Long duration of atrial high-rate episode is more favorable in predicting ischemic stroke than high CHA2 DS2 -VASc score.

OBJECTIVE: This study aimed to explore the roles of duration and burden of atrial high-rate episode (AHRE) on ischemic stroke in patients with pacemaker implantation. METHODS: Patients with pacemaker implantation for bradycardia from 2013 to 2017 were consecutively enrolled. Data such as gender, age, combined diseases, type of AF, left atrial size, left ventricular size, left ventricular ejection fraction, CHA2 DS2 -VASc score, and anticoagulants were collected. The burden and duration of AHRE based on different interval partition were also recorded in detail to evaluate the impacts on ischemic stroke. Cox regression analysis with time-dependent covariates was conducted. RESULTS: A total of 220 patients with AHRE were enrolled. The average follow-up time was 48.42 ± 17.20 months. Univariate regression analysis showed that diabetes (p = .024), high CHA2 DS2 -VASc score (≥ 2) (p = .021), long mean AHRE burden (p = .011), long maximal AHRE burden (p = .015), long AHRE duration lasting≥48 h (p = .001) or 24 h (p = .001) or 12 h (p = .005) were prone to ischemic stroke. Further multivariate regression analysis showed that long duration of AHRE (≥48 h) (HR 10.77; 95% CI 3.22-55.12; p = .030) were significantly correlated with stroke in patients with paroxysmal AF. There was no significant correlation between the type of AF and stroke (p = .927). CONCLUSION: The longer duration of AHRE (≥48 h) was more favorable in predicting ischemic stroke than high CHA2 DS2 -VASc score (≥2).

Predictors of pacing-induced cardiomyopathy detection and outcomes demonstration after conduction system pacing upgrade on patients with long-term persistent atrial fibrillation.

OBJECTIVE: To identify the predictors of pacing-induced cardiomyopathy (PICM) and illustrate the safety and feasibility of conduction system pacing (CSP) upgrade on patients with long-term persistent atrial fibrillation (AF). METHODS: All patients with long-term persistent AF and normal left ventricular ejection fraction (LVEF) ≥50% were consecutively enrolled from January 2008 to December 2017, and all the patients with atrioventricular block (AVB) and high right ventricular pacing (RVP) percentage of at least 40%. The predictors of PICM were identified, and patients with PICM were followed up for at least 1 year regardless of CSP upgrade. Cardiac performances and lead outcomes were investigated in all patients before and after CSP upgrade. RESULTS: The present study included 139 patients, out of which 37 (26.62%) developed PICM, resulting in a significant decrease in the left ventricular ejection fraction (LVEF) from 56.11 ± 2.56% to 38.10 ± 5.81% (p< .01). The median duration for the development of PICM was 5.43 years. Lower LVEF (≤52.50%), longer paced QRS duration (≥175 ms), and higher RVP percentage (≥96.80%) were identified as independent predictors of PICM. Furthermore, the morbidity of PICM progressively increased with an increased number of predictors. The paced QRS duration (183.90 ± 22.34 ms vs. 136.57 ± 20.71 ms, p < .01), LVEF (39.35 ± 2.71% vs. 47.50 ± 7.43%, p < .01), and left ventricular end-diastolic diameter (LVEDD) (55.53 ± 5.67 mm vs. 53.20 ± 5.78 mm, p = .03) improved significantly on patients accepting CSP upgrade. CSP responses and complete reverse remodeling (LVEF ≥50% and LVEDD < 50 mm) were detected in 80.95% (17/21) and 42.9% (9/21) of patients. The pacing threshold (1.52 ± 0.78 V/0.4 ms vs. 1.27 ± 0.59 V/0.4 ms, p = .16) was stable after follow-up. CONCLUSION: PICM is very common in patients with long-term persistent AF, and CSP upgrade was favorable for better cardiac performance in this patient population.

Appropriate intraprocedural initial heparin dosing in patients undergoing catheter ablation for atrial fibrillation receiving uninterrupted non-vitamin-K antagonist oral anticoagulant treatment.

