Catheter ablation of atrial arrhythmias in cardiac amyloidosis: Impact on heart failure and mortality.

BACKGROUND: Atrial arrhythmias (AA) commonly affect patients with cardiac amyloidosis (CA) and are a contributing risk factor for the development of heart failure (HF). This study sought to investigate the long-term efficacy and impact of catheter ablation on HF progression in patients with CA and AA. METHODS: Thirty-one patients with CA and AA undergoing catheter ablation were retrospectively included (transthyretin-ATTR CA 61% and light chain-AL CA 39%). AA subtypes included atrial fibrillation (AFib) in 22 (paroxysmal in 10 and persistent in 12), atrial flutter (AFl) in 17 and atrial tachycardia (AT) in 11 patients. Long-term AA recurrence rates were evaluated along with the impact of sinus rhythm (SR) maintenance on HF and mortality. RESULTS: AA recurrence was observed in 14 patients (45%) at a median of 3.5 months (AFib n = 8, AT n = 6, AFl = 0). Post-cardioversion, medical therapy or catheter ablation, 10 patients (32%) remained in permanent AA. Over a median follow-up of 19 months, all-cause mortality was 39% (n = 12): 3 with end-stage HF, 5 due to late complications of CA, 1 sudden cardiac death, 1 stroke, 1 COVID 19 (and one unknown). With maintenance of SR following catheter ablation, significant reductions in serum creatinine and natriuretic peptide levels were observed with improvements in NYHA class. Two patients required hospitalization for HF in the SR maintenance cohort compared to 5 patients in the AA recurrence cohort (p = 0.1). All 3 patients with deaths secondary to HF had AA recurrence compared to 11 out of the 28 patients whom were long-term survivors or deaths not related to HF (p = 0.04). All-cause mortality was not associated with AA recurrence. CONCLUSION: This study demonstrates moderate long-term efficacy of SR maintenance with catheter ablation for AA in patients with CA. Improvements in clinical and biological status with positive trends in HF mortality are observed if SR can be maintained.

Ventricular Tachycardia Ablation in Patients With Desmoplakin Cardiomyopathy.

BACKGROUND: Desmoplakin (DSP) pathogenic variants are rare causes of arrhythmogenic cardiomyopathy and often involve the right and left ventricles. Ventricular tachycardia (VT) ablations may be required in these patients, but procedural characteristics have not been reported. OBJECTIVES: In this study, the authors sought to report a multicenter experience of VT ablation in patients with DSP pathogenic variants. METHODS: VT ablations performed in patients with known DSP pathogenic variants were analyzed across 6 centers in 3 countries. Patient characteristics and acute and long-term procedural outcomes were reported. RESULTS: A total of 20 patients (13 men, median age 43 years [Q1-Q3: 41.5-53.0 years], left ventricular ejection fraction 43.0% [Q1-Q3: 41.5%-53.0%], 11 previous failed ablations) were referred for VT ablation procedures. All patients had symptomatic VTs, with ICD therapy in 19 patients. Epicardial procedures were performed in 16 of the 20 patients. VT target sites were located in the right ventricular (RV) endocardium (n = 11), the RV epicardium (n = 4), the left ventricular (LV) endocardium (n = 2) and the LV epicardium (n = 7). In 3 patients, the VT target sites were in close proximity to coronary arteries, limiting ablation. During follow-up, VTs recurred in 11 patients, and repeated ablations were performed in 9 patients. Allowing for multiple procedures, 19 of the 20 patients remained free of VT recurrence after a median follow-up of 18 months [Q1-Q3: 5-60 months]. CONCLUSIONS: Patients with DSP cardiomyopathy often have biventricular involvement, and ablation procedures often require ablation in both ventricles and the epicardium. Recurrences are not uncommon, and the pathologic substrate can be located in close proximity to epicardial coronary arteries, limiting the success rate of ablations.

Lack of temporal correlations between COVID pandemic waves and the occurrence of malignant ventricular arrhythmias.

