Genetic causes of many familial arrhythmia syndromes remain elusive. In this study, whole‐exome sequencing (WES) was carried out on patients from three different families that presented with ...life‐threatening arrhythmias and high risk of sudden cardiac death (SCD). Two French Canadian probands carried identical homozygous rare variant in TECRL gene (p.Arg196Gln), which encodes the trans‐2,3‐enoyl‐CoA reductase‐like protein. Both patients had cardiac arrest, stress‐induced atrial and ventricular tachycardia, and QT prolongation on adrenergic stimulation. A third patient from a consanguineous Sudanese family diagnosed with catecholaminergic polymorphic ventricular tachycardia (CPVT) had a homozygous splice site mutation (c.331+1G>A) in TECRL. Analysis of intracellular calcium (Ca2+i) dynamics in human induced pluripotent stem cell‐derived cardiomyocytes (hiPSC‐CMs) generated from this individual (TECRLHom‐hiPSCs), his heterozygous but clinically asymptomatic father (TECRLHet‐hiPSCs), and a healthy individual (CTRL‐hiPSCs) from the same Sudanese family, revealed smaller Ca2+i transient amplitudes as well as elevated diastolic Ca2+i in TECRLHom‐hiPSC‐CMs compared with CTRL‐hiPSC‐CMs. The Ca2+i transient also rose markedly slower and contained lower sarcoplasmic reticulum (SR) calcium stores, evidenced by the decreased magnitude of caffeine‐induced Ca2+i transients. In addition, the decay phase of the Ca2+i transient was slower in TECRLHom‐hiPSC‐CMs due to decreased SERCA and NCX activities. Furthermore, TECRLHom‐hiPSC‐CMs showed prolonged action potentials (APs) compared with CTRL‐hiPSC‐CMs. TECRL knockdown in control human embryonic stem cell‐derived CMs (hESC‐CMs) also resulted in significantly longer APs. Moreover, stimulation by noradrenaline (NA) significantly increased the propensity for triggered activity based on delayed afterdepolarizations (DADs) in TECRLHom‐hiPSC‐CMs and treatment with flecainide, a class Ic antiarrhythmic drug, significantly reduced the triggered activity in these cells. In summary, we report that mutations in TECRL are associated with inherited arrhythmias characterized by clinical features of both LQTS and CPVT. Patient‐specific hiPSC‐CMs recapitulated salient features of the clinical phenotype and provide a platform for drug screening evidenced by initial identification of flecainide as a potential therapeutic. These findings have implications for diagnosis and treatment of inherited cardiac arrhythmias.
Synopsis
Mutations in the novel TECRL gene were identified in patients with malignant exercise‐induced arrhythmias. Increased triggered electrical activity upon stimulation in patient‐specific hiPSC‐CMs was rescued by the antiarrhythmic drug flecainide.
Trans‐2,3‐enoyl‐CoA reductase‐like (TECRL) is preferentially expressed in the heart.
Mutations in TECRL cause lethal arrhythmias in humans.
Cardiac defects in TECRL patients are characterized by overlapping features of long QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia (CPVT).
Cardiomyocytes differentiated from patient‐specific human induced pluripotent stem cells (hiPSCs) recapitulate the electrical abnormalities observed in TECRL patients.
Mutations in the novel TECRL gene were identified in patients with malignant exercise‐induced arrhythmias. Increased triggered electrical activity upon stimulation in patient‐specific hiPSC‐CMs was rescued by the antiarrhythmic drug flecainide.
Atrial arrhythmias are the most common complication encountered in the growing and aging population with congenital heart disease.
This study sought to assess the types and patterns of atrial ...arrhythmias, associated factors, and age-related trends.
A multicenter cohort study enrolled 482 patients with congenital heart disease and atrial arrhythmias, age 32.0 ± 18.0 years, 45.2% female, from 12 North American centers. Qualifying arrhythmias were classified by a blinded adjudicating committee.
