Predictors, clinical impact, and management strategies for conduction abnormalities after transcatheter aortic valve replacement: an updated review

Transcatheter aortic valve replacement (TAVR) has increasingly become a safe, feasible, and widely accepted alternative surgical treatment for patients with severe symptomatic aortic stenosis. However, the incidence of conduction abnormalities associated with TAVR, including left bundle branch block (LBBB) and high-degree atrioventricular block (HAVB), remains high and is often correlated with risk factors such as the severity of valvular calcification, preexisting conditions in patients, and procedural factors. The existing research results on the impact of post-TAVR conduction abnormalities and permanent pacemaker (PPM) requirements on prognosis, including all-cause mortality and rehospitalization, remain contradictory, with varied management strategies for post-TAVR conduction system diseases across different institutions. This review integrates the latest research in the field, offering a comprehensive discussion of the mechanisms, risk factors, consequences, and management of post-TAVR conduction abnormalities. This study provides insights into optimizing patient prognosis and explores the potential of novel strategies, such as conduction system pacing, to minimize the risk of adverse clinical outcomes.

Post-TAVR conduction abnormalities leading to permanent pacemaker implantation: Risk factors, prevention, and management

Transcatheter aortic valve replacement (TAVR) often leads to conduction abnormalities, necessitating pacemaker implantation. This review of 38 meta-analyses identified preexisting right bundle branch block (RBBB), LAHB, and new-onset left bundle branch block as key risk factors, with a higher PPM risk in male and older patients. Procedural factors like transfemoral access and self-expandable valves also increase this risk. Prevention focuses on tailoring TAVR to individual electrophysiological and anatomical profiles. However, there's a lack of consensus in managing these conduction disturbances post-TAVR, highlighting the need for further research and standardized treatment strategies.

Transcatheter Aortic Valve Implantation and Conduction Disturbances: Focus on Clinical Implications

Transcatheter aortic valve implantation (TAVI) is an established alternative to surgery in patients with symptomatic severe aortic stenosis and has expanded its indications to even low-surgical-risk patients. Conduction abnormalities (CA) and permanent pacemaker (PPM) implantations remain a relatively common finding post TAVI due to the close proximity of the conduction system to the aortic root. New onset left bundle branch block (LBBB) and high-grade atrioventricular block are the most commonly reported CA post TAVI. The overall rate of PPM implantation post TAVI varies and is related to pre- and intra-procedural factors. Therefore, when screening patients for TAVI, Heart Teams should take under consideration the various anatomical, pathophysiological and procedural conditions that predispose to CA and PPM requirement after the procedure. This is particularly important as TAVI is being offered to younger patients with longer life-expectancy. Herein, we highlight the incidence, predictors, impact and management of CA in patients undergoing TAVI.

Clinical value of CT-derived simulations of transcatheter-aortic-valve-implantation in challenging anatomies the PRECISE-TAVI trial

BACKGROUND

Preprocedural computed tomography planning improves procedural safety and efficacy of transcatheter aortic valve implantation (TAVI). However, contemporary imaging modalities do not account for device-host interactions.

AIMS

This study evaluates the value of preprocedural computer simulation with FEops HEARTguideTM on overall device success in patients with challenging anatomies undergoing TAVI with a contemporary self-expanding supra-annular transcatheter heart valve.

METHODS

This prospective multicenter observational study included patients with a challenging anatomy defined as bicuspid aortic valve, small annulus or severely calcified aortic valve. We compared the heart team's transcatheter heart valve (THV) planning decision based on (1) conventional multislice computed tomography (MSCT) and (2) MSCT imaging with FEops HEARTguideTM simulations. Clinical outcomes and THV performance were followed up to 30 days.

RESULTS

A total of 77 patients were included (median age 79.9 years (IQR 74.2-83.8), 42% male). In 35% of the patients, preprocedural planning changed after FEops HEARTguideTM simulations (change in valve size selection [12%] or target implantation height [23%]). A new permanent pacemaker implantation (PPI) was implanted in 13% and >trace paravalvular leakage (PVL) occurred in 28.5%. The contact pressure index (i.e., simulation output indicating the risk of conduction abnormalities) was significantly higher in patients with a new PPI, compared to those without (16.0% [25th-75th percentile 12.0-21.0] vs. 3.5% [25th-75th percentile 0-11.3], p < 0.01) The predicted PVL was 5.7 mL/s (25th-75th percentile 1.3-11.1) in patients with none-trace PVL, 12.7 (25th-75th percentile 5.5-19.1) in mild PVL and 17.7 (25th-75th percentile 3.6-19.4) in moderate PVL (p = 0.04).

