The Transcatheter Aortic Valve Replacement-Conduction Study: The Value of the His-Ventricular Interval in Risk Stratification for Post-TAVR Atrioventricular-Block.

Background: There is no clear consensus regarding the optimal risk stratification of high-degree atrioventricular block (HDAVB) after transcatheter aortic valve replacement (TAVR). Methods: This prospective study sought to determine the utility of the pre- and post-TAVR His-ventricular (HV) interval in the risk stratification of post-TAVR HDAVB. One hundred twenty-one patients underwent an electrophysiology study before and after TAVR. The primary outcome was HDAVB requiring pacemaker implantation within 30 days post-TAVR. A separate retrospective cohort was analyzed to determine the postoperative interval at which the risk of HDAVB is reduced to <5%. Results: HDAVB occurred in 12 (10%) patients. Baseline right bundle branch block (RBBB) (odds ratio [OR]: 13.6), implant depth >4 mm (OR: 3.9), use of mechanically- or self-expanding valves (OR: 6.3), and post-TAVR HV > 65 â€‹ms (OR: 4.9) were associated with increased risk of HDAVB, whereas PR intervals and pre-TAVR HV were not. In patients without baseline RBBB or new persistent left bundle branch block (LBBB), not one patient with post-TAVR HV < 65 â€‹ms developed HDAVB. In the separate retrospective cohort (N = 1049), the risk of HDAVB is reduced (<5%) on postoperative days 4 and 3 in patients with pre-TAVR RBBB and post-TAVR persistent LBBB, respectively. Conclusions: Baseline RBBB, new persistent LBBB, implant depth >4 mm, and a post-TAVR HV ≥ 65 â€‹ms were associated with a higher risk of post-TAVR HDAVB, whereas an HV ≤ 65 â€‹ms was associated with a lower risk. The pre-TAVR HV was not associated with our outcome, and the delta HV did not have practical incremental prognostic value. Among those without pre-TAVR RBBB or post-TAVR persistent LBBB, no patients with post-TAVR HV < 65 â€‹ms developed HDAVB.

Impact of cardiac conduction disease in patients with cardiac amyloidosis: A national retrospective cohort study.

BACKGROUND: There is a paucity of data regarding the impact of cardiac conduction disease (CD) on clinical outcomes in patients with cardiac amyloidosis (CA). METHODS: The National Inpatient Sample (NIS) was queried to identify all CA admissions and those with CD using ICD-10 codes from 2016 to 2019. We explored baseline characteristics and used multivariate logistic regression to assess the association between CD and several clinical outcomes during index admission; a p-value of <0.05 was significant. Propensity score matching (PSM) was performed to validate our results. RESULTS: A total of 12,185 patients with CA were identified. Of these, 920 (7.6 %) had CD. The median age of the sample was 72 years (IQR: 64-80). After multivariate adjustment and PSM, the presence of CD in CA was associated with higher odds of ventricular arrhythmias (VA) (aOR = 2.97, 95 % CI 1.78-4.96, p < 0.001), syncope (aOR = 3.44, 95 % CI 1.51-7.83, p = 0.003), and cardiovascular implantable electronic device (CIED) implantation (aOR = 12.86, 95 % CI 5.50-30.04, p < 0.001) but not with sudden cardiac arrest (p = 0.092), acute heart failure (p = 0.060), all-cause in-hospital mortality (p = 0.384), and non-routine discharge in patients admitted for CA (p = 0.271). CONCLUSIONS: Although CD was not associated with all-cause in-hospital mortality, there was a significant association with VAs and syncope. Syncope is associated with worse survival in patients with CA. Further studies that prospectively follow patients are needed to determine the true effect of cardiac CD on mortality in patients with CA.

Rates and predictors for sustained ventricular tachycardia in patients with cardiac sarcoidosis and AV block as first cardiac presentation: implications for device implantation.

