High-degree Atrioventricular Block Research Articles

Predictors of post-TAVI conduction abnormalities in patients with bicuspid aortic valves

ObjectivesThis study evaluates predictors of conduction abnormalities (CA) following transcatheter aortic valve implantation (TAVI) in patients with bicuspid aortic valves (BAV).BackgroundTAVI is associated with CA that commonly necessitate a permanent...

High Degree AV Block in Infants

Background: Atrioventricular (AV) block in children may pose a challenge for phycisians. However, it can be detected with careful physical examination.
 Case illustration: A 4 month old infant presented with bradycardia that did not improve during observation period. Her electrocardiography (ECG) showed complete atrioventricular block and her echocardiography showed secundum atrial septal defect (ASD) and patent ductus arteriosus (PDA). Her father’s ECG showed first degree AV block. She was recovered well after pacemaker implantation and PDA ligation. 
 Conclusion: An infant who suffered from complete AV block was successfully treated with pacemaker.

Complications associated with the use of temporary pacemaker in patients waiting for definitive device implantation.

ABSTRACTObjective To determine the rate of complications associated with the use of temporary pacemakers in patients in the waiting list for the definitive pacemaker implantation in a public hospital located in São Paulo, SP, Brazil.Methods Retrospective observational study based on data extracted from medical records of patients admitted to Hospital Municipal Dr. Moyses Deutsch, Hospital Israelita Albert Einstein from January 2014 to December 2018. Patients aged 18 years or older, diagnosed with high degree atrioventricular block upon admission and with indications for definitive pacemaker implantation were included. All-cause mortality, clinical and surgical complications and length of hospital stay while waiting for the procedure were defined as primary outcomes.Results The sample comprised 66 patient allocated to one of two groups: with and without the need of temporary pacemaker while in hospital (n=45 and n=21, respectively). The rate of complications was higher in patients who used a temporary pacemaker (p<0.001). These included primarily pneumonia (p=0.048) and length of hospital stay (p=0.029).Conclusion Patients who required a temporary pacemaker stayed longer in hospital. Longer hospital stay is associated with higher rates of general complications and all-cause mortality.

Implantation of Permanent Pacemaker and COVID-19 coinfection: Strategy for Management at a Dedicated Cardiac Hospital in Bangladesh

Background: The pandemic existence of corona virus disease 2019 (COVID -19) in the year 2020 has initially limited the number of intervention in cardiac diseases in our country. The need for placement of permanent pacemaker is a medical emergency but in patients with concomitant COVID -19, it’s a double edged sword. The treatment strategy and planning for this group of patients with high degree atrioventricular block (AVB) or sinus node disease (SND), needing permanent pacemaker is the fundamental concern along with the safety of the attending cardiologists and other staff members. In this study we sought to comprehend the treatment strategies in patients requiring pacemaker with simultaneous COVID-19 co-infection. Methods: This study was done at the National institute of cardiovascular diseases (NICVD), Shere Bangla Nagar, Dhaka from 10th March 2020 to 9th September 2020. During these six months all patients waiting for permanent pacemaker implantation were screened for COVID-19 by real time polymerase chain reaction (RT PCR). The positive cases were included in the study and managed according to the in hospital protocol. Results: A total of 98 patients had permanent pacemaker implanted during this period, among them12 patients (12.24%) were tested positive for COVID-19. Average age of the patients was 68±7.6 years and 66.7% was male and 33.3% was female. The mean duration of RT PCR positive status was 20.6±6.4 days (range 14 to 29 days) and the mean duration of indwelling TPM was 21.25±7.05 days (range 17 to 30 days). There was no TPM related complication following PPM implantation. Conclusions: Conservative approach of medical management with TPM for stabilization of the patients with corona virus disease is a safe option for delayed PPM implantation after improvement of the patients. In hospital treatment protocol with facilities for isolation and treatment of COVID is the mainstay of the treatment strategy. Bangladesh Heart Journal 2022; 37(1): 59-64

Micra AV leadless pacemaker implantation after transcatheter aortic valve implantation.