CONCLUSION

FEops HEARTguideTM simulations may provide enhanced insights in the risk for PVL or PPI after TAVI with a self-expanding supra-annular THV in complex anatomies.

Transcatheter Aortic Valve Implantation and Cardiac Conduction Abnormalities: Prevalence, Risk Factors and Management

Over the last decades, transcatheter aortic valve implantation (TAVI) or replacement (TAVR) has become a potential, widely accepted, and effective method of treating aortic stenosis in patients at moderate and high surgical risk and those disqualified from surgery. The method evolved what translates into a noticeable decrease in the incidence of complications and more beneficial clinical outcomes. However, the incidence of conduction abnormalities related to TAVI, including left bundle branch block and complete or second-degree atrioventricular block (AVB), remains high. The occurrence of AVB requiring permanent pacemaker implantation is associated with a worse prognosis in this group of patients. The identification of risk factors for conduction disturbances requiring pacemaker placement and the assessment of their relation to pacing dependence may help to develop methods of optimal care, including preventive measures, for patients undergoing TAVI. This approach is crucial given the emerging evidence of no worse outcomes for intermediate and low-risk patients undergoing TAVI in comparison to surgical aortic valve replacement. This paper comprehensively discusses the mechanisms, risk factors, and consequences of conduction abnormalities and arrhythmias, including AVB, atrial fibrillation, and ventricular arrhythmias associated with aortic stenosis and TAVI, as well as provides insights into optimized patient care, along with the potential of conduction system pacing and cardiac resynchronization therapy, to minimize the risk of unfavorable clinical outcomes.

Progressively Prolonged PR Interval and Aortic Abscess

Regular electrocardiogram (ECG) monitoring in patients with endocarditis of the aortic region is a simple yet effective approach to help evaluate for the development of aortic abscess. It is important to recognize this condition as it carries a high morbidity and mortality. We report a case of a 62-year-old Caucasian female diagnosed with methicillin-sensitive Staphylococcus aureus (MSSA) bacteremia with mitral and aortic endocarditis. Progressive PR prolongation prompted re-evaluation, ultimately finding the progression of a new aortic abscess, changing the patient's care pathway. With a standardized approach of obtaining regular ECGs in patients with aortic endocarditis, it is possible to identify the progression of aortic valve endocarditis, thereby lowering the risk of morbidity and mortality.

Preventing Deadly Complications of Cardiac Sarcoidosis

Cardiac sarcoidosis is a rare complication of pulmonary sarcoidosis, causing granulomatous inflammation of the myocardium, ultimately resulting in infiltrative cardiomyopathy. Through fibrotic inflammation, cardiac sarcoidosis predisposes patients to multiple complications, such as conduction abnormalities, ventricular arrhythmias, heart failure, and sudden cardiac death. Due to the adverse prognosis of conduction abnormalities in these patients, dual chamber implantable cardiac defibrillator (ICD) therapy is beneficial in reducing mortality and morbidity. Early ICD placement can prevent further immune-driven fibrotic conduction complications. Here we present a case of a 50-year-old female who underwent ICD placement due to conduction abnormalities secondary to cardiac sarcoidosis.

Remdesivir-induced conduction abnormalities: A molecular model-based explanation

Purpose: Remdesivir use in COVID-19 is associated with cardiac conduction abnormalities from unclear mechanisms. A proposed mechanism is the bioaccumulation of the intermediate metabolite GS-441524 resulting in exogenous activation of cardiac adenosine A1 due to the structural similarity between adenosine and GS-441524. The prolonged half-life of GS-441524 can result in sustained activation of adenosine A1 receptors. In this study, we used molecular modeling of adenosine, GS-441524 and the adenosine A1 receptor to assess the potential mechanistic association of the proposed mechanism. Methods: Adenosine and GS-441524 structures were acquired from the PubChem database. Ligand docking was carried out using UCSF Chimera. Models were chosen based on greatest binding affinity and minimum root mean square deviation. Figures of resulting structural models were prepared using UCSF Chimera or PyMOL 2.3.5. Results: By modeling the interaction between the A1 G protein complex and both adenosine and GS-441524, we found that the proposed mechanism of exogenous A1 receptor activation is feasible based on docking compatibility. Conclusion: The proposed mechanism of exogenous cardiac A1 receptor activation from bioaccumulation of GS-441524 as a cause of observed cardiac conduction abnormalities with the use of remdesivir in COVID-19 is viable. Further studies are needed to assess causality.

Validation of reliability and predictivity of membrane septum length measurements for pacemaker need after transcatheter aortic valve replacement

OBJECTIVES

To assess the inter methodological agreement of membrane septum (MS) length measurement and additive value for risk stratification of new pacemaker implantation (PMI) over the established predictors after transcatheter aortic valve replacement (TAVR).

