Supraventricular Tachyarrhythmias Research Articles

Monochorionic Twin Pregnancy Complicated by Arrhythmia in One Twin: Longitudinal Hemodynamic Effects of Flecainide Cardioversion Assessed by Fetal Venous Doppler

AbstractA parous woman with a monochorionic twin pregnancy presented at gestational week 25 with an uncommon situation. One twin had developed hydrops, but not due to placental transfusion syndrome. The twin had a supraventricular tachyarrhythmia, a rare and severe complication that untreated would threaten the lives of both twins. We present the longitudinal Doppler ultrasound findings when assessing the hemodynamic effects of the arrhythmia and the transplacental treatment with antiarrhythmic medication (flecainide), and how the arrhythmia and the conversion to normal rhythm influenced umbilical and liver circulation in the fetus.

Comparison of the Efficacy of Atorvastatin and Rosuvastatin in Preventing Atrial Fibrillation after Coronary Artery Bypass Grafting: A Double-Blind Randomized Comparative Trial.

Atrial fibrillation (AF) is a supraventricular tachyarrhythmia characterized by disorganized atrial activity and subsequent mechanical atrial failure. Postoperative AF is a frequent complication of coronary artery bypass grafting (CABG). Although there is evidence of decreased AF after CABG with statin usage, information is scarce regarding a direct comparison between atorvastatin and rosuvastatin. The present study was conducted to compare the efficacy of rosuvastatin and atorvastatin in preventing post-CABG AF. The present double-blind randomized comparative clinical trial selected CABG candidates with stable ischemic heart disease or acute coronary syndromes. Atorvastatin (40 mg per day) or rosuvastatin (20 mg per day) was prescribed 1 week before surgery, and the outcomes were compared. Two-hundred patients, 100 cases in each group, completed the study. Twenty-five patients in each group were female, and the mean age was 59.30±8.42 years in the rosuvastatin group and 60.13±9.40 years in the atorvastatin group (P=0.513). The frequency of AF was 31% in the atorvastatin group and 27% in the rosuvastatin group (P=0.534). No significant differences existed between the groups concerning the length of hospital and ICU stay (P=0.333 and P=0.161) and in-hospital and 3-month mortality (P=0.315 and P=0.648). A subgroup analysis of only patients with stable ischemic heart disease could not detect a significant difference between the study groups in any of the investigated outcomes. Our logistic regression analysis showed an association only between age and the incidence of AF after CABG (OR, 1.12; 95% CI, 1.05 to 1.20; P<0.01). Rosuvastatin and atorvastatin are similar concerning the prevention of post-CABG AF, but there is a need for future well-designed multicenter studies on this topic.

Evaluation of cardiovascular toxicity of the atezolizumab and bevacizumab combination

Introduction: The combination of atezolizumab, an immune checkpoint inhibitor (ICI), and bevacizumab, a vascular endothelial growth factor (VEGF) inhibitor, is the first choice for systemic therapy in hepatocellular carcinoma. Immune-related cardiovascular toxicity—myocarditis and pericarditis—are known to occur during ICI treatment. By contrast, VEGF inhibitors (VEGFIs) cause cardiovascular complications such as hypertension and heart failure. Thus, different cardiovascular toxicities have been recognized for ICIs and VEGFIs, but the impact of their combination remains unclear. Here, we aimed to investigate the cardiovascular toxicity profile of atezolizumab in combination with bevacizumab using the World Health Organization adverse event reporting database—VigiBase.Methods: We analyzed data included in VigiBase till December 2022. To evaluate the frequency of reports related to atezolizumab, bevacizumab, and their combinations for 21 adverse events, we calculated the reporting odds ratio and information component. Analyses of the fatality of various cardiovascular toxicities associated with the use of each drug were performed.Results: The database included 84,951, 10,595, and 2,092 reports of treatment with bevacizumab, atezolizumab, and their combination, respectively. The disproportionality signal of hypertension, arterial embolism and thrombosis, supraventricular tachyarrhythmias, heart failure, myocarditis, hemorrhage-related clinical events, venous embolism and thrombosis, cardiomyopathy, respiratory failure with combination regimen of atezolizumab and bevacizumab was detected. Signals of these adverse events were also detected treatment with either atezolizumab or bevacizumab alone. Venous embolism and thrombosis exhibited the highest fatality rate in the two drug combination (12.82%) relative to those of atezolizumab (6.19%) and bevacizumab (4.54%).Discussion: Cardiovascular toxicity, owing to the combination of atezolizumab and bevacizumab, was similar to that of each single agent, and no new safety concerns were observed. Caution should be exercised when combining the two drugs since the fatality rate of thromboembolism increases with combination treatment.