Transvenous pacemaker (PM) implantation is a complication in patients undergoing transcatheter aortic valve implantation (TAVI). Recently, a second generation of leadless PMs able of atrioventricular (AV) synchronous pacing has been introduced and could be an alternative when ventricular pacing is required after TAVI. Real-world data on Micra AV after TAVI are still lacking. Our aim was to determine the per- and post-procedural outcomes in patients with Micra AV leadless PM implantation after TAVI. A total of 20 consecutive patients underwent Micra AV leadless PM implantation after TAVI between November 2020 and June 2021. The main indication for ventricular pacing was high-degree AV block (55% of patients) and left bundle branch block (LBBB) associated with prolonged HV interval (45% of patients). At discharge, mean (SD) ventricular pacing threshold was 0.397 ± 0.11 V at 0.24ms and ventricular impedance was 709.4 ± 139.1 Ω. At 1-month follow-up, 95% of patients were programmed in VDD pacing mode. Mean (SD) ventricular pacing threshold was 0.448 ± 0.094 V at 0.24ms. In patients with ventricular&gt; pacing&gt;90% (n=5), mean AM-VP was 72.5% ± 8.3%. Pacing threshold at 1 month was not significantly different compared to discharge (p=.1088). Mean (SD) impedance was 631.0 ± 111.9 Ω, which remained stable at discharge (p=.0813). No procedural complications occurred during implantation. At 1-month follow-up, two patients displayed atrial under-sensing. Micra AV leadless PM implantation after TAVI is associated with a low complication rate and good device performance at 1-month post-implantation.

Impact of conductive disturbances on length of stay after TAVI: A single-centre retrospective study

Conductive disturbances remain the most frequent complication after TAVI. Management of conduction disturbances is highly variable among centres and impact length of stay (LOS). Recently, an expert consensus has been proposed in order to reduce their impact on LOS. To evaluate the impact of the expert consensus for the management of conductive disturbances to reduce LOS after TAVI. We retrospectively included patients who underwent a TAVI between January 1st, 2017 and December 31st, 2018. Patients who had a pacemaker before TAVI were excluded. ECG before, immediately after and the first two days after TAVI were analysed. According to the expert consensus, patients were classified in 5 groups: group 1 (normal ECG and no modification after TAVI), group 2 (pre-implantation right bundle branch block without modification after TAVI), group 3 (PR or QRS enlargement > 20 ms in patients with pre-existing conductive disturbances), group 4 (new onset left bundle blanch block), group 5 (High degree atrioventricular block or complete heart block during procedure). We assessed the proportion of patients early discharged (within 72 hours) among these 5 groups. During the studied period, 348 patients were included. The median LOS was 2 [2–4] days and 245 (71%) patients were discharged early. LOS were longer in groups 2, 3, 4 and 5. Patients in groups 3, 4 and 5 were discharged early in 62%, 65%, and 63% of cases respectively. In contrast, group 1 patients were discharged early in 77% of cases. Patients identified as having a high risk of delayed conductive disturbances by the consensus had longer LOS (5 [2.5–6.5] days with a lower rate of early discharge (39%) ( Table 1 ). This study confirm the impact of conductive disturbances on LOS. The consensus reduces their impact on LOS and allows early discharge in 71% of cases without other complications.

Local Anesthesia versus Conscious Sedation among Patients Undergoing Transcatheter Aortic Valve Implantation-A Propensity Score Analysis.

Background: Conscious sedation (CS) has been used successfully to treat patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve implantation (TAVI) and as such is considered the standard anesthesia method. The local anesthesia (LA) only approach may be feasible and safe thanks to improvements in operators’ experience. Objective: To evaluate differences between LA only versus CS approaches on short- and long-term outcomes among patients undergoing TAVI. Methods: We performed a propensity score analysis on 1096 patients undergoing TAVI for severe AS. Two hundred and seventy-four patients in the LA group were matched in a ratio of 1:3 with 822 patients in the CS group. The primary outcome was a 1-year mortality rate. Secondary outcomes included procedural and peri-procedural complication rates and in-hospital mortality. Results: Patients in the CS group had significantly higher rates of grade 2–3 acute kidney injury and were more likely to have had new left bundle branch block and high-degree atrioventricular block. Patients who underwent TAVI under CS had significantly higher in-hospital and 1-year mortality rates compared to LA (1.6% vs. 0.0% p-value = 0.036 and 8.5% vs. 3.3% p-value = 0.004, respectively). Kaplan–Meier’s survival analysis showed that the cumulative probability of 1-year mortality was significantly higher among subjects undergoing CS compared to patients LA (p-value log-rank = 0.024). Regression analysis indicated that patients undergoing CS were twice more likely to die of at 1-year when compared to patients under LA (HR 2.18, 95%CI 1.09–4.36, p-value = 0.028). Conclusions: As compared to CS, the LA-only approach is associated with lower rates of peri-procedural complications and 1-year mortality rates.