The most common presenting arrhythmia was intra-atrial re-entrant tachycardia (IART) (61.6%), followed by atrial fibrillation (28.8%), and focal atrial tachycardia (9.5%). The proportion of arrhythmias due to IART increased with congenital heart disease complexity from 47.2% to 62.1% to 67.0% in patients with simple, moderate, and complex defects, respectively (p = 0.0013). Atrial fibrillation increased with age to surpass IART as the most common arrhythmia in those ≥50 years of age (51.2% vs. 44.2%; p < 0.0001). Older age (odds ratio OR: 1.024 per year; 95% confidence interval CI: 1.010 to 1.039; p = 0.001) and hypertension (OR: 2.00; 95% CI: 1.08 to 3.71; p = 0.029) were independently associated with atrial fibrillation. During a mean follow-up of 11.3 ± 9.4 years, the predominant arrhythmia pattern was paroxysmal in 62.3%, persistent in 28.2%, and permanent in 9.5%. Permanent atrial arrhythmias increased with age from 3.1% to 22.6% in patients <20 years to ≥50 years, respectively (p < 0.0001).
IART is the most common presenting atrial arrhythmia in patients with congenital heart disease, with a predominantly paroxysmal pattern. However, atrial fibrillation increases in prevalence and atrial arrhythmias progressively become permanent as the population ages.
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Eisenmenger syndrome is the most severe and extreme phenotype of pulmonary arterial hypertension associated with congenital heart disease. A large nonrestrictive systemic left-to-right shunt triggers ...the development of pulmonary vascular disease, progressive pulmonary arterial hypertension, and increasing pulmonary vascular resistance at the systemic level, which ultimately results in shunt reversal. Herein, we review the changing epidemiological patterns and pathophysiology of Eisenmenger syndrome. Multiorgan disease is an integral manifestation of Eisenmenger syndrome and includes involvement of the cardiac, hematological, neurological, respiratory, gastrointestinal, urinary, immunological, musculoskeletal, and endocrinological systems. Standardized practical guidelines for the assessment, management, risk stratification, and follow-up of this very fragile and vulnerable population are discussed. Multidisciplinary care is the best clinical practice. An approach to the prevention and management of a broad spectrum of complications is provided. Relevant therapeutic questions are discussed, including anticoagulation, noncardiac surgery, physical activity, transplantation, and advanced-care planning (palliative care). Advanced pulmonary arterial hypertension therapies are indicated in patients with Eisenmenger syndrome and World Health Organization functional class II or higher symptoms to improve functional capacity, quality of life, and—less well documented—survival. Specific recommendations regarding monotherapy or combination therapy are provided according to functional class and clinical response. The ultimate challenge for all care providers remains early detection and management of intracardiac and extracardiac shunts, considering that Eisenmenger syndrome is a preventable condition.
Le syndrome d'Eisenmenger est le phénotype le plus sévère et extrême de l'hypertension artérielle pulmonaire associée aux cardiopathies congénitales. Un important shunt gauche-droit systémique non restrictif engendre une maladie vasculaire pulmonaire, l'apparition d'une hypertension artérielle pulmonaire et la majoration des résistances vasculaires pulmonaires; les pressions pulmonaires atteignent un seuil systémique à l'origine du renversement du shunt. Cet article discute des bases physiopathologiques et du changement épidémiologique du syndrome d'Eisenmenger. L'atteinte multiviscérale est caractéristique du syndrome d'Eisenmenger impliquant le système cardio-vasculaire, hématologique, neurologique, respiratoire, gastro-intestinal, urinaire, immunologique, musculo-squelettique et endocrinien. Nous proposons des lignes directrices pratiques pour l’évaluation, la prise en charge, la stratification des risques et le suivi de cette population fragile et vulnérable. Les pratiques cliniques exemplaires recommandent des soins multidisciplinaires. Nous présentons aussi une approche pour la prévention et la prise en charge d'un grand éventail de complications et nous abordons des questions thérapeutiques pertinentes, notamment l'anticoagulothérapie, la chirurgie non cardiaque, l'activité physique, la greffe et la planification préalable des soins (soins palliatifs). Les traitements spécifiques de l'hypertension artérielle pulmonaire sont indiqués chez les patients atteints de syndrome d'Eisenmenger avec une classe fonctionnelle de II ou plus de l'Organisation mondiale de la Santé afin d'améliorer la capacité fonctionnelle, la qualité de vie, et bien que moins documentée la survie. Enfin, nous formulons des recommandations spécifiques concernant le recours à la monothérapie ou à l'association thérapeutique selon la classe fonctionnelle et la réponse clinique. Le diagnostic précoce et la prise en charge optimale des shunts intracardiaques et extracardiaques sont les défis ultimes des équipes traitantes médicales pour prévenir le syndrome d'Eisenmenger.