Ideal Anesthetic Agent for Cardiac Electrophysiology Study and Catheter Ablation – A Pilot Study

Objectives: Patients suffering from supraventricular tachycardia (SVT) require diagnostic or therapeutic intervention in a cardiac electrophysiology (EP) laboratory. Some anesthetic medications may adversely affect cardiac EP and conduction, altering the ability to induce the arrhythmia, and may have a negative impact on the ablation treatment. This prospective, randomized, pilot study was conducted in the cardiac EP laboratory of a tertiary care hospital with the aim to identify the ideal anesthetic agent for cardiac EP study and catheter ablation of SVT. The primary objective was to compare the effects of anesthetic agents on cardiac electrophysiological parameters and arrhythmia inducibility. The secondary objective was to compare the patient, anesthesiologist, and cardiologist satisfaction scores with respect to the anesthetic agent used. Materials and Methods: Thirty adult patients with SVT for EP study and radiofrequency catheter ablation were administered either of the anesthetic agents: midazolam, fentanyl, propofol, ketamine, or sevoflurane titrated to produce conscious sedation corresponding to bispectral index (BIS) values between 71 and 90. Electrophysiological parameters were recorded before and after administering the anesthetic agent. Results: Arrhythmia could be induced in all patients. Although electrophysiological parameters remained stable with ketamine administration; higher values of the Richmond Agitation Sedation Scale score and BIS were recorded. Propofol and sevoflurane administration was associated with deviation in electrophysiological parameters more than fentanyl and midazolam. The highest values of patient, anesthesiologist, and cardiologist satisfaction scores were obtained in the fentanyl group and the lowest in the ketamine group (P &lt; 0.002). Conclusion: In doses used to provide conscious sedation, fentanyl provided ideal conditions, and midazolam, propofol, sevoflurane, and ketamine provided satisfactory conditions for conducting EP study and catheter ablation for supraventricular tachyarrhythmias. The potential of propofol to impede cardiac conduction needs to be explored further.

Electrocardiogram in patients with pulmonary hypertension.

Pulmonary hypertension (PH) is a potentially life-threatening cardiovascular disease defined by a mean pulmonary arterial pressure (mPAP)>20mmHg. Due to non-specific symptoms, PH is often diagnosed late and at advanced stage. In addition to other diagnostic modalities, the electrocardiogram (ECG) can help in establishing the diagnosis. Knowledge of typical ECG signs could help to detect PH earlier. A non-systematic literature review on the typical electrocardiographic patterns of PH was performed. Characteristic signs of PH include right axis deviation, SIQIIITIII and SISIISIII patterns, P pulmonale, right bundle branch block, deep R waves in V1 and V2, deep S waves in V5 and V6, and right ventricular hypertrophy (R in V1+S in V5, V6>1,05mV). Repolarisation abnormalities such as ST segment depressions or T wave inversions in leads II, III, aVF, and V1 to V3 are common as well. Furthermore, a prolonged QT/QTc interval, an increased heart rate, or supraventricular tachyarrhythmias can be observed. Some parameters may even provide information about the patient's prognosis. Not every PH patient shows electrocardiographic PH signs, especially in mild PH. Thus, the ECG is not useful to completely rule out PH, but provides important clues to PH when symptoms are present. The combination of typical ECG signs and the co-occurrence of electrocardiographic signs with clinical symptoms and elevated BNP levels are particularly suspicious. Diagnosing PH earlier could prevent further right heart strain and improve patient prognosis.

