Incremental value of machine learning for risk prediction in tetralogy of Fallot

OBJECTIVE

Machine learning (ML) can facilitate prediction of major adverse cardiovascular events (MACEs) in repaired tetralogy of Fallot (rTOF). We sought to determine the incremental value of ML above expert clinical judgement for risk prediction in rTOF.

METHODS

Adult congenital heart disease (ACHD) clinicians (≥10 years of experience) participated (one cardiac surgeon and four cardiologists (two paediatric and two adult cardiology trained) with expertise in heart failure (HF), electrophysiology, imaging and intervention). Clinicians identified 10 high-yield variables for 5-year MACE prediction (defined as a composite of mortality, resuscitated sudden death, sustained ventricular tachycardia and HF). Risk for MACE (low, moderate or high) was assigned by clinicians blinded to outcome for adults with rTOF identified from an institutional database (n=25 patient reviews conducted by five independent observers). A validated ML model identified 10 variables for risk prediction in the same population.

RESULTS

Prediction by ML was similar to the aggregate score of all experts (area under the curve (AUC) 0.85 (95% CI 0.58 to 0.96) vs 0.92 (0.72 to 0.98), p=0.315). Experts with ≥20 years of experience had superior discriminative capacity compared with <20 years (AUC 0.98 (95% CI 0.86 to 0.99) vs 0.80 (0.56 to 0.93), p=0.027). In those with <20 years of experience, ML provided incremental value such that the combined (clinical+ML) AUC approached ≥20 years (AUC 0.85 (95% CI 0.61 to 0.95), p=0.055).

CONCLUSIONS

Robust prediction of 5-year MACE in rTOF was achieved using either ML or a multidisciplinary team of ACHD experts. Risk prediction of some clinicians was enhanced by incorporation of ML suggesting that there may be incremental value for ML in select circumstances.

Risk Stratification for Sudden Cardiac Death in Repaired Tetralogy of Fallot

There has been significant progress in the prevention of sudden cardiac death in repaired tetralogy of Fallot. Contemporary cohorts report greater survival attributable to improved surgical techniques, heart failure management, and proactive strategies for risk stratification and management of ventricular arrhythmias including defibrillator implantation and ablation technology. Over the last 25 years, our understanding of predictive risk factors has also improved from invasive and more limited measures to individualized risk prediction scores based on extensive demographic, imaging, electrophysiological, and functional data. Although each of these contemporary scoring systems improves prediction, there are important differences between the study cohorts, included risk factors, and imaging modalities that can significantly affect interpretation and implementation for the individual patient. In addition, accurate phenotyping of disease complexity and anatomic repair substantially modulates this risk and the mechanism of sudden death. Routine implementation of risk stratification within repaired tetralogy of Fallot management is important and directly informs primary prevention defibrillator implantation as well as consideration for proactive invasive strategies including ventricular tachycardia ablation and pulmonary valve replacement. Assessment and risk stratification by a multidisciplinary team of experts in adult congenital heart disease are crucial and critical. Although we have increased understanding, reconciliation of these complex factors for the individual patient remains challenging and often requires careful consideration and discussion with multidisciplinary teams, patients, and their families.

Incidence and Clinical Predictors of Early and Late Complications of Implantable Cardioverter-Defibrillators in Adults With Congenital Heart Disease

BACKGROUND

The implantable cardioverter-defibrillator (ICD) has been proven to improve survival in adults with congenital heart disease (ACHD), but it is associated with a high rate of complications. We aimed to quantify the incidence of early (≤ 3 months; ECs) and late (> 3 months; LCs) complications in ACHD patients implanted with an ICD and to identify their clinical predictors.

METHODS

We retrospectively reviewed 207 patients who had ICD follow-up at Toronto General Hospital from 1996 to 2019.