The Fontan procedure is the palliative procedure of choice for patients with single ventricle physiology. Pulmonary vascular disease (PVD) is an important contributor to Fontan circulatory failure.
...We review the pathophysiology of PVD in patients with Fontan palliation and share our initial experience with optical coherence tomography (OCT) in supplementing standard hemodynamics in characterizing Fontan-associated PVD. In the absence of a sub-pulmonary ventricle, low pulmonary vascular resistance (PVR; ≤2 WU/m
) is required to sustain optimal pulmonary blood flow. PVD is associated with adverse pulmonary artery (PA) remodeling resulting from the non-pulsatile low-shear low-flow circulation. Predisposing factors to PVD include impaired PA growth, endothelial dysfunction, hypercoagulable state, and increased ventricular end-diastolic pressure. OCT parameters that show promise in characterizing Fontan-associated PVD include the PA intima-to-media ratio and wall area ratio (i.e. difference between the whole-vessel area and the luminal area divided by the whole-vessel area).
OCT carries potential in characterizing PVD in patients with Fontan palliation. PA remodeling is marked by intimal hyperplasia, with medial regression. Further studies are required to determine the role of OCT in informing management decisions and assessing therapeutic responses.
Fontan palliation results in a hemodynamically complex circulation with multisystem consequences, which in the long term adversely affect many body processes. Systemic venous hypertension, ...nonpulsatile low-shear pulmonary blood flow, and low cardiac output are the 3 main characteristics of a Fontan circulation, leading to unavoidable slowly progressive failure. An appreciation of how the hemodynamics of a Fontan circulation change with time and relate to the various modes of Fontan circulatory failure is important. Accurate hemodynamic assessment aid this understanding and may permit early identification of potentially treatable drivers of decline. While no evidence-based or guideline-directed pharmacologic management strategy has been established in Fontan patients, understanding the hemodynamics of Fontan circulation failure will assist in the rational selection of potentially helpful drug therapies for individual patients. In this review, we present hemodynamic concepts of the optimal Fontan physiology and Fontan circulatory failure, review practical aspects of invasive hemodynamic assessment, and discuss the role of drug therapies in increasing systemic venous blood flow return and decreasing ventricular filling pressures in Fontan circulation. Often complementary to catheter-based or surgical interventions, pharmacologic management aims at preserving patency of the circuit, adequate systolic and diastolic ventricular function, atrioventricular valve function, an unobstructed ventricular outflow tract, and pulmonary vascular integrity in order to maintain an acceptable cardiac output.
L’intervention de Fontan donne lieu à une circulation complexe sur le plan hémodynamique ayant des répercussions multisystémiques qui, à long terme, nuisent à de nombreuses fonctions de l’organisme. L’hypertension veineuse systémique, le flux sanguin pulmonaire non pulsatile à faible contrainte de cisaillement et le bas débit cardiaque sont les trois principales caractéristiques d’une circulation de Fontan entrainant inévitablement une défaillance à évolution lente. Il importe de comprendre comment les caractéristiques hémodynamiques de la circulation de Fontan changent au fil du temps et de cerner leur rôle dans les différentes formes d’insuffisance circulatoire. Une évaluation hémodynamique complète peut permettre la détection précoce de facteurs de déclin qui pourraient être traitables. Aucune stratégie de prise en charge pharmacologique fondée sur des données probantes ou sur des lignes directrices n’a été établie chez les patients qui ont subi l’intervention de Fontan. Néanmoins, la compréhension des mécanismes hémodynamiques de l’insuffisance circulatoire observée après cette intervention peut guider le clinicien dans les choix de traitements médicamenteux susceptibles de répondre aux besoins de chaque patient. Dans le présent article de synthèse des données contemporaines, nous présentons les concepts hémodynamiques touchant les caractéristiques physiologiques optimales et l’insuffisance circulatoire dans le contexte de la circulation de Fontan. Nous passons aussi en revue les aspects pratiques d’une évaluation hémodynamique. Enfin, nous abordons le recours à des traitements médicamenteux visant à augmenter le retour veineux systémique et à réduire la pression de remplissage ventriculaire chez les patients ayant subi l’intervention de Fontan. Souvent instauré en complément d’une intervention chirurgicale ou par cathétérisme, le traitement médicamenteux vise à préserver la perméabilité du circuit, la fonction ventriculaire systolique et diastolique, la fonction de la valve atrioventriculaire, l’absence d’obstruction de la chambre de chasse du ventricule gauche et l’intégrité du système vasculaire pulmonaire afin de maintenir un débit cardiaque acceptable.