Transseptal versus left atrial approach for mitral valve surgery: postoperative need for pacemaker.

Concerns exist about higher rates of pacemaker implantation using the extended superior transseptal approach for mitral valve surgery. This study aims to compare the extended superior transseptal and the left atrial approach regarding the need for pacemaker implantation after mitral valve surgery. We performed a retrospective analysis of the data of patients undergoing mitral valve surgery through either a sternotomy and transseptal approach or a mini-thoracotomy and left atrial approach in a single centre in the period January 2010 to May 2021. The primary outcome was the evaluation of the postoperative pacemaker implantation rate. Overall, 677 patients were included, 333 with transseptal and 344 with left atrial approach, and 58 (8.6%) patients underwent pacemaker implantation postoperatively. There was no significant difference in the rate of pacemaker implantation between the 2 groups [overall: 34 (10.2%) vs 24 (7%), P = 0.133; for sinus node dysfunction: 12 (3.6%) vs 9 (2.6%), P = 0.459; for high-degree atrioventricular block: 22 (6.6%) vs 15 (4.4%), P = 0.199; transseptal vs left atrial approach, respectively]. A subgroup analysis of the relative effect of transseptal versus left atrial approach on the rate of postoperative pacemaker implantation revealed mitral replacement as a statistically significant confounder (P = 0.019). The exclusion of patients undergoing concomitant cardiac procedures did not lead to a statistically significant difference in the pacemaker implantation rate between the 2 approaches. The analysis of the data of these patients shows no significant difference in the rate of permanent pacemaker implantation between the extended superior transseptal and the left atrial approach for mitral valve surgery.

New onset of AV-nodal reentrant tachycardia (AVNRT) in the elderly- an uncommon diagnosis?

Abstract Funding Acknowledgements Type of funding sources: None. Background Arrhythmias in elderly patients (pat) are common. In this subset of pat, atrial fibrillation is by far the most frequent sustained arrhythmia but not the only one. Clinical, ECG and electrophysiological (EP) features of AV-nodal reentrant tachycardia (AVNRT) have rarely been described in the elderly, and this represents the aim of the current study. Methods At 2 EP-centres in Germany, data from all pat undergoing an EP-study (EPS) and diagnosed with AVNRT between January 2018 and May 2021 were collected and analysed. Pat &amp;gt; 65 years constituted the study population. Results During the study period AVNRT was diagnosed in a total of 329 pat. 93 pat (28%) were &amp;gt; 65 years and represent the study population [median age 74 (65-89) years, 48% female]. In the majority (85%), the duration of symptoms was short (&amp;lt; 1 year), 14 pat had symptoms of paroxysmal tachycardia for longer than 10 years. Most of the pat (n=88, 94%) had at least one ECG-documentation. In SR, the PR interval was relatively long [median 180 (120-380) ms)]. In 84% of pat, sustained AVNRT [median cycle length (CL) 400 (270-800) ms] was induced during EPS. In the remaining pat, at least 2 typical AV-nodal-echo beats were induced. Slow pathway (SP) ablation/modification was performed in all but one patient presenting with a very long baseline PR-interval, low antegrade Wenckebach-point (WP) and very slow AVNRT. In this case, the pat was treated with ß-blocker after pacemaker (PM) implantation. In 3 additional pat, PM implantation was necessary after ablation due to intermittent high-degree AV-block. In comparison to the rest of the study population, these four pat had a longer baseline PQ interval [median 275 (IQR 248- 303) ms vs. 180 (IQR 160- 192) ms], a longer baseline AH interval [median 207ms (IQR 185- 234) ms vs. 95 (IQR 80- 107) ms], a lower baseline antegrade WP CL [median 510 (IQR 435- 645) vs. 390ms (IQR 355- 470) ms], and a longer tachycardia CL [TCL 557 (IQR 454- 661) ms vs. 400 (IQR 364- 443) ms; p value &amp;lt;0,01 for all comparisons]. The overall complication rate (other than AV block) was low (2 pat with AV fistula treated conservatively) and comparable to the one described in younger pat. Discussion Elderly pat also have AVNRT, there are a slight differences in physiology (i.e. relatively long baseline PR-interval and TCL, likely due to changes of the conduction system with aging), and as in young pat, ablation is curative treatment with similar (low) complication rate. A subset of pat, characterized by longer PR- and AH-intervals, lower WP and longer TCL may be at higher risk for AV-block after SP modification. Whether this is due to pre-existing damage or to posterior location of the FP remains unknown. SP ablation is safe and effective even in elderly pat. In pat presenting with EP characteristics presumptive of a baseline impairment of the conduction properties of the FP, ablation of the FP could be attempted to avoid postprocedural high degree AV block.

