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Heart Rhythm Jun 2024The concealed nodoventricular/nodofascicular (NV/NF) pathway is mostly a bystander, retrograde bypass tract connecting right ventricle/right bundle branch (RBB) and slow...
BACKGROUND
The concealed nodoventricular/nodofascicular (NV/NF) pathway is mostly a bystander, retrograde bypass tract connecting right ventricle/right bundle branch (RBB) and slow pathway (SP), which is observed in patients with atrioventricular nodal reentrant tachycardia (AVNRT). However, its prevalence and characteristics in response to pacing maneuvers have not been fully evaluated.
OBJECTIVE
This study investigated the prevalence and characteristics of AVNRT with a bystander NV/NF-pathway.
METHODS
We retrospectively reviewed 153 consecutive patients undergoing catheter ablation of AVNRT. Excluding 52 patients with inadequate electrophysiological data, 101 patients composed the study population.
RESULTS
Three patients (3.0%) had bystander concealed NV/NF-pathways, all of which were connected to the SP. The tachycardia was typical SP/fast pathway (FP) AVNRT in two patients and atypical FP/SP AVNRT in one patient. In all cases, His-refractory ventricular extra stimuli (VESs) reset the AVNRTs with delay through the NV/NF-pathways. Ventricular overdrive pacing (VOP) in the early-phase also reset the AVNRT with delay. Earlier VESs and middle-phase of VOP did not reset the tachycardia, and further earlier VESs and late-phase of VOP reset the tachycardia with advance through the RBB-His conduction.
CONCLUSION
A bystander NV/NF-pathway was not rare in patients with AVNRT. The VESs and VOP for the AVNRTs with the bystander NV/NF-pathways were characterized by the two-phase resetting phenomenon: initial transient resetting with delay through the NV/NF-pathway, and late resetting with advance through the RBB-His conduction.
PubMed: 38942105
DOI: 10.1016/j.hrthm.2024.06.049 -
Europace : European Pacing,... Jun 2024Anticoagulation can prevent stroke and prolong lives in patients with atrial fibrillation (AF); However, anticoagulated patients with AF remain at risk of death. The aim...
AIMS
Anticoagulation can prevent stroke and prolong lives in patients with atrial fibrillation (AF); However, anticoagulated patients with AF remain at risk of death. The aim of this study was to investigate the causes of death and factors associated with all-cause and cardiovascular death in the XANTUS population.
METHODS AND RESULTS
Causes of death occurring within a year after rivaroxaban initiation in patients in the XANTUS program studies were adjudicated by a central adjudication committee and classified following international guidance.Baseline characteristics associated with all-cause or cardiovascular death were identified. Of 11,040 patients, 187 (1.7%) died. Almost half of these deaths were due to cardiovascular causes other than bleeding (n = 82, 43.9%), particularly heart failure (n = 38, 20.3%) and sudden or unwitnessed death (n = 24, 12.8%). Fatal stroke (n = 8, 4.3%), which was classified as a type of cardiovascular death, and fatal bleeding (n = 17, 9.1%) were less common causes of death. Independent factors associated with all-cause or cardiovascular death included age, AF type, body mass index, left ventricular ejection fraction, hospitalization at baseline, rivaroxaban dose, and anaemia.
CONCLUSION
The overall risk of death due to stroke or bleeding was low in XANTUS. Anticoagulated patients with AF remain at risk of death due to heart failure and sudden death. Potential interventions to reduce cardiovascular deaths in anticoagulated patients with AF, require further investigation, e.g. early rhythm control therapy and AF ablation.
PubMed: 38941511
DOI: 10.1093/europace/euae183 -
Circulation. Arrhythmia and... Jun 2024
PubMed: 38939957
DOI: 10.1161/CIRCEP.124.012915 -
JACC. Advances Jan 2024Multilevel obstruction in left ventricular inflow and outflow predisposes to arrhythmias in Shone's complex (SC).
BACKGROUND
Multilevel obstruction in left ventricular inflow and outflow predisposes to arrhythmias in Shone's complex (SC).
OBJECTIVES
The purpose of this study was to study the prevalence and outcomes (heart failure [HF] hospitalization, cardiac transplant, death) of cardiac arrhythmias in adults with SC.
