Simplifying transfemoral ACURATE neo implantation using the TrueFlow nonocclusive balloon catheter.

OBJECTIVES: This study aimed to investigate the safety and efficacy of ACURATE neo transcatheter aortic valve replacement (TAVR) facilitated by predilatation with the nonocclusive TrueFlow balloon catheter. BACKGROUND: Now that TAVR is moving forward, physicians have attempted to simplify and streamline the procedure and the so-called minimalist approach has become more popular. METHODS: We enrolled 142 patients (mean age: 82 ± 5 years, 61% female) in a prospective registry. Patients at low risk for intraprocedural third-degree atrioventricular block (AVB) underwent TAVR with the TrueFlow balloon without rapid pacing and without insertion of a provisional pacemaker (n = 121). The remaining 21 patients were predilated with rapid pacing using a provisional pacemaker and a standard balloon. RESULTS: Predilatation with the TrueFlow balloon was successful in all 121 patients. Postdilatation was less frequently required after predilatation with the TrueFlow (25% vs. 57%, p = .003). Moreover, median procedural duration with the TrueFlow was significantly shorter (42 [interquartile range, IQR: 34-53] vs. 55 [IQR: 46-61] min, p = .004). In-hospital outcomes were similar. At 30 days, there was no mortality, two (1%) patients had suffered a stroke and only four (3%) had required implantation of a new pacemaker. CONCLUSION: Among patients with a low risk for intraprocedural third-degree AVB, the TrueFlow nonocclusive balloon catheter facilitates implantation of the ACURATE neo without the necessity of rapid pacing and a provisional pacemaker.

Benefits of fetal echocardiographic surveillance in pregnancies at risk of congenital heart block: single-center study of 212 anti-Ro52-positive pregnancies.

OBJECTIVES: Assuming that autoimmune congenital heart block (CHB) is a progressive disease amenable to therapeutic modulation, we introduced a surveillance program for at-risk pregnancies with the dual aim of investigating if fetal atrioventricular block (AVB) could be detected and treated before becoming complete and irreversible, and to establish the incidence of AVB I, II and III in a large prospective cohort. METHODS: This was a prospective study of 212 anti-Ro52 antibody-exposed pregnancies at risk of fetal AVB that were followed weekly between 18 and 24 weeks' gestation at our tertiary fetal cardiology center from 2000 to 2015. A 12-lead electrocardiogram (ECG) was recorded within 1 week after birth. Fetal Doppler atrioventricular (AV) intervals were converted to Z-scores using reference standard values derived from normal pregnancies. Each fetus was represented by the average value of the two recordings, obtained at two consecutive visits, which resulted in the longest AV interval. AV interval values were classified into normal AV conduction (Z-score ≤ 2.0) and three levels of delayed AV conduction: Z-score > 2.0 and ≤ 3.0, Z-score > 3.0 and ≤ 4.0, and Z-score > 4.0. RESULTS: AVB II or III developed in 6/204 (2.9%) pregnancies without a CHB history and 1/8 (12.5%) of those with a CHB history. AV intervals > 2 and ≤ 3, > 3 and ≤ 4, and > 4 were detected in 16.0%, 7.5% and 2.8% of cases, respectively, and were related to the PR interval on 185 available ECGs. Three of the five cases with AVB III and one of two cases with 2:1 AVB II developed within 1 week of AV interval Z-score of 1.0, 1.9, 2.8 and 1.9, respectively. Transplacental treatment with betamethasone was associated with restoration of 1:1 AV conduction in the two fetuses with AVB II, with a better long-term result (normal ECG vs AVB I or II) observed in the case in which treatment was started within 1 week after AVB developed. Betamethasone treatment did not reverse AVB III, although a temporary effect on AV conduction was observed in 1/5 cases. Notably, the three cases in which treatment was started within 1 week after AVB III development responded with a higher ventricular rate than the other two cases and did not require pacemaker implantation until a later age (2-5 years vs 1.5-2 months). CONCLUSION: Fetal AV interval is a poor predictor of CHB progression, but CHB surveillance still allows detection of fetuses with AVB II or III shortly after its development, allowing for timely treatment initiation and potentially better outcome. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Pacemaker memory in post-TAVI patients: Who should benefit from permanent pacemaker implantation?

