Heart rhythm最新文献

Background: Serotonin is an important neurohormone that regulates vascular tone and autonomic reflexes, though its pathophysiological role in vasovagal syncope (VVS) remains uncertain.

Objective: This study sought to explore the involvement of serotonin and serotonergic-related metabolites in the pathogenesis of VVS.

Methods: Sixty-six patients (age 45.6±17.0 years; 33 females) with recurrent VVS underwent a head-up tilt test (HUTT). Blood samples were collected from all patients in a resting supine position, with an additional sample obtained from HUTT-positive patients during syncope. Plasma and platelet serotonin levels, and plasma concentrations of serotonergic-related metabolites-including serotonin's precursor 5-hydroxytryptophan (5-HTP), major metabolite 5-hydroxyindoleacetic acid (5-HIAA), and synthesis source tryptophan-were measured using the liquid chromatography tandem mass spectrometry (LC-MS/MS) method.

Results: HUTT was positive in 45 patients and negative in 21 patients. Significant differences were observed in plasma 5-HTP and 5-HIAA levels between HUTT+ and HUTT- patients (P<0.001 and P=0.040, respectively), as well as before and after syncope (all P<0.001), whereas no significant changes were found in serotonin and tryptophan levels. Notably, plasma serotonin levels significantly increased during syncope in patients with drug-free VVS (P=0.037), and a greater change in serotonin correlated with a shorter time to syncope (R²=0.38, P=0.015). Furthermore, certain serotonergic-related metabolites exhibited significant correlations with hemodynamic changes during VVS episodes, with 5-HTP demonstrating the highest sensitivity.

Conclusions: Despite the unchanged plasma and platelet serotonin levels, certain serotonergic-related metabolites significantly changed and correlated with hemodynamic parameters during VVS episodes, suggesting the potential involvement of an altered serotonergic metabolic pathway in VVS.

Background: Data on long-term effects of catheter ablation versus antiarrhythmic drugs (AAD) on health-related quality of life (HRQoL) and atrial fibrillation (AF) burden are limited.

Objective: The study aimed to assess long-term HRQoL and rhythm data in symptomatic AF patients.

Methods: The 75 patients who underwent ablation and 74 receiving AAD in the Catheter Ablation compared with Pharmacological Therapy for Atrial Fibrillation (CAPTAF) trial were followed for 48 months. General Health using 36-Item Short-Form Health Survey, time to first AF-episode ≥1 hour, and AF burden, recorded by implantable cardiac monitors, were compared.

Results: 147 patients completed follow-up, with seven crossovers in the ablation group and 34 crossovers in the AAD group. General Health improved by ablation, median 62 points at baseline to 79.2 points at follow-up (p<0.001), and by AAD from median 67 to 77 points (p<0.001), without treatment differences (p=0.77). Time to first AF-episode ≥1 hour was longer, median 257 days (ablation group) versus 180 days (AAD group), p=0.025. The cumulative AF burden during follow-up was lower in the ablation (median 0.3% [interquartile range 0, 1.4]) versus the AAD group (1.6% [0.1, 11.0]), p=0.01. The cumulative reduction in AF burden compared with baseline was greater in the ablation (median -89.5% [-98.4, -51.3]) versus the AAD group (-52.7% [-92.6, 263.6]), p<0.001).

Conclusions: HRQoL improvement at long-term did not differ between ablation and AAD group despite a larger reduction in AF burden after ablation. The results should be interpreted in the light of a high crossover rate in the AAD group.

Background: In hypertrophic cardiomyopathy (HCM), 48-hour ambulatory monitoring has been standard practice to detect nonsustained ventricular tachycardia (NSVT), a sudden death risk marker. Extended wear ambulatory ECG devices have more recently utilized for monitoring HCM patients.

Objective: Evaluate NSVT burden identified with continuous ambulatory monitoring for up to 2 weeks compared to initial 48 hours.

Methods: 236 consecutive HCM patients (49 ± 12 years) underwent 14-day continuous ambulatory monitoring (Zio XT, iRhythm Technologies); diagnostic yield of NSVT compared for initial 48 hours vs. extended for 14 days.

Results: Of 236 patients, 114 (48%) had ≥1 runs of NSVT (median 2) over 14 days. Median length of NSVT was 7 beats (range: 3 to 67) at rates of 120 to 240 bpm (median, 167 bpm). In 42 of the 114 patients (37%), initial NSVT occurred ≤ 48 hours and in 72 (63%) only during the extended monitoring period (3 to 14 days). Diagnostic yield for detecting NSVT over 14 days was 2.7-fold greater than ≤ 48 hours (p<0.001). NSVT judged at higher risk (≥8 beats, >200 bpm, ≥2 runs in consecutive 2-day period) was identified more frequently during extended monitoring, diagnostic yield 3.0-fold greater than ≤ 48 hours (p<0.001).