Incidental arrhythmias during atrial fibrillation screening in a hospital-based patient population

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Screening for atrial fibrillation may reveal other, incidental arrhythmias of relevance. We sought to describe such incidental arrhythmias in the prospective STARFIB cohort study, which screened for silent atrial fibrillation in hospitalized patients aged 65-84 years. Method Patients included in the STARFIB cohort study had up to three 7-day Holter ECGs, performed in two-month intervals. We analysed all the 7-day Holter ECGs of study participants for the presence of one of the following incidental arrhythmias: 1) sick-sinus-syndrome (SSS), defined as sinus arrest of ≥3 seconds duration; 2) second or higher degree atrioventricular block (AVB); 3) sustained atrial tachycardia of ≥30 seconds duration (AT); and 4) sustained ventricular tachycardia of ≥30 seconds duration (VT). Results A total of 2’077 Holter ECGs were performed in 794 patients (mean age 74.7 years; 49% females), resulting in a mean cumulative duration of an analyzable ECG signal of 414±136 hours per patient. We found incidental arrhythmias in 94 patients (11.8%). Among these were SSS in 14 patients (1.8%), AVB in 41 (5.2%), AT in 41 (5.2%), and VT in two (0.3%). The median pause duration in SSS was 4 seconds and SSS resulted in pacemaker implantation in one patient with a pause of 9 seconds duration. The most severe type of AVB found per patient was second degree AVB type Wenkebach in 23 patients (2.9%), second degree AVB type Mobitz or 2:1 AV conduction in 10 patients (1.3%) and complete AVB in 8 (1%; maximum pause 18 seconds). AVB led to pacemaker implantation in 9 patients (1.1%). The median duration and heart rate of AT was 2.2 minutes and 144 bpm, respectively. Initiation of betablocker therapy was recommended in 3 patients (0.4%) due to symptomatic AT. The duration and heart rate of VT was 3 minutes at 216 bpm in one patient and 38 seconds at 150 bpm in another. The former patient with VT experienced syncope and an ICD was implanted, whereas in the latter the betablocker dose was increased. One patient died from a non-cardiac cause during a Holter ECG, which showed progressive bradycardia and finally asystole. Conclusion Incidental arrhythmias were frequently discovered during screening for atrial fibrillation and resulted in device therapy in 1.4% of our cohort patients.

Incidence and clinical characteristics of patients with torsades de pointes complicating acquired atrioventricular block

Abstract Funding Acknowledgements Type of funding sources: None. Background Female gender, degree of QT prolongation and genetic susceptibility are known risk factors for developing torsade de pointe (TdP) during high-degree atrioventricular block (HD-AVB). Objective To analyze the incidence and clinical characteristics of patients presenting with TdP and AVB (TdP [+]) in comparison with non-TdP patients with AVB (TdP [-]). Methods All the ECG from patients prospectively admitted for advanced AVB (2 to 1 and complete) at our university hospital were analyzed. Automated corrected QT (QTc), and manual measurements of QT and JT intervals, and Tpeak-Tend were performed at the time of most severe bradycardia. Results From Sept 2020 to Nov 2021, 100 patients were admitted for HD-AVB. Among them, 17 patients with TdP were identified (8 men; 81 ± 10 years). No differences could be identified concerning automated QTc, manual QTc (Bazett correction), baseline QRS width and mean left ventricular ejection fraction between the two groups. Potassium serum level on admission and mean number of QT-prolongating drugs per patient were not significantly different between the two groups, respectively: 4.34 ± 0.5 in TdP [+] versus 4.52 ± 0.6 mmol/L (p = 0.33); and 0.6 ± 0.7 in group A versus 0.5 ± 0.7 (p = 0.15). In contrast, manual QTcFR (Fridericia correction), corrected JT, Tpeak-to-end and Tpe/QT ratio were significantly increased in the TdP [+] group: respectively 486 ± 70 versus 456 ± 53 ms (p = 0.04); 433 ± 98 versus 381 ± 80 (p = 0.02); 153 ± 57 versus 110 ± 40 (p &amp;lt; 0.001); 0.27 ± 0.08 versus 0.22 ± 0.06 (p &amp;lt; 0.001). Conclusion The incidence of TdP complicating acquired AVB was 17 % in a medium-volume center. Longer QTc (Fridericia), corrected JT and Tpeak-to-end were electrocardiographic predictors of TdP, while no clinical characteristics may predict the occurrence of this complication.