BACKGROUND: One of the most frequent complications of transcatheter aortic valve implantation (TAVI) is the occurrence of atrioventricular (AV) conduction disorders secondary to AV node or His bundle injury leading to permanent pacemaker implantation (PPI). The objective was to quantify the rate of ventricular pacing (VP), according to post-TAVI indication for PPI using recorded pacemaker memory. METHODS: From October 2009 to January 2017' all patients who had PPI following TAVI performed at Rouen University Hospital were included. Indications for PPI were: ≥ 1 episode of complete atrioventricular block (CAVB) or 2:1 atrioventricular block, and new-onset persistent left bundle branch block (NOP-LBBB) with either prolonged PR interval (> 200 ms) or HV interval (>70 ms). The primary endpoint was VP percentage at the first pacemaker interrogation (a VP percentage ≥ 1% was considered as significant). RESULTS: Out of 936 TAVI patients (Sapien-3' n = 379 [Edwards Lifesciences, Irvine, CA, USA]; Sapien-XT' n = 513; CoreValve' n = 44, Medtronic, Minneapolis, MN, USA), 87 (9.3%) had PPI. Eighty of these 87 patients were followed-up and analyzed. At the first pacemaker interrogation, a significant VP percentage was observed in 60/80 followed-up patients (75%), in 46/51 patients (90.2%) implanted for CAVB, and 12/23 patients (52.2%) implanted for NOP-LBBB associated with either prolonged PR or HV interval. No clinical predictive factor of significant VP percentage was found. CONCLUSION: In the post-TAVI period, our data support PPI in patients with CAVB even if paroxysmal. Our data also suggest PPI may be considered in patients with NOP-LBBB associated with either prolonged PR or HV interval.

Prophylactic pacemaker placement at first signs of conduction disease in Kearns-Sayre syndrome.

Cardiac conduction disease affects patients with Kearns-Sayre syndrome. We report a young asymptomatic patient with Kearns-Sayre syndrome with abnormal conduction on electrocardiogram and Holter monitor, although not advanced atrioventricular block. She underwent prophylactic pacemaker placement, and rapidly developed complete atrioventricular block, which resulted in 100% ventricular pacing. It may be reasonable to consider prophylactic pacemaker implantation in patients with Kearns-Sayre syndrome with evidence of cardiac conduction disease even without overt atrioventricular block given its unpredictable progression to complete atrioventricular block.

Functional aspects of His bundle physiology and pathophysiology: Clinical implications.

In this review we present evidence from many experimental studies which challenge the concept of predestination of His bundle fibers. Using both intra- and extracellular His bundle pacing in the context of atrio-ventricular block and the development of bundle branch blocks these experimental studies provide the underlying mechanisms for the recent clinical findings showing the benefits of permanent His bundle pacing.

A 1-year-old boy with long pauses caused by paroxysmal atrioventricular block and sinus arrest: Vagal reflex and effect of pacing.

Paroxysmal atrioventricular block (PAVB) is rare in children. A 1-year-old boy presented with PAVB and sinus arrest that resulted in refractory life-threatening symptomatic long pauses. Continuous heart rate variability analysis with high time resolution (wavelet analysis) revealed an abrupt increase in parasympathetic activity just before a long pause, which indicated a vagal reflex. Although a pacemaker is not always effective because of a concomitant vasodepressive response in such cases, the complete stabilization after pacemaker implantation in this case supports the necessity and usefulness of pacemaker implantation in patients with reflex-induced highly symptomatic bradycardia.

Spike on T wave! What went wrong?

An 80-year-old male, who previously received a dual chamber pacemaker, was referred to our ambulatory for dizziness and fatigue. The ECG obtained showed sinus rhythm, highly variable atrioventricular (AV) interval and alternation between spontaneous and paced ventricular complexes. A spike on the ascending part of the T wave was observed, suggesting ventricular undersensing. However, telemetry-supported pacemaker control showed inconstant atrial undersensing.

Reassessing Risk Factors in Pediatric Patients With Pacemakers Implanted for Atrioventricular Block: The Impact of Nonsustained Ventricular Tachycardia.