RESULTS

The most common diagnoses were tetralogy of Fallot (32.4%), dextro-transposition of the great arteries (17.9%), and congenital corrected transposition of the great arteries (13%). No intraprocedural complications were observed. Median follow-up was 3.4 years (IQR 0.1-23). 24 patients (12%) developed EC (4 hematomas, 20 lead dislodgements). A total of 56 LCs occurred (46% lead failure, 21% infection, 11% prophylactic lead extraction, 9% neurologic pain, 9% erosion, 4% other) with an incidence rate of LCs of 18% per 5 person-years. Anatomic complexity (odds ratio 2.9; P = 0.02) and cardiac resynchronization therapy defibrillator implant (odds ratio 2.5; P = 0.04) were associated with ECs. Survival rates free from LCs were 92%, 86%, and 65%, respectively, after 1, 5, and 10 years. Presence of legacy leads (hazard ratio 2.9; P = 0.006) and subpulmonary ejection fraction (5% increase, hazard ratio 1.35; P = 0.031) were associated with LCs.

CONCLUSIONS

ACHD patients at risk of sudden cardiac death continue to benefit from newer device technology. However, these patients, particularly those with greater anatomic and device complexity, remain at increased risk of developing complications over their lifetime. Given the life expectancy of this population, careful consideration needs to be given when a device for primary prevention is being contemplated.

Quantifying the impact of equity, diversity, and inclusion in electrophysiology: Training the first female electrophysiologists from Jamaica and Saint Lucia

Background

Delivery of electrophysiology (EP) care in developing nations and underserviced populations faces many hurdles, including the lack of local expertise and knowledge creation. The West Indies has experienced a paucity of local EP expertise. The University of Toronto has undertaken a unique collaborative educational effort with the University of the West Indies.

Objective

We describe the effects of equity, diversity, and inclusion (EDI) in EP training at Toronto General Hospital in Canada by quantifying the impact of training the first female electrophysiologists to practice in Jamaica and Saint Lucia.

Methods

Data from the ministries of health in Jamaica and Saint Lucia were reviewed. The number of arrhythmia clinic patients seen, EP studies and ablations performed, pacemaker clinic patients seen, and implantable devices, permanent pacemakers (PPMs), and implantable cardioverter-defibrillators (ICDs) implanted were assessed.

Results

One hundred one arrhythmia consults were seen by the new electrophysiologist in Jamaica after her return from training in 2020. She has since performed 19 EP studies/catheter ablations at a newly established ablation laboratory. Three cases of left ventricular (LV) dysfunction due to tachy-cardiomyopathy were treated successfully with catheter ablation with immense improvement in LV ejection fraction. Thirteen PPMs, 1 ICD, and 3 LV leads were implanted, after which no early complications were identified. In Saint Lucia, where there is no dedicated electrophysiology laboratory, 2 patients who required catheter ablation for tachycardia-mediated LV dysfunction were identified by the electrophysiologist since her return to the island in 2018. The patients were appropriately referred, resulting in restoration of normal LV function. Six PPMs also were implanted in Saint Lucia. Knowledge translation has been limited by the lack of accessibility to the required devices, catheters, and specialized equipment and accessories, mainly because of their costs.

Conclusion

Training the first female electrophysiologists from Jamaica and Saint Lucia led to a quantifiable impact on EP care in both of these Caribbean countries. EDI strategies in EP training programs provide much needed benefits to developing nations, but more support is needed to allow new electrophysiologists to fully utilize their EP training to care for underserviced populations.

Ebstein's Anomaly: How to Identify Intracardiac Structures When Electrical Signals Do Not Match the Anatomy

In patients with Ebstein's anomaly, the distorted anatomy with discordance between the true atrioventricular (AV) groove and the tricuspid valve poses many challenges to the electrophysiologist. Intracardiac echocardiography is a recent tool that allows visualization of the displaced tricuspid valve, the true AV groove, and the atrialized right ventricle. We present a 3-dimensional electroanatomic map built using intracardiac echocardiography and the CARTOSOUND^® module (Biosense Webster, Diamond Bar, CA, USA) in one such patient who underwent ablation of a right-sided mid-septal accessory pathway.

