胡奕然
中国医学科学院阜外医院 心律失常中心
Harvesting biomechanical energy from cardiac motion is an attractive power source for implantable bioelectronic devices. Here, we report a battery-free, transcatheter, self-powered intracardiac pacemaker based on the coupled effect of triboelectrification and electrostatic induction for the treatment of arrhythmia in large animal models. We show that the capsule-shaped device (1.75 g, 1.52 cc) can be integrated with a delivery catheter for implanting in the right ventricle of a swine through the intravenous route, which effectively converts cardiac motion energy to electricity and maintains endocardial pacing function during the three-week follow-up period. We measure in vivo open circuit voltage and short circuit current of the self-powered intracardiac pacemaker of about 6.0 V and 0.2 μA, respectively. This approach exhibits up-to-date progress in self-powered medical devices and it may overcome the inherent energy shortcomings of implantable pacemakers and other bioelectronic devices for therapy and sensing.
Nature communications 2024
BACKGROUND:We investigated the similarities and differences between two experimental approaches using tachy-pacing technology to induce desynchronized heart failure in canines.METHODS:A total of eight dogs were included in the experiment, four were tachy-paced in right ventricle apex (RVAP) and 4 were paced in right atrium after the ablation of left bundle branch to achieve left bundle branch block (RAP+LBBB). Three weeks of follow-up were conducted to observe the changes in cardiac function and myocardial staining was performed at the end of the experiment.RESULTS:Both experimental approaches successfully established heart failure with reduced ejection fraction models, with similar trends in declining cardiac function. The RAP+LBBB group exhibited a prolonged overall ventricular activation time, delayed left ventricular activation, and lesser impact on the right ventricle. The RVAP approach led to a reduction in overall right ventricular compliance and right ventricular enlargement. The RAP+LBBB group exhibited significant reductions in left heart compliance (LVGLS, %: RAP+LBBB -12.60 ± 0.12 to -5.93 ± 1.25; RVAP -13.28 ± 0.62 to -8.05 ± 0.63, p = 0.023; LASct, %: RAP+LBBB -15.75 ± 6.85 to -1.50 ± 1.00; RVAP -15.75 ± 2.87 to -10.05 ± 6.16, p = 0.035). Histological examination revealed more pronounced fibrosis in the left ventricular wall and left atrium in the RAP+LBBB group while the RVAP group showed more prominent fibrosis in the right ventricular myocardium.CONCLUSION:Both approaches establish HFrEF models with comparable trends. The RVAP group shows impaired right ventricular function, while the RAP+LBBB group exhibits more severe decreased compliance and fibrosis in left ventricle.
Animal models and experimental medicine 2024
BACKGROUND AND OBJECTIVE:Left bundle branch pacing (LBBP) has shown the benefits in the treatment of dyssynchronous heart failure (HF). The purpose of this study was to develop a novel approach for LBBP and left bundle branch block (LBBB) in a canine model.METHODS:A "triangle-center" method by tricuspid valve annulus angiography for LBBP implantation was performed in 6 canines. A catheter was then applied for retrograde His potential recording and left bundle branch (LBB) ablation simultaneously. The conduction system was stained to verify the "triangle-center" method for LBBP and assess the locations of the LBB ablation site in relation to the left septal fascicle (LSF).RESULTS:The mean LBB potential to ventricular interval and stimulus-peak left ventricular activation time were 11.8 ± 1.2 and 35.7 ± 3.1 ms, respectively. The average intrinsic QRS duration was 44.7 ± 4.7 ms. LBB ablation significantly prolonged the QRS duration (106.3 ± 8.3 ms, p < .001) while LBBP significantly shortened the LBBB-QRS duration to 62.5 ± 5.3 ms (p < .001). After 6 weeks of follow-up, both paced QRS duration (63.0 ± 5.4 ms; p = .203) and LBBB-QRS duration (107.3 ± 7.4 ms; p = .144) were unchanged when comparing to the acute phase, respectively. Anatomical analysis of 6 canine hearts showed that the LBBP lead-tip was all placed in LSF area.CONCLUSION:The new approach for LBBP and LBBB canine model was stable and feasible to simulate the clinical dyssynchrony and resynchronization. It provided a useful tool to investigate the basic mechanisms of underlying physiological pacing benefits.