BACKGROUND: Atrioventricular block (AVB) is a frequent initial presentation of cardiac sarcoidosis (CS), but dangerous ventricular arrhythmias (VA) can occur. Despite the scarcity of data, guidelines recommend ICD rather than a pacemaker implantation whenever a device is needed. OBJECTIVE: In this study, we aimed to establish predictors for sustained VA in patients with CS presenting with pacing indication due to an AVB. METHODS: We prospectively enrolled 112 patients with CS. Excluding those with VA, 82 patients remained and were divided into 2 groups: 34 individuals with AVB as initial presentation and 48 with other symptoms as first presentation (OSF). Both groups were compared for clinical characteristics, rates of VA, LVAD implantation, heart transplantation and mortality. RESULTS: During follow-up, VA was detected in 50% in the AVB and 10.4% in the OSF group; P = 0.001. Death, LVAD implantation, heart transplantation occurred in 11.8% in AVB vs. 10.4% in the OSF; P = 0.847. Late gadolinium enhancement (LGE) was equally observed in both groups: 70% vs. 70.5%; P = 0.966, whereas more patients in the AVB group exhibited abnormal PET uptake: 86.2% vs. 54.3%; P = 0.007. In multivariate analysis, AVB (HR 25.15), RV LGE in CMR (HR 7.39) were predictors for VA occurrence, whereas the use of immunosuppressive therapy was associated with less VA (HR 4.3). CONCLUSIONS: Patients with CS presenting with AVB have a high risk of sustained VA. Although immunosuppressive drugs may reduce the occurrence of VA, ICD implantation is reasonable, especially in case of right ventricular LGE.

Complications and Mortality Rate of Vagus Nerve Stimulation for Drug-Resistant Epilepsy.

OBJECTIVE: The goal of this study is to evaluate the complications and mortality associated with vagus nerve stimulation (VNS). METHODS: We retrospectively reviewed medical records of patients who underwent VNS implantation for the treatment of drug-resistant epilepsy (DRE) between 2000 and 2023. The mean follow-up time was 10.6 years, ranging from three months to 22 years. RESULTS: In total, 55 adult and pediatric patients received VNS therapy with 117 procedures performed over 23 years. The most common early complications were hoarseness and cough which were reported in eight adult patients (6.8%). Four children with intellectual disability (ID) had infection (3.4%), eight patients had lead breakage (6.8%), and two had device migration (1.7%). Four of all patients (7.3%) demonstrated late complications due to chronic nerve stimulation including vocal cord dysfunction, late-onset severe AV block, and obstructive sleep apnea (OSA). Three patients (5.5%) had VNS deactivated permanently due to complications and/or lack of efficacy. Two patients died from probable sudden unexpected death in epilepsy (SUDEP) with an incidence of 3.4/1000 person-years. CONCLUSIONS: VNS therapy is safe over long-term follow-up but not without risks. Most post-operative complications are minor and transient for adults. Children with ID tend to have infection and device migration. Late-onset cardiac complications and OSA can develop in some patients during VNS therapy and should not be overlooked. The SUDEP rate may decrease with VNS therapy over time.

Thirty-Day High-Grade Aortic Valve Block Post-Transcatheter Aortic Valve Replacement in Patients Discharged on Heart Rhythm Monitor.

Background: Conduction disease is an important and common complication post-transcatheter aortic valve replacement (TAVR). Previously, we developed a conduction disease risk stratification and management protocol post-TAVR. This study aims to evaluate high-grade aortic valve block (HAVB) incidence and risk factors in a large cohort undergoing ambulatory cardiac monitoring post-TAVR according to conduction risk grouping. Methods: This single-center, retrospective study evaluated all patients discharged on ambulatory cardiac monitoring between 2016 and 2021 and stratified them into 3 groups based on electrocardiogram predictors of HAVB risk (group 1 [low], group 2 [intermediate], and group 3 [high]). HAVB was defined as ≥2 consecutive nonconducted P waves in sinus rhythm or bradycardia <50 beats/minute with a fixed rate for atrial fibrillation/flutter. Descriptive statistics were used to show the incidence and timeline, while logistic regression was utilized to evaluate predictors of HAVB. Results: Five hundred twenty-eight patients were included (median age 80 years [74-85]; 43.8% female). Forty-one patients (7.8%) developed HAVB during ambulatory monitoring (68% were asymptomatic). Over a median follow-up of 2 years (1.3-2.7), the overall mortality rate was 15.0% (30-day mortality rate of 0.57%, n = 3). Risk factors for HAVB were male sex (odds ratio [OR] = 2.46, p = 0.02, 95% CI = 1.21-5.43), baseline right bundle branch block (OR = 2.80, p = 0.01, 95% CI = 1.17-6.19), and post-TAVR QRS >150 â€‹ms (OR = 2.16, p = 0.03, 95% CI = 1.01-4.40). The negative predictive value for patients in groups 1 and 2 for 30-day HAVB was 95.0 and 93.8%, respectively. Conclusions: The risk of 30-day HAVB post-TAVR on ambulatory monitoring post-TAVR varies according to post-TAVR electrocardiogram findings, and a 3-group algorithm effectively identifies groups with a low negative predictive value for HAVB.