AIMS: Correlations between malignant ventricular arrhythmias and the COVID waves have never been investigated. METHODS AND RESULTS: Prevalence of malignant ventricular arrhythmias/sudden cardiac death has been correlated to the four COVID waves between the onset of pandemic and end 2021. No significant correlation was present in the temporal evolution of both COVID patients/positive tests and incidence of malignant ventricular arrhythmias, which tended to decrease after vaccination onset. CONCLUSION: We present evidence of complex higher-order periodicities and the co-existence of such regions with stable non-chaotic areas in ex vivo human hearts. We infer that the oscillation of the calcium cycling machinery is the primary mechanism of higher-order dynamics. These higher-order regions may act as niduses of instability and may provide targets for substrate-based ablation of VF.

A worldwide survey on incidence, management, and prognosis of oesophageal fistula formation following atrial fibrillation catheter ablation: the POTTER-AF study.

AIMS: Oesophageal fistula represents a rare but dreadful complication of atrial fibrillation catheter ablation. Data on its incidence, management, and outcome are sparse. METHODS AND RESULTS: This international multicentre registry investigates the characteristics of oesophageal fistulae after treatment of atrial fibrillation by catheter ablation. A total of 553 729 catheter ablation procedures (radiofrequency: 62.9%, cryoballoon: 36.2%, other modalities: 0.9%) were performed, at 214 centres in 35 countries. In 78 centres 138 patients [0.025%, radiofrequency: 0.038%, cryoballoon: 0.0015% (P < 0.0001)] were diagnosed with an oesophageal fistula. Peri-procedural data were available for 118 patients (85.5%). Following catheter ablation, the median time to symptoms and the median time to diagnosis were 18 (7.75, 25; range: 0-60) days and 21 (15, 29.5; range: 2-63) days, respectively. The median time from symptom onset to oesophageal fistula diagnosis was 3 (1, 9; range: 0-42) days. The most common initial symptom was fever (59.3%). The diagnosis was established by chest computed tomography in 80.2% of patients. Oesophageal surgery was performed in 47.4% and direct endoscopic treatment in 19.8% and conservative treatment in 32.8% of patients. The overall mortality was 65.8%. Mortality following surgical (51.9%) or endoscopic treatment (56.5%) was significantly lower as compared to conservative management (89.5%) [odds ratio 7.463 (2.414, 23.072) P < 0.001]. CONCLUSION: Oesophageal fistula after catheter ablation of atrial fibrillation is rare and occurs mostly with the use of radiofrequency energy rather than cryoenergy. Mortality without surgical or endoscopic intervention is exceedingly high.

Recurrences of Atrial Fibrillation Despite Durable Pulmonary Vein Isolation: The PARTY-PVI Study.

BACKGROUND: Recurrences of atrial fibrillation (AF) after pulmonary vein isolation (PVI) are mainly due to pulmonary vein reconnection. However, a growing number of patients have AF recurrences despite durable PVI. The optimal ablative strategy for these patients is unknown. We analyzed the impact of current ablation strategies in a large multicenter study. METHODS: Patients undergoing a redo ablation for AF and presenting durable PVI were included. The freedom from atrial arrhythmia after pulmonary vein-based, linear-based, electrogram-based, and trigger-based ablation strategies were compared. RESULTS: Between 2010 and 2020, 367 patients (67% men, 63±10 years, 44% paroxysmal) underwent a redo ablation for AF recurrences despite durable PVI at 39 centers. After durable PVI was confirmed, linear-based ablation was performed in 219 (60%) patients, electrogram-based ablation in 168 (45%) patients, trigger-based ablation in 101 (27%) patients, and pulmonary vein-based ablation in 56 (15%) patients. Seven patients (2%) did not undergo any additional ablation during the redo procedure. After 22±19 months of follow-up, 122 (33%) and 159 (43%) patients had a recurrence of atrial arrhythmia at 12 and 24 months, respectively. No significant difference in arrhythmia-free survival was observed between the different ablation strategies. Left atrial dilatation was the only independent factor associated with arrhythmia-free survival (HR, 1.59 [95% CI, 1.13-2.23]; P=0.006). CONCLUSIONS: In patients with recurrent AF despite durable PVI, no ablation strategy used alone or in combination during the redo procedure appears to be superior in improving arrhythmia-free survival. Left atrial size is a significant predictor of ablation outcome in this population.