BACKGROUND

Recent studies have suggested MS length and implantation depth (ID) as predictors for PMI after TAVR. However, the measurement of MS length is neither uniform nor validated in different cohort.

METHODS

We retrospectively analyzed patients who underwent TAVR at five centers. The MS length was measured by two previously proposed methods (coronal and annular view method). Predictive ability of risk factors, including MS length and ID, for new PMI within 30 days after TAVR were evaluated.

RESULTS

Among 754 patients of study population, 31 patients (4.1%) required new PMI within 30 days of TAVR. There was a weak correlation (ρ = 0.47) and a poor agreement between the two methods. The ID and the difference between MS length and ID (ΔMSID), were independent predictors for new PMI, whereas MS length alone was not. Further, for predicting new PMI after TAVR, discrimination performance was not significantly improved when MS length was added to the model with ID alone (integrated discrimination improvement = 0, p= 0.99; continuous net-reclassification improvement = 0.10, p= 0.62).

CONCLUSIONS

External validity and predictive accuracy of MS length for PMI after TAVR were not sufficient to provide better risk stratification over the established predictors in our cohort. Moreover, the ID and ΔMSID, but not MS length alone, are predictive of future PMI after TAVR.

Early versus late discharge after transcatheter aortic valve replacement and readmissions for permanent pacemaker implantation

OBJECTIVE

To examine the rate of readmission for permanent pacemaker (PPM) implantation with early versus late discharge after transcatheter aortic valve replacement (TAVR).

BACKGROUND

There is a current trend toward early discharge after TAVR. However, paucity of data exists on the impact of such practice on readmissions for PPM implantation.

METHODS

The Nationwide Readmission Database 2016-2018 was queried for all hospitalizations where patients underwent TAVR. Hospitalizations were stratified into early (Days 0 and 1) versus late (≥Day 2) discharge groups. Observations in which PPM was required in the index admission were excluded. Multivariable regression analyses involving patient- and hospital-related variables were utilized. The primary outcome was 90-day readmission for PPM implantation.

RESULTS

The final analysis included 68,482 TAVR hospitalizations, 20,261 (29.6%) with early versus 48,221 (70.4%) with late discharge. Early discharge after TAVR increased over the study period (16.2% in 2016 vs. 37.9% in 2018, P_trend  < 0.01). Nevertheless, 90-day readmission for PPM implantation remained stable (1.8% in 2016 vs. 2.0% in 2018, P_trend  = 0.32). The 90-day readmission rate for PPM implantation (2.0% vs. 1.8%; adjusted odds ratio: 1.15; 95% confidence interval: 0.95-1.39; p = 0.15) and median time-to-readmission (5 days [interquartile range, IQR 3-9] vs. 5 days [IQR 3-14], p = 0.92) were similar with early versus late discharge. Similar rates were observed regardless of whether readmission was elective versus not. Early discharge was associated with lower hospitalization cost ($39,990 ± $13,681 vs. $46,750 ± $18,218, p < 0.01) compared with late discharge.

CONCLUSION

In patients who did not require PPM during the index TAVR hospitalization, the rate of readmission for PPM implantation was similar with early versus late discharge.

Reframing Optimal Implantation of the Sapien 3 Transcatheter Heart Valve

OBJECTIVES

To define the optimal implantation of the Sapien 3 (Edwards Lifesciences) transcatheter heart valve (THV), this study systematically analyzed the predeployment fluoroscopic THV position and correlated this to clinical outcomes.

METHODS

This was an observational study of 279 patients treated with the Sapien 3 THV. Fluoroscopic imaging was used to categorize patients into low (n = 147), intermediate (n = 86), and high (n = 46) implantation zones. These zones were based on the relationship of the balloon marker and radiolucent line of the valve frame (line of lucency) to the annular plane at deployment. The primary outcome was the rate of permanent pacemaker implantation (PPI) at 30 days. The secondary outcomes were the rates of new left bundle-branch block (LBBB) in-hospital and all-cause mortality at 1 year.

RESULTS

In the high, intermediate, and low groups, 30-day PPI rates were 4.3%, 8.1%, and 8.8% (P=.62); in-hospital LBBB rates were 10.9%, 26.7%, and 32.0% (P=.02); and all-cause mortality rates at 1 year were 3.1%, 7.3%, and 12.5% (P=.14), respectively. No differences were observed with respect to procedural success/complications or THV performance between the groups.

CONCLUSION

This study demonstrates fewer conduction abnormalities for Sapien 3 valves positioned within a higher zone defined fluoroscopically by the line of lucency and balloon marker.

