European Heart Rhythm Association (EHRA) consensus document on the management of supraventricular arrhythmias, endorsed by Heart Rhythm Society (HRS), Asia-Pacific Heart Rhythm Society (APHRS), and Sociedad Latinoamericana de Estimulación Cardiaca y Electrofisiologia (SOLAECE)

Comprehensive Analysis of Anticoagulant Therapy in Patients with Isolated Atrial Flutter

Limited comparative data exist regarding the risk of cardiogenic emboli in patients with isolated atrial flutter (AFL). Some studies suggest a lower complication risk in AFL compared to atrial fibrillation (AFib), but methodological limitations and conflicting reports necessitate a comprehensive investigation. Our analysis proposes that isolated AFL carries a lower risk of ischemic events and left atrial thrombus formation than AFib. Importantly, we caution against applying stroke risk assessment approaches designed for AFib to AFL patients, as it may lead to harmful overestimations and unnecessary anticoagulant prescriptions. Furthermore, we highlight the current lack of sufficient data to determine the overall clinical benefit of prolonged anticoagulant therapy in patients with isolated AFL, especially when CHA2DS2-VASc index values are below 4. This review challenges existing perceptions, offering insights into the nuanced risk profiles of the transitional nature of isolated AFL due to the high incidence of AFib development within a year of AFL diagnosis. In conclusion, tailored risk assessments and further research are essential for precise clinical decision-making in this dynamic landscape.

A gray zone: Role of transesophageal echocardiography before atrial tachycardia catheter ablation

INTRODUCTION

There is a lack of studies in the literature directly investigating the relationship between atrial tachycardia (AT) and left atrial (LA)/left atrial appendage (LAA) thrombus, and current guidelines do not provide strong recommendations regarding the use of transesophageal echocardiography (TEE) before AT catheter ablation. This study aims to elucidate the relationship between AT and the presence of LA/LAA thrombus and contribute to the literature on the use of TEE before AT catheter ablation.

METHODS

This single-center retrospective observational study screened patients who underwent TEE between February 10, 2019, and February 10, 2023. Patients were assigned to the AT patient and control groups. TEE was conducted to exclude thrombus in the AT ablation group. The control group included patients who underwent TEE for interatrial septum evaluation and had LA imaging during TEE but did not have atrial arrhythmia. To mitigate bias between the AT patient group and the control group, they were randomized 1:1 using propensity-score matching (PSM). Following randomization, each group consisted of 49 patients.

RESULTS

All analyses were conducted after PSM. There were no statistically significant differences between the AT patient and control groups in terms of baseline clinical characteristics and echocardiographic features. Additionally, no significant differences were found between the blood viscosities calculated at low and high shear rates in both groups. The study revealed a significant difference between the two groups in the presence of LA spontaneous echo contrast (SEC) (24.5% in AT group vs 0% in Control group, p = .001), but not in the presence of thrombi (8.2% in AT group vs 0% in Control group, p = .117).

CONCLUSION

Compared to the control group, the presence of SEC was significantly higher in the AT patient group. The increased frequency of SEC in AT patients suggests the hypothesis that AT may contribute to LA stasis. The routine use of TEE before AT catheter ablation remains controversial, despite the presence of LA thrombus and SEC in the AT patient group. The clinical assessment of thrombus presence before the procedure must be conducted on a patient-specific basis.

Prognoses and risk stratification of thrombus-associated events in heart failure patients without atrial fibrillation

AIMS

We aim to assess the risk of thrombus-associated events (TAE) in patients with heart failure (HF) without atrial fibrillation (AF) and develop an effective scoring system for a risk stratification model.

METHODS AND RESULTS

This retrospective study included 450 patients (median age 64.0 years, interquartile range [55.0, 75.0]; 31.6% women) hospitalized for HF without AF and atrial flutter, but with a left ventricular ejection fraction (LVEF) ≤ 55% and New York Heart Association (NYHA) functional class of III-IV. A median follow-up of 47 months was conducted. In the present study, TAE during follow-up was independently associated with both all-cause death [hazard ratio (HR) 1.756, 95% confidence interval (CI) 1.324-2.328, P < 0.001] and readmission for HF (HR 1.574, 95% CI 1.122-2.208, P = 0.009) after adjustment for covariates. Hypertension (HR 1.573, 95% CI 1.018-2.429, P = 0.041), atrial arrhythmia excluding AF (AAexAF) (HR 2.041, 95% CI 1.066-3.908, P = 0.031), previous ischaemic stroke (HR 2.469, 95% CI 1.576-3.869, P < 0.001), and vascular disease (HR 1.658, 95% CI 1.074-2.562, P = 0.023) were independently associated with TAE. Age (HR 1.021, 95% CI 1.008-1.033, P = 0.001), previous ischaemic stroke (HR 1.685, 95% CI 1.248-2.274, P = 0.001), LVEF ([10, 25] vs. [40, 55]) HR 1.925, 95% CI 1.311-2.826, P = 0.001; (25, 40] vs. (40, 55] HR 1.084, 95% CI 0.825-1.424, P = 0.563), and creatinine clearance rate (Ccr) (HR 0.991, 95% CI 0.986-0.996, P = 0.001) were independently associated with composite events of TAE and death (TAE-D). CHA2DS2VASc modestly predicted 5-year TAE [area under the receiver operating characteristic curves (AUC) 0.660, P < 0.001 compared with 0.5] and TAE-D (AUC 0.639, P < 0.001 compared with 0.5). (C)ACE, formed by incorporating AAexAF, LVEF, and Ccr into CHA2DS2VASc, had higher AUC for predicting 5-year TAE (0.694 vs. 0.660, P = 0.018) and TAE-D (0.708 vs. 0.639, P < 0.001) compared with CHA2DS2VASc. In patients with HF with reduced ejection fraction (HFrEF), (C)ACE and (C)ACEN [formed by incorporating NYHA into (C)ACE] had higher AUC compared with CHA2DS2VASc in predicting 5-year TAE (0.700 and 0.707 vs. 0.649, P = 0.013 and 0.030, respectively) and TAE-D (0.712 and 0.713 vs. 0.622, P < 0.001 and <0.001, respectively). The AUC did not improve statistically from (C)ACE to (C)ACEN (0.700 vs. 0.707, P = 0.600 for TAE; 0.712 vs. 0.713, P = 0.917 for TAE-D).

CONCLUSIONS

In HF without AF, TAE during follow-up was associated with adverse prognoses. The independent risk factors of TAE or TAE-D improved CHA2DS2-VASc predictive ability, especially in patients with HFrEF. Our findings provide new evidence for TAE risk stratification in HF without AF, potentially guiding prophylactic anticoagulation.

Trans-jugular approach for safe and successful cryoablation of para-Hisian/anterior-septal, anterior, and anterior-lateral accessory pathways in children

BACKGROUND

Cryoablation of APs localized near the atrioventricular (AV) junction is a well-established ablation strategy in children, and it has proved to be very safe. However, recurrence rates remain considerable for specific accessory pathway (AP) localizations. The aim of this retrospective study was to evaluate the efficacy and safety of a trans-jugular approach for cryoablation of right anterior, anterior-lateral, and anterior-septal APs in children, as compared to the conventional femoral approach.

METHODS

From June 2019 to November 2023, 24 consecutive patients (mean age 13.2 ± 4.6, 12 males (50% of total cohort)) with right anterior-lateral, anterior, and anterior-septal/para-Hisian APs underwent 3D non-fluoroscopic transcatheter cryoablation through the right jugular vein at our Institution. Ablation results were compared with 24 patients for whom a conventional trans-femoral approach was used.