Correlations Between Endocardial Voltage Mapping, Diagnosis, and Genetics in Patients With Arrhythmogenic Right Ventricular Cardiomyopathy.

The relations between endocardial voltage mapping and the genetic background of patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) have not been investigated so far. A total of 97 patients with proved or suspected ARVC who underwent 3-dimensional endocardial mapping and genetic testing have been retrospectively included. Presence, localization, and size of scar areas were correlated to ARVC diagnosis and the presence of a pathogenic variant. A total of 78 patients (80%) presented with some bipolar or unipolar scar on endocardial voltage mapping, whereas 43 carried pathogenic variants (44%). Significant associations were observed between presence of endocardial scars on voltage mapping and previous or inducible ventricular tachycardia, right ventricular function and dimensions, or electrocardiogram features of ARVC. A total of 60 of the 78 patients (77%) with an endocardial scar fulfilled the criteria for a definitive arrhythmogenic right ventricular dysplasia diagnosis versus 8 of 19 patients (42%) without scar (p = 0.003). Patients with a definitive diagnosis of ARVC had more scars from any location and the scars were larger in patients with ARVC. In the 68 patients with a definitive diagnosis of ARVC, the presence of any endocardial scar was similar whether an ARVC-causal mutation was present or not. Only scar extent was significantly greater in patients with pathogenic variants. There was no difference in the presence and characteristics of scars in PKP2 mutated versus other mutated patients. The 3-dimensional endocardial mapping could have an important role for refining ARVC diagnosis and may be able to detect minor forms with otherwise insufficient criteria for diagnosis. The trend for larger scar extent were observed in mutated patients, without any difference according to the mutated genes.

Malignant Purkinje ectopy induced by sodium channel blockers.

BACKGROUND: Sodium channel blocker (SCB) infusion is used to unmask the electrocardiographic pattern of Brugada syndrome. The test may also induce premature ventricular complexes (PVCs) in individuals without Brugada pattern, the clinical relevance of which is little known. OBJECTIVE: The purpose of this study was to describe the prevalence of short-coupled (Sc) PVCs induced by ajmaline or flecainide in patients with suspected or documented severe ventricular arrhythmias. METHODS: We reviewed the SCB tests performed in 335 patients with suspected ventricular arrhythmias and structurally normal hearts in 9 centers. ScPVCs were defined as frequent and repetitive PVCs with an R-on-T pattern on SCB tests. Repeated SCB tests were performed in 7 patients and electrophysiological mapping of ScPVCs in 9. RESULTS: Sixteen patients (8 men; mean age 36 ± 11 years) showed ScPVCs and were included. ScPVCs appeared 229 ± 118 seconds after the initiation of infusion and displayed coupling intervals of 288 ± 28 ms. ScPVC patterns were monomorphic in 12 patients, originating from the Purkinje system in mapped patients. Repetitive PVCs were induced in 15 patients (94%) including polymorphic ventricular tachycardias in 9 (56%). SCB infusion was repeated 45 (interquartile range 0.6-46) months later and induced identical ScPVC in all. SCB test was the only mean to reveal the malignant arrhythmia in 6 patients. Catheter ablation was performed in 9 patients, resulting in arrhythmia elimination in 8 with a follow-up of 6 (interquartile range 2-9) years. CONCLUSION: SCB can induce ScPVC, mostly from Purkinje tissue, in a small subset of patients with idiopathic ventricular arrhythmias. Its high reproducibility suggests a distinct individual mechanism.

Radiation dose during catheter ablation in children using a low fluoroscopy frame rate.