Journal of cardiovascular electrophysiology 2023
Background:Not all patients with heart failure derive consistent benefit from prophylactic implantable cardioverter-defibrillator (ICD). We aimed to evaluate the role of MADIT-ICD benefit score in risk-stratifying in Asian patients with left ventricular ejection fraction (LVEF) ≤35%.Methods:In this two-center, retrospective study, a total of 136 patients with LVEF ≤35% who received an ICD for primary prevention were enrolled. The endpoints were defined as the ventricular tachycardia ≥200bpm (VT) or ventricular fibrillation (VF) and non-arrhythmic death. Based on the MADIT-ICD benefit score system, all patients were categorized into three groups: highest benefit group (n = 41), intermediate benefit group (n = 80), and lowest benefit group (n = 15).Results:Forty patients experienced VT/VF and seven died of non-arrhythmic causes during a median follow-up of 44.8 ± 28.9 months. Kaplan-Meier curves showed that patients in highest benefit group had a worse VT/VF occurrence compared to those in other groups. In the highest benefit group, the predicted risk of VT/VF was 17-fold higher than the risk of non-arrhythmic mortality (41.5% vs 2.4%, P < 0.001). In the intermediate benefit group, the predicted risk of VT/VF was 4.2-fold higher than the risk of non-arrhythmic mortality (26.3% vs 6.3%, P = 0.001). In the lowest benefit group, however, the difference in the corresponding predicted risks was attenuated without statistically significant (13.3% vs 5.1%, P = 0.56).Conclusion:We demonstrate that MADIT-ICD benefit score can be used for the assessment of ICD primary prevention benefits in Asian patients with LVEF ≤35%.
International journal of general medicine 2022
PURPOSE:We aimed to evaluate the electrical characteristics and pacing parameters at different locations of His-Purkinje system pacing.METHODS:Patients who successfully underwent His-Purkinje system pacing with bradycardia indications from April 2018 to August 2019 were retrospectively analyzed according to the lead location confirmed by visualization of the tricuspid value annulus, postoperative echocardiography, and pacing electrocardiogram. The electrical characteristics and pacing parameters were compared among these patients.RESULTS:A total of 135 patients were retrospectively analyzed. Among them, 30 patients received atrial side HBP (aHBP group), 52 received ventricular side HBP (vHBP group), and 53 received left bundle branch pacing (LBBP group). The proportion of non-selective pacing was significantly lower in aHBP group (30.0%) than in vHBP (75.0%) and LBBP group (90.6%). LBBP had significantly shorter procedural and fluoroscopic duration than aHBP and vHBP. The capture threshold was significantly higher (1.07 ± 0.26 V/1.0 ms vs. 0.89 ± 0.22 V/1.0 ms vs. 0.77 ± 0.18 V/0.4 ms, P < 0.01, respectively), and the R-wave amplitude was significantly lower (3.71 ± 1.72 mV vs. 5.81 ± 2.37 mV vs. 10.27 ± 4.71 mV, P < 0.05 respectively) in aHBP group than those in the other two groups at implantation and during 3-month follow-up. No significant differences were observed in complications among groups during 3-month follow-up.CONCLUSION:VHBP and LBBP had better pacing performances than aHBP and might be more ideal pacing methods for bradycardia patients.
