Utility of noninvasive arrhythmia mapping in patients with adult congenital heart disease

Medical Emergencies in Pulmonary Hypertension

The management of acute medical emergencies in patients with pulmonary hypertension (PH) can be challenging. Patients with preexisting PH can rapidly deteriorate due to right ventricular decompensation when faced with acute physiological challenges that would usually be considered low-risk scenarios. This review considers the assessment and management of acute medical emergencies in patients with PH, encompassing both pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH), acknowledging these comprise the more severe groups of PH. Management protocols are described in a systems-based approach. Respiratory emergencies include pulmonary embolism, airways disease, and pneumonia; cardiac emergencies including arrhythmia and chest pain with acute myocardial infarction are discussed, alongside PH-specific emergencies such as pulmonary artery dissection and extrinsic coronary artery compression by a dilated proximal pulmonary artery. Other emergencies including sepsis, severe gastroenteritis with dehydration, syncope, and liver failure are also considered. We propose management recommendations for medical emergencies based on available evidence, international guidelines, and expert consensus. We aim to provide advice to the specialist alongside the generalist, and emergency doctors, nurses, and acute physicians in nonspecialist centers. A multidisciplinary team approach is essential in the management of patients with PH, and communication with local and specialist PH centers is paramount. Close hemodynamic monitoring during medical emergencies in patients with preexisting PH is vital, with early referral to critical care recommended given the frequent deterioration and high mortality in this setting.

Noninvasive ECG imaging of the intrinsic atrial pacemaker and atrial activation in surgically repaired or palliated congenital heart disease

INTRODUCTION

Sinus node location, function, and atrial activation are often abnormal in patients with congenital heart disease (CHD), due to anatomical, surgical, and acquired factors. We aimed to perform noninvasive electrocardiographic imaging (ECGI) of the intrinsic atrial pacemaker and atrial activation in patients with surgically repaired or palliated CHD, compared with control patients with structurally normal hearts.

METHODS AND RESULTS

Atrial ECGI was performed in eight CHD patients with prespecified diagnoses (Fontan circulation, dextro transposition of the great arteries post Mustard/Senning, tetralogy of Fallot), and three controls. Activation and propagation maps were constructed in presenting rhythm. Wavefront propagation was analyzed to identify (1) intrinsic atrial pacemaker breakout site, (2) morphological right atrial (RA) activation pattern, (3) morphological left atrial (LA) breakout sites (i.e., interatrial connections), (4) LA activation pattern, and (5) putative lines of block. Physiologically appropriate atrial activation and propagation maps were able to be constructed. In the majority of patients, atrial breakouts were in keeping with the sinus node, observed in a crescent-shaped distribution from the anterior superior vena cava to the posterior RA. Ectopic atrial pacemaker sites were demonstrated in the atriopulmonary (AP) Fontan patient (very diffuse posterolateral RA) and Mustard patient (very posterior RA competing with a low RA focus). RA propagation was laminar in controls, but suggested either a line of block or conduction slowing consistent with an atriotomy scar in the tetralogy of Fallot (TOF) patients. Putative lines of block were more complex and RA propagation more abnormal in the atrial switch and AP Fontan patients, compared with the TOF patients. RA activation in the extracardiac Fontan patients was relatively laminar. Earliest LA breakout was most commonly observed in the region of Bachmann's Bundle in both controls and CHD patients, except for posterior LA breakouts in two patients. LA activation was typically more homogeneous than RA activation in CHD patients.

CONCLUSION

ECGI can be utilized to create a noninvasive mapping model of atrial activation in postsurgical CHD, demonstrating atrial pacemaker location, putative lines of block and interatrial connections. Once validated invasively, this may have clinical implications in predicting risk of sinus node dysfunction and atrial arrhythmias, or in guiding catheter ablation.

Lifespan Perspective on Congenital Heart Disease Research: JACC State-of-the-Art Review

More than 90% of patients with congenital heart disease (CHD) are nowadays surviving to adulthood and adults account for over two-thirds of the contemporary CHD population in Western countries. Although outcomes are improved, surgery does not cure CHD. Decades of longitudinal observational data are currently motivating a paradigm shift toward a lifespan perspective and proactive approach to CHD care. The aim of this review is to operationalize these emerging concepts by presenting new constructs in CHD research. These concepts include long-term trajectories and a life course epidemiology framework. Focusing on a precision health, we propose to integrate our current knowledge on the genome, phenome, and environome across the CHD lifespan. We also summarize the potential of technology, especially machine learning, to facilitate longitudinal research by embracing big data and multicenter lifelong data collection.

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.

An initial experience of high-density mapping-guided ablation in a cohort of patients with adult congenital heart disease

Aims

In the management of both ventricular and supraventricular tachycardia in patients with congenital heart disease (CHD) catheter ablation has now been recognized as one of the mainstays.