INTRODUCTION: In pediatric patients with pacemakers implanted for atrioventricular block (AVB), nonsustained ventricular tachycardia (NSVT) detected during routine surveillance is a finding of unknown significance. We sought to describe the incidence of NSVT and determine if there was an association between NSVT and adverse outcomes in these patients. METHODS AND RESULTS: This is a single-center retrospective study of 136 patients (1971-2013) with pacemakers implanted for advanced and complete AVB. EXCLUSION CRITERIA: structural heart disease, diagnoses of myocarditis, cardiomyopathy or channelopathy preceding AVB diagnosis, and sustained or polymorphic ventricular tachycardia (VT) as the first occurring arrhythmia after pacemaker implant. During median follow-up of 11.6 years (IQR 4.3 years, 17 years), 14 (10%) patients had NSVT. There were 6 (4.4%) deaths. Overall, Kaplan-Meier 20-year survival from time of implant was 93%. By univariate analysis, earlier mortality was associated with NSVT (P = 0.010), sustained left ventricular (LV) dysfunction (P = 0.004), maternal autoantibodies (P = 0.017), and acquired AVB (P = 0.049). By multivariate analysis, earlier mortality was associated with NSVT (HR: 5.39 [95% CI: 1.02-28.41]; P = 0.047) and sustained LV dysfunction (HR: 10.24 [95% CI: 1.83-57.32]; P = 0.008). CONCLUSIONS: In children with pacemakers implanted for AVB, NSVT is not uncommon and may be associated with increased mortality. Persistent LV dysfunction may also be a potential factor associated with death. Closer follow-up should be considered in patients with these findings. Large, multicenter studies should be considered to confirm these findings and identify risk stratification methods for this unique patient population.

Transcatheter leadless pacemaker implantation in a patient with a transvenous dual-chamber pacemaker already in place.

An 83-year-old lady had a DDDR pacemaker inserted in 1997 for symptomatic atrioventricular block. She underwent battery replacement in 2008. In 2010, she developed atrial fibrillation; the pacemaker was switched to VVIR mode. During the last 2years, ventricular lead threshold increased progressively. In December 2015, she presented for elective battery replacement. After successful battery replacement, the ventricular lead threshold remained high; therefore, we implanted a leadless transcatheter pacemaker, via femoral vein access, using a dedicated catheter delivery system. Electrical measurements at this stage revealed a pacing threshold of 0.28V at 0.24msec, and an impedance of 650Ω.

A case of reversible third-degree AV block due to Lyme carditis.

The most common manifestation of Lyme carditis is a varying degree of atrioventricular (AV) conduction block. This case describes a 45-year-old male with third-degree AV block due to Lyme carditis. Treatment with intravenous antibiotics resulted in complete normalization of AV conduction, thereby averting permanent pacemaker implantation.

Electrophysiological observations of acute His bundle injury during permanent His bundle pacing.

BACKGROUND: Permanent His bundle pacing (HBP) is a physiological alternative to right ventricular pacing (RVP). Catheter manipulation during HBP can cause trauma to the His bundle during implantation. We sought to determine acute and long-term incidence of His bundle (HB) injury with HBP. METHODS: Patients undergoing permanent HBP at Geisinger Wyoming Valley Medical Center from 2006 to 2014 formed the study group. Patients with pre-existing His-Purkinje disease (HPD) were excluded from the study. Any development of new bundle branch block (BBB) or AV block (B) during acute HBP lead-induced block was recorded. Resolution of AVB and/or BBB was documented. RESULTS: HBP was attempted in 450 patients. In 358 patients without HPD, 28 (7.8%) developed acute HB injury in the form of complete AVB (4, 1.1%), RBBB (21, 5.9%) or LBBB (3, 0.8%) during HBP lead placement. In all 7 patients with AVB or LBBB, conduction completely recovered. The HB electrogram from the lead displayed injury current in all 7 patients. Lead-induced RBBB resolved in 12 of 21 patients and persisted in 9 (2.5%) patients. Pacing from the HBP lead resulted in correction of acute conduction block in 27 of 28 patients and 8 of 9 patients with chronic RBBB. None of the patients with transient conduction block developed new conduction disease during follow-up of 21±19months. CONCLUSIONS: Despite acute trauma to HB in 7.8% of patients undergoing permanent HBP, complete resolution of conduction block occurred in 19 of 28 patients (68%). RBBB persisted in 9 patients (32%) but mostly normalized with HBP.