Primary Hyperparathyroidism Is Associated With Shorter QTc Intervals, but Not Arrhythmia

CONTEXT

Primary hyperparathyroidism (PHPT) is associated with subclinical cardiovascular disease, but data regarding cardiac conduction abnormalities are limited.

OBJECTIVE AND DESIGN

Retrospective cross-sectional comparison of cardiac conduction in patients with PHPT or thyroid disease (TD).

PARTICIPANTS AND SETTING

Patients ≥40 years old who underwent parathyroidectomy or thyroidectomy at a single tertiary institution from 2013 to 2018.

METHODS AND OUTCOMES

Demographics and preoperative electrocardiogram (EKG) parameters were compared using the Mann-Whitney U, chi-square test, and linear regression.

RESULTS

A total of 1242 patients were included: 49.8% PHPT (n = 619) and 50.2% TD (n = 623). Median age was 60.5 years [interquartile range (IQR) 53.6-67.9]. Compared to controls, PHPT patients had higher median serum calcium [10.7 mg/dL (IQR 10.4-11.1) vs 9.5 mg/dL (IQR 9.3-9.8), P < 0.001] as expected, as well as, a higher prevalence of hyperlipidemia (49% vs 36%, P < 0.001) and hypertension (50.1% vs 42.2%, P < 0.01). Based on EKG, there was no difference in PR interval or the prevalence of arrhythmia, atrioventricular block, ST segment/T wave changes, premature ventricular complexes, right bundle branch block, or left bundle branch block after adjusting for covariates. The PHPT group had a lower mean corrected QT interval (414 ± 24) ms vs 422 ± 24 ms, P < 0.01), adjusted for covariates. Serum calcium predicted QTc independently of age, sex, and other covariates.

CONCLUSIONS

In the largest study to date, PHPT patients had shorter QTc intervals compared to TD controls but no increased prevalence of arrhythmia based on preoperative EKG.

Early pacemaker implantation for transcatheter aortic valve implantation is safe and effective

BACKGROUND

Permanent pacemaker (PPM) implantation is a common complication of transcatheter aortic valve implantation (TAVI). The optimum timing of PPM implantation is still unclear as conduction abnormalities evolve and a balance needs to be struck between conservative delays in the hope of conduction recovery and overutilization of pacing. This study aimed to assess the safety and efficacy of early PPM implantation, without an observation period, among TAVI patients.

METHODS

This is a retrospective, observational study of 1398 TAVI patients. Clinical and pacing data were collected at baseline, 30 days and at a median of 15 (4-21) months post-TAVI. Study endpoints included PPM-related complications, pacing utilization and hospital length of stay.

RESULTS

One hundred five patients (8.2%) required a PPM, of which 13 were implanted pre and 92 post-TAVI. Seventy-six percent required pacing for either second- or third-degree heart block. Time to implantation for post-TAVI PPM was 1 (0-3) day. Six patients experienced a pacing-related complication- lead displacement (n = 3), hematoma (n = 2), and device infection (n = 1). Pacing utilization defined as pacing >10% of the time or a pacing requirement at the time of the pacing check was demonstrated in 83% of patients. Multivariate analysis revealed complete heart block (CHB) was the only independent predictor of pacing utilization. Hospital length of stay for the post-TAVI PPM group was longer than the group without PPM (4 [2-8] vs. 3 [2-4] days; p < .001).

CONCLUSIONS

Early PPM implantation in TAVI patients is safe and majority of patients require pacing in the short and mid-term.

Electrophysiological Manifestations of Cardiac Amyloidosis: JACC: CardioOncology State-of-the-Art Review

Cardiac amyloidosis (CA) is an infiltrative cardiomyopathy caused by the extracellular deposition of amyloid fibrils in the myocardium. Although cardiac amyloidosis patients primarily present with heart failure symptoms, arrhythmias and conduction system disease are frequently encountered. Atrial fibrillation (AF) is observed in up to 70% of patients at the time of diagnosis, and patients typically have controlled ventricular rates caused by concomitant conduction system disease. Thromboembolic risk is particularly high in patients with CA and AF, and left atrial thrombi have been observed even in the absence of clinically diagnosed AF. Atrioventricular nodal and infra-Hisian disease are common, and permanent pacemakers are frequently required. The use of implantable cardioverter-defibrillators in this population is controversial. This review summarizes the published data and therapeutic strategies surrounding arrhythmias and conduction system disease with the goal of aiding clinicians managing the clinical complexities of CA.