Case report: Electrocardiographic (ECG) recording during the hanging process.

A 48-year-old woman was found hanged in the bathroom. She was wearing a Holter monitor, which was later analysed by a cardiologist. During autopsy, findings congruent with atypical hanging were collected. The ECG showed a 20 s asystole and four minutes later bradycardia, which progressed to a second-degree AV-block Mobitz I, then Mobitz II, then to a third-degree AV-block. Finally, only P waves could be observed, before heart action ceased. This is one of few cases reporting ECG-changes during hanging and might give further insight into the complex pathophysiology of this type of death.

Atrial Septal Defect (ASD) Repair Unveiling an Unusual Conduction Conundrum: A Wenckebach Case Report.

Atrial septal defects are a common congenital malformation that can lead to an elevated risk for stroke due to the bypass of the lungs by deep vein thrombosis, as well as the expected repercussions of pulmonary hypertension if left untreated. Surgical intervention is definitive; however, recent advancements in treatment options, such as percutaneous intervention, represent a safer and equally effective way to treat this congenital complication. While safer, percutaneous interventions can also lead to adverse events that may force patients to present to the emergency department. Here, we present a unique case of a patient with congenital atrial septal defect status post-percutaneous intervention who developed a new-onset second-degree AV block, Mobitz type 1 Wenckebach rhythm.

An Unusual Case of Paroxysmal Third-Degree Atrioventricular Block: Thinking Outside the Box.

During the assessment of a third-degree atrioventricular (AV) block in a patient with syncope, different etiologies should be considered and evaluated. Extrinsic vagal paroxysmal AV block, extrinsic idiopathic AV block and intrinsic paroxysmal AV block are among the types of third-degree AV block in the differential diagnoses. Extrinsic vagal paroxysmal third-degree atrioventricular block (EV-AVB) is linked to parasympathetic influence on cardiac conduction and can be observed in bladder distention and urinary retention. Topical and ophthalmic beta-blockers have shown systemic effects such as bradycardia with and without syncope. We present the case of an 80-year-old male with symptomatic EV-AVB likely precipitated by bladder outlet obstruction and chronic use of an ophthalmic beta-blocker, often overlooked causes of third-degree AV block.

The impact of smoking on third-degree atrioventricular block outcomes: A propensity-matched analysis.

Background: Third-degree atrioventricular (AV) blocks are rare but cause significant symptoms and require immediate intervention. Coronary artery disease (CAD) is felt to be the most common etiology. Although smoking is a prominent risk factor for CAD, there is a paucity of data assessing the direct effect of smoking on third-degree AV block. Methods: We performed a retrospective cohort study on adult-weighted admissions in 2019-2020 with a primary diagnosis of third-degree AV block and a history of smoking using the National Inpatient Sample (NIS) database. In-hospital mortality, rates of pacemaker insertion, cardiogenic shock, cardiac arrest, acute kidney injury (AKI), stroke, tracheal intubation, mechanical ventilation, mechanical circulatory support, vasopressor use, length of stay (LOS), and total hospitalization costs were analyzed using regression analysis. We performed a secondary analysis using propensity score matching to confirm the results. Results: A total of 77,650 admissions met inclusion criteria (33,625 females [43.3 %], 58,315. Caucasians [75 %], 7030 African American [9 %], 6155 Hispanic [7.9 %]; mean [SD] age 75.4.[10.2] years) before propensity matching. A total of 29,380 (37.8 %) patients with AV block were smokers.A total of 5560 patients with and without a history of smoking were matched for the analysis. Smokers had.decreased odds of mortality (aOR, 0.59; CI, 0.44-0.78; p < 0.001), cardiogenic shock, cardiac arrest, tracheal intubation, mechanical ventilation, shorter LOS, and lower total hospital costs in both the multivariable regression and propensity-matched analyses. Conclusion: Third-degree AV block had lower in-hospital mortality, cardiogenic shock, cardiac arrest, LOS, and total hospitalization cost in patients with smoking history.