Automated Identification of Ventricular Tachycardia Ablation Targets: Multicenter Validation and Workflow Characterization

Decrement evoked potentials (EPs) (DeEPs) constitute an accepted method to identify physiological ventricular tachycardia (VT) ablation targets without inducing VT. The feasibility of automated software (SW) in the detection of arrhythmogenic VT substrate has been documented. However, multicenter validation of automated SW and workflow has yet to be characterized. The objective of this study was to describe the functionality of a novel DeEP SW (Biosense Webster, Diamond Bar, CA, USA) and evaluate the independent performance of the automated algorithm using multicenter data. VT ablation cases were performed in the catheterization laboratory and retrospectively analyzed using the DeEP SW. The algorithm indicated and mapped DeEPs by first identifying capture in surface electrocardiograms (ECGs). Once capture was confirmed, the EPs of S1 paces were detected. The algorithm checked for the stability of S1 EPs by comparing the last 3 of the 8 morphologies and attributing standard deviation values. The extra-stimulus EP was then detected by comparing it to the S1 EP. Once detected, the DeEP value was computed from the extra-stimulus and displayed as a sphere on a voltage map. A total of 5,885 DeEP signals were extracted from 21 substrate mapping cases conducted at 3 different centers (in Spain, Canada, and Australia). A gold standard was established from ECGs manually marked by subject experts. Once the algorithm was deployed, 91.6% of S2 algorithm markings coincided with the gold standard, 1.9% were false-positives, and 0.1% were false-negatives. Also, 6.4% were non-specific DeEP detections. In conclusion, the automated DeEP algorithm identifies and displays DeEP points, revealing VT substrates in a multicenter validation study. The automation of identification and mapping display is expected to improve efficiency.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Canadian Cardiovascular Society 2022 Guidelines for Cardiovascular Interventions in Adults With Congenital Heart Disease

Interventions in adults with congenital heart disease (ACHD) focus on surgical and percutaneous interventions in light of rapidly evolving ACHD clinical practice. To bring rigour to our process and amplify the cumulative nature of evidence ACHD care we used the ADAPTE process; we systematically adjudicated, updated, and adapted existing guidelines by Canadian, American, and European cardiac societies from 2010 to 2020. We applied this to interventions related to right and left ventricular outflow obstruction, tetralogy of Fallot, coarctation, aortopathy associated with bicuspid aortic valve, atrioventricular canal defects, Ebstein anomaly, complete and congenitally corrected transposition, and patients with the Fontan operation. In addition to tables indexed to evidence, clinical flow diagrams are included for each lesion to facilitate a practical approach to clinical decision-making. Excluded are recommendations for pacemakers, defibrillators, and arrhythmia-directed interventions covered in separate designated documents. Similarly, where overlap occurs with other guidelines for valvular interventions, reference is made to parallel publications. There is a paucity of high-level quality of evidence in the form of randomized clinical trials to support guidelines in ACHD. We accounted for this in the wording of the strength of recommendations put forth by our national and international experts. As data grow on long-term follow-up, we expect that the evidence driving clinical practice will become increasingly granular. These recommendations are meant to be used to guide dialogue between clinicians, interventional cardiologists, surgeons, and patients making complex decisions relative to ACHD interventions.