From Millimeters to Micrometers; Re-introducing Myocytes in Models of Cardiac Electrophysiology

Computational modeling has contributed significantly to present understanding of cardiac electrophysiology including cardiac conduction, excitation-contraction coupling, and the effects and side-effects of drugs. However, the accuracy of in silico analysis of electrochemical wave dynamics in cardiac tissue is limited by the homogenization procedure (spatial averaging) intrinsic to standard continuum models of conduction. Averaged models cannot resolve the intricate dynamics in the vicinity of individual cardiomyocytes simply because the myocytes are not present in these models. Here we demonstrate how recently developed mathematical models based on representing every myocyte can significantly increase the accuracy, and thus the utility of modeling electrophysiological function and dysfunction in collections of coupled cardiomyocytes. The present gold standard of numerical simulation for cardiac electrophysiology is based on the bidomain model. In the bidomain model, the extracellular (E) space, the cell membrane (M) and the intracellular (I) space are all assumed to be present everywhere in the tissue. Consequently, it is impossible to study biophysical processes taking place close to individual myocytes. The bidomain model represents the tissue by averaging over several hundred myocytes and this inherently limits the accuracy of the model. In our alternative approach both E, M, and I are represented in the model which is therefore referred to as the EMI model. The EMI model approach allows for detailed analysis of the biophysical processes going on in functionally important spaces very close to individual myocytes, although at the cost of significantly increased CPU-requirements.

Association between atrial fibrillation and bundle branch block

BACKGROUND

The association between atrial fibrillation (Afib) and sinus and AV nodal dysfunction has previously been reported. However, no data are available regarding the association between Afib and bundle branch block (BBB).

METHODS

Patient data were obtained from the Nationwide Inpatient Sample (NIS) database between years 2009 and 2015. Patients with a diagnosis of Afib and BBB were identified using validated International Classification of Diseases, 9th revision, and Clinical Modification (ICD-9-CM) codes. Statistical analysis using the chi-square test and multivariate linear regression analysis were performed to determine the association between Afib and BBB.

RESULTS

The total number of patients with BBB was 3,116,204 (1.5%). Patients with BBB had a mean age of 73.5 ± 13.5 years, 53.6% were males, 39.1% belonged to the age group ≥80 years, and 72.9% were Caucasians. The prevalence of Afib was higher in the BBB group, as compared to the non-BBB group (29% vs 11.8%, p value<.001). This association remained significant in multivariate regression analysis with an odds ratio of 1.25 (CI: 1.24-1.25, P < .001). Among the subtypes of BBB, Afib was comparatively more associated with RBBB (1.32, CI 1.31-1.33, p value<.0001) than LBBB (1.17, CI 1.16-1.18, p value<.0001). The mean cost was higher among Afib with BBB, compared with Afib patients without BBB ($15 795 vs $14 391, p value<.0001). There was no significant difference in the mean length of stay (5.6 vs 5.9 days, p value<.0001) or inpatient mortality (4.9% vs 4.8%).

CONCLUSION

This study demonstrates that prevalence of Afib is higher in patients with BBB than without BBB. Cost are higher for Afib patients with BBB, compared to those without BBB, with no significant increase in mortality or length of stay.

Pacemaker-Related Complications in Patients Undergoing Transcatheter Aortic Valve Implantation: A Single-Center Experience

BACKGROUND

The aim of this study was to describe the rate of complications secondary to permanent pacemaker (PPM) implantation after transcatheter aortic valve implantation (TAVI).

METHODS

Patients were identified by retrospective review of a dedicated TAVI database at a single center between 2008 and 2015. Clinical and procedural data were collected to determine the incidence and severity of the main adverse events following this procedure. The overall population included 736 patients and 123 (16.7%) underwent PPM implantation. Three patients were excluded from the final analysis due to PPM implantation occurring at other institutions post discharge. The final population consisted of 120 patients (16.3%).

RESULTS

Self- and mechanically expandable valves were associated with a higher risk of PPM after TAVI compared with balloon-expandable valves (23.9% vs 27.5% vs 7.6%, respectively; P<.001). Year of procedure and operator's experience did not affect the PPM-related complication rate. A high rate of major bleeding complications (n = 29; 24.1%) was observed. Major bleeding occurred more frequently in patients who received PPM implantation within the first 24 hours post TAVI than in the group of patients who required a PPM >24 hours post TAVI (38.2% vs 12.3%, respectively; P<.01). Patients who experienced a major bleeding event following PPM insertion were more frequently on triple-antithrombotic therapy (51.7% vs 9.9%; P<.001).

CONCLUSIONS

PPM-related complications are common in elderly patients after TAVI, and some of these adverse events can be life threatening. Particular attention is required in the periprocedural management of these patients.