RESULTS

Acute procedural success rate was 100% (n = 24/24), with a non-statistically significant difference as compared to the control group (100% vs. 83%, p = 0.1). During follow-up (1.1 years, interquartile range 0.6-1.3), one patient (4%) had a recurrence in the trans-jugular group, as opposed to eight (38%) in the control group (p = 0.006). No permanent complications occurred.

CONCLUSIONS

3D cryoablation of right anterior-lateral, anterior, and anterior-septal/para-Hisian APs in children using a trans-jugular approach is extremely effective and safe, resulting in higher chronic success rate compared to the conventional femoral approach.

Cannabis for chronic pain: cardiovascular safety in a nationwide Danish study

BACKGROUND AND AIMS

A rising number of countries allow physicians to treat chronic pain with medical cannabis. However, recreational cannabis use has been linked with cardiovascular side effects, necessitating investigations concerning the safety of prescribed medical cannabis.

METHODS

Using nationwide Danish registers, patients with chronic pain initiating first-time treatment with medical cannabis during 2018-21 were identified and matched 1:5 to corresponding control patients on age, sex, chronic pain diagnosis, and concomitant use of other pain medication. The absolute risks of first-time arrhythmia (atrial fibrillation/flutter, conduction disorders, paroxysmal tachycardias, and ventricular arrhythmias) and acute coronary syndrome were reported comparing medical cannabis use with no use.

RESULTS

Among 1.88 million patients with chronic pain (46% musculoskeletal, 11% cancer, 13% neurological, and 30% unspecified pain), 5391 patients claimed a prescription of medical cannabis [63.2% women, median age: 59 (inter-quartile range 48-70) years] and were compared with 26 941 control patients of equal sex- and age composition. Arrhythmia was observed in 42 and 107 individuals, respectively, within 180 days. Medical cannabis use was associated with an elevated risk of new-onset arrhythmia {180-day absolute risk: 0.8% [95% confidence interval (CI) 0.6%-1.1%]} compared with no use [180-day absolute risk: 0.4% (95% CI 0.3%-0.5%)]: a risk ratio of 2.07 (95% CI 1.34-2.80) and a 1-year risk ratio of 1.36 (95% CI 1.00-1.73). No significant association was found for acute coronary syndrome [180-day risk ratio: 1.20 (95% CI 0.35-2.04)].

CONCLUSIONS

In patients with chronic pain, the use of prescribed medical cannabis was associated with an elevated risk of new-onset arrhythmia compared with no use-most pronounced in the 180 days following the initiation of treatment.

JinJiang ablation catheter is no inferior than Johnson ablation catheter in radiofrequency ablation of paroxysmal supraventricular tachycardia

BACKGROUND

Paroxysmal supraventricular tachycardia (PSVT) is characterized by episodes of rapid tachycardia with sudden onset and sudden termination. PSVT treatment has evolved considerably over the past 30 years. Currently, radiofrequency catheter ablation is the first-line treatment.

HYPOTHESIS

We conducted a randomized controlled trial to compare safety and effectiveness of PSVT ablation between the Jinjiang and Johnson (J&J) catheters in 57 patients in our hospital.

METHODS AND RESULTS

Patients were randomly assigned to ablation procedures using either the Jinjiang system or the J&J Carto system. Follow-up was performed 3 days, 1, and 6 months after the procedure. Success rate, ablation time, frequency of ablation, and rates of complications and recurrence did not significantly differ between the groups. One Jinjiang group patient (3.6%) experienced arrhythmia recurrence during the 6-month follow-up.

CONCLUSIONS

The Jinjiang catheter for radiofrequency ablation of PSVT is as safe and effective as the J&J catheter.

Ablation of CTI-dependent flutter using different ablation technologies: acute and long-term outcome from the LEONARDO study

BACKGROUND

A novel ablation catheter has been released to map and ablate the cavo-tricuspid isthmus (CTI) in patients with atrial flutter (AFL), improving ablation efficiency.

METHODS

We evaluated the acute and long-term outcome of CTI ablation aiming at bidirectional conduction block (BDB) in a prospective, multicenter cohort study enrolling 500 patients indicated for typical AFL ablation. Patients were grouped on the basis of the AFL ablation method (linear anatomical approach, Conv group n = 425, or maximum voltage guided, MVG group, n = 75) and ablation catheter (mini-electrodes technology, MiFi group, n = 254, or a standard 8-mm ablation catheter, BLZ group, n = 246).

RESULTS

Complete BDB according to both validation criteria (sequential detailed activation mapping or mapping only the ablation site) was achieved in 443 patients (88.6%). The number of RF applications needed to achieve BDB was lower in the MiFi MVG group vs both the MiFi Conv group and the BLZ Conv group (3.2 ± 2 vs 5.2 ± 4 vs 9.3 ± 5, p < 0.0001 for all comparisons). Fluoroscopy time was similar among groups, whereas we observed a reduction in the procedure duration from the BLZ Conv group (61.9 ± 26min) to the MiFi MVG group (50.6 ± 17min, p = 0.048). During a mean follow-up of 548 ± 304 days, 32 (6.2%) patients suffered an AFL recurrence. No differences were found according to BDB achieved by both validation criteria.

CONCLUSIONS

Ablation was highly effective in achieving acute CTI BDB and long-term arrhythmia freedom irrespective of the ablation strategy or the validation criteria for CTI chosen by the operator. The use of an ablation catheter equipped with mini-electrodes technology seems to improve ablation efficiency.

CLINICAL TRIAL REGISTRATION

Atrial Flutter Ablation in a Real World Population. (LEONARDO).

CLINICALTRIALS

gov Identifier: NCT02591875.

2023 HRS expert consensus statement on the management of arrhythmias during pregnancy

This international multidisciplinary expert consensus statement is intended to provide comprehensive guidance that can be referenced at the point of care to cardiac electrophysiologists, cardiologists, and other health care professionals, on the management of cardiac arrhythmias in pregnant patients and in fetuses. This document covers general concepts related to arrhythmias, including both brady- and tachyarrhythmias, in both the patient and the fetus during pregnancy. Recommendations are provided for optimal approaches to diagnosis and evaluation of arrhythmias; selection of invasive and noninvasive options for treatment of arrhythmias; and disease- and patient-specific considerations when risk stratifying, diagnosing, and treating arrhythmias in pregnant patients and fetuses. Gaps in knowledge and new directions for future research are also identified.

Effect of Direct Slow Pathway Capture Mapping-Guided Ablation on Typical Atrioventricular Nodal Re-Entrant Tachycardia

BACKGROUND

Direct slow pathway capture (DSPC) mapping is a novel electrophysiological technique for detecting antegrade slow pathway input sites. However, the effect of DSPC mapping-guided ablation on atrioventricular nodal re-entrant tachycardia (AVNRT) is unknown.

OBJECTIVES

This study aimed to evaluate the efficacy and safety of DSPC mapping-guided ablation in typical AVNRT patients.

METHODS

A multicenter retrospective study was conducted in 301 consecutive typical AVNRT patients. The outcomes in patients who underwent DSPC mapping-guided ablation (DSPC group) and those who underwent conventional anatomical ablation (conventional group) were compared. The conventional group was established before introducing DSPC mapping-guided ablation. Positive DSPC sites were defined as sites with a return cycle atrioventricular prolongation of ≥20 ms with high-output (10-20 V) pacing during tachycardia or the last paced beat of the atrial extrastimulation.