Procedural safety, short and long-term follow up after pacemaker implantation in nonagenarians

Abstract Funding Acknowledgements Type of funding sources: None. Background Permanent cardiac stimulation is increasingly necessary in very old patients, due to the augmented life expectancy. This raise concerns in physicians, patients and caregivers, because pacemaker (PM) implantation can be perceived as too invasive for frail patients with significant comorbidities. Purpose The aim of the present study is to provide data about peri-operative complications, short and long-term survival and their predictors in this specific setting. Materials and methods All consecutive patients aged ≥90 years undergoing pacemaker implantation in our Centre from 2008 to 2020 were enrolled in the registry. Their baseline and follow up data were recorded in a specific database. Results Among the 2437 patients undergoing PM implantation in a 13-year period, 153 were nonagenarians (6.3%). Mean age was 92.7±2.3 years. Most of the patients (66.7%) received a ventricular single chamber PM. High-degree atrio-ventricular block was the first indication for implant (59.5%), followed by sick sinus syndrome or atrial fibrillation with slow ventricular response (30.1%). 15.7% patients needed temporary pacing at presentation. 4 patients (2.6%) experienced acute complications: 3 pneumothorax, 1 ventricular lead displacement with need of repositioning. Mean follow up duration was 2.5±2.0 years. 117 patients (78.5%) died during the follow up. Death occurred after a mean of 2.47 years after PM implantation (range 1-3272 days). Survival rates were 70.0%, 35.3% and 10.0% at 1, 3 and 5 years respectively. No pacemaker-related long-term complication was recorded during the follow up. 2 patients underwent generator replacement due to battery end of life. Chronic kidney insufficiency (p = 0.030) and congestive heart failure (p = 0.021) but not age were predictors of precocious mortality (within 1 month). Age at implant and longer length of hospital stay before PM implantation were predictors of long-term death (p = 0.001 and p = 0.043 respectively). Conclusions Extremely old age should not discourage PM implantation, when indicated; age is obviously predictor of long-term death but is not predictor of precocious mortality. Acute periprocedural complication rate is low and generally comparable to that of younger populations.

P14 PROCEDURAL SAFETY, SHORT AND LONG–TERM FOLLOW UP AFTER PACEMAKER IMPLANTATION IN NONAGENARIANS

Abstract Background Permanent cardiac stimulation is increasingly necessary in very old patients, due to the augmented life expectancy. This raise concerns in physicians, patients and caregivers, because pacemaker (PM) implantation can be perceived as too invasive for frail patients with significant comorbidities. The aim of the present study is to provide data about peri–operative complications, short and long–term survival and their predictors in this specific setting. Materials and Methods All consecutive patients aged ≥ 90 years undergoing pacemaker implantation in our Centre from 2008 to 2020 were enrolled in the registry. Their baseline and follow up data were recorded in a specific database. Results Among the 2437 patients undergoing PM implantation in a 13–year period, 153 were nonagenarians (6.3%). Mean age was 92.7 ± 2.3 years. Most of the patients (66.7%) received a ventricular single chamber PM. High–degree atrio–ventricular block was the first indication for implant (59.5%), followed by sick sinus syndrome or atrial fibrillation with slow ventricular response (30.1%). 15.7% patients needed temporary pacing at presentation. 4 patients (2.6%) experienced acute complications: 3 pneumothorax, 1 ventricular lead displacement with need of repositioning. Mean follow up duration was 2.5 ± 2.0 years. 117 patients (78.5%) died during the follow up. Death occurred after a mean of 2.47 years after pacemaker implantation (range 1 – 3272 days). Survival rates were 70.0%, 35.3% and 10.0% at 1, 3 and 5 years respectively. No pacemaker–related long–term complication was recorded during the follow up. 2 patients underwent generator replacement due to battery end of life. Chronic kidney insufficiency (p = 0.030) and congestive heart failure (p = 0.021) but not age were predictors of precocious mortality (within 1 month). Age at implant and longer length of hospital stay before PM implantation were predictors of long–term death (p = 0.001 and p = 0.043 respectively).

Atrioventricular Block Necessitating Chronic Ventricular Pacing After Tricuspid Valve Surgery in Patients With a Systemic Right Ventricle: Long-Term Follow-Up.

