Carbon footprint of atrial fibrillation catheter ablation.

AIMS: Climate change represents the biggest global health threat of the 21st century. Health care system is itself a large contributor to greenhouse gas (GHG) emissions. In cardiology, atrial fibrillation (AF) catheter ablation is an increasing activity using numerous non-reusable materials that could contribute to GHG emission. Determining a detailed carbon footprint analysis of an AF catheter ablation procedure allows the identification of the main polluting sources that give opportunities for reduction of environmental impact. To assess the carbon footprint of AF catheter ablation procedure. To determine priority actions to decrease pollution. METHODS AND RESULTS: An eco-audit method used to predict the GHG emission of an AF catheter ablation procedure was investigated. Two workstations were considered including surgery and anaesthesia. In the operating room, every waste produced by single-use medical devices, pharmaceutical drugs, and energy consumption during intervention were evaluated. All analyses were limited to the operating room. Thirty procedures were analysed over a period of 8 weeks: 18 pulmonary veins isolation RF ablations, 7 complex RF procedures including PVI, roof and mitral isthmus lines, ethanol infusion of the Marshall vein and cavo tricuspid isthmus line, and 5 pulmonary vein isolation with cryoballoon. The mean emission during AF catheter ablation procedures was 76.9 kg of carbon dioxide equivalent (CO2-e). The operating field accounted for 75.4% of the carbon footprint, while only 24.6% for the anaesthesia workstation. On one hand, material production and manufacturing were the most polluting phases of product life cycle which, respectively, represented 71.3% (54.8 kg of CO2-e) and 17.0% (13.1 kg of CO2-e) of total pollution. On the other hand, transport contributed in 10.6% (8.1 kg of CO2-e), while product use resulted in 1.1% (0.9 kg of CO2-e) of GHG production. Electrophysiology catheters were demonstrated to be the main contributors of environmental impact with 29.9 kg of CO2-e (i.e. 38.8%). Three dimensional mapping system and electrocardiogram patches were accounting for 6.8 kg of CO2-e (i.e. 8.8% of total). CONCLUSION: AF catheter ablation involves a mean of 76.9 kg of CO2-e. With an estimated 600 000 annual worldwide procedures, the environmental impact of AF catheter ablation activity is estimated equal to 125 tons of CO2 emission each day. It represents an equivalent of 700 000 km of car ride every day. Electrophysiology catheters and patches are the main contributors of the carbon footprint. The focus must be on reducing, reusing, and recycling these items to limit the impact of AF ablation on the environment. A road map of steps to implement in different time frames is proposed.

Catheter ablation of atrial tachyarrhythmias in patients with atrioventricular septal defect.

AIMS: The incidence of atrial tachyarrhythmias is high in patients with atrioventricular septal defect (AVSD). No specific data on catheter ablation have been reported so far in this population. We aimed to describe the main mechanisms of atrial tachyarrhythmias in patients with AVSD and to analyse outcomes after catheter ablation. METHODS AND RESULTS: This observational multi-centric cohort study enrolled all patients with AVSD referred for catheter ablation of an atrial tachyarrhythmia at six tertiary centres from 2004 to 2022. The mechanisms of the different tachyarrhythmias targeted were described and outcomes were analysed. Overall, 56 patients (38.1 ± 17.4 years, 55.4% females) were included. A total of 87 atrial tachyarrhythmias were targeted (mean number of 1.6 per patient). Regarding main circuits involved, a cavo-annular isthmus-dependent intra-atrial re-entrant tachycardia (IART) was observed in 41 (73.2%) patients and an IART involving the right lateral atriotomy in 10 (17.9%) patients. Other tachyarrhythmias with heterogeneous circuits were observed in 13 (23.2%) patients including 11 left-sided and 4 right-sided tachyarrhythmias. Overall, an acute success was achieved in 54 (96.4%) patients, and no complication was reported. During a mean follow-up of 2.8 ± 3.8 years, 22 (39.3%) patients had at least one recurrence. Freedom from atrial tachyarrhythmia recurrences was 77.5% at 1 year. Among 15 (26.8%) patients who underwent repeated ablation procedures, heterogeneous circuits including bi-atrial and left-sided tachyarrhythmias were more frequent. CONCLUSION: In patients with AVSD, most circuits involve the cavo-annular isthmus, but complex mechanisms are frequently encountered in patients with repeated procedures. The acute success rate is excellent, although recurrences remain common during follow-up.