How valvular calcification can affect the outcomes of transcatheter aortic valve implantation

Introduction In transcatheter aortic valve implantation (TAVI), assessment of aortic valve calcification is not as standardized as aortic annulus measurement. Aortic valve calcification is important for stable anchoring of the prosthesis to the aortic annulus. However, excessive aortic valve calcification is related to procedural complications. Areas covered This review covers the methods to assess aortic valve calcification and the implications of aortic valve calcium burden for TAVI outcomes. We performed a systematic review of the literature in Pubmed and secondary sources. Furthermore, future perspectives on how to integrate aortic valve calcification assessment in the management of patients with aortic stenosis is discussed. Expert opinion Thorough assessment of the aortic valve and aortic root components including aortic valve calcification is key in the planning of TAVI. Aortic valve calcification load, location and extension are important contributors to paravalvular regurgitation. Asymmetric calcification burden with greater calcification of the left-coronary cusp related to higher need of permanent pacemaker implantation. Patients with moderate and severe left ventricular outflow tract/subannular calcification are more susceptible to aortic annular rupture. Periprocedural dislodgement of calcium form cusps and commissures is one of the main reasons of coronary artery ostial occlusion during transcatheter aortic valve implantation. Abbreviations Ao, aorta; LA, left atrium; LAA, left atrial appendage; LV, left ventricle; LVOT, left ventricular outflow tract; THV, transcatheter heart valve.

Syncope After Transcatheter Aortic Valve Replacement: Two Faces of Abnormal Intraventricular Conduction

Conduction system damage is the most common complication of transcatheter aortic valve replacement (TAVR), which frequently requires placement of a permanent pacemaker. Bundle branch reentry (BBR) is a well-recognized mechanism of ventricular tachycardia (VT) in the setting of abnormal intraventricular conduction. We describe a case of a patient with post-TAVR intraventricular conduction abnormalities who presented with intermittent advanced atrioventricular block and BBR VT and discuss the potential risks, diagnosis, and management of BBR after TAVR.

Impact of atrial programmed electrical stimulation techniques on unipolar electrogram morphology

INTRODUCTION

Intra-atrial conduction abnormalities are associated with the development of atrial fibrillation (AF) and cause morphological changes of the unipolar atrial electrogram (U-AEGM). This study examined the impact of different atrial programmed electrical stimulation (APES) protocols on U-AEGM morphology to identify the most optimal APES protocol provoking conduction abnormalities.

METHODS

APES techniques (14 protocols) were applied in 30 patients referred for an electrophysiology study, consisting of fixed rate, extra, and decremental stimuli at different frequencies. U-AEGM morphologies including width, amplitude, and fractionation for patients without (control group) and with a history of AF (AF group) were examined during APES. In addition, sinus rhythm (SR) U-AEGMs preceding different APES protocols were compared to evaluate the morphology stability over time.

RESULTS

U-AEGM morphologies during SR before the APES protocols were comparable (all P > .396). Atrial refractoriness was longer in the AF group compared to the control group (298 ± 48 vs 255 ± 33 ms; P ≤ .020), but did not differ between AF patients with and without amiodarone therapy (278 ± 48 vs 311 ± 40 ms; P ≥ .126). Compared to the initial SR morphology, U-AEGM width, amplitude, and fractionation changed significantly during the 14 different APES protocols, particularly in the AF group. In both groups, U-AEGM changes in morphology were most pronounced during fixed-rate stimulation with extra stimuli (8S1-S2 = 400-250 ms).

CONCLUSION

APES results in significant changes in U-AEGM morphology, including width, amplitude, and fractionation. The impact of APES differed between APES sequence and between patients with and without AF. These findings suggest that APES could be useful to identify AF-related conduction abnormalities in the individual patient.

Inadvertent pacemaker lead dislodgement

Transcatheter aortic valve implantation (TAVI) has become an established treatment option for aortic valve stenosis in patients with a high risk for conventional surgical valve replacement. A well-known complication is the development of conduction abnormalities. In the case of a new third-degree atrioventricular block, the complication can be life-threatening and permanent pacing is needed. Often these patients have a venous sheath placed in the jugular vein for the perioperative period. We report a case of inadvertent dislodgement of a permanent pacemaker lead after removal of a preoperatively placed venous sheath in a TAVI patient.

Imaging-based predictors of permanent pacemaker implantation after transcatheter aortic valve replacement

BACKGROUND

Cardiac conduction abnormalities requiring permanent pacemaker (PPM) implantation are major complications of transcatheter aortic valve replacement (TAVR). We aimed to investigate whether the relationship between prosthetic valve size and cardiac-gated computed tomography (CT)-based aortic root complex measurements can aid in recognizing patients at risk for PPM implantation post-TAVR.