Anticoagulation in atrial fibrillation: Special scenarios

Atrial fibrillation is the most common cardiac arrhythmia in the world, with an estimated prevalence of 2 to 4%, and represents a high burden of disease worldwide. It is defined as a supraventricular tachyarrhythmia with loss of atrial activity, diagnosed by specific electrocardiographic findings. Its classification is clearly defined, based on the form of presentation, duration and the resolution of the episodes. One of the pillars in the treatment of this pathology is anticoagulant therapy, which represents a challenge due to the heterogeneity of the patients, however there are specific situations such as chronic kidney disease, oncological diseases and liver disease, where the situation becomes even more complex, however different studies have been carried out in which the best strategies based on scientific evidence have been proposed for the approach of these patients in special situations.

Evaluation of troponinI serum levels in patients with arrhythmias with and without coronary artery disease.

Elevated levels of cardiac enzymes in the blood are an indicator of ongoing cardiac ischemia. Persistent tachycardia may lead to myocardial ischemia due to oxygen supply-demand mismatch. We sought to evaluate the probability of underlying coronary artery disease (CAD) in patients with symptomatic supraventricular (SVT) or ventricular tachyarrhythmias (VT) based on cardiac enzyme level fluctuation. Troponin I (TNI) levels were measured twice and coronary angiography was also performed in patients without a history of cardiovascular disease and symptomatic SVT or VT. Of the 114 (group A: CAD (n = 40), group B: no CAD (n = 74)) patients eligible for the study, 34patients in group A and 64patients in group B had SVT, while 6patients in group A and 10 patients in group B had VT. All patients with underlying CAD developed a significantly elevated TNI level compared to baseline, irrespective of arrhythmia type (2.02 ± 7.98 ng/ml vs. 5.64 ± 13.38, p = 0.031). In patients without CAD, TNI level was not significantly elevated compared to the baseline level, irrespective of arrhythmia type (0.34 ± 1.38 ng/ml vs. 0.48 ± 1.48 ng/ml, p = 0.158). Most patients with normal TNI levels (46 of 47 patients; 98 %) had SVT. CAD was present in 13 of 47 patients (27 %) with tachycardia, despite normal TNI levels. Elevated TNI levels are not helpful to discriminate between SVT and VT. An increase in TNI level in repeated blood sampling can help identify patients with higher probability of underlying CAD. Patients with VT demonstrated higher increases in TNI levels, compared to patients with SVT.

Tachyarrhythmias after extracardiac conduit Fontan procedure in the long-term follow-up: may native anatomy of single ventricle predict their occurrence?

Abstract Funding Acknowledgements Type of funding sources: None. Background Arrhythmic complications, especially tachycardias, represent a common and important comorbidity during long-term follow up (FU) in patients with Fontan palliation for complexes congenital heart diseases (CHDs) with univentricular hearts. Surgical Fontan technique has evolved from direct atrio-pulmonary connection via the intracardiac lateral tunnel to the latest extracardiac conduit (ECC) procedure. Despite its shorter FU compared to previous techniques, the ECC variation is nowadays the main approach for many improvements, including lower incidence of arrhythmic complications (especially atrial arrhythmias). Purpose The aim of this study was to evaluate, during a long-term FU, the incidence of tachyarrhythmias and their correlation with the morphology of CHDs’ single ventricle native anatomy in a large cohort of patients with previous ECC Fontan procedure. Methods In this single centre observational cohort study, we retrospectively evaluated 351 patients treated with ECC Fontan palliation in our Institution between January 1987 and October 2017. Exclusion criteria were ECC Fontan take-down and a FU less than 5 years. CHD diagnosis, single ventricle native anatomy and surgical history were reviewed. Patients had cardiac examination once a year. We divided the overall study population in 2 groups based on unique ventricle's morphology: left-type (LV group) or right-type (RV group). Results A total of 303 patients [56% males; mean age at last FU 20 (IQR 15-28) years; 64.7% LV group] with ECC Fontan were enrolled. The mean FU was 16 (IQR 11-20, the longest 33) years. No sudden arrhythmic cardiac death occurred. Ten patients (6 of the LV group) underwent cardiac transplantation for Fontan failure. During FU, 34 patients of the LV (17.3%) and 22 of the RV group (20.2%) showed at least one tachyarrhythmia after a mean time of 12.1 and 12.9 years from ECC procedure, respectively. One patient (LV group) had one tachyarrhythmia in the early time period, &amp;lt;30 days from procedure. LV group showed a higher incidence of supraventricular tachyarrhythmias (SVTs) than RV group (68% vs 41% of total arrhythmias, p=0.08); in contrast, in RV group we found a higher number of ventricular tachyarrhythmias (VTs) compared to the other group (73% vs 41%, p=0.04). We observed both types of tachyarrhythmias (SVT and VT) in 3 patients of LV and 2 of RV group. Conclusions This study, with one of the largest cohort and longest FU after ECC Fontan, shows that ECC is associated with higher arrhythmic complications than previously reported, even though with longer latency period than other Fontan procedures. Moreover, our results suggest that patients with right-type single ventricle native anatomy are significantly more prone to develop VTs compared to those with left-type ventricle. This may reflect the drawbacks of the right ventricle physiology within Fontan circulation where the right ventricle acts for long time as the main pump of the circulatory system.