Wearable electrocardiogram devices in patients with congenital long QT syndrome: The SMART-QT study.

BACKGROUND: In patients with congenital long QT syndrome (LQTS), the risk of ventricular arrhythmia is correlated with the duration of the corrected QT interval and the changes in the ST-T wave pattern on the 12-lead surface electrocardiogram (12L-ECG). Remote monitoring of these variables could be useful. AIM: To evaluate the abilities of two wearable electrocardiogram devices (Apple Watch and KardiaMobile 6L) to provide reliable electrocardiograms in terms of corrected QT interval and ST-T wave patterns in patients with LQTS. METHODS: In a prospective multicentre study (ClinicalTrials.gov identifier: NCT04728100), a 12L-ECG, a 6-lead KardiaMobile 6L electrocardiogram and two single-lead Apple Watch electrocardiograms were recorded in patients with LQTS. The corrected QT interval and ST-T wave patterns were evaluated manually. RESULTS: Overall, 98 patients with LQTS were included; 12.2% were children and 92.8% had a pathogenic variant in an LQTS gene. The main genotypes were LQTS type 1 (40.8%), LQTS type 2 (36.7%) and LQTS type 3 (7.1%); rarer genotypes were also represented. When comparing the ST-T wave patterns obtained with the 12L-ECG, the level of agreement was moderate with the Apple Watch (k=0.593) and substantial with the KardiaMobile 6L (k=0.651). Regarding the corrected QT interval, the correlation with 12L-ECG was strong for the Apple Watch (r=0.703 in lead II) and moderate for the KardiaMobile 6L (r=0.593). There was a slight overestimation of corrected QT interval with the Apple Watch and a subtle underestimation with the KardiaMobile 6L. CONCLUSIONS: In patients with LQTS, the corrected QT interval and ST-T wave patterns obtained with the Apple Watch and the KardiaMobile 6L correlated with the 12L-ECG. Although wearable electrocardiogram devices cannot replace the 12L-ECG for the follow-up of these patients, they could be interesting additional monitoring tools.

Lessons from radiofrequency redo-procedure after cryoballoon pulmonary vein isolation for paroxysmal atrial fibrillation.

BACKGROUND: To gain further insights into mechanisms leading to atrial fibrillation (AF) recurrence after a first ablation procedure using cryoballoon technique, the data collected during redo procedure were analyzed. METHODS AND RESULTS: From a total of 112 patients who underwent cryoballoon pulmonary vein isolation (PVI) for paroxysmal AF, 44 had a second ablation procedure using radiofrequency catheter, because of recurrent atrial arrhythmia. PV reconduction was observed in 109 of the 171 initially isolated veins (64%). Conduction recovery was found, respectively, at the left inferior PV, right inferior PV, right superior PV and left superior PV in 35 patients (80%), 26 patients (67%), 23 patients (52%) and 17 patients (39%). The mean number of reconnected PVs per patient was significantly lower with the 23-mm cryoballoon as compared to the 28-mm. Conduction gaps were focal and located at inferior parts of inferior veins and at the ridge between left atrial appendage and left veins. Mean procedure and fluoroscopy time were 109 ± 32 min and 14.7 ± 8.3 min, respectively. A 3-D mapping system was used in only 8 patients (18%). CONCLUSIONS: Atrial arrhythmia recurrences following cryoballoon PVI were associated with focal PV reconnections, occurring at preferential anatomical sites. These gaps were readily ablated with focal radiofrequency delivery, explaining the lack of need of 3-D mapping system and short procedure time. These results do not support the use of cryoballoon to perform redo procedures.

Spironolactone as a Potential New Treatment to Prevent Arrhythmias in Arrhythmogenic Cardiomyopathy Cell Model.