BackgroundPatients with transposition of the great arteries (TGA) after an atrial switch or congenitally corrected TGA (ccTGA) are prone to systemic right ventricular (sRV) failure. Tricuspid valve (TV) regurgitation aggravates sRV dysfunction. Timely TV surgery stabilizes sRV function, yet the development of atrioventricular (AV)-conduction disturbances in the course of sRV failure can contribute to sRV dysfunction through pacing-induced dyssynchrony. This study aims to explore the incidence, timing, and functional consequences of AV-block requiring ventricular pacing after TV surgery in patients with sRV.MethodsConsecutive adolescent and adult patients with an sRV who underwent TV surgery between 1989 and 2020 and followed-up at our center were included in this observational cohort study.ResultsThe data of 28 patients (53% female, 57% ccTGA, and a mean age at surgery 38 ± 13 years) were analyzed. The mean follow-up was 9.7 ± 6.8 years. Of the remaining 22 patients at the risk of developing high degree AV-block after TV surgery, 9 (41%) developed an indication for chronic ventricular pacing during follow-up, of which 5 (56%) within 24 months postoperatively (3 prior to hospital discharge). The QRS duration, a surrogate marker for dyssynchrony, was significantly higher in patients with chronic left ventricular pacing than in patients with native AV-conduction (217 ± 24 vs. 116 ± 23 ms, p = 0.000), as was the heart failure biomarker NT-pro-BNP [2,746 (1,242–6,879) vs. 495 (355–690) ng/L, p = 0.004] and the percentage of patients with ≥1 echocardiographic class of deterioration of systolic sRV function (27 vs. 83%, p = 0.001). Of the patients receiving chronic subpulmonary ventricular pacing (n = 12), 9 (75%) reached the composite endpoint of progressive heart failure [death, ventricular assist device implantation, or upgrade to cardiac resynchronization therapy (CRT)]. Only 4 (31%) patients with native AV-conduction (n = 13) reached this composite endpoint (p = 0.027).ConclusionPatients with a failing sRV who undergo TV surgery are prone to develop AV-conduction abnormalities, with 41% developing an indication for chronic ventricular pacing during 10 years of follow-up. Patients with chronic subpulmonary ventricular pacing have a significantly longer QRS complex duration, have higher levels of the heart failure biomarker NT-pro-BNP, and are at a higher risk of deterioration of systolic sRV function and progressive heart failure.

PO-699-02 CARDIONEUROABLATION: SELECTIVE TREATMENT OPTION FOR CARDIOINHIBITORY SYNCOPE

Reflex cardioinhibitory syncope is common, and until recently, permanent pacemaker implantation was the only treatment option - and even then, an option with only modest efficacy in preventing recurrent syncope. Radiofrequency (RF) catheter ablation of epicardial ganglionated plexi (GP) is increasingly being explored as a therapeutic option. To assess the safety and efficacy of a consecutive group of patients (with a substantial rate of implantable monitoring follow-up) treated by cardio-neuroablation (CNA) in a single center. CNA is considered in pts after a positive atropine test. Under general anesthesia, electroanatomical LA / RA maps are created (CARTO, NavX). RF energy is applied to the GP predilection sites in both atria until the vagal response to high-frequency (HF) stimulation of the vagal nerve (at jugular vein level) is completely eliminated. A total of 31 patients (age 40.0 ± 8.5 yrs; 18 M / 13 W; BMI 26.6 ±4.9; normal LVEF and LA size) with cardioinhibitory syncope were treated with CNA. Three patients had prior pacemakers including two leadless pacers, and 15 pts (50%) had implantable loop recorders (ILRs). All patients had a positive atropine test pre-CNA. The indications for CNA were: syncope based on sinus bradycardia/arrest in 18 patient s, high degree AV block in 12 patients, and a combination of both in 1 patient. The average longest asystolic pause was 5 sec (range 3 - 40). The average number of syncopal events was 4 per patient (range 0-20). The median procedural time was 156 ± 46.9 min; the mean fluoroscopy time was 8.2 ± 4.4 min. Using a total of 28 ± 15 RF applications (total ablation time was 1736 ± 839 sec), the endpoint of abolishing any vagal response to HF stimulation was achieved in 100% of patients. There was one serious complication - a femoral artery pseudoaneurysm requiring surgery. During clinical follow-up (mean 10 months), including ILR interrogation, only 1 in 30 (3.3%) pts had recurrent syncope or significant bradycardia were. No patient required permanent pacing after CNA. Our observational study demonstrated that GP ablation is a safe procedure with an efficacy exceeding 95%. CNA should be evaluated in a randomized clinical trial.