Journal of interventional cardiac electrophysiology : an international journal of arrhythmias and pacing 2022
BACKGROUND:Implantable cardioverter-defibrillator (ICD) is the most effective strategy for prevention of ventricular tachyarrhythmia in patients with arrhythmogenic cardiomyopathy (ACM). However, some patients receive ventricular electrical storm (VES), characterized by multiple episodes of sustained ventricular tachyarrhythmia. The purpose of this study was to determine the incidence, predictors and prognostic implications of VES in ACM patients with an ICD.METHODS:A total of 88 patients with definite ACM who received an ICD and followed up continuously were included in this study. VES was defined as the occurrence of ≥3 separate episodes of sustained ventricular arrhythmias within a 24-hour period.RESULTS:During a median follow-up time of 4.0 years (range 1.6-6.9), VES occurred in 19/88 patients (21.6%). The interval between the ICD implantation and the first VES ranged from 1 month to 128 months. The median number of ventricular tachyarrhythmia events per VES was 7.5 (range 3-32). Multivariate analysis showed that VES was associated with a high body mass index (BMI) [adjusted hazard ratio (HR) 1.21, 95% confidence interval (CI) 1.00-1.45, P=0.048)] and extensive T-wave inversion (TWI) (HR 23.39, 95% CI 1.74-314.58, P=0.017). Kaplan-Meier method showed that patients with VES did not have a worse cardiac mortality compared to those without such an event.CONCLUSION:There is a relatively high incidence of VES in ACM patients. The presence of high BMI and extensive TWI were strong predictors of VES occurrence in ACM patients with ICD. VES does not independently confer increased cardiac mortality.
International journal of general medicine 2021
BACKGROUND:Left bundle branch pacing (LBBP) is a novel conduction system pacing modality, but pacing lead deployment remains challenging.OBJECTIVES:This study aimed to evaluate the feasibility of visualization-enhanced lead deployment for LBBP implantation and to assess LBBP characteristics on the basis of lead tip location.METHODS:Successful LBBP with a well-defined lead tip location by visualization of the tricuspid value annulus in 20 patients was retrospectively analyzed to develop an image-guided technique to identify the LBBP target site. This technique was then prospectively tested in 60 patients who were randomized into 2 groups, one using the standard approach (the standard group) and the other using the image-guided technique (the visualization group). The procedural details, electrophysiological characteristics, and short-term follow-up were compared between groups.RESULTS:LBBP was successfully achieved in 28 patients in the standard group and in 29 in the visualization group. The procedural and fluoroscopic durations in the visualization group (66.76 ± 14.62 and 7.83 ± 2.05 minutes) were significantly shorter than those in the standard group (85.46 ± 20.19 and 11.11 ± 3.51 minutes) (P < .01). The number of lead deployment attempts in the visualization group was lower than that in the standard group (2.03 ± 1.18 vs 2.96 ± 1.17; P < .01), and the proportion of left bundle branch potential recorded was higher (79.3% vs 46.4%; P = .01).CONCLUSION:Using a visualization technique, the procedural and fluoroscopic durations for LBBP implantation were significantly shortened with fewer lead repositioning attempts.
Heart rhythm 2021
BACKGROUND:Arrhythmogenic cardiomyopathy (ACM) is characterized by a high incidence of ventricular tachyarrhythmia and sudden death. Implantable cardioverter-defibrillator (ICD) implantation is the cornerstone of management.OBJECTIVE:This study aims to reveal the prognostic value of the contrast-enhanced cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE) amount in predicting varying lethal outcomes among ACM patients with ICDs.METHODS:The 88 patients with definite ACM who were all referred for contrast-enhanced CMR received an ICD and were followed up for a median of 4.0 years.RESULTS:Fifty-four patients had no left ventricular (LV) involvement and sixteen had an LV LGE amount > 15%. During the follow-up time, appropriate ICD therapy was seen in 57, electrical storm (ES) in 19, and cardiac death in 9 patients. Compared with those without LV involvement, patients with LV LGE amount > 15% had a higher risk of cardiac death (log-rank P = 0.021). LV LGE amount was associated with an increased risk of ICD therapy [adjusted hazard ratio (HR) 1.035, 95% confidence interval (CI) 1.008-1.062, P = 0.010], and cardiac death (adjusted HR 1.082, 95% 1.006-1.164, P = 0.034), independently of LV ejection fraction. LV LGE mass of >15% demonstrated an over 2-fold increase in ICD therapy (adjusted HR 2.180, 95%CI 1.058-4.488, P = 0.035) and an over 7-fold increase in cardiac death (unadjusted HR 7.198, 95%CI 1.399-37.043, P = 0.018) than those without LV involvement, respectively.CONCLUSIONS:The LV LGE-CMR in ACM shows a dose-dependent association with ICD therapy and cardiac death. And LV LGE amount of >15% is a strong predictor.