BACKGROUND: Catheter ablation (CA) in children using fluoroscopy carries risks inherent to ionizing radiation exposure. AIMS: The objective of this study was to demonstrate the feasibility of using low frames rate during ablation in children to maximally decrease radiation dose. METHODS: Hundred sixty eight successive patients<18 years of age undergoing CA performed under a 3.75 frames/second rate were retrospectively included. Demographics, procedural and dosimetry data were analysed. The effective dose (ED) was evaluated in a subgroup of 14 patients. RESULTS: Median age and weight were 15 years and 54kg, 72% had WPW, 10% AV node reentrant tachycardia, 10% ventricular tachycardia (atrial tachycardia, flutter and atrial fibrillation for the other cases). Acute success was achieved in 98.5% without any complication. Median procedure and fluoroscopy duration were 120 and 16minutes. Median Dose Area Product (DAP) and Air Kerma were 2.46Gy.cm2 and 18 mGy respectively (2Gy.cm2 and 15 mGy for WPW ablation). A significant reduction of median DAP was noted over the years for WPW, from 3.1Gy.cm2 in 2011 to 1.4 in 2019. Median estimated ED was 0.19 mSv (0.03 to 1.64), falling into the range of yearly normal natural irradiation or caused by leasure or professional activity. CONCLUSION: Low frame rate fluoroscopy is a highly effective and safe approach in decreasing radiation exposure during CA in children without altering the success rate of the procedure. ED is low, similar to natural/leisure irradiation. This approach can be considered a good alternative to 3D-based procedures in terms of efficiency and radiation issues, at least for WPW ablations.

The prevalence of left and right bundle branch block morphology ventricular tachycardia amongst patients with arrhythmogenic cardiomyopathy and sustained ventricular tachycardia: insights from the European Survey on Arrhythmogenic Cardiomyopathy.

AIMS: In arrhythmogenic cardiomyopathy (ACM), sustained ventricular tachycardia (VT) typically displays a left bundle branch block (LBBB) morphology while a right bundle branch block (RBBB) morphology is rare. The present study assesses the VT morphology in ACM patients with sustained VT and their clinical and genetic characteristics. METHODS AND RESULTS: Twenty-six centres from 11 European countries provided information on 954 ACM patients who had ≥1 episode of sustained VT spontaneously documented during patients' clinical course. Arrhythmogenic cardiomyopathy was defined according to the 2010 Task Force Criteria, and VT morphology according to the QRS pattern in V1. Overall, 882 (92.5%) patients displayed LBBB-VT alone and 72 (7.5%) RBBB-VT [alone in 42 (4.4%) or in combination with LBBB-VT in 30 (3.1%)]. Male sex prevalence was 79.3%, 88.1%, and 56.7% in the LBBB-VT, RBBB-VT, and LBBB + RBBB-VT groups, respectively (P = 0.007). First RBBB-VT occurred 5 years after the first LBBB-VT (46.5 ± 14.4 vs 41.1 ± 15.8 years, P = 0.011). An implanted cardioverter-defibrillator was more frequently implanted in the RBBB-VT (92.9%) and the LBBB + RBBB-VT groups (90%) than in the LBBB-VT group (68.1%) (P < 0.001). Mutations in PKP2 predominated in the LBBB-VT (65.2%) and the LBBB + RBBB-VT (41.7%) groups while DSP mutations predominated in the RBBB-VT group (45.5%). By multivariable analysis, female sex was associated with LBBB + RBBB-VT (P = 0.011) while DSP mutations were associated with RBBB-VT (P < 0.001). After a median follow-up of 103 (51-185) months, death occurred in 106 (11.1%) patients with no intergroup difference (P = 0.176). CONCLUSION: RBBB-VT accounts for a significant proportion of sustained VTs in ACM. Sex and type of pathogenic mutations were associated with VT type, female sex with LBBB + RBBB-VT, and DSP mutation with RBBB-VT.

New Oral Anticoagulants vs. Vitamin K Antagonists Among Patients With Cardiac Amyloidosis: Prognostic Impact.

Background: Atrial arrhythmia (AA) is common among patients with cardiac amyloidosis (CA), who have an increased risk of intracardiac thrombus. The aim of this study was to explore the prognostic impact of vitamin K-antagonists (VKA) and direct oral anticoagulants (DOAC) in patients with CA. Methods and Results: 273 patients with CA and history of AA with long term anticoagulation-69 (25%) light chain amyloidosis (AL), 179 (66%) wild-type transthyretin amyloidosis (ATTRwt) and 25 (9%) variant transthyretin amyloidosis (ATTRv)-were retrospectively included between January 2012 and July 2020. 147 (54%) and 126 (46%) patients received VKA and DOAC, respectively. Patient receiving VKA were more likely to have AL with renal dysfunction, higher NT-proBNP and troponin levels. Patients with ATTRwt were more likely to receive DOAC therapy. There were more bleeding complications among patients with VKA (20 versus 10%; P = 0.013) but no difference for stroke events (4 vs. 2%; P = 0.223), as compared to patients with DOAC. A total of 124 (45%) patients met the primary endpoint of all-cause mortality: 96 (65%) and 28 (22%) among patients with VKAs and DOACs, respectively (P < 0.001). After multivariate analysis including age and renal function, VKA was no longer associated with all-cause mortality. Conclusion: Among patients with CA and history of AA receiving oral anticoagulant, DOACs appear to be at least as effective and safe as VKAs.