Conclusion: In HCM, NSVT episodes are frequent, however, in most patients, both NSVT and higher risk NSVT were not detected during initial 48-hours and confined solely to extended monitoring period. These data support additional clinical studies to evaluate the significance of NSVT on extended monitoring on sudden death risk in HCM.

Background: No data regarding subcutaneous-ICD (S-ICD) technology in patients actively engaging in sports activities is available.

Objective: To compare S-ICD performance between athletes and non-athletes.

Methods: The primary outcome of the study was the comparison of overall device-related complications between athletes and non-athletes. Appropriate shocks, inappropriate shocks, and individual device-related complications were secondary outcomes.

Results: A total of 1493 patients were extracted from the iSUSI registry, of which 152 (10.2%) were athletes, mostly engaging in dynamic sports (54.2%). Brugada syndrome, myocarditis, and ARVC were more common in athletes (11.2%vs.3.3%, p<0.001; 19.1%vs.9.0%, p<0.001; 8.6%vs.2.8%, p<0.001, respectively). During a median follow-up time of 25.5 [12.0-41.2] months, athletes were more likely to experience appropriate shocks (yearly-rate: 7.2 [4.9-10.7]% vs. 4.3 [3.6-5.1]%, p=0.028), occurring more frequently during exercise (3.9%vs.0.6%, p < 0.001). This finding lost significance when adjusting for confounders (aHR=1.440[0.909-2.281], p=0.120). No differences were found in overall device-related complications (yearly-rate: 3.3%vs.3.4%, p=0.448) and inappropriate shocks (yearly-rate: 5.3% vs. 3.7%, p=0.111). Myopotential oversensing (4.0%vs.1.3%, p=0.011) was more common in athletes, as were lead infections (3.3%vs.0.9%, p=0.008), with the latter clustering in the early post-implantation period.

Conclusion: The S-ICD is a valid therapeutic option for preventing sudden cardiac death in athletes. Sports practice was not associated with an increased risk of complications or inappropriate shocks, although athletes are exposed to a higher risk of S-ICD infections in the early post-operative period.

Background: A subset of heart failure (HF) patients qualifies for cardiac resynchronization therapy (CRT). However, a 30% CRT non-responder rate persists, with patients with narrower QRS durations (i.e., QRSd 120-149 ms) receiving less or inconsistent benefit. CCM may be an important alternative therapy option but has largely been evaluated only in HF patients with QRSd <120 ms.

Objectives: Primarily to evaluate the impact of cardiac contractility modulation (CCM) on HF-related hospitalizations and secondarily on left ventricular EF (LVEF) as well as quality of life in HF patients with QRSd 120-149 ms, compared to QRSd <120 ms.

Methods: CCM-REG enrolled 503 HF patients with a follow-up of up to 2 yrs. Hospitalization rates were available for 1 yr pre-implant. Safety was assessed by comparison of actual versus MAGGIC score- or SHFM-predicted mortality.

Results: Among 111/455 subjects with QRSd 120-149 ms (mean QRSd 130±8 ms, age 68±10 yrs, 20% female, LVEF 29±9%, 82% NYHA class III), CCM diminished HF-related hospitalization rate by 72% (pre- vs. post-implant 0.90 vs. 0.25 events/per patient-yr over 2 yrs; p<0.001). LVEF improved by 7±8% (p=0.01 vs. baseline), MLWHFQ score by 10±23 pts (p=0.01 vs. baseline), and NYHA class by 0.5±0.7 classes (<0.001 vs. baseline). The effect size was similar to that in the QRSd <120 ms patients. Mortality within first year was 19% in QRSd 120-149 ms patients, i.e., not significantly different from the MAGGIC score or SHFM prediction.

Conclusions: CCM significantly improved HF control in NYHA III HFrEF patients with moderately prolonged QRSd 120-149 ms. The effect was similar to patients with QRSd <120ms.

Background: Current epicardial ablation technologies are limited by the inability to create adequate depth lesions and risk of collateral injury to extracardiac structures.

Objective: To evaluate the feasibility and efficacy of ventricular epicardial ablation with a novel balloon-expandable extreme-low temperature (XLT) cryoablation catheter with an embedded insulation pontoon for protection of extracardiac structures which has been specifically designed for epicardial ablation.