Catheter ablation of atrial arrhythmias in patients post-Fontan

Atrial arrhythmias are highly prevalent in the aging Fontan population and contribute importantly to morbidity and mortality. Although the most common arrhythmia is scar-based intra-atrial re-entrant tachycardia, various other arrhythmias may occur including focal atrial tachycardia, atrioventricular node-dependent tachycardias, and atrial fibrillation. The type and prevalence of atrial arrhythmia is determined, in part, by the underlying congenital defect and variant of Fontan surgery. While the cumulative incidence of atrial tachyarrhythmias has decreased substantially from the atriopulmonary anastomosis to the more recent total cavopulmonary connection Fontan, the burden of atrial arrhythmias remains substantial. Management is often multi-faceted and can include anticoagulation, anti-arrhythmic drug therapy, pacing, and cardioversion. Catheter ablation plays a key role in arrhythmia control. Risks and benefits must be carefully weighed. Among the important considerations are the clinical burden of arrhythmia, ventricular function, hemodynamic stability in tachycardia, suspected arrhythmia mechanisms, risks associated with anaesthesia, venous access, approaches to reaching the pulmonary venous atrium, and accompanying co-morbidities. Careful review of surgical notes, electrocardiographic tracings, and advanced imaging is paramount, with particular attention to anatomic abnormalities such as venous obstructions and displaced conduction systems. Despite numerous challenges, ablation of atrial arrhythmias is effective in improving clinical status. Nevertheless, onset of new arrhythmias is common during long-term follow-up. Advanced technologies such as high-density mapping catheters and remote magnetic guided ablation carry the potential to further improve outcomes. Fontan patients with atrial arrhythmias should be referred to centers with dedicated expertise in congenital heart disease including catheter ablation, anaesthesia support, and advanced imaging.

Role of amiodarone in the management of atrial arrhythmias in adult Fontan patients

BACKGROUND

Patients with Fontan circulation are known to be at high risk for developing atrial tachyarrhythmias (AAs). Our objective was to examine the efficacy and safety of amiodarone in the management of ATs in adult Fontan patients.

METHODS

Primary outcomes of this single-centre, retrospective study included freedom from AAs and incidence of adverse effects of amiodarone on Fontan patients. Heart failure (HF) events and composite outcomes of death from any cause, Fontan revision and heart transplantation were evaluated as secondary outcomes. Predictors of HF and discontinuing amiodarone were also evaluated.

RESULTS

A total of 61 patients (mean age 31.6±11.3 years, 40.9% female), who were treated with amiodarone in between 1995 and 2018, were included. AAs free survival at 1, 3 and 5 years were 76.2%, 56.9% and 30.6%, respectively. During a median follow-up of 50.5 months, 34 (55.7%) patients developed side effects, and 20 (32.8%) patients discontinued amiodarone due to side effects. Thyroid dysfunction was the most common side effect (n=26, 76.5%), amiodarone-induced thyrotoxicosis (AIT) (n=16, 27.1%) being most common thyroid dysfunction. Young age (age <28.5 years) was associated with discontinuing amiodarone (HR 5.50, 95% CI 1.19 to 25.4, p=0.029). AIT significantly increased risk of HF (HR 4.82, 95% CI 1.71 to 13.6, p=0.003).

CONCLUSIONS

Short-term efficacy of amiodarone in Fontan physiology is acceptable. However, long-term administration is associated with a reduction of efficacy and a significant prevalence of non-cardiac side effects. AIT is associated with exacerbation of HF. The judicious use of amiodarone administration should be considered in this population.

Outcome of catheter ablation of arrhythmias in adult congenital heart disease with high density multi-electrode mapping with automatic annotation algorithm

Funding Acknowledgements

Type of funding sources: None.

Introduction

Arrhythmias are frequently encountered in adult congenital heart disease (ACHD) and respond poorly to pharmacological therapies. Catheter ablation is challenging due to anatomical variation and complexity of the arrhythmia substrate. High density multi electrode mapping (MEM) with automatic annotation of activation time may aid mapping of arrhythmia, decrease procedure time and improve the accuracy of targeting of ablation therapy.

Purpose

To compare the acute and long term outcomes and procedural characteristics of catheter ablation in ACHD patients with and without automatic annotation of activation with MEM.

Methods

Retrospective analysis of the acute and long term outcomes of ACHD patients in a single centre undergoing ablation procedures from 1 Jan 2014 to 18 August 2017 was undertaken. 2 groups were identified.

Group 1 included patients who had arrhythmia mapping performed with the CARTO 3D electroanatomic mapping system without the use of automatic signal annotation. Most patients in this group had sequential mapping performed with the ablation catheter (78%), the rest had multi-electrode mapping with the PentaRay 20 pole catheter.