RESULTS

Among 116 patients in the DSPC group, 102 (88%) had positive DSPC sites, and 86 (74%) had a successful ablation at that site. Of the remaining 30 patients, 27 had a successful anatomical ablation. The DSPC group had a significantly lower frequency of radiofrequency applications and shorter total application time than the conventional group (median: 5.5 [IQR: 3-11] times vs 9 [IQR: 5-15] times, and 168 [IQR: 108-266] seconds vs 244 [IQR: 158-391] seconds, respectively; P < 0.01). Moreover, the DSPC group had a numerically lower incidence of permanent pacemaker implantations and AVNRT recurrences than the conventional group (0% vs 1.6%; P = 0.17, and 1.7% vs 3.2%; P = 0.43, respectively).

CONCLUSIONS

DSPC mapping-guided ablation was associated with a lower operative time, which can reduce the risk of AV conduction injury in typical AVNRT.

Management of pregnant patients with pulmonary arterial hypertension

Pregnant individuals with pulmonary arterial hypertension (PAH) have significantly high risks of maternal and perinatal mortality. Profound changes in plasma volume, cardiac output and systemic vascular resistance can all increase the strain being placed on the right ventricle, leading to heart failure and cardiovascular collapse. Given the complex network of opposing physiological changes, strict contraception and reduction of hemodynamic fluctuations during pregnancy are important methods of minimizing the risk of maternal mortality and improving the outcomes following pregnancy. In this review, we discuss the recent research progress into pre-conception management and the various therapeutic strategies for pregnant individuals with PAH.

Case report: Efficacy analysis of radiofrequency catheter ablation combined with atrial appendage resection for atrial tachycardia originating from the atrial appendage in children

Objective

The aim of this study was to investigate the efficacy of radiofrequency catheter ablation (RFCA) combined with atrial appendage (AA) resection to treat atrial tachycardia (AT) originating from the AA in children.

Materials and methods

Using the Ensite three-dimensional electroanatomic mapping system, three children with AT originating from the AA were diagnosed. Clinical features and electrocardiographic (ECG) manifestations were analyzed. Ablations were performed using a cold saline-infused catheter at appendages targeting loci of AT origin under the guidance of the Ensite system. Atrial appendage resection was performed in combination with cardiac surgery, and the curative effect was evaluated.

Results

The ages of the three patients were 3.5, 5.75, and 12.9 years. Two cases originated from the right atrial appendage (RAA) and one originated from the left atrial appendage (LAA). The ECG characteristics of AT from the RAA were as follows: (1) negative P waves in lead V1; (2) positive P waves in leads II, III, and aVF; (3) positive P wave in lead I with varying shapes in lead aVL; and (4) prolonged PR interval with no QRS wave after some P waves. The ECG of the LAA was characterized by (1) positive P waves in lead V1 with a bimodal pattern; (2) positive P waves in leads II, III, and aVF; and (3) negative P waves in leads I and aVL. Preoperative echocardiography showed cardiac enlargement and a decreased left ventricular ejection fraction (LVEF) in all three cases. One case was cured after RFCA, and the remaining two cases required AA resection after RFCA. No recurrence was detected at 1-18 months of follow-up, and the left ventricular end-diastolic diameter and LVEF returned to normal.

Conclusion

Atrial tachycardia originating from the AA in children showed a characteristic P-wave presentation on ECG, and sustained episodes of AT resulted in tachycardia-induced cardiomyopathy. Children who are not successfully controlled by RFCA or who have a recurrence after RFCA could benefit from AA resection.

Detection of the origin of atrial tachycardia by 3D electro-anatomical mapping and treatment by radiofrequency catheter ablation in horses

BACKGROUND

Atrial tachycardia (AT) can be treated by medical or electrical cardioversion but the recurrence rate is high. Three-dimensional electro-anatomical mapping, recently described in horses, might be used to map AT to identify a focal source or reentry mechanism and to guide treatment by radiofrequency ablation.

OBJECTIVES

To describe the feasibility of 3D electro-anatomical mapping and radiofrequency catheter ablation to characterize and treat sustained AT in horses.

ANIMALS

Nine horses with sustained AT.

METHODS

Records from horses with sustained AT referred for radiofrequency ablation at Ghent University were reviewed.

RESULTS

The AT was drug resistant in 4 out of 9 horses. In 8 out of 9 horses, AT originated from a localized macro-reentrant circuit (n = 5) or a focal source (n = 3) located at the transition between the right atrium and the caudal vena cava. In these 8 horses, local radiofrequency catheter ablation resulted in the termination of AT. At follow-up, 6 out of 8 horses remained free of recurrence.

CONCLUSIONS AND CLINICAL IMPORTANCE

Differentiation between focal and macro-reentrant AT in horses is possible using 3D electro-anatomical mapping. In this study, the source of right atrial AT in horses was safely treated by radiofrequency catheter ablation.

Discrimination of atypical atrioventricular nodal reentrant tachycardia from atrial tachycardia by the V-A-A-V response

INTRODUCTION

The electrophysiological discrimination between fast-slow (F/S-) atrioventricular (AV) nodal reentrant tachycardia (NRT) and atrial tachycardia (AT) originating from the interatrial septum remains challenging. While a V-A-A-V response may occur immediately after ventricular induction or entrainment of either tachycardia, the electrophysiological dissimilarities in that response between the two tachycardias remain unclear. The purpose of this study was to identify a diagnostic indicator discriminating F/S-AVNRT from AT by examining the difference in the V-A-A-V response between the two tachycardias.

METHODS

This retrospective study included 17 patients with F/S-AVNRT [7 with common-form F/S-AVNRT using a typical slow pathway (SP) and 10 with superior type F/S-AVNRT using a superior SP] and 10 patients with reentrant AT. All 27 patients presented with long RP supraventricular tachycardia and an initial V-A-A-V response upon ventricular induction or entrainment. The V-A-A-V response in patients with F/S-AVNRT was due to dual atrial responses. We measured the interval between the first (A1) and second atrial electrogram (A2) of V-A-A-V and calculated ΔAA by subtracting A1-A2 from the tachycardia cycle length.

RESULTS

V-A-A-V responses were observed most often upon ventricular induction of F/S-AVNRT (6±5 times) as well as AT (6±6 times; P = 0.87). The V-A-A-V response upon ventricular entrainment was observed in a single patient with F/S-AVNRT versus 10 all patients with AT (P<0.001). ΔAA ranged between -80 and 228 ms in F/S-AVNRT and between -184 and 26 ms in AT. A ΔAA >26 ms predicted a diagnosis of F/S-AVNRT with a 76% sensitivity and 100% specificity, while a ΔAA ←80 ms predicted a diagnosis of AT with a 50% sensitivity and 100% specificity.

CONCLUSIONS

ΔAA is a useful, confirmatory, diagnostic indicator of F/S-AVNRT versus AT associated with the V-A-A-V response. This article is protected by copyright. All rights reserved.

Underuse of Catheter Ablation as First-Line Therapy for Supraventricular Tachycardia

Background

Catheter ablation (CA) is a safe, effective, cost‐effective technique and may be considered a first‐line strategy for the treatment of symptomatic supraventricular tachycardias (SVT). Despite the high prospect of cure and the recommendations of international guidelines in considering CA as a first‐line treatment strategy, the average time between diagnosis and the procedure may be long. The present study aims to evaluate predictors related to non‐referral for CA as first‐line treatment in patients with SVT.