BACKGROUND: To clarify the appropriate initial dosage of heparin during radiofrequency catheter ablation (RFCA) in patients with atrial fibrillation (AF) receiving uninterrupted nonvitamin K antagonist oral anticoagulant (NOAC) treatment. METHODS: A total of 187 consecutive AF patients who underwent their first RFCA in our center were included. In the warfarin group (WG), an initial heparin dose of 100 U/kg was administered (control group: n = 38). The patients who were on NOACs were randomly divided into 3 NOAC groups (NG: n = 149), NG110, NG120, and NG130, and were administered initial heparin doses of 110 U/kg, 120 U/kg, and 130 U/kg, respectively. During RFCA, the activated clotting time (ACT) was measured every 15 min, and the target ACT was maintained at 250-350 s by intermittent heparin infusion. The baseline ACT and ACTs at each 15-min interval, the average percentage of measurements at the target ACT, and the incidence of periprocedural bleeding and thromboembolic complications were recorded and analyzed. RESULTS: There was no significant difference in sex, age, weight, or baseline ACT among the four groups. The 15 min-ACT, 30 min-ACT, and 45 min-ACT were significantly longer in the WG than in NG110 and NG120. However, no significant difference in 60 min-ACT or 75 min-ACT was detected. The average percentages of measurements at the target ACT in NG120 (82.2 ± 23.6%) and NG130 (84.8 ± 23.7%) were remarkably higher than those in the WG (63.4 ± 36.2%, p = 0.007, 0.003, respectively). These differences were independent of the type of NOAC. The proportion of ACTs in 300-350 s in NG130 was higher than in WG (32.4 ± 31.8 vs. 34.7 ± 30.6, p = 0.735). Severe periprocedural thromboembolic and bleeding complications were not observed. CONCLUSIONS: For patients with AF receiving uninterrupted NOAC treatment who underwent RFCA, an initial heparin dosage of 120 U/kg or 130 U/kg can provide an adequate intraprocedural anticoagulant effect, and 130 U/kg allowed ACT to reach the target earlier. TRIAL REGISTRATION: Registration number: ChiCTR1800016491, First Registration Date: 04/06/2018 (Chinese Clinical Trial Registry http://www.chictr.org.cn/index.aspx ).

Brady-arrhythmias in patients with atrial fibrillation and heart failure of reduced ejection fraction: is his-bundle pacing superior to biventricular pacing？.

OBJECTIVE: To investigate the efficacy and safety of His-bundle pacing (HBP) compared with the traditional biventricular pacing (BVP) on patients with brady-arrhythmias, who suffer from permanent atrial fibrillation (AF) and heart failure with reduced ejection fraction (HFrEF). METHODS: All patients with brady-arrhythmias, permanent AF and HFrEF were continuously enrolled from January 2017 to July 2019 and followed up for at least 12 months. The differences in QRS duration (QRSd), New York Heart Association (NYHA) classification, left ventricular ejection fraction (LVEF), tricuspid regurgitation grade, mitral regurgitation grade, left ventricular end-diastolic diameter (LVEDD), and left atrial size were compared. RESULTS: A total of 52 patients were enrolled: 37 patients were with HBP and 15 patients with BVP. There was no electrode dislodged, perforation, infection or thrombosis during the follow-up of 18.12 ± 4.45 months. The success rate for HBP implantation was 88.10%. The capture threshold of his-bundle and the threshold of the left ventricular lead remained stable during follow-up. LVEF increased to higher than 50% in 11 patients with HBP (29.73%). The NYHA classification (both p < .001), LVEF (both p < .001) and LVEDD improved significantly during the follow-up in both groups. NYHA (p = .030), LVEF (p = .013), and LVEDD (p = .003) improved in patients with HBP compared with BVP. CONCLUSION: HBP was safe and more effective in improving the cardiac function and remodeling in patients with brady-arrhythmias, permanent AF and HFrEF compared with BVP.

[Long term outcome of atrial fibrillation patients with KCNA5 and NPPA mutations post circumferential pulmonary vein ablation].

OBJECTIVE: The outcome of atrial fibrillation patients with genetic mutations post ablation was not well evaluated. METHODS AND RESULTS: Three atrial fibrillation patients with evidence of mutations in KCNA5 and NPPA post successful circumferential pulmonary vein ablation were included. Mutation in KCNA5 was found in one male patient with paroxysmal atrial fibrillation. He was free of atrial fibrillation post ablation after 46 months follow-up. Mutations in NPPA were found in two male patients with persistent atrial fibrillation and they were free from atrial fibrillation after 64 months and 38 months follow-up post circumferential pulmonary vein ablation, roof line and mitral isthmus line ablation. CONCLUSION: Satisfactory long term results are observed in atrial fibrillation patients with KCNA5 and NPPA mutations post circumferential pulmonary vein ablation.

Conduction system pacing improves the outcomes on patients with high percentage of ventricular pacing and heart failure with mildly reduced ejection fraction.