Outcomes after catheter ablation of ventricular tachycardia without implantable cardioverter-defibrillator in selected patients with arrhythmogenic right ventricular cardiomyopathy.

AIMS: The roles of implantable cardioverter-defibrillators (ICDs) and radiofrequency catheter ablation (RCA) in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) and well-tolerated monomorphic ventricular tachycardia (MVT) are debated. In this multicentre retrospective study, we aimed at reporting the outcome of selected patients with ARVC after RCA without a back-up ICD. METHODS AND RESULTS: Patients with ARVC who underwent RCA of well-tolerated MVT at 10 tertiary centres across 5 countries, without an ICD before and 3 months after RCA, without syncope or electrical storm, and with left ventricular ejection fraction ≥50% were included. In total, 65 ARVC patients [mean age 44.5 ± 13.2 years, 78% males] underwent RCA of MVT between 2003 and 2016. Clinical presentation was palpitations in 51 (80%) patients. One (2%) patient had >1 clinical MVT. At the ablative procedure, clinical MVTs (mean rate 185 ± 32 b.p.m.) were inducible in 50 (81%) patients. Epicardial ablation was performed in 19 (29%) patients. Complete acute success was achieved in 47 (72%) patients. After a median follow-up of 52.4 months (range 12.3-171.4), there was no death or aborted cardiac arrest, and VT recurred in 19 (29%) patients. Survival without VT recurrence was estimated at 88%, 80%, and 68%, 12, 36, and 60 months after RCA, respectively, and was significantly associated with the approach and the procedural outcome. CONCLUSION: In patients with ARVC, well-tolerated MVT without a back-up ICD did not lead to fatal arrhythmic event after RCA despite VT recurrences in some. Our data suggest that RCA may be an alternative to ICD in selected ARVC patients.

Focus on stereotactic radiotherapy: A new way to treat severe ventricular arrhythmias?

Ventricular tachycardia has a significant recurrence rate after ablation for several reasons, including inaccessible substrate. A non-invasive technique to ablate any defined areas of myocardium involved in arrhythmogenesis would be a potentially important therapeutic improvement if shown to be safe and effective. Early feasibility studies of single-fraction stereotactic body radiotherapy have demonstrated encouraging results, but rigorous evaluation and follow-up are required. In this document, the basic concepts of stereotactic body radiotherapy are summarized, before focusing on stereotactic arrhythmia radioablation. We describe the effect of radioablation on cardiac tissue and its interaction with intracardiac devices, depending on the dose. The different clinical studies on ventricular tachycardia radioablation are analysed, with a focus on target identification, which is the key feature of this approach. Our document ends with the indications and requirements for practicing this type of procedure in 2020. Finally, because of the limited number of patients treated so far, we encourage multicentre registries with long-term follow-up.

Position paper concerning the competence, performance and environment required for the practice of ablation in children and in congenital heart disease.