METHODS
Adults with SC (defined as ≥2 lesions out of supramitral ring, parachute mitral valve, subvalvular/valvular aortic stenosis (AS), and aortic coarctation) seen at Mayo Clinic between January 1999 and March 2020 were identified and evaluated for the presence of sustained atrial fibrillation, atrial flutter, and ventricular arrhythmias (VA). Kaplan-Meier survival analysis was used to calculate the occurrence of these arrhythmias.
RESULTS
Seventy-three patients with SC (mean age at first visit 33 ± 13 years) were identified. Most common anomalies were valvular AS (88%), coarctation (85%), parachute mitral valve (44%), subvalvular AS (44%), and supramitral ring (25%). Atrial arrhythmias were diagnosed in 24 patients (33%) at a mean age of 34.6 ± 12.7 years. Patients with atrial fibrillation and atrial flutter had higher number of surgeries, left atrial size, right ventricular systolic pressure, and HF hospitalizations. A rhythm control approach was used in majority of patients (75% on antiarrhythmic drugs and 50% underwent catheter ablation). Sustained VA occurred in 6 of 73 patients of whom 4 had an ejection fraction <40%. Death and cardiac transplantation occurred in 11 and 3 patients, respectively, during a median follow-up of 7.3 ± 6.0 years.
CONCLUSIONS
In adults with SC, atrial arrhythmias occurred in one-third of patients, were associated with more HF hospitalizations, and frequently required rhythm control. Prevalence of sustained VA was 8% and implantable cardioverter-defibrillator implantation should be considered in those with reduced ejection fraction.
PubMed: 38939811
DOI: 10.1016/j.jacadv.2023.100715 -
Journal of Arrhythmia Jun 2024Intraoperative ventricular tachycardia (VT) ablation targeting the epicardial substrate using three-dimensional electroanatomic mapping (EAM) was performed during left...
Intraoperative ventricular tachycardia (VT) ablation targeting the epicardial substrate using three-dimensional electroanatomic mapping (EAM) was performed during left ventricular assist device (LVAD) implantation. We proved that EAM can be safely performed during LVAD implantation and that an ablation strategy based on electrophysiological information may reduce VT recurrence after LVAD implantation.
PubMed: 38939782
DOI: 10.1002/joa3.13029 -
Journal of Arrhythmia Jun 2024Electrocardiography and 3D mapping images of the case.
Electrocardiography and 3D mapping images of the case.
PubMed: 38939761
DOI: 10.1002/joa3.13022 -
Journal of Applied Physiology... Jun 2024In a 77-year-old former world-record holding male marathoner (2:08:33.6) this study sought to investigate the impact of lifelong intensive endurance exercise on cardiac...
In a 77-year-old former world-record holding male marathoner (2:08:33.6) this study sought to investigate the impact of lifelong intensive endurance exercise on cardiac structure, function and the trajectory of functional capacity (determined by maximal oxygen consumption, V̇Omax) throughout the adult lifespan. As a competitive runner, our athlete (DC) reported performing up to 150-300 miles/wk of moderate-to-vigorous exercise, and sustained 10-15 hours/wk of endurance exercise after retirement from competition. DC underwent maximal cardiopulmonary exercise testing in 1970 (aged 27yrs), 1991 (aged 49yrs) and 2020 (aged 77yrs) to determine V̇Omax. At his evaluation in 2020, DC also underwent comprehensive cardiac assessments including resting echocardiography, and resting and exercise cardiac magnetic resonance to quantify cardiac structure and function at rest and during peak supine exercise. DC's V̇Omax showed minimal change from 27yrs (69.7mL/kg/min) to 49yrs (68.1mL/kg/min), although it eventually declined by 36% by the age of 77yrs (43.6mL/kg/min). DC's V̇Omax at 77yrs, was equivalent to the 50 percentile for healthy 20-29 year-old males and 2.4 times the requirement for maintaining functional independence. This was partly due to marked ventricular dilatation (left-ventricular end-diastolic volume: 273mLs), which facilitates a large peak supine exercise stroke volume (200mLs) and cardiac output (22.2L/min). However, at the age of 78 years, DC developed palpitations and fatigue, and was found to be in atrial fibrillation requiring ablation procedures to revert his heart to sinus rhythm. Overall, this life study of a world champion marathon runner exemplifies the substantial benefits and potential side effects of many decades of intense endurance exercise.
PubMed: 38935800
DOI: 10.1152/japplphysiol.00070.2024 -
JACC. Clinical Electrophysiology Jun 2024Ventricular tachycardia (VT), which can lead to sudden cardiac death, occurs frequently in patients after myocardial infarction. Radiofrequency catheter ablation (RFA)...