Methods and Results

The model was derived from a retrospective cohort of patients with SVT or ventricular pre‐excitation referred for CA in a tertiary center. Clinical and demographical features were used as independent variables and non‐referral for CA as first‐line treatment the dependent variable in a stepwise logistic regression analysis. Among 20 clinical‐demographic variables from 350 patients, 10 were included in initial logistic regression analysis: age, women, presence of pre‐excitation on ECG, palpitation, dyspnea and chest discomfort, number of antiarrhythmic drugs before ablation, number of concomitant symptoms, symptoms’ duration and evaluations in the emergency room due to SVT. After multivariable adjusted analysis, age (odds ratio [OR], 1.2; 95% CI 1.01–1.32; P=0.04), chest discomfort during supraventricular tachycardia (OR, 2.7; CI 1.6–4.7; P<0.001) and number of antiarrhythmic drugs before ablation (OR, 1.8; CI 1.4–2.3; P<0.001) showed a positive independent association for non‐referral for CA as SVT first‐line treatment.

Conclusions

The independent predictors of non‐referral for CA as first‐line treatment in our logistic regression analysis indicate the existence of biases in the decision‐making process in the referral process of patients who would benefit the most from catheter ablation. They very likely suggest a skewed medical decision‐making process leading to catheter ablation underuse.

Emergency catheter ablation: A feasible option for acute treatments of patients with unstable pre-excited atrial fibrillation

BACKGROUND

Pre-excited atrial fibrillation (AF) is associated with increased risk of life-threatening events. However, at times, patients with pre-excited AF still repetitively suffer from hemodynamic disturbance, with resistance to acute treatments of antiarrhythmic therapy and cardioversion.

METHODS

To evaluate the feasibility in correcting hemodynamic disturbance, patients with pre-excited AF who underwent catheter ablation of accessory pathway as an emergency procedure, were retrospectively collected from two centers of China. The medical records of patients were analyzed and summarized in this case series.

RESULTS

Five patients with pre-excited AF who received emergency catheter ablation of accessory pathway, were collected from two contributor centers and reported in this case series. All collected patients still repetitively suffered from hemodynamic disturbance induced by rapid anterograde conduction of AF via pathway, even guideline recommended acute interventions of intravenous antiarrhythmic therapy and cardioversion had been performed. Finally, as an emergency procedure, catheter ablation of accessory pathway was performed in collected patients. Correspondingly, the hemodynamic unstable status was greatly relieved. Meanwhile, all collected patients with high risk of pre-excited AF were combined with left-sided accessory pathway, with shortest RR interval of widened pre-excited QRS complex less than 250ms. Thus, combination with left-sided pathway is proposed as an indicator for the increased risk of life-threatening events in patients with high risk of pre-excited AF.

CONCLUSIONS

Emergency catheter ablation of accessory pathway is an effective option for the acute managements of patients with high risk of pre-excited AF in unstable hemodynamics, which is resistant to antiarrhythmic therapy and cardioversion. This article is protected by copyright. All rights reserved.

Supraventricular arrhythmia in pregnancy

The physiological changes during pregnancy predispose a woman for the development of new-onset or recurrent arrhythmia. Supraventricular arrhythmia is the most common form of arrhythmia during pregnancy and, although often benign in nature, can be concerning. We describe three complex cases of supraventricular arrhythmia during pregnancy and review the currently available literature on the subject. In pregnancies complicated by arrhythmia, a plan for follow-up and both maternal and fetal monitoring during pregnancy, delivery and post partum should be made in a multidisciplinary team. Diagnostic modalities should be used as in non-pregnant women if there is an indication. All antiarrhythmic drugs cross the placenta, but when necessary, medical treatment should be used with consideration to the fetus and the mother’s altered pharmacodynamics and kinetics. Electrical cardioversion is safe during pregnancy, and electrophysiological study and catheter ablation can be performed in selected patients, preferably with zero-fluoroscopy technique. Sometimes, delivering the fetus (if viable) is the best therapeutic option. In this review, we provide a framework for the workup and clinical management of supraventricular arrhythmias in pregnant women, including cardiac, obstetric and neonatal perspectives.

Randomized trial of intracardiac echocardiography-guided slow pathway ablation

PURPOSE

Radiofrequency (RF) catheter ablation of the slow pathway (SP) in atrioventricular nodal reentry tachycardia (AVNRT) is highly effective; however, it may require prolonged fluoroscopy and RF time. We postulated that visualization of the SP region with intracardiac echocardiography (ICE) could decrease ablation time, minimize radiation exposure, and facilitate SP ablation compared to the standard, fluoroscopy-guided approach.

METHODS

In our study, we randomized 91 patients undergoing electrophysiologic study and SP ablation for AVNRT into 2 groups: fluoroscopy-only (n = 48) or ICE-guided (n = 43) group. Crossover to ICE-guidance was allowed after 8 unsuccessful RF applications.

RESULTS

Mapping plus ablation time (mean ± standard deviation: 18.8 ± 16.1 min vs 11.6 ± 15.0 min, p = 0.031), fluoroscopy time (median [interquartile range]: 4.9 [2.93-8.13] min vs. 1.8 [1.2-2.8] min, p < 0.001), and total ablation time (144 [104-196] s vs. 81 [60-159] s, p = 0.001) were significantly shorter in the ICE group. ICE-guidance was associated with reduced radiation exposure (13.2 [8.2-13.4] mGy vs. 3.7 [1.5-5.8] mGy, p < 0.001). The sum of delivered RF energy (3866 [2786-5656] Ws vs. 2283 [1694-4284] Ws, p = 0.002) and number of RF applications (8 [4.25-12.75] vs. 4 [2-7], p = 0.001) were also lower with ICE-guidance. Twelve (25%) patients crossed over to the ICE-guided group. All were treated successfully thereafter with similar number, time, and cumulative energy of RF applications compared to the ICE group. No recurrence occurred during the follow-up.

CONCLUSIONS

ICE-guidance during SP ablation significantly reduces mapping and ablation time, radiation exposure, and RF delivery in comparison to fluoroscopy-only procedures. Moreover, early switching to ICE-guided ablation seems to be an optimal choice in challenging cases.

Ventricular versus atrial side ablation for treatment of atrioventricular accessory pathways: a randomized controlled clinical trial

BACKGROUND

The earliest atrial (A)/ventricular (V) activation potentials, or fused A/V potentials, are commonly used as ablation targets for atrioventricular (AV) accessory pathways (APs). However, these targets can be achieved in a relatively wide area of the heart around AV rings at both atrial and ventricular sides. The aim of this study is to analyze the height of intracardiac A and V waves and their correlation to find the most appropriate side for successful delivery of radiofrequency energy, atrial or ventricular edge.

METHODS

Ninety patients diagnosed with orthodromic AV re-entrant tachycardia (AVRT) or Wolff-Parkinson-White syndrome were enrolled. Local atrial/ventricular (A/V) amplitude potentials with the earliest activation or fused AV potentials were measured. Patients were randomly assigned into two groups with a 2:1 ratio. In group 1, ablation was done at the site where A was greater than V. In group 2, V was greater than A. Primary endpoint was success at first attempt, achieving antegrade AP conduction block, AV block during right ventricle pacing, or AVRT termination with no AP conduction.

RESULTS

Fifty-one patients (56.7%) were male. Thirty patients had an ablation at an atrial site (A > V) and 60 at a ventricular site (V > A). Ablation was more successful at the ventricular site (87% vs 100%, P = 0.011). All 30 patients in the atrial arm and 71% of the ventricular group underwent ablation via the antegrade method.