Cardiac Involvement and Arrhythmias Associated with Myotonic Dystrophy.

Myotonic dystrophy is an autosomal dominant genetic disease of nucleotide expansion resulting in neuromuscular disease with two distinct subtypes. There are significant systemic manifestations of this condition including progressive muscular decline, neurologic abnormalities, and cardiac disease. Given the higher prevalence of cardiac dysfunction compared to the general population, there is significant interest in early diagnosis and prevention of cardiac morbidity and mortality. Cardiac dysfunction has an origin in abnormal and unstable nucleotide repeats in the DMPK and CNBP genes which have downstream effects leading to an increased propensity for arrhythmias and left ventricular systolic dysfunction. Current screening paradigms involve the use of routine screening electrocardiograms, ambulatory electrocardiographic monitors, and cardiac imaging to stratify risk and suggest further invasive evaluation. The most common cardiac abnormality is atrial arrhythmia, however there is significant mortality in this population from high-degree atrioventricular block and ventricular arrhythmia. In this review, we describe the cardiac manifestations of myotonic dystrophy with an emphasis on arrhythmia which is the second most common cause of death in this population after respiratory failure.

Horse, Donkey, Or Zebra: Delayed Diagnosis Of Giant Cell Myocarditis

<h3>Introduction</h3> Giant cell myocarditis (GCM) classically presents in a dramatic fashion. Initial manifestations may include fulminant heart failure, refractory ventricular arrhythmias, and high degree AV block. Treatment includes aggressive immunosuppression, but even with proper treatment, the risk of progression to end stage heart failure is high. Although the clinical scenario can strongly suggest GCM, endomyocardial biopsy (EMB) remains the gold diagnostic standard. <h3>Case Report</h3> A 70-year-old female with hypertension and hyperlipidemia presented to the hospital with syncope. She was found to have new systolic heart failure with a left ejection fraction of 32%. She had a new first degree AV block with intermittent 2:1 AV block. Cardiac MRI showed multiple areas of delayed enhancement thought to be consistent with RCA territory infarct pattern versus infiltrative cardiomyopathy, specifically, sarcoidosis. Subsequent coronary angiogram demonstrated mild, non-obstructive coronary artery disease. EMB at this time showed focal histiocytic infiltrate with scattered eosinophils. No granulomas or giant cells were identified. Given the clinical picture and EMB findings, presentation was felt to be most consistent with cardiac sarcoidosis, although other inflammatory etiologies remained in the differential. Prednisone and neurohormonal blockade were started. Given her intermittent AV block, a CRT-D device was implanted. The remainder of the patient's index admission was uneventful and she had NYHA Class II symptoms on discharge. However, the patient quickly returned to the emergency department after 17 appropriate ICD discharges in the setting of VT storm. She quickly deteriorated requiring emergent peripheral VA-ECMO cannulation. A second EMB was obtained at this time which showed profound inflammation as well as giant cells (Figure 1). She was treated for giant cell myocarditis with aggressive immunosuppression but had worsening end-organ dysfunction and continued to deteriorate clinically. Ultimately, the decision was made to transition to comfort measures and the patient expired. <h3>Discussion</h3> Both GCM and cardiac sarcoidosis can present with new onset heart failure, refractory ventricular arrhythmias, and life-threatening conduction abnormalities. Endomyocardial biopsy is critical to establish the diagnosis, yet the yield is not 100%. Given the exceedingly high mortality without proper treatment, repeat EMB may be necessary to establish the diagnosis of GCM.

Patient-Specific Computer Simulation to Predict Conduction Disturbance With Current-Generation Self-Expanding Transcatheter Heart Valves