PR prolongation with alternating wide and narrow QRS complexes: What is the mechanism?

The alternating wide and narrow QRS complexes following prolonged PR interval is a challenging issue. The scalar diagrams with the graphic representation of the electrical events and the careful analysis of their temporal relationship can help to better understand the surface electrocardiogram.

A systematic review of the clinical characteristics and course of atrioventricular blocks in hyperthyroidism.

BACKGROUND: Atrioventricular block (AVB) is rare in hyperthyroidism (HTH). Little is known about the true prevalence, clinical course, optimal management, and outcomes of different types of AVBs in patients with HTH. To address these uncertainties, we aimed to conduct a systematic review by combining the available literature to provide more meaningful data regarding AVBs in HTH. METHODS: We systematically searched PubMed, Scopus, Embase, and Google Scholar for articles reporting patients who developed AVB in the context of HTH. Data were analysed in STATA 16. The main outcomes included types of AVB, frequency of pacemaker insertion, and resolution of AVB. The systematic review is registered with the International Prospective Register of Systematic Reviews (PROSPERO) with the identification number CRD42022335598. RESULTS: A total of 56 studies (39 case reports, 12 case series, 3 conference abstracts, 1 retrospective study, and 1 prospective observational study) with 87 patients were included in the analysis, with a mean age of 39.1 ± 17.6 years. Females constituted 65.7% (n = 48) of the cohort. Complete heart block (CHB) was the most commonly reported AVB (N = 45, 51.7%), followed by first-degree AVB (16.1%) and second-degree AVB (14.9%). Overall, 21 patients underwent pacing. A permanent pacemaker was inserted in one patient with second-degree AVB and six patients with CHB. Mortality was reported in one patient with CHB. The clinical course and management of HTH and AVBs did not differ in patients with CHB or lower-degree blocks. Apart from lower rates of goitre and more use of carbimazole in those who underwent pacing, no differences were found when compared to the patients managed without pacing. CONCLUSION: Current data suggest that CHB is the most common type of AVB in patients with HTH. Most patients can be managed with anti-thyroid management alone. Additionally, whether pacemaker insertion alters the clinical outcomes needs further exploration.

Simultaneous Occurrence of Transient Complete Heart Block With Acute Lateral Medullary Infarct.

Lateral Medullary Syndrome (LMS) poses clinical challenges, often resulting from ischemic events in the medulla oblongata. We present a unique case of LMS in a woman in her 60s with a complex medical history. Alongside neurological deficits, she experienced a transient high-grade atrioventricular block (HgAVB), a rare cardiac manifestation linked to LMS. Given the rarity of simultaneous transient HgAVB with acute lateral medullary infarct, only a handful of case reports documenting similar findings are available in the existing literature. More research and case reporting are needed to better our understanding of this area. The patient's condition, marked by a sudden onset of severe headache and left-sided weakness, revealed an acute infarct in the medulla territory. Notably, her HgAVB spontaneously resolved after 72 hours. This case emphasises the crucial need for extended cardiac surveillance in LMS patients due to their susceptibility to life-threatening arrhythmias. The intricate interplay between the brainstem and cardiovascular system highlights autonomic dysregulation as a potential mechanism for cardiac abnormalities. The report advocates for a holistic approach to managing LMS cases, stressing interdisciplinary collaboration for timely diagnosis and intervention, ultimately improving patient outcomes and reducing the risk of fatal arrhythmias.

High-Grade Atrioventricular Block Reveals Rare Transthyretin Cardiac Amyloidosis With Unique Hemodynamics.