Background
There is a paucity of data regarding late‐onset pulmonary hypertension (PH) in patients with transposition of the great arteries and atrial switch surgery.
Methods and Results
A ...retrospective cohort study was conducted on 140 adults with transposition of the great arteries and atrial switch surgery, age 37.3±7.8, 37.1% female, in order to assess the prevalence and characteristics of late‐onset PH and explore associated factors. Patients were followed for a median of 32.3 years after atrial switch surgery and 10.0 years after their first referral visit. PH was detected in 18 of 33 (54.5%) patients who had invasive hemodynamic studies. Average age at diagnosis of PH was 33.9±8.1 years. PH was postcapillary in all, with a mean pulmonary artery pressure of 36±12 mm Hg and mean pulmonary capillary wedge pressure of 28±8 mm Hg. PH was diagnosed in 13 of 17 (76.5%) patients who had cardiac catheterization for heart failure or decreased exercise tolerance. In multivariable analyses, systemic hypertension (odds ratio 9.4, 95% confidence interval 2.2‐39.4, P=0.002) and heart failure or New York Heart Association class III or IV symptoms (odds ratio 49.8, 95% confidence interval 8.6‐289.0, P<0.001) were independently associated with PH. Patients with PH were more likely to develop cardiovascular comorbidities including atrial (P=0.001) and ventricular (P=0.008) arrhythmias, require hospitalizations for heart failure (P<0.001), and undergo tricuspid valve surgery (P<0.001). Mortality was significantly higher in patients with PH (hazard ratio 9.4, 95% confidence interval 2.1‐43.0, P<0.001).
Conclusions
Late‐onset postcapillary PH is highly prevalent in adults with transposition of the great arteries and atrial switch surgery and is associated with an adverse prognosis.
Fenestrating a Fontan baffle has been associated with improved perioperative outcomes in patients with univentricular hearts. However, longer-term potential adverse effects remain debated. We sought ...to assess the impact of a fenestrated Fontan baffle on adverse cardiovascular events including all-cause mortality, cardiac transplantation, atrial arrhythmias, and thromboemboli.
A multicentre North American retrospective cohort study was conducted on patients with total cavopulmonary connection Fontan baffle, with and without fenestration. All components of the composite outcome were independently adjudicated. Potential static and time-varying confounders were taken into consideration, along with competing risks.
A total of 407 patients were followed for 10.4 (7.1-14.4) years; 70.0% had fenestration of their Fontan baffle. The fenestration spontaneously closed or was deliberately sealed in 79.9% of patients a median of 2.0 years after Fontan completion. In multivariable analysis in which a persistent fenestration was modelled as a time-dependent variable, an open fenestration did not confer a higher risk of the composite outcome (hazard ratio, 1.18; 95% confidence interval, 0.71-1.97; P = 0.521). In secondary analyses, an open fenestration was not significantly associated with components of the primary outcome: that is, mortality or transplantation, atrial arrhythmias, or thromboemboli. However, sensitivity analyses to assess the possible range of error resulting from imprecise dates for spontaneous fenestration closures could not rule out significant associations between an open fenestration and atrial arrhythmias or thromboemboli.
In this multicentre study, no significant association was identified between an open fenestration in the Fontan baffle and major adverse cardiovascular events.