The population of patients with congenital heart disease (CHD) is continuously increasing, and a significant proportion of these patients will experience arrhythmias because of the underlying congenital heart defect itself or as a consequence of interventional or surgical treatment. Arrhythmias are a leading cause of mortality, morbidity and impaired quality of life in adults with CHD. Arrhythmias may also occur in children with or without CHD. In light of the unique issues, challenges and considerations involved in managing arrhythmias in this growing, ageing and heterogeneous patient population and in children, it appears both timely and essential to critically appraise and synthesize optimal treatment strategies. The introduction of catheter ablation techniques has greatly improved the treatment of cardiac arrhythmias. However, catheter ablation in adults or children with CHD and in children without CHD is more technically demanding, potentially causing various complications, and thus requires a high level of expertise to maximize success rates and minimize complication rates. As French recommendations regarding required technical competence and equipment are lacking in this situation, the Working Group of Pacing and Electrophysiology of the French Society of Cardiology and the Affiliate Group of Paediatric and Adult Congenital Cardiology have decided to produce a common position paper compiled from expert opinions from cardiac electrophysiology and paediatric cardiology. The paper details the features of an interventional cardiac electrophysiology centre that are required for ablation procedures in adults with CHD and in children, the importance of being able to diagnose, monitor and manage complications associated with ablations in these patients and the supplemental hospital-based resources required, such as anaesthesia, surgical back-up, intensive care, haemodynamic assistance and imaging. Lastly, the need for quality evaluations and French registries of ablations in these populations is discussed. The purpose of this consensus statement is therefore to define optimal conditions for the delivery of invasive care regarding ablation of arrhythmias in adults with CHD and in children, and to provide expert and - when possible - evidence-based recommendations on best practice for catheter-based ablation procedures in these specific populations.

Catheter ablation of electrical storm in patients with arrhythmogenic right ventricular cardiomyopathy.

BACKGROUND: Therapeutic strategies for electrical storm (ES) in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) are not well defined. OBJECTIVE: The purpose of this study was to report the acute and long-term results of ventricular tachycardia (VT) radiofrequency catheter ablation (RFCA) as a treatment of ES in patients with ARVC. METHODS: This multicenter study retrospectively enrolled 23 consecutive patients with ARVC (mean age 43.6 ± 16.7 years; all men) who underwent 24 RFCA procedures for ES between 2003 and 2015. RESULTS: Thirteen patients (57%) had a previous VT RFCA procedure; 14 (61%) had right ventricular dysfunction and 7 (30%) left ventricular ejection fraction ≤ 50%. The clinical VT was inducible in 19 procedures (79%). Epicardial ablation was performed in 4 procedures (17%). The median number of targeted VTs was 1 (range 1-6). Complete acute success (no VT inducible) was achieved in 11 procedures (46%) and partial acute success (clinical VT nor inducible) in 11 (46%). After a median follow-up of 3.9 years (range 1 month-10 years), ES recurred in 2 patients and end-stage heart failure developed in 4 (17%), leading to 1 death and 3 heart transplantations. At 1-year follow-up, the probability of freedom from VT recurrence was 75% and did not significantly predict long-term survival. At the last evaluation, 8 patients (35%) were free of non-ß-blocker antiarrhythmic drugs as compared with 1 (4%) at baseline (P = .02). CONCLUSION: Catheter ablation was efficient to prevent ES recurrence in patients with ARVC. However, these patients were at high risk of evolution toward ARVC-related heart failure that was not associated with VT recurrence.

Ultra-High-Density Activation Mapping to Aid Isthmus Identification of Atrial Tachycardias in Congenital Heart Disease.

OBJECTIVES: A new electroanatomic mapping system (Rhythmia, Boston Scientific, Marlborough, Massachusetts) using a 64-electrode mapping basket is now available; we systematically assessed its use in complex congenital heart disease (CHD). BACKGROUND: The incidence of atrial arrhythmias post-surgery for CHD is high. Catheter ablation has emerged as an effective treatment, but is hampered by limitations in the mapping system's ability to accurately define the tachycardia circuit. METHODS: Mapping and ablation data of 61 patients with CHD (35 males, age 45 ± 14 years) from 8 tertiary centers were reviewed. RESULTS: Causes were as follows: Transposition of Great Arteries (atrial switch) (n = 7); univentricular physiology (Fontans) (n = 8); Tetralogy of Fallot (n = 10); atrial septal defect (ASD) repair (n = 15); tricuspid valve (TV) anomalies (n = 10); and other (n = 11). The total number of atrial arrhythmias was 86. Circuits were predominantly around the tricuspid valve (n = 37), atriotomy scar (n = 10), or ASD patch (n = 4). Although the majority of peri-tricuspid circuits were cavo-tricuspid-isthmus dependent (n = 30), they could follow a complex route between the annulus and septal resection, ASD patch, coronary sinus, or atriotomy. Immediate ablation success was achieved in all but 2 cases; with follow-up of 12 ± 8 months, 7 patients had recurrence. CONCLUSIONS: We demonstrate the feasibility of the basket catheter for mapping complex CHD arrhythmias, including with transbaffle and transhepatic access. Although the circuits often involve predictable anatomic landmarks, the precise critical isthmus is often difficult to predict empirically. Ultra-high-density mapping enables elucidation of circuits in this complex anatomy and allows successful treatment at the isthmus with a minimal lesion set.

