Surface and intracardiac ECG for discriminating conduction disorders after CoreValve implantation

Building capacity through open approaches: Lessons from developing undergraduate electrophysiology practicals

Background: Electrophysiology has a wide range of biomedical research and clinical applications. As such, education in the theoretical basis and hands-on practice of electrophysiological techniques is essential for biomedical students, including at the undergraduate level. However, offering hands-on learning experiences is particularly difficult in environments with limited resources and infrastructure. Methods: In 2017, we began a project to design and incorporate electrophysiology laboratory practicals into our Biomedical Physics undergraduate curriculum at the Universidad Nacional Autónoma de México. We describe some of the challenges we faced, how we maximized resources to overcome some of these challenges, and in particular, how we used open scholarship approaches to build both educational and research capacity. Results: We succeeded in developing a number of experimental and data analysis practicals in electrophysiology, including electrocardiogram, electromyogram, and electrooculogram techniques. The use of open tools, open platforms, and open licenses was key to the success and broader impact of our project. We share examples of our practicals and explain how we use these activities to strengthen interdisciplinary learning, namely the application of concepts in physics to understanding functions of the human body. Conclusions: Open scholarship provides multiple opportunities for universities to build capacity. Our goal is to provide ideas, materials, and strategies for educators working in similar resource-limited environments.

Predictors of high-degree conduction disturbances and pacemaker implantation after transcatheter aortic valve replacement: Prognostic role of the electrophysiological study

BACKGROUND

Predictors of high-degree atrioventricular block (HAVB) after transcatheter aortic valve replacement (TAVR) are recognized, but the electrophysiological study's (EPS) role is still a subject to debate. The objective of our study was to determine factors associated with PPM implantation including the potential role of EPS before and/or after TAVR.

METHODS AND RESULTS

Seventy four consecutive patients (pts) were included and 21 pts (28.4%) received a PPM during the immediate postoperative follow-ups (until Day 5): HAVB in 15 pts (71.4%), prophylactic implantation due to a documented increased HV interval ≥ 95-100 ms plus LBBB in 2 pts (9.5%), a high-degree HV block evidenced at the EPS plus LBBB in 3 pts (14.3%) and one additional patient was implanted for AV-block in presence of AFib (4.8%). In the multivariate model 1 including parameters before TAVR, both prosthesis diameter and PR lengthening remained significantly associated with PPM as well RBBB. In the multivariate model 2 including parameters after TAVR, only HV remained significantly associated with the risk of PPM (OR = 1.15 (1.05-1.26), p = .004). When all the significant variables in models 1 and 2 were analyzed together in model 3, only HV after TAVR remained significantly associated with an increased risk of PPM.

CONCLUSIONS

In this prospective observational study, it was revealed that a Day 4-5 EPS is likely to more precisely stratify the risk of PPM implantation regarding its ability to discover asymptomatic severe infra-hisian conduction disturbances particularly in presence of LBBB. Multivariate analysis confirmed the prognostic value of HV alteration.

Intraprocedural dynamics of cardiac conduction during transcatheter aortic valve implantation: Assessment by simultaneous electrophysiological testing

BACKGROUND

Transcatheter aortic valve implantation (TAVI) is an established treatment for patients with severe aortic stenosis and high to intermediate surgical risk. However, the proximity of the conduction system to the prosthesis landing zone bears the risk of atrioventricular conduction disorders. The underlying pathophysiology is not fully understood.

OBJECTIVE

The purpose of this study was to characterize the impact of TAVI on the conduction system as assessed by simultaneous electrophysiological testing.

METHODS

AH and HV intervals and QRS duration were measured using a quadripolar His catheter and surface electrocardiogram in 108 patients at baseline (BL), after balloon predilation (timepoint 1 [T1]), after implantation of the valve prosthesis (T2), and after postdilation, if deemed necessary (T3).

RESULTS

Between BL and T2, significant increases of HV interval and QRS duration were observed, with a mean delta of +12.4 ms and +32.7 ms, respectively. Both balloon predilation and valve implantation had an impact on infranodal conduction. No significant increase of AH intervals was documented. The increase of QRS duration led to left bundle branch block (LBBB) in 57 patients (52.8%). Implantation depth positively correlated with QRS prolongation (ρ = 0.21, P = .042) but not with changes of AH or HV interval (ρ = -0.03, P = .762; and ρ = 0.15, P = .130, respectively).