Methods and results

We review our initial experience of using the Rhythmia mapping system in a cohort of 12 adult CHD patients presenting with multiple arrhythmia substrates. A total of 78 arrhythmia maps were attempted in a total of 15 procedures, but possible due to the dilatation of the target chamber only 44% of maps were able to reconstruct the entire arrhythmia. All patients underwent pre-procedure 3D imaging (either cardiac magnetic resonance or computed tomography), but image integration was suboptimal. A median of two maps per patient were finally analysed and acquisition took in median 22 min with a median number of 12 574 (8230–18 167) mapping points. Procedural data with a total duration amounting to in median 285 (194–403) min, with a median total fluoroscopy exposure of 7.5 (5.2–10.7) min. After a median of 1.5 procedures [median of 12 (8–16 months)], nine patients remained in stable sinus rhythm or atrial paced rhythm, while three patients had further sustained recurrences. One of these passed away in end-staged heart failure.

Conclusion

This initial experience of using high-density mapping for arrhythmia management in patients with CHD allowed rapid acquisition of multiple maps with high accuracy to identify surgical scars and fibrosis, however, it was limited by large atrial volumes and a high percentage of incomplete maps resulting in modest clinical success.

Catheter Ablation of Atrial Fibrillation: State of the Art and Future Perspectives

PURPOSE OF REVIEW

Atrial fibrillation (AF), the most common sustained arrhythmia, is associated with high rates of morbidity and mortality. Maintenance of stable sinus rhythm (SR) is the intended treatment target in symptomatic patients, and catheter ablation aimed at isolating the pulmonary veins provides the most effective treatment option, supported by encouraging clinical outcome data. A variety of energy sources and devices have been developed and evaluated. In this review, we summarize the current state of the art of catheter ablation of AF and describe future perspectives.

RECENT FINDINGS

Catheter ablation is a well-established treatment option for patients with symptomatic AF and is more successful at maintaining SR than antiarrhythmic drugs. Antral pulmonary vein isolation (PVI) as a stand-alone ablation strategy results in beneficial clinical outcomes and is therefore recommended as first-line strategy for both paroxysmal and persistent AF. While radiofrequency-based PVI in conjunction with a three-dimensional mapping system was for many years considered to be the "gold standard", the cryoballoon has emerged as the most commonly used alternative AF ablation tool, especially in patients with paroxysmal AF. Patients with persistent or long-standing persistent AF and with arrhythmia recurrence after previous PVI may benefit from additional ablation strategies, such as substrate modification of various forms or left atrial appendage isolation. New technologies and techniques, such as identification of the AF sources and magnetic resonance imaging-guided substrate modification, are on the way to further improve the success rates of catheter ablation for selected patients and might help to further reduce arrhythmia recurrence.

CONCLUSIONS

Pulmonary vein isolation is the treatment of choice for symptomatic patients with paroxysmal and persistent drug-refractory AF. The reconnection of previously isolated pulmonary veins remains the major cause of AF recurrence. Novel ablation tools, such as balloon technologies or alternative energy sources, might help to overcome this limitation. Patients with non-paroxysmal AF and with AF recurrence might benefit from alternative ablation strategies. However, further studies are warranted to further improve our knowledge of the underlying mechanisms of AF and to obtain long-term clinical outcomes on new ablation techniques.

Catheter ablation for patients with end-stage complex congenital heart disease or cardiomyopathy considered for transplantation: Trials and tribulations

INTRODUCTION

Arrhythmia contributes significantly to morbidity and mortality of patients with congenital heart disease (CHD) or cardiomyopathy (CMP). It also has the potential to worsen symptoms and is particularly detrimental to patients with advanced heart failure awaiting cardiac transplantation. We report our experience using catheter ablation to treat recurrent arrhythmia in patients with CHD or CMP considered for transplantation.

METHODS

Five consecutive patients (3 female, mean age 47.8 ± 12.8 years) with complex CHD or CMP (tricuspid atresia, mitral atresia, double inlet left ventricle, arrhythmogenic right ventricular cardiomyopathy, left ventricular non-compaction) presented with either atrial (n = 3) or ventricular (n = 2) arrhythmias. All ablations were guided by three-dimensional (3D) electro-anatomical mapping, plus remote magnetic navigation in 3 patients.

RESULTS

Patients underwent a median of 2 ablation procedures for a total number of 26 tachycardias. None of the 5 patients experienced further arrhythmia at a median of 939 days (range 4-1375) from their last ablation. During a median follow up of 31 months (range 1-70), three patients underwent successful transplantation at 1375, 1062 and 321 days following their last ablation. One patient with a Fontan circulation died from hepatic cancer and one from end-stage heart failure despite urgent transplant listing.