International journal of cardiology 2021
To validate externally and recalibrate three European risk scores for all-cause mortality and transplantation in patients receiving cardiac resynchronization therapy (CRT) in an Asian population. Data were collected at our institution between January 2010 and December 2017. The primary endpoints were all-cause mortality and heart transplantation. Of the 506 patients who were followed for 2 years, 104 reached the primary endpoint. The Kaplan-Meier event-free survival analysis, stratified according to the three scores, yielded significant results (log-rank test, all P < 0.05), with a good fit between the predicted and observed event rates (Hosmer-Lemeshow goodness-of-fit test, all P > 0.05). The ScREEN score yielded the best discriminatory power for the primary endpoints compared with the VALID-CRT and EAARN scores. ScREEN was the best predictor of all-cause mortality and heart transplantation. Risk scores based on different populations should be selected cautiously. Graphical Abstract.
Journal of cardiovascular translational research 2021
AIMS:Left ventricular ejection fraction (LVEF) is considered an indicator of cardiac resynchronization therapy (CRT). Longitudinal studies on the predictive value of LVEF are scarce. We aimed to comprehensively evaluate the prognostic role of LVEF in the outcomes of Chinese patients with CRT.METHODS AND RESULTS:Three hundred ninety-two patients were divided into three tertiles of LVEF: ≤25%, 25-30%, and 30-35%, and four groups by LVEF changes: <0% (negative response); ≥0% and ≤5% (non-response); >5% and ≤15% (response); and >15% (super-response). One hundred six patients were super-responders. During a median follow-up of 3.6 years, 141 reached the composite endpoint. Odds ratios (ORs) for super-response depicted a reversed U-shaped relationship for baseline LVEF with a peak at 25-30%. Independent predictors of super-response were smaller left atrial diameter [odds ratio 0.897, 95% confidence interval (CI) 0.844-0.955, P = 0.001], smaller left ventricular end-diastolic diameter (OR 0.937, 95% CI 0.889-0.989, P = 0.018), and higher estimated glomerular filtration rate (OR 1.018, 95% CI 1.001-1.035, P = 0.042) in Tertile 1; atrial fibrillation (OR 0.278, 95% CI 0.086-0.901, P = 0.033), left bundle branch block (OR 4.096, 95% CI 1.046-16.037, P = 0.043), and left ventricular end-diastolic diameter (OR 0.929, 95% CI 0.876-0.986, P = 0.016) in Tertile 2; while female sex (OR 2.778, 95% CI 1.082-7.132, P = 0.034) and higher systolic blood pressure (OR 1.045, 95% CI 1.013-1.079, P = 0.006) in Tertile 3. An inverse association with the composite endpoint was found in Tertile 1 vs. Tertile 2 (hazard ratio 1.934, 95% CI 1.248-2.996, P = 0.003). The prognostic effects of CRT response in Tertile 3 and Tertile 1 varied significantly (P for trend = 0.017 and <0.001). Among three tertiles in super-responders, event-free survival was similar (P for trend = 0.143).CONCLUSIONS:Left ventricular ejection fraction of 25-30% is associated with a better prognosis of super-response. Predictors of super-response are different for LVEF tertiles. CRT responses would have better prognostic performance than LVEF tertiles at baseline, which should be considered when clinicians screening eligible patients for CRT.
ESC heart failure 2021