Near-zero fluoroscopy during electroanatomic mapping-guided pediatric catheter ablation

Abstract Funding Acknowledgements Type of funding sources: None. Background The use of fluoroscopy in pediatric catheter ablation has decreased because of mapping systems. However, the safety, feasibility and efficacy of the technique in pediatric populations have yet to be delineated. Objective In this study, we present the efficiency and reliability of the electroanatomic mapping system in near/zero fluoroscopic pediatric catheter ablation. Methods The medical records of patients aged &amp;lt;18 years who underwent ablation between April 2022 and November 2022 were evaluated. Fluoroscopy was not used in cases involving ablation of right sided-arrhythmia foci. Fluoroscopy was used only for trans-septal puncture or retroaortic approach/coronary angiography. Results A total of 28 patients underwent catheter ablation for supraventricular and ventricular tachyarrhythmia substrates under the guidance of mapping system. Fluoroscopy was used in only 4 (14.2%) of these substrates. The mean fluoroscopy duration in these 4 procedures was 4.2±3.13 min. No complications were noted. The acute success rate in achieving complete elimination of arrhythmia substrates was 100%. The recurrence rate was 3,5% (1/28) at follow-up. Conclusion The fluoroscopy can be completely eliminated in most pediatric catheter ablation procedures with the use of mapping systems by achieving high acute success rates and this technique is safe, feasible and effective.

Predictors of atrial flutter recurrence after atrial fibrillation ablation: the crucial role of structural and morphological left atrial remodeling

Abstract Funding Acknowledgements Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Unrestricted Grant - Abbott Medical Introduction Recurrence of supraventricular tachyarrhythmias after catheter ablation of atrial fibrillation (AF) is common, representing 30% of patients. Although AF recurrence occurs mostly, 10% of the patients face arrhythmia recurrence through atypical atrial flutter (AFL). The diagnostic and therapeutic management of atypical AFL is challenging. Predicting atypical AFL after AF catheter ablation is critical. Purpose To identify morphological and structural predictors of recurrence in the form of atypical AFL compared to AF based on Late Gadolinium Enhancement Cardiac Magnetic Resonance (LGE-CMR). Methods – From January 2013 to December 2021, 56 patients facing post AF-CA atypical AFL were included in the monocentric and retrospective cohort. 112 patients with AF recurrence were randomly included in the cohort from the general database. Pre-procedure LGE-CMR was post-processed for every patient to assess global and regional left and right atrial (LA, RA) fibrosis quantification using an image intensity ratio &amp;gt; 1.32 as fibrosis. Sphericity was calculated as the percentage of similarity with respect to a sphere, and the volume of LA and RA were calculated. Results – 168 patients who had faced supraventricular arrhythmia recurrence after AF-CA were included in the monocentric retrospective cohort. They were mainly male (72.1%), with a median CHADS-VASc score of 1.4 +/- 1.3, a number of previous CA of 2,2 +/- 0.4, and a biatrial dilation (LA volume index of 53.5 ml/m2, RA volume index of 59.6 ml/m2). An age superior to 65 (OR=6.61, CI95%:2.18-14.41, p&amp;lt;0.01), the number of previous CA procedures (OR=3.03, CI95%:1.17-7.81, p=0.02), a history of management of invasive additional lines (OR=2.48, CI95%:1.01-6.27, p=0.05), an elevated LA sphericity (OR=1.33, CI95%:1.11-1.59, p&amp;lt;0.01) and an increased LA fibrotic burden (OR=1.03, CI95%:1.00-1.07, p=0.04) independently predicted the occurrence of atypical AFL compared with AF recurrence after AF-CA (Figure 1). Specifically, an increased amount of fibrosis in the lateral LA zone area (OR=1.03, CI95%:1.01-1.04, p&amp;lt;0.01)] was an independent predictor of recurrence in the form of atypical AFL compared with AF recurrence (Figure 2). Conclusion The structural LA remodeling of AE, including LA fibrosis and LA sphericity, is a predictor of recurrence in the form of atypical atrial flutter compared with AF recurrence after AF-CA.