Left ventricular pacing in neonates and infants with isolated congenital complete or advanced atrioventricular block: short- and medium-term outcome.

AIMS: Right ventricular (RV) pacing may induce left ventricular (LV) dysfunction: neonates and infants with isolated congenital complete/advanced atrioventricular block (CCAVB) are at high risk of developing RV pacing-induced LV dyssynchrony, remodelling, and dysfunction. We prospectively investigated whether LV pacing results in normal LV function and good clinical status in the short/medium term. METHODS AND RESULTS: In this single-centre, prospective study, 10 consecutive patients with CCAVB (median age 4 months, range: 0.1-16) underwent pacemaker implantation (4 VVIR, 6 DDD) using epicardial leads (on the LV apex in 8, on the LV free wall in 2). Data were collected at implantation and at 1- and 12-month follow-up. Echocardiographic evaluation included two-dimensional/three-dimensional assessment of LV dimensions, function (ejection fraction, EF), and ventricular synchrony (interventricular and intraventricular dyssynchrony). Prior to pacemaker implantation, EF was normal in six patients, 50% in two, ≤40% in two. All patients showed good clinical status and normal LV dimensions at follow-up. Patients with LV dilatation and impaired EF at implantation showed LV reverse remodelling and enhanced LV function. Normal LV function and synchrony were observed in most patients (one patient with EF 53% and three patients with mild dyssynchrony at 12-month follow-up). Paced QRS complex tended to be wider than native QRS complexes (P = 0.07); QTc duration of paced complexes was within normal limits or only slightly prolonged, without significant differences compared with QTc interval of native complexes. CONCLUSION: At short- and medium-term follow-up, LV pacing results in satisfactory LV electromechanical function and synchrony in neonates and infants with CCAVB.

Recovery of Ventriculo-Atrial Conduction after Adrenaline in Patients Implanted with Pacemakers.

BACKGROUND: Ventriculo-atrial (VA) conduction can have negative consequences for patients with implanted pacemakers and defibrillators. There is concern whether impaired VA conduction could recover during stressful situations. Although the influence of isoproterenol and atropine are well established, the effect of adrenaline has not been studied systematically. The objective of this study was to determine if adrenaline can facilitate recovery of VA conduction in patients implanted with pacemakers. METHODS: A prospective study was conducted on 61 consecutive patients during a 4-month period (April-July 2014). The presence of VA conduction was assessed during the pacemaker implantation procedure. In case of an impaired VA conduction, adrenaline infusio was used as a stress surrogate to test conduction recovery. RESULTS: The indications for pacemaker implantation were: sinus node dysfunction in 18 patients, atrioventricular (AV) block in 40 patients, binodal dysfunction (sinus node+ AV node) in two patients and other (carotid sinus syndrome) in one patient. In the basal state, 15/61 (24.6%) presented spontaneous VA conduction and 46/61 (75.4%) had no VA conduction. After administration of adrenaline, there was VA conduction recovery in 5/46 (10.9%) patients. CONCLUSIONS: Adrenaline infusion produced recovery of VA conduction in 10.9% of patients with absent VA conduction in a basal state. Recovery of VA conduction during physiological or pathological stresses could be responsible for the pacemaker syndrome, PMT episodes, or certain implantable cardiac defibrillator detection issues.

Torsade de pointes in a patient with complete atrioventricular block and pacemaker failure, misdiagnosed with epilepsy.

A case of torsade de pointes (TdP) with complete atrioventricular block and pacemaker failure that was misdiagnosed as epilepsy is presented herein. An 82-year-old female with recurrent seizure-like attacks showed epileptiform discharge during an electroencephalogram recording. A long QT interval and severe hypokalemia induced runs of TdP, which was related to pacemaker lead fracture, was detected during Holter recording and accompanied with episodes of seizures. After a DDD pacemaker with a new ventricular lead was replaced, there was no recurrence of any seizure-like attacks. Bradycardia-mediated TdP associated with complete atrioventricular block should not be missed in patients with recurrent seizure-like attacks even after pacemaker implantation.