CONCLUSIONS

Catheter ablation is feasible in complex cardiac patients considered for heart transplantation and should be offered for rhythm management and patient optimization until a suitable donor is found.

Missing pouches in high-density mapping of atrial tachyarrhythmia in congenital heart diseases

BACKGROUND

The use of high-density electroanatomical mapping in the Chinese population for congenital heart disease (CHD) is not well reported.

METHODS

Retrospective review of consecutive transcatheter ablation of atrial tachyarrhythmia using high-density mapping for CHD patients (at least moderate complexity) in the only tertiary congenital heart center in the territory from January 2017 to January 2019 was conducted. Orion mapping catheter in Rhythmia system (Boston Scientific) was used to create activation and voltage maps. Parameters including mechanism of arrhythmia, acute success, and follow-up data were recorded.

RESULTS

Eight patients were identified (median age 35.5 years) who underwent transcatheter ablation of atrial arrhythmia. More than one reentry circuits of IART were identified in five patients. It took a median of 32.4 minutes with 15,952 (IQR 13,395-18,530) mapping points per map. Cavo-annulus isthmus-dependent mechanism was the predominant reentry mechanism. Acute success with the elimination of all inducible tachycardia was achieved in six patients (75%), and partial success in two patients. There was recurrence of atrial arrhythmia in four patients (50%), in which three patients could be maintained in sinus rhythm with low-dose antiarrhythmic medication. Targeted substrate ablation was performed in six patients with multiple IART circuits. Critical anatomical pouches were identified in three patients, which were missed in the initial mapping using Orion basket mapping catheter.

CONCLUSIONS

High acute success rate of atrial arrhythmia ablation can be achieved using high-density anatomical mapping in CHD. Substrate ablation was required with multiple IART circuits identified. Vigilance should be sought to identify anatomical pouches.

Advanced mapping strategies for ablation therapy in adults with congenital heart disease

Background

Ultra-high density mapping (HDM) is a promising tool in the treatment of patients with complex arrhythmias. In adults with congenital heart disease (CHD), rhythm disorders are among the most common complications but catheter ablation can be challenging due to heterogenous anatomy and complex arrhythmogenic substrates. Here, we describe our initial experience using HDM in conjunction with novel automated annotation algorithms in patients with moderate to great CHD complexity.

Methods

We studied a series of consecutive adult patients with moderate to great CHD complexity and an indication for catheter ablation due to symptomatic arrhythmia. HDM was conducted using the Rhythmia™ mapping system and a 64-electrode mini-basket catheter for identification of anatomy, voltage, activation pattern and critical areas of arrhythmia for ablation guidance. To investigate novel advanced mapping strategies, postprocedural signal processing using the Lumipoint™ software was applied.

Results

In 19 patients (53±3 years; 53% male), 21 consecutive ablation procedures were conducted. Procedures included ablation of atrial fibrillation (n=7; 33%), atrial tachycardia (n=11; 52%), atrioventricular accessory pathway (n=1; 5%), the atrioventricular node (n=1; 5%) and ventricular arrhythmias (n=4; 19%). A total of 23 supraventricular and 8 ventricular arrhythmias were studied with the generation of 56 complete high density maps (atrial n=43; ventricular n=11, coronary sinus n=2) and an average of 12,043±1,679 mapping points. Multiple arrhythmias were observed in n=7 procedures (33% of procedures; range of arrhythmias detected 2-4). A total range of 1-4 critical areas were defined per procedure and treated within a radiofrequency application time of 16 (interquartile range 12-45) minutes. Postprocedural signal processing using Lumipoint™ allowed rapid annotation of fractionated signals within specific windows of interest. This supported identification of a practical critical isthmus in 20 out of 27 completed atrial and ventricular tachycardia activation maps.

Conclusions

Our findings suggest that HDM in conjunction with novel automated annotation algorithms provides detailed insights into arrhythmia mechanisms and might facilitate tailored catheter ablation in patients with moderate to great CHD complexity.

Noninvasive Mapping and Electrocardiographic Imaging in Atrial and Ventricular Arrhythmias (CardioInsight)

Electrocardiographic imaging is a mapping technique aiming to noninvasively characterize cardiac electrical activity using signals collected from the torso to reconstruct epicardial potentials. Its efficacy has been demonstrated clinically, from mapping premature ventricular complexes and accessory pathways to of complex arrhythmias. Electrocardiographic imaging uses a standardized workflow. Signals should be checked manually to avoid automatic processing errors. Reentry is confirmed in the presence of local activation covering the arrhythmia cycle length. Focal breakthroughs demonstrate a QS pattern associated with centrifugal activation. Electrocardiographic imaging offers a unique opportunity to better understand the mechanism of cardiac arrhythmias and guide ablation.