Atrioventricular (AV) block is a common cardiac conduction disorder that is frequently encountered in clinical practice; however, the association with rare systemic conditions such as transthyretin amyloidosis (ATTR) is heavily underdiagnosed. ATTR amyloidosis is a systemic disorder characterized by the deposition of abnormal transthyretin protein fibrosis in various organs including the heart and vasculature, resulting in progressive organ dysfunction. We present a rare case of high-grade AV block unveiling ATTR cardiac amyloidosis with unusual hemodynamics, specifically severe supine hypertension with severe orthostatic hypotension. These findings posed a diagnostic challenge, underscoring the importance of a comprehensive diagnostic approach and meticulous review of medical history. Following pacemaker placement and the diagnosis of ATTR cardiac amyloidosis, our patient was started on a Tafamidis regimen.

Feasibility of cardiac magnetic resonance imaging in temporary permanent pacemaker implants in pediatric myocarditis and complete atrioventricular block.

Background: Diagnosing myocarditis in children presenting with complete AV block (CAVB) is challenging. Temporary permanent pacing support using standard transvenous active fixation lead can be inserted percutaneously until recovery. However, access to cardiac magnetic resonance (CMR) imaging may be limited due to safety concerns. Cases: We report three cases where CMR was performed using temporary permanent pacemaker in situ. We evaluated the effect of device artefacts on image quality and examined any instances of device malfunction. Conclusion: In children with CAVB and myocarditis, a temporary permanent pacemaker can provide reliable pacing until recovery, and CMR can be safely performed with the implanted pacemaker without compromising image quality.

What are those intermittent "S" waves?

A 69-year-old woman had three syncopal events while flying on an airplane. She was found to be profoundly bradycardic. Two 12­lead electrocardiograms (ECGs) showed ventricular rates in the thirties. In one, the QRS complexes were narrow. In the second ECG, there were wide negative deflections following the QRS complexes. Analysis of telemetry recordings revealed the underlying mechanism and helped establish appropriate programing of an implanted pacemaker.

AV-optimized conduction system pacing for treatment of AV dromotropathy: A randomized, cross-over study.

BACKGROUND: Severe first-degree atrioventricular (AV) block may produce symptoms similar to heart failure due to AV dyssynchrony, a syndrome termed AV dromotropathy. According to guidelines, it should be considered for permanent pacemaker implantation, yet evidence supporting this treatment is scarce. OBJECTIVES: This study aimed to determine the impact of AV-optimized conduction system pacing (CSP) in patients with symptomatic severe first-degree AV block and echocardiographic signs of AV dyssynchrony. METHODS: Patients with symptomatic first-degree AV block (PR > 250 ms), preserved left ventricular ejection fraction, narrow QRS, and AV dyssynchrony were included in the study. In a single-blind cross-over design, patients were randomized to AV sequential CSP or backup VVI pacing with a base rate of 40 bpm. We compared exercise capacity, echocardiographic parameters, and symptom occurrence at the end of 3 months of each period. RESULTS: Fourteen patients completed the study. During the AV-optimized CSP compared to the backup pacing period, patients achieved a higher workload on exercise test (147.2 ± 50.9 vs. 140.7 ± 55.8 W; p = .032), with a trend towards higher peak VO2 (23.3 ± 7.1 vs. 22.8 ± 7.1 mL/min/kg; p = .224), and higher left ventricular stroke volume (LVSV 74.5 ± 13.8 vs. 66.4 ± 12.5 mL; p < .001). Symptomatic improvement was recorded, with fewer patients reporting general tiredness and 71% of patients preferring the AV-optimized CSP (p = .008). CONCLUSIONS: AV-optimized CSP could improve symptoms, exercise capacity and LVSV in patients with severe first-degree AV block.

A boy with fatigue and heart block: what's the mechanism?

When the atrioventricular node is damaged, accessory pathways can perform primary atrioventricular conduction but may spontaneously degrade during childhood. After surgical atrial septal defect repair during infancy, an adolescent male presented with fatigue due to iatrogenic complete atrioventricular node block with a degrading antegrade accessory pathway resulting in symptomatic bradyarrhythmia.