BackgroundPatient-specific computer simulation may predict the development of conduction disturbance following transcatheter aortic valve replacement (TAVR). Validation of the computer simulations with current-generation devices has not been undertaken. MethodsA retrospective study was performed on patients who had undergone TAVR with a current-generation self-expanding transcatheter heart valve (THV). Preprocedural computed tomography imaging was used to create finite element models of the aortic root. Procedural contrast angiography was reviewed, and finite element analysis performed using a matching THV device size and implantation depth. A region of interest corresponding to the atrioventricular bundle and proximal left bundle branch was identified. The percentage of this area (contact pressure index [CPI]) and maximum contact pressure (CPMax) exerted by THV were recorded. Postprocedural electrocardiograms were reviewed, and major conduction disturbance was defined as the development of persistent left bundle branch block or high-degree atrioventricular block. ResultsA total of 80 patients were included in the study. THVs were 23- to 29-mm Evolut PRO (n = 53) and 34-mm Evolut R (n = 27). Major conduction disturbance occurred in 27 patients (33.8%). CPI (28.3 ± 15.8 vs. 15.6 ± 11.2%; p < 0.001) and CPMax (0.51 ± 0.20 vs. 0.36 ± 0.24 MPa; p = 0.008) were higher in patients who developed major conduction disturbance. CPI (area under the receiver operating characteristic curve [AUC], 0.74; 95% CI, 0.63-0.86; p < 0.001) and CPMax (AUC, 0.69; 95% CI, 0.57-0.81; p = 0.006) demonstrated a discriminatory power to predict the development of major conduction disturbance. ConclusionsPatient-specific computer simulation may identify patients at risk for conduction disturbance after TAVR with current-generation self-expanding THVs.

Evaluation of the 2021 European Society of Cardiology guidelines in pre-existing right bundle branch block patients undergoing transcatheter aortic valve implantation with a balloon-expandable valve.

AimsThe 2021 European Society of Cardiology guidelines recommend early pacemaker implantation in pre-existing right bundle branch block (RBBB) patients who develop PR prolongation or QRS axis change after transcatheter aortic valve implantation (TAVI). We aimed to evaluate this recommendation in TAVI recipients with a balloon-expandable valve (BEV).Methods and resultsWe retrospectively reviewed 188 pre-existing RBBB patients without pre-existing permanent pacemaker (PPM) who underwent TAVI with a BEV at our institution in 2015–19. Patients who developed high-degree atrioventricular block (HAVB) during TAVI or within 24 h post-TAVI were excluded. Eligible patients were divided according to the guideline-directed criteria (ΔPR interval ≥20 ms and/or QRS axis change). Patients who met the criteria (n = 102, 54.3%), compared with those who did not (n = 86), had a higher prevalence of baseline right axis deviation and were more likely to have received a larger valve with greater oversizing. The 30-day delayed HAVB rate did not differ significantly between the groups (3.9% vs. 4.7%, P = 1.00; odds ratio = 0.84, 95% confidence interval = 0.20–3.45). There was also no significant difference in terms of death (5.0% vs. 8.4% at 1 year; overall log-rank P = 0.94) or a composite of death or PPM implantation (14.8% vs. 16.6% at 1 year; overall log-rank P = 0.94) during follow-up post-TAVI. The majority of PR prolongations (79.4%) and QRS axis changes (52.0%) regressed within the following 24 h.ConclusionThe present data did not demonstrate an association of significant changes in PR interval or QRS axis with heightened delayed HAVB risk in BEV recipients with pre-existing RBBB. Prospective studies are warranted to confirm these findings.

Bifascicular block in unexplained syncope is underrecognized and under-evaluated: A single-center audit of ESC guidelines adherence.

BackgroundThe presence of bifascicular block on electrocardiography suggests that otherwise-unexplained syncope may be due to complete heart block. European Society of Cardiology (ESC) recommends investigating it with electrophysiology study (EPS). PPM is indicated if high-degree atrioventricular block is inducible. Long term rhythm monitoring with implantable loop recorder (ILR) is recommended if EPS is negative. We evaluated adherence to these guidelines.MethodsThis is a single-center retrospective audit of adult patients with bifascicular block hospitalized for unexplained syncope between January 2018 and August 2019 under general medicine service. Patients with an alternative explanation for syncope were excluded. Guideline adherence was assessed by formal cardiology consult and whether EPS followed by ILR and/or PPM were offered.Results65 out of 580 adult patients (11.2%) admitted to general medicine service for syncope had a bifascicular block; 29 (5%) were identified to have bifascicular block and unexplained syncope. Median age was 77 ±10 years; 9 (31%) were female, and 6 (20.7%) patients had at least one prior hospital visit for syncope at our academic medical center. Cardiology was consulted on 17 (58.6%) patients. Two patients were evaluated by EPS (1 refused) followed by ILR. Overall, 3 out of 29 patients (10.3%) received guideline-directed evaluation during the hospitalization based on ESC guidelines. None of the patients received empiric PPM during the index hospitalization.ConclusionAmong patients admitted to the general medicine service with unexplained syncope and bifascicular block, a minority (10.3%) underwent guideline-directed evaluation per ESC recommendations. Cardiology was consulted in 58.6% of cases.