Group 2 included patients who had arrhythmia mapping performed with the CARTO 3D electroanatomic mapping system using the automated CONFIDENSE mapping algorithm.

Results

Group 1: n = 27, mean age 44.6 +/-3 years. Male 46.6%. Group 2: n = 38, mean age 44.0 +/- 1.9 years. Male 56.7%. All patients had CHD of at least moderate complexity. 25% of patients in group 1 and 45% in group 2 were repeat ablations. 45 arrhythmias were induced in group 1 of which 29 were targeted and 74 arrhythmias were induced in group 2 of which 46 were targeted. Acute success rates (after attempts at reinduction) were 96.3% in group 1 and 94.7% in group 2. Recurrences of arrhythmia occurred significantly less in patients in group 2 compared to group 1  (44.7% and 70.4% respectively,  p &lt; 0.05) after a follow up duration of 17.3+/-0.43 months in group 2 and 45.3 +/-1.19 months in group 1. Fluoroscopy time, procedure time and ablation time were not significantly different between groups.

Conclusions

The use of multi-electrode mapping with an automatic annotation algorithm was associated with a significantly lower risk of recurrence during the follow up period of this study.

New developments in catheter ablation for patients with congenital heart disease

Introduction: There are numerous challenges to catheter ablation in patients with congenital heart disease (CHD), including access to cardiac chambers, distorted anatomies, displaced conduction systems, multiple and/or complex arrhythmia substrates, and excessively thickened walls, or interposed material. Areas covered: Herein, we review recent developments in catheter ablation strategies for patients with CHD that are helpful in addressing these challenges. Expert opinion: Remote magnetic navigation overcomes many challenges associated with vascular obstructions, chamber access, and catheter contact. Patients with CHD may benefit from a range of ablation catheter technologies, including irrigated-tip and contact-force radiofrequency ablation and focal and balloon cryoablation. High-density mapping, along with advances in multipolar catheters and interpolation algorithms, is contributing to new mechanistic insights into complex arrhythmias. Ripple mapping allows the activation wave front to be tracked visually without prior assignment of local activation times or window of interest, and without interpolations of unmapped regions. There is growing interest in measuring conduction velocities to identify arrhythmogenic substrates. Noninvasive mapping with a multielectrode-embedded vest allows prolonged bedside monitoring, which is of particular interest in those with non-sustained or multiple arrhythmias. Further studies are required to assess the role of radiofrequency needle catheters and stereotactic radiotherapy in patients with CHD.

The rationale for repurposing funny current inhibition for management of ventricular arrhythmia

Management of ventricular arrhythmia in structural heart disease is complicated by the toxicity of the limited antiarrhythmic options available. In others, proarrhythmia and deleterious hemodynamic and noncardiac effects prevent practical use. This necessitates new thinking in therapeutic agents for ventricular arrhythmia in structural heart disease. Ivabradine, a funny current (I_f) inhibitor, has proven safety in heart failure, angina, and inappropriate sinus tachycardia. Although it is commonly known that funny channels are primarily expressed in the sinoatrial node, atrioventricular node, and conducting system of the ventricle, ivabradine is known to exert effects on metabolism, ion homeostasis, and membrane electrophysiology of remodeled ventricular myocardium. This review considers novel concepts and evidence from clinical and experimental studies regarding this paradigm, with a potential role of ivabradine in ventricular arrhythmia.

Minimalistic strategy for coronary sinus lead implant: A single tool capable of electrophysiological mapping, pressure measurement, and angiography

BACKGROUND

Left ventricular (LV) lead implantation for cardiac resynchronization therapy (CRT) may be confounded by contrast load during attempted cannulation and lead dislodgement during guiding catheter splitting. An LV lead implant system with a steerable single catheter that completely avoids the use of guiding catheters when needed, acquires atrioventricular electrograms, measures intracardiac pressures, permits CS angiography, and has the ability to direct a coronary angioplasty wire that will lead the final delivery of LV lead into a CS tributary, may help limit contrast use and avoid lead dislodgement at CS guide sheath removal.