Thromboembolic Complications in Adult Patients Following Fontan Procedure-A Multicenter Study.

Morbidity and mortality following Fontan (FO) surgery are primarily thromboembolic in nature. However, follow-up data regarding thromboembolic complications (TECs) in adult patients after FO procedure are inconsistent. In this multicenter study, we investigated the incidence of TECs in FO patients. We studied 91 patients who underwent FO procedure. Clinical data, laboratory, and imaging investigations were collected prospectively during the scheduled medical appointments in 3 Adult Congenital Heart Disease Departments in Poland. TECs were recorded during a median follow-up of 31 months. Four patients (4.4%) were lost to follow-up. The mean age of patients was 25.3 (±6.0) years at enrollment, and the mean time between FO operation and investigation was 22.1 (±5.1) years. A total of 21 out of 91 patients (23.1%) had a history of 24 TECs since an FO procedure, mainly pulmonary embolism (PE; n = 12, 13.2%), including 4 (33.3%) silent PE. The mean time since FO operation to the first TEC was 17.8 (±5.1) years. During follow-up, we documented 9 TECs in 7 (8.0%) patients, mainly PE (n = 5, 5.5%). Most patients with TEC had a left type of systemic ventricle (57.1%). Three patients (42.9%) were treated with aspirin, 3 (3.4%) with Vitamin K antagonists or novel oral anticoagulants, and 1 patient had no antithrombotic treatment at the time of TEC occurrence. Supraventricular tachyarrhythmias were present in 3 patients (42.9%). This prospective study shows that TECs are common in FO patients, and a significant number of these events occur during adolescence and young adulthood. We also indicated how much TECs are underestimated in the growing adult FO population. The complexity of the problem requires more studies, especially to standardize the prevention of TECs in the whole FO population.

Aberrant Ventricular Conduction: Revisiting an Old Concept.

The well-defined concept of aberrant ventricular conduction was introduced over 100 years ago and, despite advances in cardiac physiology and electrophysiologic testing, it is still widely misunderstood. Aberrant ventricular conduction is due to physiologic refractoriness of the His-Purkinje system and in most cases does not reflect underlying conduction system disease. Electrophysiologically, aberrant ventricular conduction can manifest with premature atrial ectopics, the Ashman phenomenon with atrial tachyarrhythmias, concealed conduction, echo beats and with the sinus mechanism including rate dependent bundle branch block, bradycardia dependent bundle branch block and early sinus beats. It is important to recognise aberrant ventricular conduction in the context of a broad complex tachycardia, as the differentiation between supraventricular tachyarrhythmias with aberrant ventricular conduction and ventricular tachyarrhythmias carry different therapeutic and prognostic implications. This review will define the ECG footprints of aberrant ventricular conduction to allow accurate ECG interpretation.