Aims: This study aimed to investigate the efficacy and safety of CSP in patients with a high percentage of ventricular pacing and heart failure with HFmrEF. Methods: Patients who underwent CSP for HFmrEF and ventricular pacing >40% were consecutively enrolled from January 2018 to May 2021. All participants were followed up at least 12 months. Clinical data including cardiac performance and lead outcomes were compared before and after the procedure. Left ventricular ejection fraction (LVEF) was measured using the biplane Simpson's method. HFmrEF was defined as heart failure with the LVEF ranging from 41%-49%. Results: CSP was successfully performed in 64 cases (96.97%), which included 16 cases of left bundle branch pacing (LBBP) and 48 cases of His bundle pacing (HBP). After a mean of 23.12 ± 8.17 months follow-up, NYHA classification (P < 0.001), LVEF (42.45 ± 1.84% vs. 49.97 ± 3.57%, P < 0.001) and left ventricular end diastolic diameter (LVEDD) (55.59 ± 6.17 mm vs. 51.66 ± 3.48 mm, P < 0.001) improved significantly. During follow-up, more than half (39/64,60.9%) of patients returned to normal LVEF and LVEDD with complete reverse remodeling. The pacing threshold in LBBP was lower (0.90 ± 0.27 V@0.4 ms vs. 1.61 ± 0.71 V@0.4 ms, P < 0.001) than that in HBP. No perforation, electrode dislodging, thrombosis or infection was observed during follow-up. Conclusions: CSP could improve the clinical outcomes in patients with HFmrEF and a high percentage of ventricular pacing. LBBP might be a better choice because of its feasibility and safety, especially in patients with infranodal atrioventricular block.

Cumulative non-high-density lipoprotein cholesterol burden and risk of atherosclerotic cardiovascular disease: a prospective community-based study.

Background: The relationship between cumulative non-high-density lipoprotein cholesterol (non-HDL-C) burden and atherosclerotic cardiovascular disease (ASCVD) remains unclear. Objective: To prospectively examine the association between cumulative non-HDL-C burden and ASCVD risk in the Kailuan cohort of China. Methods: A total of 49,679 subjects who were free of ASCVD participated in three consecutive examinations in 2006, 2008 and 2010 were enrolled. Duration and concentration of cumulative exposure to non-HDL-C (cumNon-HDL-C) were respectively used to estimate the extent of cumulative non-HDL-C burden. The participants were divided into four groups according to durations of cumNon-HDL-C (0, 2, 4 and 6 years) and five groups according to the quintiles of cumNon-HDL-C concentration (<10.93, 10.93-12.68, 12.69-14.32, 14.33-16.72 and ≥16.73 mmol/L). Cox regression models were used to analyze the influence of cumulative non-HDL-C burden on ASCVD risk. Results: We identified 1,134 incident ASCVD cases during a mean of 4.89 years of follow-up. Multivariable adjusted analysis revealed that compared with no exposure, cumNon-HDL-C duration 2, 4 and 6 years increased ASCVD risk by 26% (HR: 1.26, 95% CI: 1.07-1.47), 56% (HR: 1.56, 95% CI: 1.31-1.86) and 91% (HR: 1.91, 95% CI: 1.59-2.31) respectively; The hazard ratios (HRs) for the fourth and fifth versus lowest quintile of cumNon-HDL-C concentration were 1.25 and 1.72 for ASCVD. Each standard deviation increment in cumNon-HDL-C concentration was associated with a 10% increased risk of ASCVD. Conclusion: Long-term and higher cumNon-HDL-C were all significantly associated with an increased risk of ASCVD independent of single non-HDL-C level.

Left ventricular lead position for cardiac resynchronization: a comprehensive cinegraphic, echocardiographic, clinical, and survival analysis.

AIMS: We sought to determine the clinical and survival outcomes of cardiac resynchronization therapy (CRT) associated with left ventricular (LV) lead location. The lateral left ventricle has been considered the optimal LV lead location for CRT. METHODS AND RESULTS: Left ventricular lead cinegrams taken in 30° right and left anterior oblique views were evaluated in 457 recipients of CRT with a pacemaker or a defibrillator from 1 January 2002 to 31 December 2008 in this retrospective study. Left ventricular lead placement was prioritized at implantation into posterolateral (PL), anterolateral (AL), middle cardiac, and anterointerventricular coronary veins. Using echocardiographic LV 16-segment analysis, we grouped the leads as anterior, AL, PL, and posterior locations. New York Heart Association (NYHA) class and echocardiography were assessed before and after CRT. Clinical and survival outcomes after CRT were compared among the four LV lead locations.  Patient baseline demographic characteristics were similar among these four groups. Improvement in NYHA class was significantly greater in the AL (P= 0.04) and PL (P= 0.03) locations than in the anterior location. There was a tendency for greater improvement in LV ejection fraction among the AL (P= 0.11) and PL (P= 0.08) locations than the anterior location. Kaplan-Meier survival estimate at 4 years varied for location: AL, 72%; anterior, 48%; PL, 62%; and posterior, 72% (P= 0.003). CONCLUSION: Cardiac resynchronization therapy recipients are profiting from all lead positions. However, LV lead placed in the AL and PL positions is more preferential for achieving optimal CRT benefit than leads placed in the anterior position.