METHODS

We included 83 of 114 consecutive patients who underwent TAVR with the Edwards Sapien valve (Edwards Lifesciences, Irving, CA, USA) at our institution. We excluded patients with preexisting PPM, patients who required conversion to an open surgical procedure, and patients without CT data. We assessed the significance of various potential predictors of PPM placement post-TAVR.

RESULTS

Following TAVR, eight patients (9.6%) required PPM. Prosthetic valve to sinus of Valsalva (SOV) index was significantly higher in those patients requiring a PPM post-TAVR (84.1 ± 9.3 vs 76.8 ± 7.1, P  =  0.009).

CONCLUSIONS

The prosthetic valve size to diameter of SOV index was identified as a novel predictor of PPM implantation after TAVR.

An Exploratory Study to Determine Whether BRCA1 and BRCA2 Mutation Carriers Have Higher Risk of Cardiac Toxicity

Anthracycline-based cardiotoxicity is concerning for women with breast cancer and portends a dose-dependent risk of developing left ventricular dysfunction. Overall, the prevalence of heart failure (HF) is ≈2% of the total US population; however, BRCA-deficient mice have shown increased HF. We evaluated for the inherent risk of HF in women with BRCA mutations to determine whether treatment with anthracycline-based therapy increased this risk. We obtained results on BRCA mutation carriers regarding cancer treatment and HF, identified through the BRCA patient advocacy organization Facing Our Risk for Cancer Empowered (FORCE) and the Moffittbased Inherited Cancer Registry. In our patient group (232 BRCA1 and 159 BRCA2 patients; 10 with both mutations), 7.7% reported HF, with similar proportions in BRCA1 versus BRCA2 carriers (7.4% and 8.2%, respectively). These proportions are significantly higher than published rates (p < 0.001). There was no statistically significant difference in HF rates comparing anthracycline-treated versus anthracycline-naïve patients however (7.1% vs. 8.3%; p = 0.67). In addition, 9.1% of BRCA1 carriers and 8.2% of BRCA2 carriers reported arrhythmias. BRCA mutation carriers showed increased risk of cardiotoxicity versus the general population and an overall increased risk of cardiotoxicity from anthracycline-based therapy. Our study supports data that BRCA carriers have increased noncancer mortality from cardiotoxicity. A prospective trial to determine HF and conduction abnormalities in this population is warranted.

Cardiac device implantation in Fabry disease: A retrospective monocentric study

The incidence and predictive factors of arrhythmias and/or conduction abnormalities (ACAs) requiring cardiac device (CD) implantation are poorly characterized in Fabry disease (FD). The aim of our retrospective study was to determine the prevalence, incidence, and factors associated with ACA requiring CD implantation in a monocentric cohort of patients with confirmed FD who were followed up in a department of internal medicine and reference center for FD.Forty-nine patients (20M, 29F) were included. Nine patients (4M, 5F; 18%) had at least one episode of ACA leading to device therapy. Six patients (4M/2F) required a pacemaker (PM) for sinus node dysfunction (n = 4) or atrioventricular disease (n = 2). One female patient required an internal cardioverter-defibrillator (ICD) to prevent sudden cardiac death because of nonsustained ventricular tachycardia (nSVT). One female patient required PM-ICD for sinus node dysfunction and nSVT. One patient underwent CD implantation before the diagnosis of FD. The annual rate of CD implantation was estimated at 1.90 per 100 person years. On univariate analysis at the end of the follow-up period, the factors associated with ACAs requiring CD implantation were as follows: delayed diagnosis of FD, delayed initiation of enzyme replacement therapy, age at the last follow-up visit, and severe multiorgan phenotype (hypertrophic cardiomyopathy, chronic kidney disease, and/or sensorineural hearing loss). On multivariate analysis, age at diagnosis of FD and age at the last follow-up visit were independently associated with an increased risk of ACAs requiring CD (P < 0.05).Considering the high frequency of ACAs requiring CD implantation and the risk of sudden death in patients with FD, regular monitoring is mandatory, especially in patients with a late diagnosis of FD and/or with a severe phenotype. Regular Holter ECGs, therapeutic education of patients, and deliverance of an emergency card including a phenotype summary are crucial in the care of FD patients.Available guidelines for device therapy and the efficacy of enzyme replacement therapy for arrhythmias or conduction abnormalities are discussed.

Full-blown cardiac manifestations in ankylosing spondylitis

Ankylosing spondylitis often involves a heart, such as aortic or mitral regurgitation, conduction disorder, or cardiomyopathy. We present a 34-year-old male patient with ankylosing spondylitis who has severe aortic regurgitation, mild mitral stenosis, and a conduction disturbance of the left bundle branch block, identified using multimodal images.