METHODS AND RESULTS

In this article as a proof of concept, we describe the use of this minimalist technique as a first line approach in six patients who had standard indications for CRT. The LV lead was successfully implanted in a target vein in all patients without acute complications. Contrast was not used in half the group and the LV lead was successfully implanted without guiding catheter in four patients. The implantation technique evolved through the series and in the final patient, no guiding sheath or contrast was used. Postimplant lead positions on chest X-ray and lead parameters were stable in all patients at follow-up.

CONCLUSION

In proof of concept paper, we describe a technique of LV lead implantation potentially without the use of contrast and standard CS guiding catheters. Once familiar, this approach may provide a less complicated strategy.

Safety and Long-term Outcomes of Defibrillator Therapy in Patients With Right-Sided Implantable Cardiac Devices in Adults With Congenital Heart Disease

BACKGROUND

Implantable cardioverter-defibrillators (ICDs) have been proven to prevent sudden cardiac death in adult congenital heart disease (ACHD) patients. Although the left side is chosen by default, implantation from the right side is often required. However, little is known about the efficacy and safety of right-sided ICDs in ACHD patients.

METHODS

In this study we reviewed a total of 191 ACHD patients undergoing ICD/cardioverter resynchronisation therapy-defibrillator (CRT-D) implantation at our hospital between 2001 and 2019 (134 men and 57 women; age [mean ± standard deviation], 41.5 ± 14.8 years).

RESULTS

Twenty-seven patients (14.1%) had right-sided devices. The most common causes of right-sided implantation were persistent left superior vena cava and vein occlusion (37.0%). Although procedure time (202.8 ± 60.5 minutes vs 143.8 ± 69.1 minutes, P = 0.008) was longer and the procedural success was lower (92.6% vs 99.4%, P = 0.008) for right-sided devices, no difference in R-wave and pacing threshold were noted. Among the 47 patients (24.6%) who underwent defibrillation threshold testing (DFT), no difference in DFT was observed (25.2 ± 5.3 J vs 23.8 ± 4.1 J, P = 0.460). During the median follow-up of 42.4 months, appropriate ICD therapy was observed in 5 (18.5%) and 30 (18.3%) patients for right- and left-sided ICDs/CRTDs, respectively (P = 0.978). No significant difference was seen in complications between them.

CONCLUSIONS

Implantation of an ICD on the right side is technically challenging, but it is feasible as an alternative approach for ACHD patients with contraindications to left-sided device implantation.

Empirical mode decomposition based ECG features in classifying and tracking ventricular arrhythmias

Ventricular arrhythmias (VA) are life-threatening pathophysiological conditions that seriously impact the normal functioning of the heart. Ventricular tachycardia (VT) and ventricular fibrillation (VF) are the two well known types of VA. VF is the lethal of the VAs and could be characterized by its organizational progression over time. The success of cardiac resuscitation strongly depends on the type of VA, its evolution over time and response to therapy. Due to the time critical nature of VF, computationally efficient quantification of VAs and swift feedback are essential. This work attempted to arrive at computationally efficient and data-driven techniques based on Empirical Mode Decomposition for classifying and tracking VAs over time. The approaches are divided into two aims: (1) 'in-hospital' scenarios for characterizing the dynamics of VA episodes to assist clinicians in planning long-term therapy options, and (2) 'out-of-hospital' scenarios for providing near real-time feedback to detect/track the progression of VAs over time to assist medical personnel select/modify therapy options. Using an ECG database of 61 60-s VA segments obtained for classifying VT vs. VF and sub-classifying VF into organized VF (OVF) and disorganized VF (DVF), maximum classification accuracies of 96.7% (AUC = 0.993) and 87.2% (AUC = 0.968) were obtained for classifying VT vs. VF and OVF vs. DVF during 'in-hospital' analysis. Additionally, two near real-time approaches were presented for 'out-of-hospital' analysis where average accuracies of 71% and 73% were achieved for VT/VF and OVF/DVF classification, as well as demonstrating strong potential for monitoring VA progressions over time.