Methods: 10 healthy swine underwent surgical (6) and subxiphoid percutaneous (4) epicardial access respectively. A total of 3-6 sites were targeted in the right and left ventricular wall for different exposure durations. Ablation was performed with a large footprint (surgical) and smaller footprint (percutaneous) version of the HeartPad® (Corfigo Inc., Montclair, NJ) XLT system. The system consists of the balloon-expandable cryoablation catheter and a console. The console vaporizes liquid helium (-269˚C) and controls continuous delivery of extremely cold helium gas at high flow rates through a high-efficiency ablation element mounted on an expandable insulation pontoon to protect extracardiac structures. Ablation lesions were assessed by gross pathology and histological examination.

Results: A total of 42 epicardial lesions were created. The mean lesion depth increased progressively with the ablation time (surgical catheter: 11±2 mm at ≤30 seconds, 13±4 mm at 60 seconds, 15±3 mm at ≥120 seconds, P =0.001; percutaneous catheter: 10±2 mm at 30 seconds, 14±2 mm at 60 seconds, 16±2 mm at 120 seconds], P =0.001). Lesion geometry appeared unaffected by presence and thickness of epicardial fat. One episode of ventricular fibrillation occurred following ablation over the atrioventricular groove and 2 adjacent obtuse marginal arteries.

Conclusion: Surgical or percutaneous epicardial ablation using the HeartPad® XLT cryoablation system is feasible and can efficiently produce deep ventricular lesions in different epicardial locations.

Background: Data regarding the effects of pulsed field ablation (PFA) on atrioventricular nodal reentrant tachycardia (AVNRT) are limited.

Objective: To evaluate the outcomes of PFA for AVNRT, and its impact on dual-pathway electrophysiology.

Methods: A larger cohort of patients with typical AVNRT underwent slow pathway (SP) modification (SPM) using a focal PFA catheter in a biphasic/bipolar manner. The primary endpoints were the efficacy and safety of PFA during the procedure and 6-month follow-up.

Results: The acute success of SPM was achieved in all 40 patients. The total ablation time was 7.9±3.8 seconds for 6.4±2.2 ablation sites (ASs). Slow junctional rhythm (SJR) was induced in 32 (80%) patients lasting 28.9±10.3 seconds in 3.0±1.1 ASs per patient. SP was located 11.1±1.2 mm from the largest His activation (LHA). At 9 ASs, SJR could be reinduced after an increase of contact force (CF) from 1.3±0.5g to 6.4±1.3g (P<0.0001). Transient atrioventricular block (AVB) was recorded in 7(17.5%) patients (1 second-degree and 6 third-degree AVB) lasting 435.3±227.4 seconds, with a shorter AS-LHA distance than patients without AVB (7.7±0.6 mm vs. 11.3±1 mm, P<0.0001). PFA-related delayed atrial-His (n=6) and His-atrial (n=1) conduction preceded transient AVB with a constant His-ventricular interval. Normal PR interval was restored within 24 hours. All patients maintained sinus rhythm without any significant adverse events during 6-month follow-up.

Conclusion: Despite the high efficiency of PFA for SPM, the notable incidence of transient AVB warranted caution when applying it near the His bundle. SJR frequently occurred during SPM and was dependent on moderate CF.

Background: Pacing cycle length (PCL)-dependent changes in left atrial (LA) electrophysiological properties have not been fully elucidated.

Objective: To elucidate these changes using a high-resolution mapping system.

Methods: Forty-eight patients underwent atrial fibrillation ablation with RHYTHMIA HDx™. Paired LA maps under a baseline PCL (600 ms) and rapid PCL (300 ms) were acquired after pulmonary vein isolation under right atrial appendage pacing. The PCL-dependent change in the low-voltage area (LVA) (area with <0.5 mV bipolar voltage), LA activation time (interval from first LA activation to wavefront collision at lateral wall), regional mean voltage, regional mean wave propagation velocity, and slow conduction area (area with <0.3-m/s wave propagation velocity) were quantitatively analyzed.

Results: Under the rapid PCL, the total LVA was significantly increased (7.6 ± 9.5 vs. 6.7 ± 7.6 cm², p = 0.031), especially in patients with a ≥10 cm² LVA on the baseline PCL map (21.5 ± 9.1 vs. 18.1 ± 6.5 cm², p = 0.013). The LA activation time was also prolonged (87.9 ± 16.2 vs. 84.0 ± 14.0 ms, p < 0.0001). Although the rapid PCL did not decrease the regional mean voltage, it significantly decreased the regional mean wave propagation velocity and increased the slow conduction area in all measured regions.

Conclusion: LVA and slow conduction area can be emphasized by rapid PCL LA mapping. There may be poor validity in using these areas as absolute atrial fibrillation substrates without considering the PCL-dependent changes.