[Predictive value of HATCH score on atrial fibrillation recurrence post radiofrequency catheter ablation].

OBJECTIVE: To determine the predictive value of HATCH score on recurrence of atrial fibrillation (AF) after radiofrequency catheter ablation (RFCA). METHODS: The data of 123 consecutive AF patients (74 paroxysmal and 49 persistent AF) who underwent RFCA between April 2009 and December 2010 in our department were retrospectively analyzed. Of theses patients, 65 (52.9%) patients had HATCH score = 0, 41 (33.3%) patients had HATCH score = 1, and 17 (13.8%) patients had HATCH score ≥ 2 (HATCH = 2 in 11 patients, HATCH = 3 in 5 patients, HATCH = 4 in 1 patient). The recurrence was defined as atrial tachyarrhythmia lasting more than 30 seconds after 3 months post RFCA. The patients were divided into recurrence group and no recurrence group. Relationship between HATCH score and recurrence was observed. RESULTS: There were 43 cases in recurrence group and 80 cases in no recurrence group. After 12 months follow-up, HATCH score was significant higher in recurrence group than in non-recurrence group [(0.91 ± 0.94) score vs. (0.53 ± 0.80) score, P < 0.05]. The ratio of patients with HATCH ≥ 2 in recurrence group was higher than in non-recurrence group [23.3% (10/43) vs. 8.8% (7/80), P < 0.01]. The sensitivity and specificity of HATCH ≥ 2 to define the risk of recurrence was 25.0%, 92.4% respectively. Cumulative non-recurrence rate of patients with HATCH score ≥ 2 was lower than patients with HATCH score = 0 and 1 (P < 0.05). CONCLUSION: Higher HATCH score is associated with increased risk of AF recurrence post RFCA.

Short QRS Duration After His-Purkinje Conduction System Pacing Predicts Left Ventricular Complete Reverse Remodeling in Patients With True Left Bundle Branch Block and Heart Failure.

Objective: This study aimed to explore the outcomes of His-Purkinje conduction system pacing (HPCSP) and to screen the predictors of left ventricular (LV) complete reverse remodeling in patients with true left bundle branch block (LBBB) and heart failure with reduced ejection fraction (HFrEF). Methods: Patients who underwent HPCSP for true LBBB and HFrEF from April 2018 to August 2020 were consecutively enrolled. All participants were followed up for at least 1 year. Thrombosis, infection, lead dislodgement, perforation, and other complications were observed after HPCSP. Clinical data, including echocardiographic parameters, electrocardiogram measurements, and cardiac function, were assessed before and after the procedure. Results: A total of 46 patients were enrolled. HPCSP was successfully deployed in 42 cases (91.30%), which included 37 cases with His bundle pacing (HBP) and 5 cases with left bundle branch pacing (LBBP). The QRS duration decreased significantly (169.88 ± 19.17 ms vs. 113.67 ± 20.68 ms, P < 0.001). Left ventricular end-systolic volume (LVESV) (167.67 ± 73.20 ml vs. 85.97 ± 62.24 ml, P < 0.001), left ventricular end-diastolic diameter (LVEDD) (63.57 ± 8.19 mm vs. 55.46 ± 9.63 mm, P = 0.003) and left ventricular ejection fraction (LVEF) (26.52 ± 5.60% vs. 41.86 ± 11.56%, P < 0.001) improved dramatically. Complete reverse remodeling of the LV with normalized LVEF and LVEDD was found in nearly half of the patients (45.24%). A short QRS duration after HPCSP was a strong predictor of normalized LVEF and LVEDD (P < 0.001). The thresholds increased markedly in two patients approximately 6 months after HBP. No patients died during the total follow-up period of 20.07 ± 6.45 months. Conclusion: Complete reverse remodeling of the LV could be found in nearly half of the patients with HFrEF and true LBBB after HPCSP, and the short QRS duration after HPCSP was a strong predictor.