The acute and chronic effects of different right ventricular site pacing on left ventricular mechanical synchrony as assessed by phase analysis of SPECT myocardial perfusion imaging.

BACKGROUND: This study aimed to assess acute and chronic effects of right ventricular mid-septum (RVS) versus right ventricular apex (RVA) pacing on left ventricular (LV) mechanical dyssynchrony using phase analysis of gated single photon emission computed tomography myocardial perfusion imaging (MPI). METHODS: Thirty-nine patients with complete atrioventricular (AV) block, who were indicated for permanent pacing, were recruited and randomized to receive RVA (n = 20) or RVS (n = 19) pacing. All patients underwent MPI at 1 week and 6 months after pacemaker implantation. LV dyssynchrony and cardiac function were assessed by MPI and compared between the two groups. RESULTS: There were no significant differences in baseline characteristics between the RVS and RVA groups. The paced QRS duration was significantly longer in the RVA group than in the RVS group. LV dyssynchrony parameters were not significantly different between the groups at the 1-week follow-up, but they were significantly smaller in the RVS group than in the RVA group at the 6-month follow-up. LV dyssynchrony parameters significantly decreased in the RVS group from the 1-week follow-up to the 6-month follow-up, but were unchanged in the RVA group. No differences in LV function parameters were observed between the groups at the 1-week and 6-month follow-ups. CONCLUSIONS: RVS pacing produces better electrical and mechanical synchrony than RVA pacing for patients with complete AV block.

Characteristics of a large sample of candidates for permanent ventricular pacing included in the Biventricular Pacing for Atrio-ventricular Block to Prevent Cardiac Desynchronization Study (BioPace).

AIMS: The general clinical profile of European pacemaker recipients who require predominant ventricular pacing (VP) is scarcely known. We examined the demographic and clinical characteristics of the 1808 participants (out of 1833 randomized patients) of the ongoing Biventricular Pacing for Atrio-ventricular Block to Prevent Cardiac Desynchronization (BioPace) study. METHODS AND RESULTS: BioPace recruited patients between May 2003 and September 2007 predominantly in European medical centres. We analysed demographic data and described clinical characteristics and electrophysiological parameters prior to device implantation in 1808 enrolled patients. The mean age ± standard deviation (SD) of the 1808 patients was 73.5 ± 9.2 years, 1235 (68%) were men, 654 (36%) presented without structural heart disease, 547 (30%) had ischemic, 355 (20%) hypertensive, 146 (8%) valvular, and 102 (6%) non-ischemic dilated cardiomyopathy. Mean left ventricular ejection fraction was 55.4 ± 12.3%. The main pacing indications were (a) permanent and intermittent atrioventricular (AV) block in 973 (54%), (b) atrial fibrillation with slow ventricular rate in 313 (17%), and (c) miscellaneous bradyarrhythmias in 522 (29%) patients. Mean QRS duration was 118.5 ± 30.5 ms, left bundle branch block was present in 316 (17%), and atrial tachyarrhythmias in 426 (24%) patients. CONCLUSION: To the best of our knowledge, this sample is a representative source of description of the general profile of European pacemaker recipients who require predominant VP. Patients' characteristics included advanced age, predominantly male gender, preserved left ventricular systolic function, high-grade AV block, narrow QRS complex, and atrial tachyarrhythmias, the latter being present in nearly one-fourth of the cohort.

Exercise capacity and N-terminal pro-brain natriuretic peptide levels with biventricular vs. right ventricular pacing for atrioventricular block: results from the PREVENT-HF German Substudy.

