary composite endpoint. Patients with the primary composite endpoint were more likely to have wide QRS complex (>120 ms) and lateral ST-T segment abnormality. The multivariable Cox regression showed increasing odds of the primary composite endpoint associated with acute respiratory distress syndrome (odds ratio 7.76, 95% CI 2.67–22.59; p 120 ms (odds ratio 3.62, 95% CI 1.39–9.380; p = 0.008) Patients with a wide QRS complex (>120 ms) had significantly higher median level of troponin T and pro-BNP than those without it. Patients with abnormality of lateral ST-T segment had significantly higher median level of troponin T and pro-BNP than patients without. Conclusions The presence of QRS duration longer than 120 ms and lateral ST-T segment abnormality were associated with worse clinical outcomes and higher levels of myocardial injury biomarkers.

Setting up a randomized trial to assess the association of mechanical dyssynchrony (MD) and the success of cardiac resynchronization therapy (CRT) in heart failure with a wide QRS complex is ethically challenging. We therefore investigated this association in a retrospective cohort study observing different treatment strategies which were chosen based on the availability of health care resources. The survival of 500 patients from six Western European centers treated with CRT was compared to their 137 Eastern European counterparts not treated with CRT, with regard to the presence of MD. MD was visually assessed and was defined as the presence of apical rocking and/or septal flash. Patients were followed for a mean of 26 ± 8 months for the occurrence of death of any cause. As compared with medical therapy alone, CRT was associated with a more favorable survival (hazard ratio (HR), 0.53; 95% confidence interval (CI) 0.35–0.79; P = 0.002). Patients with MD treated by CRT had better survival than patients belonging to all other groups—they showed 72%, 66% and 56% reduction in all-cause mortality, respectively, compared to patients with MD not treated by CRT (HR 0.28; 95% CI 0.17–0.44), patients without MD treated by CRT (HR 0.34; 95% CI 0.22–0.52) and patients without MD not treated by CRT (HR 0.44; 95% CI 0.25–0.76). Patients with wide QRS complex who are treated with CRT have a significantly better survival when MD is present.

OBJECTIVES Timing of pulmonary valve replacement (PVR) remains one of the most heavily debated topics in congenital cardiac surgery. We aimed to analyse the temporal evolution of QRS duration before and after PVR. METHODS We included 158 consecutive patients who underwent PVR after previous correction with transannular patch. All 3549 available serial standard 12-lead surface QRS measurements of 158 (100%) patients were analysed with linear mixed-effect modelling. RESULTS PVR was performed at a mean age of 28.0 ± 10.7 years, 23.4 ± 8.4 years after correction. Hospital survival was 98.1%. A longer time interval between ToF correction and PVR (P CONCLUSIONS Prolongation of QRS duration after PVR was associated with a longer time between correction and PVR, older age at correction and male sex. Prevention of progressive QRS prolongation by earlier PVR can potentially reduce the hazard of adverse events after PVR.