CONCLUSION

Electrophysiological testing during TAVI shows impairment of infranodal atrioventricular conduction by balloon predilation and valve implantation. This impairment is positively correlated with valve implantation depth and results in an increase of QRS duration with mainly LBBB pattern on surface electrocardiogram.

Conduction Abnormalities After Transcatheter Aortic Valve Replacement

Transcatheter aortic valve replacement (TAVR) has been established as a therapeutic option for patients with severe symptomatic aortic stenosis who are of intermediate or higher surgical risk. Several periprocedural complications are reduced with newer transcatheter heart valve generations; however, conduction abnormalities and the need for permanent pacemaker implantation have remained unchanged and are the most frequent TAVR complications. The close relationship of the atrioventricular node and left bundle branch to the subaortic region explains these potential conduction abnormalities. This article highlights conduction abnormalities after TAVR with a focus on basic conduction system anatomy in relation to the aortic valve, the mechanism, incidence, predisposing factors for occurrence, impact on mortality and finally, proposed treatment algorithms for management.

Prognosis assessment of persistent left bundle branch block after TAVI by an electrophysiological and remote monitoring risk-adapted algorithm: rationale and design of the multicentre LBBB-TAVI Study

INTRODUCTION

Percutaneous aortic valve replacement (transcatheter aortic valve implantation (TAVI)) notably increases the likelihood of the appearance of a complete left bundle branch block (LBBB) by direct lesion of the LBB of His. This block can lead to high-grade atrioventricular conduction disturbances responsible for a poorer prognosis. The management of this complication remains controversial.

METHOD AND ANALYSIS

The screening of LBBB after TAVI persisting for more than 24 hours will be conducted by surface ECG. Stratification will be performed by post-TAVI intracardiac electrophysiological study. Patients at high risk of conduction disturbances (≥70 ms His-ventricle interval (HV) or presence of infra-Hisian block) will be implanted with a pacemaker enabling the recording of disturbance episodes. Those at lower risk (HV <70 ms) will be implanted with a loop recorder device with remote monitoring of cardiovascular implantable electronic devices (CIEDs). Clinical, ECG and implanted device follow-up will also be performed at 3, 6 and 12 months. The primary objective is to assess the efficacy and safety of a decisional algorithm based on electrophysiological study and remote monitoring of CIEDs in the prediction of high-grade conduction disturbances in patients with LBBB after TAVI. The primary end point is to compare the incidence (rate and time to onset) of high-grade conduction disturbances in patients with LBBB after TAVI between the two groups at 12 months. Given the proportion of high-grade conduction disturbances (20-40%), a sample of 200 subjects will allow a margin of error of 6-7%. The LBBB-TAVI Study has been in an active recruiting phase since September 2015 (21 patients already included).

ETHICS AND DISSEMINATION

Local ethics committee authorisation was obtained in May 2015. We will publish findings from this study in a peer-reviewed scientific journal and present results at national and international conferences.

TRIAL REGISTRATION NUMBER

NCT02482844; Pre-results.

One-year follow-up of conduction disturbances following transcatheter aortic valve implantation

AIMS

To describe the postprocedural and 1-year follow-up incidence of heart conduction disturbances in patients with severe symptomatic aortic stenosis undergoing transcatheter aortic valve implantation (TAVI).

METHODS

Ninety-five patients were enrolled from 2008 to 2011 (mean age 81.8 ± 7.2 years, 63.1% women). Clinical and ECG data were recorded at admission, discharge, and 3, 6 and 12 months following TAVI.