[Effects of ventricular demand and dual-chamber pacing models on the long-term clinical outcome and cardiac remodeling in patients with symptomatic bradycardia].

OBJECTIVE: To assess the effects of VVI (ventricular demand) and DDD (dual-chamber) pacing models on cardiac remodeling and the long-term clinical outcome of patients with symptomatic bradycardia. METHODS: All patients with DDD and VVI pacing models at our hospital from January 1991 to January 2003 were retrospectively analyzed. RESULTS: After a follow-up period of over 8 years in DDD and VVI groups (97 ± 27, 107 ± 44 months), left atrial diameter [(45 ± 12) mm vs (39 ± 12) mm, P < 0.01] and left ventricular end-diastolic diameter [(53 ± 11) mm vs (50 ± 9) mm, P = 0.01] in 57 patients with VVI pacing model were markedly enlarged than those at pre-implantation. And tricuspid regurgitation increased (42.4% vs 16.9%, P < 0.05). But in 59 patients with DDD pacing model, except for increased tricuspid regurgitation (42.1% vs 10.5%, P < 0.01), left atrial diameter [(37 ± 5) mm vs. (35 ± 5) mm, P = 0.07] and left ventricular end-diastolic diameter [(47 ± 7) mm vs (47 ± 5) mm, P = 0.32] were not significantly different. Mitral regurgitation significantly increased only in the VVI group (P < 0.01). The increases of left ventricular end-diastolic diameter (P = 0.04), mitral valve (P = 0.02) and tricuspid regurgitation (P < 0.01) were much more pronounced in the VVI group than those in the DDD group. Left ventricular ejection fraction (LVEF) showed no difference with that at pre-implantation (P = 0.11 in DDD group, P = 0.05 in VVI group). But the LVEF value was lower (P = 0.04) while the incidence of thrombosis was higher (P = 0.03) in the VVI group than those in the DDD group at post-implantation. However, the incidence of atrial fibrillation (P = 0.14), hospitalization (P = 0.08) and survival (P = 0.77) showed no significant difference between two groups. CONCLUSION: DDD pacing offers more benefits over VVI pacing through improving cardiac functions and arresting left ventricular remodeling. However, neither groups showed any difference in decreasing mortality rate and hospitalization. Moreover, both pacing modes fail to reverse cardiac electrical and anatomical remodeling. It is imperative to explore more physiological pacing site and rational atrioventricular (AV) interval to improve the prognosis of patients.

His-purkinje system pacing upgrade improve the heart performances in patients suffering from pacing-induced cardiomyopathy with or without permanent atrial fibrillation.

INTRODUCTION: The efficacy and safety of his-purkinje system pacing (HPSP) upgrades in patients with pacing-induced cardiomyopathy (PICM) and atrial fibrillation (AF) are still unknown. METHODS AND RESULTS: Patients with PICM were continuously enrolled from January 2018 to March 2020. All patients were further divided into AF subgroup and sinus rhythm subgroup. Clinical data including echocardiographic examination parameters, electrocardiogram (ECG) measurements, and New York Heart Association (NYHA) classification, were assessed before and after the procedure. The HPSP upgrades, including his bundle pacing (HBP) and left bundle branch pacing (LBBP) were completed in 34 of 36 (94%) patients, Complications including electrode dislodged, perforation, infection or thrombosis were not observed in the perioperative period. During a mean of 11.52 ± 5.40 months of follow-up. The left ventricular ejection fraction (LVEF) increased significantly (33.76 ± 7.54 vs 40.41 ± 9.06, P < 0.001), and the QRS duration decreased (184.22 ± 23.76 ms vs 120.52 ± 16.67 ms, P < 0.001) after the upgrades. LVEDD reversed from 59.29 ± 7.74 mm to 53.91 ± 5.92 mm (P < 0.001), and the NYHA functional class also improved to 2.00 ± 0.76 from 2.55 ± 0.91 at the first follow-up (P < 0.001). The left atrium (LA) size also slightly decreased compared to the initial state (47.44 ± 7.14 mm VS 45.56 ± 7.78, P = 0.010). BNP significantly decreased from a median value of 458.06(256.35-755.10) to 172.31(92.69-552.14) (P = 0.004). The threshold did not increase significantly (1.18 ± 0.76 mv@0.4 ms vs 1.26 ± 0.91mv @ 0.4 ms, P = 0.581). These improvements in patients with AF were similar with those in patients without AF (P > 0.05). CONCLUSIONS: HPSP upgrades improved the heart performance and reversed the left ventricular remodeling in patients suffering from PICM with or without AF, and it should be a promising choice in these patients.