CONCLUSIONS

Success of catheter ablation of APs is higher where V > A (ventricular site of AP), indicating the priority of the ventricular edge of the mitral ring for a better outcome.

Higher Incidence of Stroke in Severe COVID-19 Is Not Associated With a Higher Burden of Arrhythmias: Comparison With Other Types of Severe Pneumonia

Aims: Thromboembolic events, including stroke, are typical complications of COVID-19. Whether arrhythmias, frequently described in severe COVID-19, are disease-specific and thus promote strokes is unclear. We investigated the occurrence of arrhythmias and stroke during rhythm monitoring in critically ill patients with COVID-19, compared with severe pneumonia of other origins.

Methods and Results: This retrospective study included 120 critically ill patients requiring mechanical ventilation in three European tertiary hospitals, including n =60 COVID-19, matched according to risk factors for the occurrence of arrhythmias in n = 60 patients from a retrospective consecutive cohort of severe pneumonia of other origins. Arrhythmias, mainly atrial fibrillation (AF), were frequent in COVID-19. However, when compared with non-COVID-19, no difference was observed with respect to ventricular tachycardias (VT) and relevant bradyarrhythmias (VT 10.0 vs. 8.4 %, p = ns and asystole 5.0 vs. 3.3%, p = ns) with consequent similar rates of cardiopulmonary resuscitation (6.7 vs. 10.0%, p = ns). AF was even more common in non-COVID-19 (AF 18.3 vs. 43.3%, p = 0.003; newly onset AF 10.0 vs. 30.0%, p = 0.006), which resulted in a higher need for electrical cardioversion (6.7 vs. 20.0%, p = 0.029). Despite these findings and comparable rates of therapeutic anticoagulation (TAC), the incidence of stroke was higher in COVID-19 (6.7.% vs. 0.0, p = 0.042). These events also happened in the absence of AF (50%) and with TAC (50%).

Conclusions: Arrhythmias were common in severe COVID-19, consisting mainly of AF, yet less frequent than in matched pneumonia of other origins. A contrasting higher incidence of stroke independent of arrhythmias also observed with TAC, seems to be an arrhythmia-unrelated disease-specific feature of COVID-19.

Modified Valsalva maneuver for treatment of supraventricular tachycardias: A Meta-analysis

BACKGROUD

Valsalva maneuver (VM) is a simple and easy method for acute termination of supraventricular tachycardia (SVT), while a postural modification to the VM has been suggested to be superior to the standard VM (SVM). The objective of this meta-analysis is to explore the efficacy and safety of the modified VM (MVM) to terminate SVT compared with the SVM.

METHODS

Extensive literature was conducted using the database such as PubMed, Embase, Web of Science, Cochrane library and included randomized controlled trials (RCTs) assessing the efficacy and safety of the MVM and SVM for SVT. Meta-analysis was performed using mean difference (MD), relative risk (RR) and 95% confidence interval (CI). Statistical analysis was performed using Review Manager 5.4.1 software. The quality of the published studies was evaluated using the Oxford quality scoring system (Jadad scale).

RESULTS

Six RCTs involving 1208 patients were reviewed, including 603 patients in the MVM group and 605 patients in the SVM group. The results of the meta-analysis showed that MVM was found to significantly increase the success rate of the sinus rhythm after single VM (RR = 2.83; 95% CI = 2.19 to 3.66; P < 0.00001), sinus rhythm after multiple VM (RR = 3.83; 95% CI = 2.26 to 6.50; P < 0.00001), and single and multiple VM (RR = 2.85, 95% CI = 2.35 to 3.45; P < 0.00001). MVM also decreased the emergency anti-arrhythmic treatments (RR = 0.70; 95% CI = 0.62 to 0.79; P < 0.00001), and use of adenosine and verapamil (RR = 0.69; 95% CI = 0.61 to 0.78; P < 0.00001). There was no significant difference in adverse events (RR = 1.48; 95% CI = 0.91 to 2.42; P = 0.11) and time in emergency department (ED) (RR = 0.03; 95% CI = -0.17 to 0.23, P = 0.79) between MVM and SVM.

CONCLUSION

Compared with MVM, the conversion rate of SVT to sinus rhythm was more effective than SVM. MVM also reduced the use of anti-arrhythmic measures and drugs, and had no increased time in ED and adverse events.

Ultralow temperature cryoablation using near-critical nitrogen for cavotricuspid isthmus-ablation, first-in-human results

INTRODUCTION

Cryoablation has evolved as a safe alternative to radiofrequency ablation in the treatment of several supraventricular arrhythmias and has potential advantages, yet is limited by the properties of the cryogen used. We investigated a novel ultralow temperature cryoablation (ULTC) system using nitrogen near its liquid-vapor critical point as a freezing source, achieving temperatures as low as -196 degrees Celsius in a long linear catheter with a continuous energy release. Initial safety, procedural and efficacy outcomes of ULTC are described in patients undergoing cavotricuspid isthmus (CTI) ablation.

METHODS AND RESULTS

The Cryocure studies (NCT02355106, NCT02839304) are prospective, single-arm, multi-center, first-in-human clinical studies in 17 patients with atrial flutter (AFL) and 13 patients with atrial fibrillation (AF). A total of 30 patients, mean age 65 ± 8 years old and 67% male, were enrolled and underwent ablation of the CTI. Acute success, defined as the confirmation of stable bidirectional conduction block across the CTI, was achieved in all 30 patients. After 12 months of follow-up, 14 out of 17 AFL patients remained free from any AFL. One (3.3%) procedure-related but not device-related serious adverse event was reported, involving transient inferolateral ST-elevation associated with temporary AV conduction block.

CONCLUSION

In this first-in-human clinical study the safety and performance results demonstrate the capabilities of ultralow temperature near-critical nitrogen as an effective energy source for CTI ablation. Ongoing, larger, studies should confirm our findings and evaluate the capabilities to create linear and focal transmural lesions in other arrhythmias.

Arrhythmias and Conduction Disturbances in Autoimmune Rheumatic Disorders

Rhythm and conduction disturbances and sudden cardiac death are important manifestations of cardiac involvement in autoimmune rheumatic diseases (ARD), which have a serious impact on morbidity and mortality. While the underlying arrhythmogenic mechanisms are multifactorial, myocardial fibrosis plays a pivotal role. It accounts for a substantial portion of cardiac mortality and may manifest as atrial and ventricular arrhythmias, conduction system abnormalities, biventricular cardiac failure or sudden death. In patients with ARD, myocardial fibrosis is considered to be the hallmark of cardiac involvement as a result of inflammatory process or to coronary artery occlusive disease. Myocardial fibrosis constitutes the pathological substrates for reentrant circuits. The presence of supraventricular extra systoles, tachyarrhythmias, ventricular activity and conduction disturbances are not uncommon in patients with ARDs, more often in systemic lupus erythematosus, systemic sclerosis, rheumatoid arthritis, inflammatory muscle disorders and anti-neutrophil cytoplasm antibody-associated vasculitis. In this review, the type, the relative prevalence and the underlying mechanisms of rhythm and conduction disturbances in the emerging field of cardiorheumatology are provided.