Lateral tunnel Fontan atrial tachycardia ablation trans-baffle access is not mandatory as the initial strategy

BACKGROUND

Mapping and ablation of atrial tachycardia (AT) is commonly performed in lateral tunnel Fontan (LTF) patients, yet there is little information on the need of baffle puncture to access the pulmonary venous atrium (PVA). This study aimed to evaluate the most common chamber location of critical sites for majority of AT in LTF patients.

METHODS

Consecutive LTF patients underwent catheter-based high-density mapping and ablation of AT from Nov. 2015 to Mar. 2019. Critical sites were identified by a combination of activation and entrainment mapping. Acute procedural success was defined as AT termination with ablation and non-inducibility of any AT. Predictors for ablation failure were evaluated in retrospect.

RESULTS

Fifteen catheter ablation procedures were performed in 9 patients. A total of 15 clinical ATs (mean TCL 369 ± 91 ms) were mapped. The mechanism was macro re-entry in 11 (73%) and micro re-entry in 2. In 11 ATs (73%), 94 ± 5% of tachycardia cycle length (TCL) were mapped inside the tunnel. The commonest site of successful ablation in the tunnel was on the lateral wall (60%). Trans-baffle access was obtained during 5 of 15 procedures (33%). Overall, procedural success was achieved in 9 of 15 procedures (60%). There were no complications. Recurrence of AT was 42% over a follow-up period of 4.3 ± 3.2 years. Faster TCL of 200-300 ms showed a trend towards ablation failure, (OR 17, 95% CI 0.7 to 423, p = 0.08).

CONCLUSIONS

Catheter ablation can be performed effectively for ATs in LTF patients usually from inside the tunnel. ATs with critical sites in the PVA are uncommon. This information will help plan ablation in LTF patients without resorting to initial trans-baffle access.

Arts for the Blues - a new creative psychological therapy for depression: a pilot workshop report

INTRODUCTION

Research over the last decade has identified both strengths and limitations in the use of routinely prescribed psychological therapies for depression. More recently, a focus on how creative art therapies and 'arts on prescription' are developing a growing recognition of their potential additional therapeutic mechanisms for depression.

AIM

In an attempt to develop a new therapeutic intervention for depression, this research aligned both the evidence base surrounding the arts on prescription movement, collating these with client-reported helpful factors and preferences for therapeutic interventions.

METHODS

We developed a framework for a new pluralistic 'meta-approach' of therapy for depression, based on; an interdisciplinary thematic synthesis of active ingredients, considered specific features implemented in therapy, and client-reported helpful factors considered to be the broad features or experiences in therapy from both talking therapies and creative approaches. This framework contributed to the development of a pilot workshop entitled Arts for the Blues - A New Creative Psychological Therapy for Depression. An outline of, and evaluation from this workshop is presented in this article. Workshop participants were recruited via a voluntary workshop taking place at a North West Higher Education Institution Arts and Health conference ( N = 15).

RESULTS

The workshop was evaluated using quantitative measures, with results indicating around a 70% overall satisfaction, followed up with qualitative commentary around areas of good practice and areas for development. These included the positive reflection on the application of creative arts and the multimodal nature of the approach, while others reflected on the potential overwhelming nature of utilising multimodal methods for individuals with depression.

CONCLUSION

Overall feedback from the pilot workshop is discussed in relation to prior research, giving credence to the potential for incorporating arts into therapy.

The effect of left ventricular pacing on transmural activation delay in myopathic human hearts

Aims

Left ventricular (LV) epicardial pacing (LVEpiP) in human myopathic hearts does not decrease global epicardial activation delay compared with right ventricular (RV) endocardial pacing (RVEndoP); however, the effect on transmural activation delay has not been evaluated. To characterize the transmural electrical activation delay in human myopathic hearts during RVEndoP and LVEpiP compared with global epicardial activation delay.