Preprodynorphin gene mutation causes progressive cardiac conduction disease: A whole-exome analysis of a pedigree.

AIMS: Progressive cardiac conduction disease (PCCD) is a rare heart disease that usually shows familial inheritance. Potential genetic risk factors for PCCD have been mostly limited to genes that encode ion channels, cardiac transcription factors, T-box transcription factors, gap junction proteins, energy metabolism regulators and structural proteins. MAIN METHODS: Subjects in the present study came from a family who exhibited the autosomal dominant inheritance of PCCD. The primary proband had syncope and an electrocardiogram typical for PCCD, which started in the left bundle branch block, and passed to the atrioventricular block. The patient received a permanent pacemaker in 2013. Pathogenic mutations in the proband's family were identified using whole-exome sequencing and Sanger sequencing. KEY FINDINGS: The results for the family members were verified using Sanger sequencing, while the results for healthy unrelated individuals were verified using SNaPShot. All patients in the family shared two adjacent missense mutations in the preprodynorphin (PDYN) gene (c.581A > T, c.580G > C; p.D194L). SIGNIFICANCE: The PDYN double mutation c.581A > T and c.580G > C (p.D194L) may be linked to the onset of familial PCCD. The effects of these mutations on electrophysiology require further investigation.

Comparison of cryoballoon ablation for atrial fibrillation guided by real-time three-dimensional transesophageal echocardiography vs. contrast agent injection.

BACKGROUND: Pulmonary vein (PV) occlusion generally depends on repetitive contrast agent injection when cryoballoon ablation for atrial fibrillation (AF). The present study was to compare the effect of cryoballoon ablation for AF guided by transesophageal echocardiography (TEE) vs. contrast agent injection. METHODS: Eighty patients with paroxysmal AF (PAF) were enrolled in the study. About 40 patients underwent cryoballoon ablation without TEE (non-TEE group) and the other 40 underwent cryoballoon ablation with TEE for PV occlusion (TEE group). In the TEE group during the procedure, PVs were displayed in 3-dimensional images to guide the balloon to achieve PV occlusion. The patients were followed up at regularly scheduled visits every 2 months. RESULTS: No differences were identified between the groups in regard to the procedure time and cryoablation time for each PV. The fluoroscopy time (6.7 ±â€Š4.2 min vs. 17.9 ±â€Š5.9 min, P < 0.05) and the amount of contrast agent (3.0 ±â€Š5.1 mL vs.18.1 ±â€Š3.4 mL, P < 0.05) in the TEE group were both less than the non-TEE group. At a mean of 13.0 ±â€Š3.3 mon follow-up, success rates were similar between the TEE group and non-TEE group (77.5% vs. 80.0%, P = 0.88). CONCLUSIONS: Cryoballoon ablation with TEE for occlusion of the PV is both safe and effective. Less fluoroscopy time and a lower contrast agent load can be achieved with the help of TEE for PV occlusion during procedure.

Impact of right upper pulmonary vein isolation on atrial vagal innervation and vulnerability to atrial fibrillation.

BACKGROUND: Based on the hypothesis that pulmonary vein isolation could result in the damage of the epicardial fat pads, this study aimed to investigated the impact of right upper pulmonary vein (RUPV) isolation on vagal innervation to atria. METHODS: Bilateral cervical sympathovagal trunks were decentralized in 6 dogs. Metoprolol was given to block sympathetic effects. Multipolar catheters were placed into the right atrium (RA) and coronary sinus (CS). RUPV isolation was performed via transseptal procedure. Atrial effective refractory period (ERP), vulnerability window (VW) of atrial fibrillation (AF), and sinus rhythm cycle length (SCL) were measured at RA and distal coronary sinus (CSd) at baseline and vagal stimulation before and after RUPV isolation. Serial sections of underlying tissues before and after ablation were stained with haematoxylin and eosin. RESULTS: SCL decreased significantly during vagal stimulation before RUPV isolation (197 +/- 21 vs 13 +/- 32 beats per minute, P < 0.001), but remained unchanged after RUPV isolation (162 +/- 29 vs 140 +/- 39 beats per minute, P > 0.05). ERP increased significantly before RUPV isolation compared with that during vagal stimulation [(85.00 +/- 24.29) ms vs (21.67 +/- 9.83) ms at RA, P < 0.001; (90.00 +/- 15.49) ms vs (33.33 +/- 25.03) ms at CSd P < 0.005], but ERP at baseline hardly changed after RUPV isolation compared with that during vagal stimulation [(103.33 +/- 22.50) vs (95.00 +/- 16.43) ms at RA, P = 0.09; (98.33 +/- 24.83) vs (75.00 +/- 29.50) ms at CSd, P = 0.009]. The ERP shortening during vagal stimulation after RUPV isolation decreased significantly [(63.33 +/- 22.51) ms vs (8.33 +/- 9.83) ms at RA, P < 0.005; (56.67 +/- 20.66) ms vs (23.33 +/- 13.66) ms at CSd, P < 0.05]. AF was rarely induced at baseline before and after RUPV isolation (VW close to 0), while VW of AF to vagal stimulation significantly decreased after RUPV isolation [(40.00 +/- 10.95) vs 0 ms at RA, P < 0.001; (45.00 +/- 32.09) vs (15.00 +/- 23.45) ms at CS, P < 0.05]. The architecture of individual ganglia was significantly altered after ablation. CONCLUSIONS: The less ERP shortening to vagal stimulation and altered architecture of individual ganglia after right upper pulmonary vein isolation indicate that isolation may result in damage of the epicardial fat pads, thereby attenuating the vagal innervation to atria. The decreased vulnerability window of atrial fibrillation indicates that vagal denervation may contribute to its suppression.