Catheter Ablation: General Principles and Advances

Besides antiarrhythmic medication, there are now very good options for a potentially curative therapy by catheter ablation targeting the origin of the underlying arrhythmias in patients with complex congenital heart disease. Three-dimensional (3D) reconstruction of tomographic imaging (MRI or computed tomography) is helpful to understand the underlying cardiac anatomy, identify the most likely target chamber, and help with planning access. Use of the available 3D mapping systems (sequential or simultaneous acquisition) and (if available) more advanced navigation systems, such as remote magnetic navigation, can improve the acute and long-term outcomes of catheter ablation in congenital heart disease.

Health Care Costs for Adults With Congenital Heart Disease in the United States 2002 to 2012

More adults than children with congenital heart disease (CHD) are alive today. Few studies have evaluated adult congenital heart disease (ACHD) health care utilization in the United States. Data from the National Inpatient Sample from 2002 to 2012, using International Classification of Diseases, Ninth Revision, codes for moderate and complex CHD were analyzed. Hospital discharges, total billed and reimbursed amounts, length of stay, and gender/age disparities were evaluated. There was an increase in CHD discharges (moderate CHD: 4,742 vs 6,545; severe CHD: 807 vs 1,115) and total billed and reimbursed dollar amounts across all CHD (billed: $2.7 vs $7.0 billion, 155% increase; reimbursed: $1.3 vs $2.3 billion, 99% increase) and in the ACHD subgroup (billed: $543 million vs $1.5 billion, 178% increase; reimbursed: $221 vs $433 million, 95% increase). Women comprised more discharges in 2002 but not in 2012 (men:women, 2002: 6,503 vs 7,805; 2012: 7,715 vs 7,200, p = 0.39). Gender-based billed amounts followed similar trends (2002: $263 vs $280 million; 2012: $845 vs $662 million, p = 0.006) as did reimbursements (2002: $108 vs $114 million; 2012: $243 vs $190 million, p = 0.008). All age subgroups demonstrated increased health care expenditures, including the >44 versus 18- to 44-year-old age subgroup (billed: $618 vs $347 million, p <0.001; reimbursed: $136 vs $75 million, p <0.001). Our results reveal increased ACHD billed and reimbursed amounts and hospital discharges with a shift in gender-based ACHD hospitalizations: men now account for more hospitalizations in the United States. In conclusion, increased health care expenditure in older patients with ACHD is likely to increase further as health care system use and costs continue to grow.

[Arrhythmia in adults with congenital heart defects : Atrial tachycardia]

Atrial arrhythmias are frequently encountered in patients with congenital heart disease (CHD) with or without corrective surgery and respond to pharmacological therapies with only limited success. This review describes the technologies currently available for performing successful ablation procedures in this very complex patient cohort. In addition to an understanding of the underlying anatomy, which can be supplemented by 3D imaging with the aid of magnetic resonance imaging (MRI) or computed tomography (CT), the choice between the different 3D mapping systems (sequential versus simultaneous) is presented. Finally, conventional manual navigation is compared with magnetic navigation and then discussed with regard to the respective arrhythmias encountered with the different forms of CHD.

Catheter Ablation to Treat Supraventricular Arrhythmia in Children and Adults With Congenital Heart Disease: What We Know and Where We Are Going

BACKGROUND

Catheter ablation has been used to manage supraventricular arrhythmia in children since 1990. This article reviews the history of catheter ablation used to treat arrhythmia in children and discusses new frontiers in the field. We also address ablation in adult patients with a history of congenital heart disease (CHD) that was diagnosed and initially treated in childhood.

METHODS

We conducted an evidence-based literature review to gather available data on ablation for supraventricular tachycardia in children and adult patients with CHD.

RESULTS

Ablations can be performed safely and effectively in children. Complication rates are higher in children <4 years and <15 kg. In one study, the overall success rate of radiofrequency ablation in pediatrics was 95.7%, with the highest success rate in left free wall pathways (97.8%). Recurrence was higher in septal pathways. Cryoablation has been reported to have a 93% acute success rate for atrioventricular (AV) nodal reentrant tachycardia and septal pathways with no risk of AV block and a 5%-9% risk of recurrence. Three-dimensional mapping, intracardiac echocardiography, remote magnetic navigation, and irrigated catheter ablation are new technologies used to treat pediatric and adult patients with CHD. The population of adult patients with CHD is growing, and these patients are at particularly high risk for arrhythmia. A paucity of data is available on ablation in adult patients with CHD.

CONCLUSION

Electrophysiology for pediatric and adult patients with CHD is a rapidly growing and progressing field. We benefit from continuous development of ablation techniques for adults with structurally normal hearts and have the unique challenge and responsibility to ensure the safe and effective application of these techniques in the vulnerable population of pediatric and adult patients with CHD.