Atrial fibrillation and subtype of atrial fibrillation in cardiac amyloidosis: clinical and echocardiographic features, impact on mortality.

Background: Atrial fibrillation (AF) commonly affects patients with cardiac amyloidosis (CA). Amyloid deposition within the left atrium may be responsible for the subtype of AF in either permanent or non-permanent form. The prognostic implications of AF and its clinical subtype according to the type of CA are still controversial in this population. This study sought to investigate the prevalence, incidence and prognostic implications of AF and the clinical subtype of AF (permanent or non-permanent) in patients with CA. Methods: Two hundred and thirty-eight patients with CA and full medical records were retrospectively enrolled in the study: About 115 (48%) with light chain (AL) amyloidosis and 123 (52%) with transthyretin amyloidosis (ATTR). Patient's medical records were reviewed to establish baseline prevalence, incidence and impact on all-cause and cardiovascular mortality during follow-up of AF. Results: One hundred and four (44%) patients had history of AF at the time of diagnosis: 62 (60%) permanent and 42 (40%) non-permanent. There were 30 (26%) and 74 (60%) patients with history of AF among patients with AL and ATTR (including 5 hereditary and 69 wild-type), respectively (p<.0001). During the follow-up, 48 new patients developed AF (29, 12 and 7 among patients with AL, wild-type ATTR and hereditary ATTR). After adjustment for age, survival was similar in patients with or without history of AF (HR 0.87 (95% CI, 0.60 to 1.27; p = .467). AF had no impact on cardiovascular mortality. Among the 152 patients with history of AF included in the whole study, there were 75 (49%) patients with permanent AF. After adjustment for age, survival was similar in patients with permanent and non-permanent AF: HR 1.29 (95% CI, 0.84 to 1.99; p = .251). The results were the same among patients with AL or wild-type amyloidosis. Subtype of AF had no impact on cardiovascular mortality. Conclusions: AF is common in patients with CA. However, AF and clinical subtype of AF have no impact on all-cause mortality, whatever the type of amyloidosis.

Characteristics of Single-Loop Macroreentrant Biatrial Tachycardia Diagnosed by Ultrahigh-Resolution Mapping System.

BACKGROUND: Biatrial tachycardia (BiAT) is a rare form of atrial macroreentrant tachycardia, in which both atria form a critical part of the circuit. We aimed to identify the characteristics and precise circuits of single-loop macroreentrant BiATs. METHODS AND RESULTS: We identified 8 patients (median age, 59.5 years old) with 9 BiATs in a cohort of 336 consecutive patients from 2 institutions who had undergone AT catheter ablation using an automatic ultrahigh-resolution mapping system. Seven of the 8 patients had a history of persistent AF ablation, including septal or anterior left atrium ablation before developing BiAT. One of the 8 patients had a history of an atrial septal patch closure with a massively enlarged right atrium. Nine ATs (median cycle length, 334 ms; median 12 561 points in the left atrium; 8814 points in the right atrium) were diagnosed as single-loop macroreentrant BiATs. We observed 3 types of BiAT (1) BiAT with a perimitral and peritricuspid reentrant circuit (n=3), (2) BiAT using the right atrium septum and a perimitral circuit (n=3), and (3) BiAT using only the left atrium and right atrium septum (n=3). Catheter ablation successfully terminated 8 of the 9 BiATs. CONCLUSIONS: All patients who developed BiAT had an electric obstacle on the anteroseptal left atrium, primarily from prior ablation lesions. In this situation, mapping of both atria should be considered during AT. Because 3 types of single-loop BiAT were observed, ablation strategies should be adjusted to the type of BiAT circuit.