Effect of ventricular leads position on the clinic outcome of cardiac resynchronization therapy.

The RV lead position, either RVA or RVHS appears to make no difference in the response to CRT but the LV lead placement play a vital role.9,30 The latest activated regions of LV or areas without transmural myocardial scar for an optimal CRT are preferred. Currently, data demonstrate that no significant difference of clinical outcomes in posterior, anterior, and lateral LV lead position was found, while the ideal pacing site of the LV should be avoided in the apex position as suggested in COMPANION trial and MADIT-CRT trial. And dual-site LV CRT, which is a new technique, is also still in progress and we are looking forward to getting more updates from that.

Left ventricular 12 segmental strain imaging predicts response to cardiac resynchronization therapy.

BACKGROUND: The number of non-responders to cardiac resynchronization therapy (CRT) exposes the need for better patient selection criteria for CRT. This study aimed to identify echocardiographic parameters that would predict the response to CRT. METHODS: Forty-five consecutive patients receiving CRT-D implantation for heart failure (HF) were included in this prospective study. New York Heart Association (NYHA) class, 6-minute walk distance, electrograph character, and multi echocardiographic parameters, especially in strain patterns, were measured and compared before and six months after CRT in the responder and non-responder groups. Response to CRT was defined as a decrease in left ventricular endsystolic volume (LVESV) of 15% or more at 6-month follow up. RESULTS: Twenty-two (48.9%) patients demonstrated a response to CRT at 6-month follow-up. Significant improvement in NYHA class (P < 0.01), left ventricular end-diastolic volume (LVEDV) (P < 0.01), and 6-minute walk distance (P < 0.01) was shown in this group. Although there was an interventricular mechanical delay determined by the difference between left and right ventricular pre-ejection intervals ((42.87 ± 19.64) ms vs. (29.43 ± 18.19) ms, P = 0.02), the standard deviation of time to peak myocardial strain among 12 basal, mid and apical segments (Tε-SD) ((119.97 ± 43.32) ms vs. (86.62 ± 36.86) ms, P = 0.01) and the non-ischemic etiology (P = 0.03) were significantly higher in responders than non-responders, only the Tε-SD (OR = 1.02, 95% CI = 1.01 - 1.04, P = 0.02) proved to be a favorable predictor of CRT response after multivariate Logistic regression analysis. CONCLUSION: The left ventricular 12 segmental strain imaging is a promising echocardiographic parameter for predicting CRT response.

Substrate of complex fractionated atrial electrograms: evidence by pathologic analysis.

BACKGROUND: Ablation of complex fractionated atrial electrograms (CFAE) is an important adjunctive therapy in atrial fibrillation (AF). The present study was to elucidate the substrate underlying CFAE. METHODS: Nine adult mongrel dogs were involved in the present study. AF was induced through rapid atrial pacing with vagosympathetic nerve stimulation. CFAE was recorded during AF. Ablation was performed at CFAE sites. Based on the location of the ablation scar, the atrial specimens were divided into CFAE and non-CFAE sites. Serial sections of the atrium were stained respectively with hematoxylin-eosin (HE) and the general neural marker protein gene product 9.5 (PGP9.5). We compared the characteristics of the myocardium and the ganglionated plexus (GPs) distribution between the CFAE and non-CFAE sites. RESULTS: The myocardium of non-CFAE sites was well-organized with little intercellular substance. However, the myocardium in the CFAE site was disorganized with more interstitial tissue ((61.7 ± 24.3)% vs. (34.1 ± 9.2)%, P < 0.01). GPs in the CFAE site were more abundant than in non-CFAE sites ((34.45 ± 37.46) bundles/cm(2) vs. (6.73 ± 8.22) bundles/cm(2), P < 0.01). CONCLUSION: The heterogeneity of the myocardium and GPs distribution may account for the substrate of CFAE and serve as a potential target of ablation.