Methods and results

Explanted hearts from seven patients (5 male, 46 ± 10 years) undergoing cardiac transplantation were Langendorff-perfused and mapped using an epicardial sock electrode array (112 electrodes) and 25 transmural plunge needles (four electrodes, 2 mm spacing), for a total of 100 unipolar transmural electrodes. Electrograms were recorded during LVEpiP and RVEndoP, and epicardial (sock) and transmural (needle) activation times, along with patterns of activation, were compared. There was no difference between the global epicardial activation times (LVEpiP 147 ± 8 ms vs. RVEndoP 156 ± 17 ms, P = 0.46). The mean LV transmural activation time during LVEpiP was significantly shorter than that during RVEndoP (125 ± 44 vs. 172 ± 43 ms, P < 0.001). During LVEpiP, of the transmural layers endo-, mid-myocardium and epicardium, LV endocardial layer was often the earliest compared with other transmural layers.

Conclusion

In myopathic human hearts, LVEpiP did not decrease global epicardial activation delays compared with RVEndoP. LV epicardial pacing led to early activation of the LV endocardium, revealing the importance of the LV endocardium even when pacing from the LV epicardium.

Atrial tachyarrhythmia in adult congenital heart disease

The adult congenital heart disease (ACHD) population continues to grow and most cardiologists, emergency room physicians and family doctors will intermittently come into contact with these patients. Oftentimes this may be in the setting of a presentation with atrial tachyarrhythmia; one of the commonest late complications of ACHD and problem with potentially serious implications. Providing appropriate initial care and ongoing management of atrial tachyarrhythmia in ACHD patients requires a degree of specialist knowledge and an awareness of certain key issues. In ACHD, atrial tachyarrhythmia is usually related to the abnormal anatomy of the underlying heart defect and often occurs as a result of surgical scar or a consequence of residual hemodynamic or electrical disturbances. Arrhythmias significantly increase mortality and morbidity in ACHD and are the most frequent reason for ACHD hospitalization. Intra-atrial reentrant tachycardia and atrial fibrillation are the most prevalent type of arrhythmia in this patient group. In hemodynamically unstable patients, urgent cardioversion is required. Acute management of the stable patient includes anticoagulation, rate control, and electrical or pharmacological cardioversion. In ACHD, rhythm control is the preferred management strategy and can often be achieved. However, in the long-term, medication side-effects can prove problematic. Electrophysiology studies and catheter ablation are important treatments modalities and in certain cases, surgical or percutaneous treatment of the underlying cardiac defect has a role. ACHD patients, especially those with complex CHD, are at increased risk of thromboembolic events and anticoagulation is usually required. Female ACHD patients of child bearing age may wish to pursue pregnancies. The risk of atrial arrhythmias is increased during pregnancy and management of atrial tachyarrhythmia during pregnancy needs specific consideration.

Ventricular Arrhythmias in Adult Congenital Heart Disease: Mechanisms, Diagnosis, and Clinical Aspects

The risk of ventricular arrhythmias in the adult congenital heart disease population increases with age. The mechanism, type, and frequency vary depending on the complexity of the defect, whether it has been repaired, and the type and timing of repair. Risk stratification for sudden death in patients with congenital heart disease is often challenging. Current recommendations provide a useful guide for management of these patients and risk stratification continues to evolve. Internal cardiac defibrillator implantation is often challenging due to limited transvenous access, often resulting in the need for epicardial or subcutaneous devices.

When Ventricular Safety Standby Does Not Work

Dual chamber pacemakers have inbuilt advanced safety systems such as ventricular safety standby (crosstalk detection) to prevent ventricular oversensing resulting in inappropriate pacing inhibition. We describe a case where this safety mechanism does not reliably work and the management required to rectify the situation in an educational format.