Ventricular arrhythmias and sudden death in tetralogy of Fallot.

Malignant ventricular arrhythmias and sudden cardiac death may late happen in repaired tetralogy of Fallot, although probably less frequently than previously thought, especially with the advent of new surgical techniques/management. Ventricular tachycardias are caused by reentry around the surgical scars/patches and valves. Many predictive factors have been proposed, which suffer from poor accuracy. There is currently no recommended indication for prophylactic implantable cardioverter defibrillator implantation-except maybe in the case of multiple risk factors-while radiofrequncy ablation may be proposed in secondary prevention with or even without a back-up implantable cardioverter defibrillator in selected cases. Repeated cardiological investigations and monitoring should be proposed for every operated patient.

Benign vs. malignant inferolateral early repolarization: Focus on the T wave.

BACKGROUND: Inferolateral early repolarization (ER) is highly prevalent and is associated with idiopathic ventricular fibrillation (VF). OBJECTIVE: The purpose of this study was to evaluate the potential role of T-wave parameters to differentiate between malignant and benign ER. METHODS: We compared the ECGs of patients with ER and VF (n = 92) with control subjects with asymptomatic ER (n = 247). We assessed J-wave amplitude, QTc interval, T-wave/R-wave (T/R) ratio in leads II and V5, and presence of low-amplitude T waves (T-wave amplitude <0.1 mV and <10% of R-wave amplitude in lead I, II, or V4-V6). RESULTS: Compared to controls, the VF group had longer QTc intervals (388 ms vs. 377 ms, P = .001), higher J-wave amplitudes (0.23 mV vs. 0.17 mV, P <.001), higher prevalence of low-amplitude T waves (29% vs. 3%, P <.001), and lower T/R ratio (0.18 vs. 0.30, P <.001). Logistic regression analysis demonstrated that QTc interval (odds ratio [OR] per 10 ms: 1.15, 95% confidence interval [CI} 1.02-1.30), maximal J-wave amplitude (OR per 0.1 mV: 1.68, 95% CI 1.23-2.31), lower T/R ratio (OR per 0.1 unit: 0.62, 95% CI 0.47-0.81), presence of low-amplitude T waves (OR 3.53, 95% CI 1.26-9.88). and presence of J waves in the inferior leads (OR 2.58, 95% CI 1.18-5.65) were associated with malignant ER. CONCLUSION: Patients with malignant ER have a higher prevalence of low-amplitude T waves, lower T/R ratio (lead II or V5), and longer QTc interval. The combination of these parameters with J-wave amplitude and distribution of J waves may allow for improved identification of malignant ER.

The medical history of adults with complex congenital heart disease affects their social development and professional activity.

BACKGROUND: In recent decades, advances in surgery and therapeutic catheterization have steadily increased the life expectancy and prevalence of adults with congenital heart disease (CHD). AIMS: We assessed medical and psychosocial variables of adults with CHD, according to the disease complexity. METHODS: We included, from a single-centre observational cohort study, 135 consecutive adults with CHD (median age of 40 years, interquartile range: 28.0-51.0) followed in our cardiology unit, who answered a questionnaire assessing daily activity and psychosocial functioning. Disease complexity was classified according to the Bethesda conference. RESULTS: Cardiac malformation complexity was simple in 61 (45.2%), moderate in 50 (37.0%) and complex in 24 (17.8%) patients. Cardiac surgery had been performed in 86.5% of moderate and complex patients. Complications (such as heart failure, arrhythmia and pulmonary hypertension) were mainly observed in the complex group (P=0.003). Physical activity was lower in the complex group (no activity in 58.8%, but sport previously contraindicated in 50% of these; P=0.03). Education level tended to be lower in the complex and moderate groups than in the simple group (respectively, 31.2% and 33.3% vs. 45.7% had passed the Baccalaureate; P=0.47). The pass rate was lower in patients with complications (P=0.037) or more than one cardiac surgery (P=0.03). In the complex group, 56.3% of patients were unemployed (P=0.048). CONCLUSIONS: Complexity of heart disease and medical history affect education level and employment of adults with CHD. Academic education of children with a complex defect and career counselling are important to prevent unemployment among adults with CHD.