RESULTS

Fifty-seven Edwards SAPIEN (31 transapical, 26 transfemoral) and 38 transfemoral CoreValve implants were used. Two (2.1%) patients died during the procedure and 11 (11.6%) patients received a pacemaker prior to discharge (7 CoreValve, 3 transapical, 1 transfemoral SAPIEN; P = 0.18). Among the surviving patients not receiving a pacemaker, TAVI increased the PQ interval (176 ± 29 vs. 188 ± 36 ms; P = 0.001), QRS width (90 ± 15 vs. 108 ± 26 ms; P < 0.001), and first-grade atrioventricular block (17 vs. 29%; P < 0.001). Postprocedural complete left bundle branch block was reported most in transapical (from 10 to 36%; P = 0.01) and CoreValve (from 8 to 64%; P < 0.001) recipients compared to the transfemoral SAPIEN group. At the 12-month follow-up, 24 (25.3%) patients had died [two (2.1%) sudden deaths] and four (4.2%) required pacemaker implantation. Among the survivors not receiving a pacemaker at the 1-year follow-up, the PQ interval (178 ± 27 vs. 188 ± 36 ms; P = 0.39) remained unchanged in the ECG, whereas the QRS width (100 ± 22 vs. 108 ± 26 ms; P = 0.008) decreased compared to measurements taken at discharge.

CONCLUSION

Conduction disturbances following TAVI primarily develop during hospitalization and subsequently stabilize. However, the small percentage of patients suffering sudden death or pacemaker implantation requires attention.

Sudden Death After Transcatheter Aortic Valve Implantation. Are Bradyarrhythmias Always The Cause?

Transcatheter Aortic-Valve Implantation (TAVI) is considered to be highly effective in the treatment of high-risk patients with severe aortic stenosis. After TAVI, the rate of pacemaker implantation is 6.5%-40%. Some reports of sudden death after TAVI are mostly attributed to bradyarrhythmias. We report the case of three patients who experienced sudden cardiac death or aborted sudden cardiac death after TAVI. All patients were affected from ischemic heart disease with an ejection fraction of approximately 40% and underwent pacemaker implantation (PM) after the procedure due to 1rst degree atrioventricular block (AV) and left bundle branch block (LBBB). One of the patients died suddenly 30 days after the procedure. The PM interrogation revealed many episodes of non sustain ventricular tachycardias (NSVT) and one episode of ventricular fibrillation (VF) that led to death. The other two patients had syncope and during PM interrogation episodes of ventricular tachycardia >12 sec were recorded. Patients affected by ischemic heart disease undergoing TAVI, especially with borderline coronary lesions should receive particular attention in order to avoid potentially lethal ventricular arrhythmias. In addition, the physiopathologic mechanism of sudden arrhythmic death in these patients needs to be clarified.

Hotline update of clinical trials and registries presented at the American College of Cardiology Congress 2014

This article provides information and commentaries on trials which were presented at the Hotline and Clinical Trial Update Sessions during the Late Breaking Clinical Trial Sessions at the 63rd annual meeting of the American College of Cardiology in Washington, USA, from 29th to 31st March 2014. This article gives an overview on a number of novel clinical trials in the field of cardiovascular medicine, which were presented. Comprehensive summaries have been generated from the oral presentation and the webcasts of the American College of Cardiology, similar to as previously reported and should provide the readers with the most comprehensive information of relevant publications. The discussed studies are US CoreValve, Choice, Symplcity-HTN-3, GRS, ZEUS, GIPS-III, HEAT-PPCI, COPR-2, MSC-HF, POISE-2, SIRS. The data were presented by leading experts in the field.

Feasibility of sheathless transfemoral aortic valve implantation in patients with small access vessel diameters

OBJECTIVES

We intended to show feasibility of sheathless transfemoral aortic valve implantation in patients with small access vessel diameters.

BACKGROUND

Transcatheter aortic valve implantation (TAVI) has emerged as a valid treatment option in patients with aortic valve stenosis who are poor candidates for surgical aortic valve replacement. Few patients, who cannot undergo transfemoral or transsubclavian aortic valve implantation due to small access vessel diameters, are not suitable for transapical or direct aortic valve implantation, either.

METHODS

In more than 700 transcatheter aortic valve implantations since 2008 we identified 17 patients who had to be excluded from transfemoral valve implantation due to vessel diameters <6 mm and who were no candidates for transapical or direct aortic implantation. We performed CoreValve™ implantations in these patients without the required 18F sheath to cross the vessels despite their small size (4.6-5.9 mm).