Arrhythmogenic cardiomyopathy (ACM) is a rare genetic disease associated with ventricular arrhythmias in patients. The occurrence of these arrhythmias is due to direct electrophysiological remodeling of the cardiomyocytes, namely a reduction in the action potential duration (APD) and a disturbance of Ca2+ homeostasis. Interestingly, spironolactone (SP), a mineralocorticoid receptor antagonist, is known to block K+ channels and may reduce arrhythmias. Here, we assess the direct effect of SP and its metabolite canrenoic acid (CA) in cardiomyocytes derived from human-induced pluripotent stem cells (hiPSC-CMs) of a patient bearing a missense mutation (c.394C>T) in the DSC2 gene coding for desmocollin 2 and for the amino acid replacement of arginine by cysteine at position 132 (R132C). SP and CA corrected the APD in the muted cells (vs. the control) in linking to a normalization of the hERG and KCNQ1 K+ channel currents. In addition, SP and CA had a direct cellular effect on Ca2+ homeostasis. They reduced the amplitude and aberrant Ca2+ events. In conclusion, we show the direct beneficial effects of SP on the AP and Ca2+ homeostasis of DSC2-specific hiPSC-CMs. These results provide a rationale for a new therapeutical approach to tackle mechanical and electrical burdens in patients suffering from ACM.

Systematic Electrophysiological Study Prior to Pulmonary Valve Replacement in Tetralogy of Fallot: A Prospective Multicenter Study.

BACKGROUND: Ventricular arrhythmias and sudden death are recognized complications in tetralogy of Fallot. Electrophysiological studies (EPS) before pulmonary valve replacement (PVR), the most common reintervention in tetralogy of Fallot, could potentially inform therapy to improve arrhythmic outcomes. METHODS: A prospective multicenter study was conducted to systematically assess EPS with programmed ventricular stimulation in patients with tetralogy of Fallot referred for PVR from January 2020 to December 2021. A standardized stimulation protocol was used across all centers. RESULTS: A total of 120 patients were enrolled, mean age 39.2±14.5 years, 53.3% males. Sustained ventricular tachycardia was induced in 27 (22.5%) patients. When identifiable, the critical isthmus most commonly implicated (ie, in 90.0%) was between the ventricular septal defect patch and pulmonary annulus. Factors independently associated with inducible ventricular tachycardia were history of atrial arrhythmia (odds ratio, 8.56 [95% CI, 2.43-34.73]) and pulmonary annulus diameter >26 mm (odds ratio, 5.05 [95% CI, 1.47-21.69]). The EPS led to a substantial change in management in 23 (19.2%) cases: 18 (15.0%) had catheter ablation, 3 (2.5%) surgical cryoablation during PVR, and 9 (7.5%) defibrillator implantation. Repeat EPS 5.1 (4.8-6.2) months after PVR was negative in 8 of 9 (88.9%) patients. No patient experienced a sustained ventricular arrhythmia during 13 (6.1-20.1) months of follow-up. CONCLUSIONS: Systematically performing programmed ventricular stimulation in patients with tetralogy of Fallot referred for PVR yields a high rate of inducible ventricular tachycardia and carries the potential to alter management. It remains to be determined whether a standardized treatment approach based on the results of EPS will translate into improved outcomes. REGISTRATION: URL: https://clinicaltrials.gov/ct2/show/NCT04205461; Unique identifier: NCT04205461.

Incidence, Risk Factors, and Outcomes of Atrial Arrhythmias in Adult Patients With Atrioventricular Septal Defect.

OBJECTIVES: This study aimed to assess the incidence, associated factors, and outcomes of atrial arrhythmias in adults with atrioventricular septal defect (AVSD). BACKGROUND: Data regarding atrial arrhythmias in adults with AVSD are particularly scarce. METHODS: Data were analyzed from a multicentric cohort of adult patients with AVSD. Lifetime cumulative incidences of atrial arrhythmias were studied. Multiple logistic regression models were used to identify risk factors. RESULTS: A total of 391 patients (61.6% women) were enrolled with a mean age of 36.3 ± 16.3 years and a mean follow-up of 17.3 ± 14.2 years after initial surgical repair. Overall, 98 patients (25.1%) developed at least 1 episode of atrial arrhythmia at a mean age of 39.2 ± 17.2 years. The mean ages of patients at first episode of intra-atrial re-entrant tachycardia (IART)/ focal atrial tachycardia (FAT) and atrial fibrillation were 33.7 ± 15.3 and 44.3 ± 16.5 years, respectively. The lifetime risks for developing atrial arrhythmia to ages 20, 40, and 60 years were 3.7%, 17.8%, and 55.3%, respectively. IART/FAT was the leading arrhythmia until the age of 45, then atrial fibrillation surpassed IART/FAT. Age (odds ratio [OR]: 1.4; 95% confidence interval [CI]: 1.2-1.6), number of cardiac surgeries (OR: 4.1; 95% CI: 2.5-6.9), left atrial dilatation (OR: 3.1; 95% CI: 1.4-6.8), right atrial dilatation (OR: 4.1; 95% CI: 1.7-10.3), and moderate or severe left atrioventricular valve regurgitation (OR: 3.7; 95% CI: 1.2-11.7) were independently associated with a higher risk of atrial arrhythmias, whereas the type of AVSD and the age at repair were not. The occurrence of atrial arrhythmias was associated with pacemaker implantation (41.8% vs. 8.5%; P < 0.001), heart failure (24.5% vs. 1.0%; P < 0.001), and cerebrovascular accidents (11.2% vs. 3.4%; P = 0.007). CONCLUSIONS: The lifetime risk of atrial arrhythmias in patients with AVSD is considerable with more than half of patients developing ≥1 atrial arrhythmia by the age of 60 and is associated with a significant morbidity. The risk in partial/intermediate AVSD is as high as in complete AVSD and is not impacted by age at repair.