Electrophysiological and hemodynamic characteristics associated with obesity in patients with atrial fibrillation.

OBJECTIVES: The authors sought to characterize the left atrial (LA) and pulmonary vein (PV) electrophysiological and hemodynamic features in obese patients with atrial fibrillation (AF). BACKGROUND: Obesity is associated with increased risk for AF. METHODS: A total of 63 consecutive patients with AF who had normal left ventricular (LV) ejection fraction and who underwent catheter ablation were studied. Atrial and PV electrophysiological studies were performed at the time of ablation with hemodynamic assessment by cardiac catheterization, and LA/LV structure and function by echocardiography. Patients were compared on the basis of body mass index (BMI): <25 kg/m(2) (n = 19) and BMI ≥30 kg/m(2) (n = 44). RESULTS: At a 600-ms pacing cycle length, obese patients had shorter effective refractory period (ERP) in the left atrium (251 ± 25 ms vs. 233 ± 32 ms, p = 0.04), and in the proximal (207 ± 33 ms vs. 248 ± 34 ms, p < 0.001) and distal (193 ± 33 ms vs. 248 ± 44 ms, p < 0.001) PV than normal BMI patients. Obese patients had higher mean LA pressure (15 ± 5 mm Hg vs. 10 ± 5 mm Hg, p < 0.001) and LA volume index (28 ± 12 ml/m(2) vs. 21 ± 14 ml/m(2), p = 0.006), and lower LA strain (5.5 ± 3.1% vs. 8.8 ± 2.8%; p < 0.001) than normal BMI patients. CONCLUSIONS: Increased LA pressure and volume, and shortened ERP in the left atrium and PV are potential factors facilitating and perpetuating AF in obese patients with AF.

Effect of cardiac resynchronization therapy on broad neurohormone biomarkers in heart failure.

BACKGROUND: Neurohormonal dysregulation contributes to heart failure (HF) progression. We sought to determine the effect of cardiac resynchronization therapy (CRT) on nerve growth factor (NGF), a biomarker that promotes the maturation and survival of sympathetic nerve endings, and amino-terminal propeptide of type III procollagen (PIIINP), a marker of type III collagen synthesis. METHODS: This prospective study consisted of 45 consecutive patients who received cardiac resynchronization therapy defibrillator for advanced HF and 20 healthy age-matched controls. New York Heart Association class, distance of 6-min walk, echocardiography and plasma concentrations of NGF, PIIINP, b-type natriuretic peptide (BNP), norepinephrine, and epinephrine were measured before and 6 months after CRT. Response to CRT was defined as 15% or greater reduction in left ventricular end-systolic volume index at 6-month follow-up. RESULTS: The baseline BNP (2.61 ± 0.51 vs. 1.53 ± 0.44 ug/L, P < 0.01) and PIIINP (0.88 ± 0.21 vs. 0.71 ± 0.14 µg/L, P = 0.01), but not other biomarkers, were elevated in HF compared to controls. Twenty-two of 45 patients (49%) responded to CRT. The responder group demonstrated significant decrease only in BNP level from 2.61 ± 0.51 to 2.31 ± 0.41 µg/L (P = 0.04) at 6-month follow-up, paralleling the clinical improvements. The baseline PIIINP, rather than the other biomarkers, was lower in CRT responders than non-responders (0.80 ± 0.20 vs. 0.96 ± 0.19 µg/L, P = 0.03). Univariate and multivariate analysis showed that less elevated plasma PIIINP level in HF might be an independent biomarker predicting better response to CRT (odds ratio = 0.20, 95% CI = 0.03-1.17, P = 0.07). CONCLUSION: The less elevated PIIINP level in HF, which is suggestive of a lesser amount of cardiac fibrosis, has a trend in association with a favorable response to CRT. Contrary to previous reports, NGF levels are not reduced during HF with optimal medical therapy, and there is no NGF rebound in CRT responders.