Cardiac pacing in 21 patients with Emery-Dreifuss muscular dystrophy: a single-centre study with a 39-year follow-up

BACKGROUND

Emery-Dreifuss muscular dystrophy (EDMD) is a genetic condition associated with cardiac arrhythmias. The patients typically develop early, asymptomatic bradyarrhythmia, which may lead to sudden death, preventable with a cardiac implantable electronic device (CIED). EDMD may be characterised by atrial electrical silence. Intra-operative electrophysiological evaluation of the myocardium helps ultimately determine the true nature of the disorder and select an appropriate CIED.

AIM

To analyse permanent electrotherapy procedures in EDMD patients: atrial pacing limitations that stem from the electrophysiological properties of the myocardium and long-term follow-up of implanted devices.

METHODS

A total of 21 EDMD patients (mean age 29 ± 9 years) with a CIED implanted (1976-2014) due to bradyarrhythmia were included in the study. The implantation procedures and factors determining the CIED type selection were analysed.

RESULTS

CIEDs were implanted in five women and in 16 men with EDMD types 1 and 2 (mean follow-up: 11 ± 8 years). Intra-operatively assessed atrial electrophysiology resulted in changing the planned CIED type during the procedure in three men with EDMD type 1. Eventually, we implanted: eight DDD, one VDD, 11 VVI, and one CD-DR device, with four of the patients' devices switched later from DDD to VVI mode in response to electrophysiological changes in the atria.

CONCLUSIONS

Intra-operative assessment of atrial electrophysiological properties resulted in changing the planned DDD mode for VVI in 19% of patients with EDMD type 1. Progression of the underlying disease over a 39-year follow-up resulted in a later change of the initially selected pacing mode from DDD to VVI in 40% of cases.

Optimizing clinical outcomes of transcatheter aortic valve implantation patients with comorbidities

Transcatheter aortic valve implantation (TAVI) has revolutionized the management of high-risk or inoperable patients presenting with symptomatic severe aortic stenosis (AS). There are several factors to consider to optimize patient outcomes from TAVI. Before TAVI, patient selection is key and an understanding the effects of common comorbidities on outcomes after TAVI is critical. Some comorbidities share common risk factors with AS (e.g. coronary artery disease), others are directly or indirectly caused or exacerbated by severe AS (e.g. atrial fibrillation, pulmonary hypertension, mitral regurgitation, tricuspid regurgitation and right ventricular dysfunction), whereas others are not directly related to severe AS (e.g. chronic kidney disease and chronic lung disease). Choice of transcatheter heart valve prosthesis, vascular access route and mode of anesthesia are important considerations during TAVI. New onset conduction disturbances and arrhythmias remain a vexing issue after TAVI. The aim of the present review is to provide an overview of these issues.

Permanent Pacemaker Implantation after TAVR - Predictors and Impact on Outcomes

The number of patients undergoing transcatheter aortic valve replacement (TAVR) worldwide is increasing steadily. Atrioventricular conduction disturbances, with or without the need for permanent pacemaker (PPM) implantation, are one of the most common adverse events after TAVR. Among transcatheter heart valves (THV), rates of conduction abnormalities vary from less than 10 % to more than 50 %. Depending on the reported data referred to, historical data showed that up to one-third of the patients required implantation of a PPM following TAVR. Although generally considered as a minor complication, PPM may have a profound impact on prognosis and quality of life after TAVR. Current data support the hypothesis that conduction abnormalities leading to pacemaker dependency result from mechanical compression of the conduction system by the prosthesis stent frame and individual predisposing conduction defects such as right bundle-branch block (RBBB). With several large randomised trials and registry studies having been published recently and second generation THV having been introduced, the debate about predictors for pacemaker implantation and their impact on outcome after TAVR is still ongoing.

Rare, potentially fatal, poorly understood propofol infusion syndrome

We present the case of a 7-year old boy with traumatic brain injury who received propofol during 38 h. Thirty-six hours after cessation of propofol infusion asystole occurred. After immediate mechanical and medical resuscitation, unreactive dilated pupils were observed. The following computed tomography scan revealed a generalized brain edema with transtentorial herniation. Prolonged bradyarrhythmia, rhabdomyolysis, and peracute renal failure were observed. Despite immediate craniectomy, barbiturate treatment, hemofiltration, and recovery of appropriate cardiac function, the patient died four days after discontinuation of propofol. In this case, metabolic acidosis, cardiac failure, rhabdomyolysis, and renal failure are in accordance with the symptoms of propofol infusion syndrome (PRIS), while seizure, brain edema, and transtentorial herniation could be caused by traumatic brain injury. However, it may be assumed that the entire clinical picture was caused by PRIS. This view could be explained by a common loss of function of ryanodine receptors in patients presenting with PRIS.