Flecainide How and When: A Practical Guide in Supraventricular Arrhythmias

Transcatheter ablation was increasingly and successfully used to treat symptomatic drug refractory patients affected by supraventricular arrhythmias. Antiarrhythmic drug treatment still plays a major role in patient management, alone or combined with non-pharmacological therapies. Flecainide is an IC antiarrhythmic drug approved in 1984 from the Food and Drug Administration for the suppression of sustained ventricular tachycardia and later for acute cardioversion of atrial fibrillation and for sinus rhythm maintenance. Currently, flecainide is mostly used for sinus rhythm maintenance in atrial fibrillation (AF) patients without structural cardiomyopathy although recent studies enrolling different patient populations have demonstrated a good effectiveness and safety profile. How should we interpret the results of the CAST after the latest evidence? Is it possible to expand the indications of flecainide, and therefore, its use? This review aims to highlight the main characteristics of flecainide, as well as its optimal clinical use, delineating drug indications and contraindications and appropriate monitoring, based on the most recent evidence.

Clinical predictors for bradycardia and supraventricular tachycardia necessitating therapy in patients with unexplained syncope monitored by insertable cardiac monitor

Background

Insertable cardiac monitors (ICMs) improve diagnostic yield in patients with unexplained syncope. The most of cardiac syncope is arrhythmic causes include paroxysmal bradycardia and supraventricular tachycardia (SVT) in patients with unexplained syncope receiving ICM. Predictors for bradycardia and SVT that necessitate therapy in patients with unexplained syncope are not well known.

Hypothesis

This study aimed to investigate predictors of bradycardia and SVT necessitating therapy in patients with unexplained syncope receiving ICMs.

Methods

We retrospectively reviewed medical records of consecutive patients who received ICMs to monitor unexplained syncope. We performed Cox's stepwise logistic regression analysis to identify significant independent predictors for bradycardia and SVT.

Results

One hundred thirty‐two patients received ICMs to monitor unexplained syncope. During the 17‐month follow‐up period, 19 patients (14%) needed pacemaker therapy for bradycardia; 8 patients (6%) received catheter ablation for SVT. The total estimated diagnostic rates were 34% and 48% at 1 and 2 years, respectively. Stepwise logistic regression analysis indicated that syncope during effort (odds ratio [OR] = 3.41; 95% confidence interval [CI], 1.21 to 9.6; p = .02) was an independent predictor for bradycardia. Palpitation before syncope (OR = 9.46; 95% CI, 1.78 to 50.10; p = .008) and history of atrial fibrillation (OR = 10.1; 95% CI, 1.96 to 52.45; p = .006) were identified as significant independent predictors for SVT.

Conclusion

Syncope during effort, and palpitations or history of atrial fibrillation were independent predictors for bradycardia and for SVT. ICMs are useful devices for diagnosing unexplained syncope.

Efficacy of medical and ablation therapy for inappropriate sinus tachycardia: A single-center experience

BACKGROUND

Effective therapy for inappropriate sinus tachycardia (IST) remains challenging with high rates of treatment failure and symptom recurrence. It is uncertain how effective pharmacotherapy and procedural therapy are long-term, with poor response to medical therapy in general.

METHODS

We retrospectively reviewed all patients with the diagnosis of IST at a tertiary academic medical center from 1998 to 2018. We extracted data related to prescribing patterns and symptom response to medical therapy and sinus node modification (SNM), assessing efficacy and periprocedural complication rates.

RESULTS

A total of 305 patients with a formal diagnosis of IST were identified, with 259 (84.9%) receiving at least one prescription medication related to the condition. Beta-blockers were the most commonly used medication (n = 245), with a majority of patients reporting no change or worsening of symptoms, and poor response was seen to other medication classes. Improvement was seen significantly more often with ivabradine than beta blockers, though the sample size was limited (p = .003). Fifty-five patients (18.0% of all IST patients), mean age 32.0 ± 9.1 years, underwent a SNM procedure, with an average of 1.8 ± 0.9 procedures per patient. Acute symptomatic improvement (<6 months) was seen in 58.2% of patients. Long-term complete resolution of symptoms was seen in 5.5% of patients, modest improvement in 29.1%, and no long-term benefit was seen in 65.5% of patients.

CONCLUSIONS

Among all medical therapies, there were high rates of treatment failure or symptom worsening in over three-quarters of patients in our study. Ivabradine was most beneficial, though the sample size was small. While most patients receiving SNM ablation for IST perceive an acute symptomatic improvement, almost two-thirds of patients have no long-term improvement, and resolution of symptoms is quite rare. AV node ablation with pacemaker implantation following lack of response to SNM offered increased success, though the sample size was limited.

A simplified differential pacing technique for the evaluation of bidirectional cavo-tricuspid isthmus block during ablation of typical atrial flutter

PURPOSE

Bidirectional block of the cavo-tricuspid isthmus (CTI) is an established endpoint of CTI-dependent atrial flutter (AFl) ablation. Differential pacing has been used to evaluate the CTI block. The purpose of this study is to describe a modified differential pacing technique to evaluate the CTI block.

METHODS

Sixty-two patients underwent radiofrequency (RF) ablation of CTI-dependent AFl. The acute endpoints were non-inducibility of the AFl, and verification of the bidirectional CTI block by our methodology. Pacing was performed in the CS with an ablation catheter positioned immediately lateral to the CTI ablation line, and then 1-2 cm more laterally. The stimulus-to-ablation catheter atrial electrogram intervals were measured at these sites (Stim_CS-Abl₁ and Stim_CS-Abl₂, respectively). Pacing with the ablation catheter also was performed at these 2 sites, and the stimulus-to-CS electrogram intervals (Stim_ABL1-CS and Stim_ABL2-CS) were measured. The criteria for the bidirectional block were Stim_CS-Abl₁ > Stim_CS-Abl₂, and Stim_ABL1-CS > Stim_ABL2-CS. Clinical efficacy was defined as freedom from recurrent AFl during follow-up.

RESULTS

Following 12.2 ± 3.7 min of RF delivery across the CTI, intervals were Stim_CS-Abl₁ = 181.2 ± 22.7 ms and Stim_ABL1-CS = 181.0 ± 23.6 ms, and Stim_CS-Abl₂ = 152.2 ± 26.5 ms and Stim_ABL2-CS = 151.2 ± 22.7 (P < 0.001). Atrial flutter was rendered not inducible in all patients, and no procedural complications were encountered. During the next 15.9 ± 0.7 months, two patients were lost to follow-up, and among the 62 other patients, one (1.7%) had flutter recurrence.

CONCLUSIONS

The bidirectional CTI block can be assessed quickly and easily using only the ablation and CS catheters for differential pacing.

Prehospital conversion of paroxysmal supraventricular tachycardia using the modified Valsalva maneuver: A case report

The modified Valsalva maneuver (MVM) has never before been performed in the prehospital setting by the Hamad Medical Corporation Ambulance Service (HMCAS) clinicians in the State of Qatar. Currently, their clinical practice guidelines (CPG) prescribe the vagal maneuver (VM) using a 10 cc syringe as first-line therapy for patients presenting with symptomatic paroxysmal supraventricular tachycardia (pSVT). The effectiveness of the MVM in terminating pSVT compared to the traditional VM is well documented, although prehospital studies in this area are lacking. In this case, a generally healthy, 47-year-old male migrant worker presented with new-onset symptomatic pSVT, which was successfully terminated by a MVM after initial failed attempts of the traditional VM. The MVM is a postural technique performed by initially placing the patient in a semirecumbent position. The patient is then encouraged to blow into a manometer to achieve a 40 mmHg intrathoracic pressure for 15 seconds. Once the 40 mmHg intrathoracic pressure is achieved, the patient is repositioned supine, and their legs are raised passively to 45 degrees for 15 seconds. The patient is then returned to the semirecumbent position for 45 seconds before cardiac rhythm reassessment. The MVM has shown to have an increased termination rate of pSVT with no documented serious adverse events. The MVM can be performed in a time-effective manner and is cost effective as intravenous (IV) cannulation is not required. The prevention of adenosine-associated transient asystole is prevented. It is recommended that ambulance services consider the inclusion of the MVM in their CPGs for the treatment of new-onset pSVT.