PO-04-052 FLECAINIDE INDUCED WIDE COMPLEX TACHYCARDIA

Flecainide is a class IC antiarrhythmic that blocks cardiac sodium channels and is used to treat a variety of supraventricular tachyarrhythmias. Flecainide has use dependent properties with a greater effect at higher heart rates and carries a risk of atrial flutter with 1:1 AV conduction, Describing a case of wide complex tachycardia secondary to flecainide use. N/A A 72-year-old female with COPD, diabetes, history of typical atrial flutter, and persistent atrial fibrillation treated with flecainide and diltiazem called EMS when she awoke with sudden onset dyspnea and epigastric pain. EMS found her diaphoretic, tachycardic, and normotensive. EKG showed a wide complex tachycardia (WCT) with rate 230 bpm. She received an amiodarone bolus but remained in WCT. In the ER, she became hypotensive and was electrically cardioverted to sinus rhythm with resolution of dyspnea and hypotension. She was started on heparin and amiodarone drips. Troponin peaked at 0.04 ng/mL. A coronary angiogram showed no significant coronary artery disease and a transthoracic echocardiogram showed ejection fraction 60-65% with normal wall motion. However, a prior EKG on flecainide was reviewed and demonstrated atrial flutter with a 2:1 AV conduction and an atrial rate of 230 bpm. The WCT was most likely due to atrial flutter with 1:1 AV conduction and aberrancy. Flecainide slows conduction velocity in myocardial tissue, increasing the cycle length of the flutter circuit, and this can allow for 1:1 AV conduction with atrial flutter. Flecainide also demonstrates use dependent properties, with more sodium blocking effect at higher heart rates, and this can cause QRS widening in the setting of tachycardia. Although flecainide is also reported to cause ventricular tachycardia, the patient’s heart rate was exactly the same as a prior atrial rate in atrial flutter, so this was felt to be atrial flutter with 1:1 conduction and aberrancy. The patient’s flecainide and diltiazem were discontinued, and she was started on amiodarone. Medications should be reviewed as a possible cause of WCT after structural and ischemic causes are ruled out. While not a common cause of WCT, flecainide can organize atrial fibrillation into atrial flutter, which could result in 1:1 AV conduction, aberrancy, and wide complex tachycardia.

PO-02-197 PREDICTORS OF ATRIAL FLUTTER RECURRENCE AFTER ATRIAL FIBRILLATION ABLATION: THE CRUCIAL ROLE OF STRUCTURAL AND MORPHOLOGICAL LEFT ATRIAL REMODELING

Recurrence of supraventricular tachyarrhythmias after catheter ablation of atrial fibrillation (AF) is common, representing 30% of patients. Although AF recurrence occurs mostly, 10% of the patients face arrhythmia recurrence through atypical atrial flutter (AFL). The diagnostic and therapeutic management of atypical AFL is challenging. Predicting atypical AFL after AF catheter ablation is critical. To identify morphological and structural predictors of recurrence in the form of atypical AFL compared to AF based on Late Gadolinium Enhancement Cardiac Magnetic Resonance (LGE-CMR). From January 2013 to December 2021, 56 patients facing post-AF-CA atypical AFL were included in the monocentric and retrospective cohort. 112 patients with AF recurrence were randomly included in the cohort from the general database. Pre-procedure LGE-CMR was post-processed for every patient to assess global and regional left and right atrial (LA, RA) fibrosis quantification using an image intensity ratio > 1.32 as fibrosis. Sphericity was calculated as the percentage of similarity with respect to a sphere, and the volume of LA and RA were calculated. 168 patients who had faced supraventricular arrhythmia recurrence after AF-CA were included in the monocentric retrospective cohort. They were mainly male (72.1%), with a median CHADS-VASc score of 1.4 +/- 1.3, a number of previous CA of 2,2 +/- 0.4, and a biatrial dilation (LA volume index of 53.5 ml/m2, RA volume index of 59.6 ml/m2). An age superior to 65 (OR=6.61, CI95%:2.18-14.41, p<0.01), the number of previous CA procedures (OR=3.03, CI95%:1.17-7.81, p=0.02), a history of management of invasive additional lines (OR=2.48, CI95%:1.01-6.27, p=0.05), an elevated LA sphericity (OR=1.33, CI95%:1.11-1.59, p<0.01) and an increased LA fibrotic burden (OR=1.03, CI95%:1.00-1.07, p=0.04) independently predicted the occurrence of atypical AFL compared with AF recurrence after AF-CA (Figure). Specifically, an increased amount of fibrosis in the lateral LA zone area (OR=1.03, CI95%:1.01-1.04, p<0.01)] was an independent predictor of recurrence in the form of atypical AFL compared with AF recurrence (Table). The structural LA remodeling of AE, including LA fibrosis and LA sphericity, is a predictor of recurrence in the form of atypical atrial flutter compared with AF recurrence after AF-CA.

The Outcome of Electrical Cardioversion in Hyperthyroid Induced Atrial Fibrillation.