Atypical twin atrioventricular nodal re-entrant tachycardia in a congenitally corrected transposition of the great arteries patient with a surgical repair of a ventricular septal defect: a case report.

BACKGROUND: Twin atrioventricular (AV) nodal tachycardia is a rare mechanism of supraventricular arrhythmia, only seen in some specific congenital heart defects (CHD). It consists of a re-entrant circuit between two distinct AV nodes (anterior and inferior). Since both nodes have antegrade and retrograde conduction, there is usually two QRS morphologies in sinus rhythm. CASE SUMMARY: This case is about an atypical twin AV nodal tachycardia in a 15 years old patient with congenitally corrected transposition of the great arteries and previous history of a ventricular septal defect repair. The surgical closure was probably responsible of a poor antegrade conduction over the inferior AV node, which was responsible for a unique QRS morphology. He finally received a catheter ablation of the inferior AV node. He remained asymptomatic without anti-arrhythmic drugs at 8-months post-ablation. DISCUSSION: Twin AV nodal re-entrant tachycardia is a rare phenomenon. The presentation and electrophysiological study can be both atypical due to previous surgical repair. The operator should be aware of specific CHD where twin AV nodal re-entrant tachycardias are expected.

Impact of Pulmonary Valve Replacement on Ventricular Arrhythmias in Patients With Tetralogy of Fallot and Implantable Cardioverter-Defibrillator.

OBJECTIVES: This study aimed to assess the impact of pulmonary valve replacement (PVR) on ventricular arrhythmias burden in a population of tetralogy of Fallot (TOF) patients with continuous cardiac monitoring by implantable cardioverter-defibrillators (ICDs). BACKGROUND: Sudden cardiac death is a major cause of death in TOF, and right ventricular overload is commonly considered to be a potential trigger for ventricular arrhythmias. METHODS: Data were analyzed from a nationwide French ongoing study (DAI-T4F) including all TOF patients with an ICD since 2000. Survival data with recurrent events were used to compare the burden of appropriate ICD therapies before and after PVR in patients who underwent PVR over the study period. RESULTS: A total of 165 patients (mean age 42.2 ± 13.3 years, 70.1% male) were included from 40 centers. Over a median follow-up period of 6.8 (interquartile range: 2.5 to 11.4) years, 26 patients (15.8%) underwent PVR. Among those patients, 18 (69.2%) experienced at least 1 appropriate ICD therapy. When considering all ICD therapies delivered before (n = 62) and after (n = 16) PVR, the burden of appropriate ICD therapies was significantly lower after PVR (HR: 0.21; 95% confidence interval [CI]: 0.08 to 0.56; p = 0.002). Respective appropriate ICD therapies rates per 100 person-years were 44.0 (95% CI: 35.7 to 52.5) before and 13.2 (95% CI: 7.7 to 20.5) after PVR (p < 0.001). In the overall cohort, PVR before ICD implantation was also independently associated with a lower risk of appropriate ICD therapy in primary prevention patients (HR: 0.29 [95% CI: 0.10 to 0.89]; p = 0.031). CONCLUSIONS: In this cohort of high-risk TOF patients implanted with an ICD, the burden of appropriate ICD therapies was significantly reduced after PVR. While optimal indications and timing for PVR are debated, these findings suggest the importance of considering ventricular arrhythmias in the overall decision-making process. (French National Registry of Patients With Tetralogy of Fallot and Implantable Cardioverter Defibrillator [DAI-T4F]; NCT03837574).