[Management of acute complications during electrophysiological procedures]

Catheter ablation is an established treatment option in patients suffering from symptomatic cardiac arrhythmias. However, despite technical advances, catheter ablation is still associated with an incidence of severe complications of up to 5%. Therefore, electrophysiologists should be trained to prevent complications, maintain a high index of suspicion to recognize them quickly and implement necessary treatment strategies. This article reviews the incidence, risk factors, management and preventative strategies of the major complications associated with ablation procedures such as transseptal puncture-related risks, cardiac tamponade, aortic puncture and air embolism.

[Supraventricular tachycardia - ECG interpretation and clinical management]

Supraventricular tachycardia (SVT) is a very common cause of hospital admission and its diagnostic and treatment may be difficult sometimes. While vagal maneuvers or intravenous adenosis administration during 12-lead ECG recording should be performed in hemodynamically stable patients for diagnosis and treatment, hemodynamically unstable patients should be carioverted immediately. The new ESC guideline (2019) on diagnosis and clinical management of SVT significantly upgrades catheter ablation and gives it a new preferential status. For example, in patients with symptomatic recurrence, atrioventricular nodal re-entrant tachycardia should be ablated due to the very low risk of AV block. Furthermore, catheter ablation should also be offered as first-line therapy to patients with reentrant and focal arrhythmias. The diagnosis and therapy of tachycardiomyopathy is of particular importance and treatment should incorporate the ablation of the underlying supraventricular tachycardia. The therapy of supraventricular tachycardia during pregnancy should be free of antiarrhythmic medication, especially in the first trimester. If ablation is necessary during pregnancy, only fluoroscopy-free mapping systems should be used. This review covers aspects of ECG diagnosis and guideline-based treatment of SVT.

Differential Diagnosis of Wide QRS Tachycardias

In this article, the authors discuss the differential diagnostic methods used in clinical practice to identify types of wide QRS tachycardias (QRS duration >120 ms). A correct diagnosis is critical to management, as misdiagnosis and the administration of drugs usually utilised for supraventricular tachycardia can be harmful for patients with ventricular tachycardia.

Modern treatment of supraventricular tachycardia

Supraventricular tachycardia (SVT) is one of the most common arrhythmias. The prevalence of SVT varies widely in different countries and is 2,25 per 1,000 people in the general population. SVT reduce the quality of life of patients, and in some cases can worsen the prognosis. In patients with cardiovascular disease, the risk of SVT increases. Therapy of SVT is selected depending on the stability of hemodynamic and the QRS width. Until now, the treatment of SVT remains an urgent issue of modern cardiology, since despite the high effectiveness of catheter ablation, antiarrhythmic therapy plays an important role.

Comparison of the efficacy and safety of different doses of nifekalant in the instant cardioversion of persistent atrial fibrillation during radiofrequency ablation

Nifekalant has been used in the treatment of atrial arrhythmia recently. However, there is no consensus on the preferable nifekalant dose to treat atrial fibrillation (AF). The purpose of this study was to explore efficacy and safety of different doses of nifekalant in the cardioversion of persistent AF. The study was a single-centre, randomized controlled trial. All subjects received nifekalant or placebo intravenously, and the nifekalant was given at the dosage of 0.3, 0.4 or 0.5 mg/kg. Primary efficacy end-point: compared with 0.3 mg group, the rate of cardioversion to sinus rhythm from AF in 0.4 and 0.5 mg group was higher. The 0.4 and 0.5 mg/kg doses were associated with a similar magnitude of efficacy (P > .05). Secondary efficacy end-point: termination rates of AF in the group of 0.4 mg and 0.5 mg were higher than 0.3 mg. Primary safety end-point: the rate of Torsades de Pointes or ventricular fibrillation was numerically lower in the 0.4 mg group than 0.5 mg group (P = .02). Secondary safety end-point: The rates of the majority of other common drug-related adverse events in the group of 0.5 and 0.4 mg were higher than the 0.3 mg group. A 0.4 mg/kg dose of intravenous nifekalant may be recommended during the radiofrequency ablation for persistent AF considering the benefit-risk profile.

[Wolff Parkinson white syndrome in a young infant]

Wolff Parkinson White Syndrome occurs due to the presence of accessory pathways that abnormally communicate the atria with the ventricles. It is one of the main causes of paroxysmal supraventricular tachycardia in young people and adolescents, in whom the ideal management is catheter ablation. This syndrome can also occur in younger patients such as neonates and infants, where the therapeutic options are different. We present the case of a 47-day-old patient who was admitted to a public pediatric hospital in Peru due to vomiting. Upon admission, she showed a heart rate of 250 beats per minute; wide QRS complex tachycardia was documented; later, on the electrocardiogram in sinus rhythm, signs of pre-excitation were evident.

Management of ventricular electrical storm: a contemporary appraisal

Ventricular electrical storm (VES) is a clinical scenario characterized by the clustering of multiple episodes of sustained ventricular arrhythmias (VA) over a short duration. Patients with VES are prone to psychological disorders, heart failure decompensation, and increased mortality. Studies have shown that 10–28% of the patients with secondary prevention ICDs can sustain VES. The triad of a susceptible electrophysiologic substrate, triggers, and autonomic dysregulation govern the pathogenesis of VES. The rate of VA, underlying ventricular function, and the presence of implantable cardioverter-defibrillator (ICD) determine the clinical presentation. A multi-faceted approach is often required for management consisting of acute hemodynamic stabilization, ICD reprogramming when appropriate, antiarrhythmic drug therapy, and sedation. Some patients may be eligible for catheter ablation, and autonomic modulation with thoracic epidural anesthesia, stellate ganglion block, or cardiac sympathetic denervation. Hemodynamically unstable patients may benefit from the use of left ventricular assist devices, and extracorporeal membrane oxygenation. Special scenarios such as idiopathic ventricular fibrillation, Brugada syndrome, Long and short QT syndrome, early repolarization syndrome, catecholaminergic polymorphic ventricular tachycardia, arrhythmogenic right ventricular cardiomyopathy, and cardiac sarcoidosis have been described as well. VES is a cardiac emergency that requires swift intervention. It is associated with poor short and long-term outcomes. A structured team-based management approach is paramount for the safe and effective treatment of this sick cohort.

An expert consensus document on the management of cardiovascular manifestations of Fabry disease

Fabry disease (FD) is an X-linked lysosomal storage disorder caused by pathogenic variants in the α-galactosidase A (GLA) gene that leads to reduced or undetectable α-galactosidase A enzyme activity and progressive accumulation of globotriaosylceramide and its deacylated form globotriaosylsphingosine in cells throughout the body. FD can be multisystemic with neurological, renal, cutaneous and cardiac involvement or be limited to the heart. Cardiac involvement is characterized by progressive cardiac hypertrophy, fibrosis, arrhythmias, heart failure and sudden cardiac death. The cardiac management of FD requires specific measures including enzyme replacement therapy or small pharmacological chaperones in patients carrying amenable pathogenic GLA gene variants and more general management of cardiac symptoms and complications. In this paper, we summarize current knowledge of FD-related heart disease and expert consensus recommendations for its management.