Hyperthyroidism is a prevalent cause of atrial fibrillation (AF). High cardiac output with low systemic vascular resistance, driven by hyperthyroidism, is associated with a rapid heartbeat, enhanced left ventricular systolic and diastolic function, and a higher incidence of supraventricular tachyarrhythmias. After returning to euthyroid status, hyperthyroidism-induced AF generally spontaneously reverts to sinus rhythm (SR), and a significant number of patients remain in chronic AF and require electrical cardioversion (ECV). After effective cardioversion, the long-term outcome of hyperthyroidism-induced persistent AF is unknown. Early ECV before the antithyroid medication should be explored for hyperthyroidism-induced AF to reduce the risk of thromboembolic consequences. The recurrence rate of AF between Hyperthyroid and Euthyroid Patients after ECV did not significantly differ. This review article compares the recurrence rate of AF as an outcome of ECV in Hyperthyroid induced atrial fibrillation.

Comparison of the effects of conventional method and primary sutureless techniques on early postoperative rhythm problems in patients with total abnormal pulmonary venous return anomaly.

Total abnormal pulmonary venous return anomaly is a CHD characterised by abnormal pulmonary venous flow directed to the right atrium. In this study, we aimed to compare the effects of these techniques on early rhythm problems in total abnormal pulmonary venous return anomaly cases operated with conventional or primary sutureless techniques. Seventy consecutive cases (median age 1 month, median weight 4 kg) who underwent total abnormal pulmonary venous return anomaly repair with conventional or primary sutureless technique between May 1 2020 and May 1 2022 were evaluated. The rate, diagnosis, and possible risk factors of postoperative arrhythmias were investigated. The results were evaluated statistically. When the total abnormal pulmonary venous return anomaly subgroup of 70 cases was evaluated, 40 cases were supracardiac, 18 cases were infracardiac, 7 cases were cardiac, and 5 cases were mixed type. Twenty-eight (40%) cases had a pulmonary venous obstruction. Primary sutureless technique (57%, supracardiac n = 24, mixed = 3, infracardiac = 13) was used in 40 patients. Median cardiopulmonary bypass time (110 versus 95 minutes) and median aortic clamp time (70 versus 60 minutes), median peak lactate (4.7 versus 4.8 mmol/l) in the first 72 hours, and median peak vasoactive inotropic score in the first 72 hours of the primary sutureless and conventional technique used cases value (8 versus 10) were similar. The total incidence of arrhythmias in the conventional group was significantly higher than in the primary sutureless group (46.7% versus 22.5%, p = 0.04). Supraventricular early beat was observed in 3 (7.5%), sinus tachycardia was seen in 6 (15%), junctional ectopic tachycardia was seen in 1 (2.5%), intra-atrial reentry tachycardia was seen in 1 (2.5%), usual supraventricular tachyarrhythmia was seen in 2 cases (5%) in the primary sutureless group. In the conventional group, supraventricular early beat was observed in six of the cases (20%), sinus tachycardia in five (16.7%), junctional ectopic tachycardia in four (13.3%), intra-atrial reentry tachycardia (10%) in three, and supraventricular tachyarrhythmia in seven cases (23.3%). In the first 30 days, there was a similar mortality rate (10% versus 10%), with four patients in the primary sutureless group and three in the conventional group. The median follow-up period of the cases was 8 months (interquartile range(IQR) 6-10 months). In the follow-up, arrhythmias were detected in two cases (one supraventricular tachyarrhythmia and one intra-atrial reentry tachycardia) in the primary sutureless group and three cases (two supraventricular tachyarrhythmia, one intra-atrial reentry tachycardia) in the conventional technique. All cases were converted to normal sinus rhythm with cardioversion and combined antiarrhythmic therapy. Different arrhythmias can be observed in the early period in patients with operated total abnormal pulmonary venous return anomaly. Although a higher rate of rhythm problems was observed in the early period in the conventional method compared to the primary sutureless technique, no significant effect was found on mortality and morbidity between the groups.