BACKGROUND
Ventricular tachycardia (VT), which can lead to sudden cardiac death, occurs frequently in patients after myocardial infarction. Radiofrequency catheter ablation (RFA) is a modestly effective treatment of VT, but it has limitations and risks. Cardiac magnetic resonance (CMR)-based heart digital twins have emerged as a useful tool for identifying VT circuits for RFA treatment planning. However, the CMR resolution used to reconstruct these digital twins may impact VT circuit predictions, leading to incorrect RFA treatment planning.
OBJECTIVES
This study sought to predict RFA targets in the arrhythmogenic substrate using heart digital twins reconstructed from both clinical and high-resolution 2-dimensional CMR datasets and compare the predictions.
METHODS
High-resolution (1.35 × 1.35 × 3 mm), or oversampled resolution (Ov-Res), short-axis late gadolinium-enhanced CMR was acquired by combining 2 subsequent clinical resolution (Clin-Res) (1.35 × 1.35 × 6 mm) short-axis late gadolinium-enhanced CMR scans from 6 post-myocardial infarction patients undergoing VT ablation and used to reconstruct a total of 3 digital twins (1 Ov-Res, 2 Clin-Res) for each patient. Rapid pacing was used to assess VT circuits and identify the optimal ablation targets in each digital twin. VT circuits predicted by the digital twins were compared with intraprocedural electroanatomic mapping data and used to identify emergent VT.
RESULTS
The Ov-Res digital twins reduced partial volume effects and better predicted unique VT circuits compared with the Clin-Res digital twins (66.6% vs 54.5%; P < 0.01). Only the Ov-Res digital twin successfully identified emergent VT after a failed initial ablation.
CONCLUSIONS
Digital twin infarct geometry and VT circuit predictions depend on the magnetic resonance resolution. Ov-Res digital twins better predict VT circuits and emergent VT, which may improve RFA outcomes.
PubMed: 38934970
DOI: 10.1016/j.jacep.2024.04.032 -
Cryobiology Jun 2024Echocardiography-guided percutaneous intramyocardial septal radiofrequency ablation (PIMSRA, Liwen procedure) is a novel treatment option for hypertrophic obstructive...
Echocardiography-guided percutaneous intramyocardial septal radiofrequency ablation (PIMSRA, Liwen procedure) is a novel treatment option for hypertrophic obstructive cardiomyopathy (HOCM). The safety and feasibility of using this procedure for cryoablation are unknown. We aimed to investigate the feasibility and safety of echocardiography-guided percutaneous intramyocardial septal cryoablation (PIMSCA) for septal thickness reduction in a canine model. Eight canines underwent PIMSCA, and had electrocardiography, echocardiography(ECG), myocardial contrast echocardiography (MCE), serological and pathological examinations during the preoperative, immediate postoperative, and 6-month follow-up. All eight canines underwent successful cryoablation and continued to be in sinus rhythm during ablation and without malignant arrhythmias. MCE showed that the ablation area had decreased myocardial perfusion after the procedure. Troponin I levels were significantly elevated [0.010 (0.005, 0.297) ng/mL vs. 3.122 (1.152,7.990) ng/mL, p < 0.05)]. At 6-month follow-up after the procedure, all animals were alive, with thinning of the interventricular septum (7.26 ± 0.52 mm vs. 3.86 ± 0.29 mm, p < 0.05). Echocardiography showed no significant decrease in the left ventricular ejection fractions (LVEF) (54.32 ± 2.93 %vs. 54.70 ± 2.47 %, p > 0.05) or changes by pulse-wave Doppler E/A (1.17 ± 0.43 vs. 1.07 ± 0.43, p > 0.05), E/e'(8.09 ± 1.49 vs. 10.05 ±2.68, p > 0.05). Pathological findings proved the effectiveness of cryoablation in myocardial tissues. We observed pericardial effusions and premature ventricular complexes (PVCs) associated with the procedure. Our findings provided preliminary evidence of the safety and feasibility of PIMSCA in reducing interventricular septum, which provides a potentially new treatment option for HOCM.
PubMed: 38925358
DOI: 10.1016/j.cryobiol.2024.104933 -
Journal of Interventional Cardiac... Jun 2024
PubMed: 38913134
DOI: 10.1007/s10840-024-01852-5