AIMS: Previous studies showed unfavourable effects of right ventricular (RV) pacing. Ventricular pacing (VP), however, is required in many patients with atrioventricular (AV) block. The PREVENT-HF study explored left ventricular (LV) remodelling during RV vs. biventricular (BIV) pacing in AV block without advanced heart failure. The pre-specified PREVENT-HF German Substudy examined exercise capacity and N-terminal pro-brain natriuretic peptide (NT-proBNP). METHODS AND RESULTS: Patients with expected VP ≥80% were randomized to RV or BIV pacing. Endpoints were peak oxygen uptake (pVO2), oxygen uptake at the anaerobic threshold (VO2AT), ventilatory efficiency (VE/VCO2), and logNT-proBNP. Considering crossover, intention to treat (ITT), and on-treatment (OT) analyses of covariance (ANCOVA) were performed. For exercise testing 44 (RV: 25, BIV: 19), and for NT-proBNP 53 patients (RV: 29, BIV: 24) were included. The ITT analysis revealed significant differences in pVO2 [ANCOVA effect 2.83 mL/kg/min, confidence interval (CI) 0.83-4.91, P = 0.007], VO2AT (ANCOVA effect 2.14 mL/min/k, CI 0.14-4.15, P = 0.03), and VE/VCO2 (ANCOVA effect -5.46, CI -10.79 to -0.13, P = 0.04) favouring BIV randomization. The significant advantage in pVO2 persisted in OT analysis, while VO2AT and VE/VCO2 showed trends favouring BIV pacing. LogNT-proBNP did not differ between groups. (ITT: ANCOVA effect 0.008, CI -0.40 to +0.41, P = 0.97; OT: ANCOVA effect -0.03, CI -0.44 to 0.30, P = 0.90). CONCLUSION: Our study suggests that BIV pacing produces better exercise capacity over 1 year compared with RV pacing in patients without advanced heart failure and AV block. In contrast, we observed no significant changes of NT-proBNP. Larger trials will allow appraising the clinical usefulness of BIV pacing in AV block. ClinicalTrials.gov Identifier: NCT00170326.

Effects of atrioventricular conduction delay on the outcome of cardiac resynchronization therapy.

BACKGROUND AND PURPOSE: First-degree atrioventricular (AV) block in relation to the outcome of cardiac resynchronization therapy (CRT) has not been well examined. METHODS: Patients who received a CRT defibrillator or pacemaker between January 2002 and September 2010 at Mayo Clinic were classified into 2 groups: normal PR interval and prolonged PR interval. Standard sensed (100 milliseconds) and paced (130 milliseconds) AV delay was programmed after CRT. Clinical presentations and echocardiography were assessed before CRT and at a median of 6 months after CRT. RESULTS: The normal PR interval group (n=199) had greater improvements in heart failure functional class (mean [SD], 0.7 [0.8] vs 0.5 [0.9]; P=.03) and left ventricular ejection fraction (9.4% [12.4%] vs 5.9% [9.5%]; P=.007) than the prolonged PR group (n=204). CONCLUSION: Compared with prolonged PR interval, the presence of normal PR interval was associated with a greater improvement in heart failure.

The underrecognized and neglected compact atrioventricular nodal potential: clinical significance for preventing atrioventricular block during so-called slow pathway radiofrequency ablation.

BACKGROUND: The radiofrequency (RF) ablation target may be located at the compact atrioventricular node (AVN) region during so-called slow pathway (SP) RF ablation, potentially leading to transient or permanent atrioventricular block (AVB). However, related data are rare. METHODS: Among 715 index consecutive patients who underwent RF ablation for atrioventricular nodal re-entry tachycardia, 17 patients subsequently experienced transient or permanent AVB and were included in this retrospective observational study. RESULTS: Among the 17 patients, two patients (11.8%) developed transient first-degree AVB, four patients (23.5%) developed transient second-degree AVB, seven patients (41.2%) developed transient third-degree AVB, and four patients (23.5%) developed permanent third-degree AVB. During baseline sinus rhythm before the start of RF ablation, no His-bundle potential was recorded from the RF ablation catheter. During the so-called SP RF ablation that led to transient or permanent AVB, junctional rhythm with ventriculoatrial (VA) conduction block followed by subsequent AVB was observed in 14 of 17 patients (82.4%), and a low-amplitude, low-frequency hump-shaped atrial potential was recorded before the start of RF ablation in 7 of the 17 patients (41.2%). Direct AVB occurred in 3 of the 17 patients (17.6%), and a low-amplitude, low-frequency hump-shaped atrial potential was recorded before the start of RF ablation in all 3 patients. CONCLUSIONS: The low-amplitude, low-frequency hump-shaped atrial potential recorded at the so-called SP region may reflect the electrogram of compact AVN activation, and RF ablation to this site heralds impending AVB even when a His-bundle potential is not recorded.