Treatment and prevention of atrial fibrillation and flutter: new approaches and unsolved questions

The article highlights the modern understanding of etiology, epidemiology and pathogenesis of atrial fibrillation and flutter and their global burden as the most frequent form of supraventricular sustained tachyarrhythmia. The recent international and Russian national clinical guidelines on the treatment and prevention of atrial fibrillation are briefly discussed. The new antiarrhythmic drugs, presented in recent guidelines are also highlighted. The authors analyze their own experience in the treatment of paroxysmal atrial fibrillation with IC class drugs (propafenone) at the prehospital stage.

Repurposing Verapamil to Enhance Killing of T-ALL Cells by the mTOR Inhibitor Everolimus.

New therapies are needed for patients with T-cell lymphoblastic leukemia (T-ALL) who do not respond to standard chemotherapy. Our previous studies showed that the mTORC1 inhibitor everolimus increases reactive oxygen species (ROS) levels, decreases the levels of NADPH and glucose-6-phosphate dehydrogenase (G6PD), the rate-limiting enzyme of the pentose phosphate pathway (PPP), and induces apoptosis in T-ALL cells. Studies in T-ALL-xenografted NOD/SCID mice demonstrated that everolimus improved their response to the glucocorticoid (GC) dexamethasone. Here we show that verapamil, a calcium antagonist used in the treatment of supraventricular tachyarrhythmias, enhanced the effects of everolimus on ROS and cell death in T-ALL cell lines. The death-enhancing effect was synergistic and was confirmed in assays on a panel of therapy-resistant patient-derived xenografts (PDX) and primary samples from T-ALL patients. The verapamil-everolimus combination produced a dramatic reduction in the levels of G6PD and induction of p38 MAPK phosphorylation. Studies of NOD/SCID mice inoculated with refractory T-ALL PDX cells demonstrated that the addition of verapamil to everolimus plus dexamethasone significantly reduced tumor growth in vivo. Taken together, our results provide a rationale for repurposing verapamil in association with mTORC inhibitors and GC to treat refractory T-ALL.

Cardiac Rhythm Implications of Extracellular Magnesium

Although magnesium is mainly an intracellular cation, magnesium in the extracellular space is an important mechanism by which this cation exerts its effects on the electrical system of the heart. This is an important concept for two reasons: 1) a serum magnesium level reflects extracellular magnesium and is a sensitive indicator to determine whether magnesium is affecting cardiac rhythms, and 2) because rapid changes in serum magnesium may occur in clinical situations independent of total body magnesium resulting in important arrhythmias. Hypomagnesemia depolarizes heart cells resulting in both supraventricular and ventricular tachyarrhythmias. Keeping serum magnesium levels greater than 2 milliequivalents per liter is recommended. In contrast, hypermagnesemia hyperpolarizes heart cells suppressing atrial and ventricular arrhythmias.

Acute and long-term results with the 3rd generation visually guided laser balloon ablation system for pv isolation

BackgroundVisually guided laser balloon ablation is known as an effective pulmonary vein (PV) isolation device. The third-generation laser balloon ablation system (X3) equipped with compliant balloon and an automated motor-driven laser output mechanism, namely RAPID mode, has been clinically proven for PV isolation.MethodsPV isolation with X3 was performed in all the patients with paroxysmal and early-stage persistent atrial fibrillation (AF). Acute data for PV isolation and clinical outcomes including supraventricular tachyarrhythmia (SVT: AF, atrial flutter, or atrial tachycardia)-free survival rate beyond 1 year were analyzed.ResultsA total of 110 patients (62 ± 13 years old, 80% of paroxysmal AF) were treated with X3. RAPID mode with was utilized to achieve PV isolation in all cases. In combination with RAPID mode and spot mode laser ablation, 91.1% (380/417) of veins were isolated on the first circumferential lesion set and did not require touch-up ablation and during the index procedure 100% of attempted veins were isolated. The mean procedure time was 77.0 ± 22.7 min and LA dwell time was 61.9 ± 22.0 min. Total duration of laser application was 5.1 ± 2.3 min per vein. At 1 year, SVT-free survival rate was 93.7% in paroxysmal AF patients, and 81.1% in persistent AF patients.ConclusionsA novel continuous automatic laser balloon ablation system was proved to be safe and effective for both paroxysmal and persistent AF patients. The clinical result demonstrated that PV isolation with X3 could achieve a high SVT-free survival rate.