RESULTS

Sixteen sheathless implantations were successful. In all 17 patients, bleeding during the procedure due to the smaller delivery catheter was minimal. Sixteen patients had a successful access site closure at the end of the procedure.

CONCLUSIONS

Sheathless implantation of a self-expanding aortic valve can be safely considered in selected patients with access vessel diameters below 6 mm, if transapical or direct aortic implantation is not suitable.

Worldwide TAVI registries: what have we learned?

With a rapidly aging society, the number of patients with cardiovascular disease-in particular aortic stenosis-is progressively increasing. Although conventional aortic valve replacement remains the only treatment known to improve prognosis and symptoms in symptomatic patients with aortic stenosis, about one-third are still withhold from the life-saving therapy. Based on the compelling evidence of the randomized Placement of Aortic transcatheter valves (PARTNER) A and B cohort, TAVI is now considered standard of care for extreme risk and inoperable patients and is an alternative to surgery for high-risk patients with symptomatic aortic stenosis. However, these patients were super-selected, which does not reflect a clinical real-world situation. TAVI registries represent a real-world scenario, and therefore provide the evidence for the treatment of high-risk patients (regarding comorbidities and anatomical factors) in daily clinical life. The review will focus on the recently published Edwards SAPIEN, Medtronic CoreValve and mixed (national) registries with the focus on short- and midterm outcome. These registries suggest that the growing experience of the operators with regard to patient selection, prevention, recognition and treatment of procedural complications together with the developments in valve design will improve the short-term results of TAVI. However, randomized trials in intermediate risk patients and data on long-term valve durability are a prerequisite before indications can be expanded to younger and lower risk patient population.

Pacemaker implantation after transcatheter aortic valve implantation

Thirty- to 35% of patients after transcatheter aortic valve implantation undergo implantation of a permanent pacemaker (PPM) because of development of atrioventricular block (AVB) or development of a condition with high risk of progression to AVB. There are insufficient data regarding long-term follow-up on pacing dependency. From February 2009 to July 2011, 191 transcatheter aortic valve implantation procedures were performed at the Rabin Medical Center (125 CoreValve and 66 Edwards SAPIEN). Thirty-two patients (16.7%) received a PPM (30 with CoreValve and 2 with Edwards SAPIEN). Data from the pacemaker clinic follow-up was available in 27 patients. After a mean follow-up of 52 weeks (range, 22 to 103), only 8 (29%) of 27 patients were pacing dependent. The indication of PPM in these 8 patients was complete AVB. In conclusion, in our center, the rate of PPM implantation was 16%, which is lower than that reported in the published works. Only 29% of those patients implanted with PPM were pacemaker dependent. Further studies are necessary to define reliable predictors for long-term pacing.

Predictive factors for pacemaker requirement after transcatheter aortic valve implantation

Background

Transcatheter aortic valve implantation (TAVI) has been established as a treatment option for inoperable patients with symptomatic aortic valve stenosis. However, patients suffer frequently from conduction disturbances after TAVI.

Methods

Baseline, procedural as well as surface and intracardiac ECG parameters were evaluated for patients treated with TAVI and a comparison between patients requiring pacemaker with those not suffering from relevant conduction disorders were done.

Results

TAVI was successfully in all patients (n=45). Baseline surface and intracardiac ECG recording revealed longer PQ (197.1±51.2 msec versus 154.1±32.1 msec; p<0.001), longer AH (153.6±43.4 msec versus 116.1±31.2 msec; p<0.001) and HV interval (81.7±17.8 msec versus 56.8±8.5 msec; p<0.001) in patients with need for a pacemaker (n=23) versus control group (n=22); furthermore, 7-day follow-up analysis showed a higher prevalence of new left bundle branch block (LBBB) (87.0% versus 31.9%; p<0.001). Multivariate analysis revealed that only new LBBB, QRS duration >120 msec and a PQ interval >200 msec immediately (within 60 minutes) after implantation of the aortic valve were predictors for high-grade (type II second-degree and third-degree) AV block. Other clinical parameters as well as baseline electrocardiographic parameters had no impact on critical conduction delay.

Conclusion

Cardiac conduction disturbances are common after TAVI. The need for pacing after TAVI is predictable by surface ECG evaluation immediately (within 60 minutes) after the procedure.