Congenital heart disease(CHD) is the most common type of birth defect. Traditionally, a polygenic model defined by the interaction of multiple genes and environmental factors was hypothesized to ...account for different forms of CHD. It is now understood that the contribution of genetics to CHD extends beyond a single unified paradigm. For example, monogenic models and chromosomal abnormalities have been associated with various syndromic and non-syndromic forms of CHD. In such instances, genetic investigation and testing may potentially play an important role in clinical care. A family tree with a detailed phenotypic description serves as the initial screening tool to identify potentially inherited defects and to guide further genetic investigation. The selection of a genetic test is contingent upon the particular diagnostic hypothesis generated by clinical examination. Genetic investigation in CHD may carry the potential to improve prognosis by yielding valuable information with regards to personalized medical care, confidence in the clinical diagnosis, and/or targeted patient followup. Moreover, genetic assessment may serve as a tool to predict recurrence risk, define the pattern of inheritance within a family, and evaluate the need for further family screening. In some circumstances, prenatal or preimplantation genetic screening could identify fetuses or embryos at high risk for CHD. Although genetics may appear to constitute a highly specialized sector of cardiology, basic knowledge regarding inheritance patterns, recurrence risks, and available screening and diagnostic tools, including their strengths and limitations, could assist the treating physician in providing sound counsel.
Arrhythmias and heart failure are among the most common complications encountered by adults with congenital heart disease (CHD). In this contemporary review, we explore the interactions between ...arrhythmias and heart failure and discuss management strategies. Major knowledge gaps are highlighted throughout. Interactions between arrhythmias and heart failure are complex and bidirectional, with one begetting the other. Arrhythmias can provoke heart failure through various mechanisms: conduction disturbances may contribute to inefficient ventricular filling and contraction patterns; bradyarrhythmias and tachyarrhythmias can result in a reduction in cardiac output; hypoxemia may be exacerbated by right-to-left shunting; and tachycardia-induced cardiomyopathy has potentially devastating consequences if the diagnosis is delayed. In turn, heart failure promotes arrhythmogenesis through various structural (eg, fibrosis, chamber dilation, hypertrophy) and electrical remodeling effects that include changes to ion currents and channels and connexin expression, along with shortening of atrial and ventricular refractory periods with increased heterogeneity. Several shared comorbidities can contribute to, and modulate the impact of, arrhythmias and heart failure. Preemptive arrhythmia management can potentially mitigate effects on heart failure exacerbations. Similarly, optimal heart failure control could curtail its impact on arrhythmogenesis. Treatment strategies to prevent or treat heart failure in adults with CHD encompass pharmacological agents, catheter ablation, and device therapies including defibrillators, cardiac resynchronization therapy, and His bundle pacing. High-priority research avenues with major knowledge gaps include tachycardia-induced cardiomyopathy, catheter ablation of atrial fibrillation, defibrillator indications in high-risk subsets, and the role of cardiac resynchronization therapy and His bundle pacing in diverse forms of CHD.
Abstract Exercise capacity in adults with various forms of congenital heart disease is substantially lower than that of the general population. Although the underlying congenital heart defect, and ...its sequelae, certainly contribute to observed exercise limitations, there is evidence suggesting that deconditioning and a sedentary lifestyle are important implicated factors. The prevalence of acquired cardiovascular comorbidities is on the increase in the aging population with congenital heart disease, such that obesity and a sedentary lifestyle confer increased risk. Health fears and misconceptions are common barriers to regular physical activity in adults with congenital heart disease, despite evidence linking lower functional capacity to poor outcomes, and data supporting the safety and efficacy of exercise in bestowing numerous physical and psychosocial rewards. With few exceptions, adults with congenital heart disease should be counselled to exercise regularly. In this contemporary review, we provide a practical approach to assessing adults with congenital heart disease before exercise training. We examine available evidence supporting the safety and benefits of exercise training. Risks associated with exercise training in adults with congenital heart disease are discussed, particularly with regard to sudden cardiac death. Finally, recommendations for exercise training are provided, with consideration for the type of congenital heart disease, the nature (ie, static vs dynamic) and intensity (ie, low, medium, high) of the physical activity, and associated factors such as systemic ventricular dysfunction and residual defects. Further research is required to determine optimal exercise regimens and to identify effective strategies to implement exercise training as a key determinant of healthy living.
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