Junctional ectopic tachycardia in infants and children

Tachyarrhythmias originating in the atrioventricular (AV) node and AV junction including the bundle of His complex (BH) are called junctional tachycardia (JT) or junctional ectopic tachycardia (JET). Congenital JET (CJET) is a rare arrhythmia that occurs in patients without a preceding cardiac surgery and can be refractory to medical therapy and associated with high morbidity and mortality. CJET has a high rate of morbidity and mortality with death occurring in 35% of cases. JET occurring within 72 hours after cardiac surgery is referred to as postoperative JET (POJET) and caused by direct trauma, ischemic, or stretch injury to the AV conduction tissues during surgical repair of congenital heart defects. Focal junctional tachycardia (FJT) is also known as automatic junctional tachycardia and includes paroxysmal or non-paroxysmal forms. We discuss a staged approach to therapy with improved pharmacological therapies and the use of catheter-based therapies.

The role of the right atrium in development of postoperative atrial fibrillation: A speckle tracking echocardiography study

PURPOSE

Atrial fibrillation (AF) is relatively frequent in the postoperative period, and is associated with an increased frequency of adverse events. The role of right atrial (RA) volume and functions in the development of AF is unknown. In this study, we investigated the effect of RA echocardiographic indices on AF development in the postoperative period.

METHOD

We enrolled 142 consecutive patients who underwent coronary artery bypass surgery, and assigned them into two groups depending on the occurrence or not of AF development in the postoperative period.

RESULTS

A propensity score matching analysis was performed to balance the groups, and 37 pairs were eventually included in the analysis. The median age was 67.5 (63-75) years and 73.3% of them were males. In the univariate analysis, right atrial volume index (RAVi), right atrial strain during reservoir phase (RASr), left ventricular global longitudinal strain, right ventricular strain, left atrial volume index, left atrial strain during reservoir phase, and systolic pulmonary artery pressure were associated with AF development. In the regression analysis, we found that RAVi (OR: 3.1, 95% CI: 2.2-6.3, P: .033) and RASr (OR: 0.82, 95% CI: 0.67-0.93, P: .048) were independent predictors of AF development.

CONCLUSIONS

RA structure and functions are closely associated with AF development in the postoperative period, and screening of RA functions prior to surgery may be useful for preventing AF development.

Arrhythmia-Induced Cardiomyopathy

BACKGROUND

Heart failure affects 1–2% of the population and is associated with elevated morbidity and mortality. Cardiac arrhythmias are often a result of heart failure, but they can cause left-ventricular systolic dysfunction (LVSD) as an arrhythmia-induced cardiomyopathy (AIC). This causal relationship should be borne in mind by the physician treating a patient with systolic heart failure in association with cardiac arrhythmia.

METHODS

This review is based on pertinent publications retrieved by a selective search in PubMed (1987–2017) and on the recommendations in current guidelines.

RESULTS

The key criterion for the diagnosis of an AIC is the demonstration of a persistent arrhythmia (including pathological tachycardia) together with an LVSD whose origin cannot be explained on any other basis. Nearly any type of tachyarrhythmia or frequent ventricular extrasystoles can lead, if persistent, to a progressively severe LVSD. The underlying pathophysiologic mechanisms are incompletely understood; the increased ventricular rate, asynchronous cardiac contractions, and neurohumoral activation all seem to play a role. The most common precipitating factors are supraventricular tachycardias in children and atrial fibrillation in adults. Recent studies have shown that the causal significance of atrial fibrillation in otherwise unexplained LVSD is underappreciated. The treatment of AIC consists primarily of the treatment of the underlying arrhythmia, generally with drugs such as beta-blockers and amiodarone. Depending on the type of arrhythmia, catheter ablation for long-term treatment should also be considered where appropriate. The diagnosis of AIC is considered to be well established when the LVSD normalizes or improves within a few weeks or months of the start of targeted treatment of the arrhythmia.

CONCLUSION

An AIC is potentially reversible. The timely recognition of this condition and the appropriate treatment of the underlying arrhythmia can substantially improve patient outcomes.

High incidence of atrial fibrillation after successful catheter ablation of atrioventricular nodal reentrant tachycardia: a 15.5-year follow-up

Atrioventricular nodal reentrant tachycardia (AVNRT) is the most common type of supraventricular tachycardia. Slow pathway (SP) ablation is the treatment of choice with a high acute success rate and a negligible periprocedural risk. However, long-term outcome data are scarce. The aim of this study was to assess long-term outcome and arrhythmia free survival after SP ablation. In this study, 534 consecutive patients with AVNRT, who underwent SP ablation between 1994 and 1999 were included. During a mean follow-up of 15.5 years, 101 (18.9%) patients died unrelated to the procedure or any arrhythmia. Data were collected by completing a questionnaire and/or contacting patients. Clinical information was obtained from 329 patients (61.6%) who constitute the final study cohort. During the electrophysiological study, sustained 1:1 slow AV nodal pathway conduction was eliminated in all patients. Recurrence of AVNRT was documented in 9 patients (2.7%), among those 7 patients underwent a successful repeat ablation procedure. New-onset atrial fibrillation (AF) was documented in 39 patients (11.9%) during follow-up. Pre-existing arterial hypertension (odds ratio 2.61, 95% CI 1.14–5.97, p = 0.023), age (odds ratio 1.05, 95% CI 1.02–1.09, p = 0.003) and the postinterventional AH interval (odds ratio 1.02, 95% CI 1.00–1.04, p = 0.038) predicted the occurrence of AF. The present long-term observational study after successful SP ablation of AVNRT confirms its clinical value reflected by low recurrence and complication rates. The unexpectedly high incidence of new-onset AF (11.9%) may impact long-term follow-up and requires further clinical attention.

Clinical and Electrophysiological Correlates of Incessant Ivabradine-Sensitive Atrial Tachycardia

Background:

Incessant focal atrial tachycardia (FAT), if untreated, can lead to ventricular dysfunction and heart failure (tachycardia-induced cardiomyopathy). Drug therapy of FAT is often difficult and ineffective. The efficacy of ivabradine has not been systematically evaluated in the treatment of FAT.

Methods:

The study group consisted of patients with incessant FAT (lasting >24 hours) and structurally normal hearts. Patients with ventricular dysfunction as a consequence of FAT were not excluded. All antiarrhythmic drugs were discontinued at least 5 half-lives before the initiation of ivabradine. Oral ivabradine (adults, 10 mg twice 12 hours apart; pediatric patients: 0.28 mg/kg in 2 divided doses) was initiated in the intensive care unit under continuous electrocardiographic monitoring. A positive response was defined as the termination of tachycardia with the restoration of sinus rhythm or suppression of the tachycardia to <100 beats per minute without termination within 12 hours of initiating ivabradine.

Results:

Twenty-eight patients (mean age, 34.6±21.5 years; women, 60.7%) were included in the study. The most common symptom was palpitation (85.7%) followed by shortness of breath (25%). The mean atrial rate during tachycardia was 170±21 beats per minute, and the mean left ventricular ejection fraction was 54.7±14.3%. Overall, 18 (64.3%) patients responded within 6 hours of the first dose of ivabradine. Thirteen of 18 ivabradine responders subsequently underwent successful catheter ablation. FAT originating in the atrial appendages was a predictor of ivabradine response compared with those arising from other atrial sites ( P =0.046).

Conclusions:

Ivabradine-sensitive atrial tachycardia constitutes 64% of incessant FAT in patients without structural heart disease. Incessant FAT originating in the atrial appendages is more likely to respond to ivabradine than that arising from other atrial sites. Our findings implicate the funny current in the pathogenesis of FAT.