Atrioventricular Conduction Disorders Research Articles

LEFT BUNDLE BRANCH AREA PACING IN COMPLETE ATRIOVENTRICULAR BLOCK DUE TO LYME CARDITIS

Lyme disease, also known as Lyme borreliosis, is caused by Borrelia bacteria. In Europe, 0.3–4% of untreated cases end up with cardiovascular complications known as Lyme carditis which are often associated with atrioventricular conduction disorders. We present the case of a 26-year-old male who was diagnosed with a complete atrioventricular block in the course of Lyme carditis. After a full course of antibiotic therapy, the block did not resolve, so the patient was qualified for permanent pacing. In the course of the procedure, the left bundle branch area pacing was achieved with no early or long-term complications. This is the first reported case of a left bundle branch area pacing in the atrioventricular complete block due to Lyme carditis.

Preclinical evaluation of combined therapy with amiodarone and low-dose benznidazole in a mouse model of chronic Trypanosoma cruzi infection

Chagasic chronic cardiomyopathy (CCC) is the primary clinical manifestation of Chagas disease (CD), caused by Trypanosoma cruzi. Current therapeutic options for CD are limited to benznidazole (Bz) and nifurtimox. Amiodarone (AMD) has emerged as most effective drug for treating the arrhythmic form of CCC. To address the effects of Bz and AMD we used a preclinical model of CCC. Female C57BL/6 mice were infected with T. cruzi and subjected to oral treatment for 30 consecutive days, either as monotherapy or in combination. AMD in monotherapy decreased the prolonged QTc interval, the incidence of atrioventricular conduction disorders and cardiac hypertrophy. However, AMD monotherapy did not impact parasitemia, parasite load, TNF concentration and production of reactive oxygen species (ROS) in cardiac tissue. Alike Bz therapy, the combination of Bz and AMD (Bz/AMD), improved cardiac electric abnormalities detected T. cruzi-infected mice such as decrease in heart rates, enlargement of PR and QTc intervals and increased incidence of atrioventricular block and sinus arrhythmia. Further, Bz/AMD therapy ameliorated the ventricular function and reduced parasite burden in the cardiac tissue and parasitemia to a degree comparable to Bz monotherapy. Importantly, Bz/AMD treatment efficiently reduced TNF concentration in the cardiac tissue and plasma and had beneficial effects on immunological abnormalities. Moreover, in the cardiac tissue Bz/AMD therapy reduced fibronectin and collagen deposition, mitochondrial damage and production of ROS, and improved sarcomeric and gap junction integrity. Our study underlines the potential of the Bz/AMD therapy, as we have shown that combination increased efficacy in the treatment of CCC.

Atrioventricular conduction disorders in aortic valve infective endocarditis

BackgroundAortic valve infective endocarditis may be complicated by high-degree atrioventricular block in up to 10–20% of cases. AimTo assess high-degree atrioventricular block occurrence, contributing factors, prognosis and evolution in patients referred for aortic infective endocarditis. MethodsTwo hundred and five patients referred for aortic valve infective endocarditis between January 2018 and March 2021 were included in this study. A comprehensive assessment of clinical, electrocardiographic, biological, microbiological and imaging data was conducted, with a follow-up carried out over 1 year. ResultsHigh-degree atrioventricular block occurred in 22 (11%) patients. In univariate analysis, high-degree atrioventricular block was associated with first-degree heart block at admission (odds ratio 3.1; P=0.015), periannular complication on echocardiography (odds ratio 6.9; P<0.001) and severe biological inflammatory syndrome, notably C-reactive protein (127 vs 90mg/L; P=0.011). In-hospital mortality (12.7%) was higher in patients with high-degree atrioventricular block (odds ratio 4.0; P=0.011) in univariate analysis. Of the 16 patients implanted with a permanent pacemaker for high-degree atrioventricular block and interrogated, only four (25%) were dependent on the pacing function at 1-year follow-up. ConclusionsHigh-degree atrioventricular block is associated with high inflammation markers and periannular complications, especially if first-degree heart block is identified at admission. High-degree atrioventricular block is a marker of infectious severity, and tends to raise the in-hospital mortality rate. Systematic assessment of patients admitted for infective endocarditis suspicion, considering these contributing factors, could indicate intensive care unit monitoring or even temporary pacemaker implantation in those at highest risk.

Influence of the Apelinergic System on Conduction Disorders in Patients after Myocardial Infarction.

There is a growing body of evidence for an important role of the apelinergic system in the modulation of cardiovascular homeostasis. The aim of our study was to (1) examine the relationship between apelin serum concentration at index myocardial infarction (MI) and atrioventricular conduction disorders (AVCDs) at 12-month follow-up, and (2) investigate the association between initial apelin concentration and the novel marker of post-MI scar (Q/QRS ratio) at follow-up. In 84 patients with MI with complete revascularization, apelin peptide serum concentrations for apelin-13, apelin-17, elabela (ELA) and apelin receptor (APJ) were measured on day one of hospitalization; at 12-month follow-up, 54 of them underwent thorough examination that included 12-lead electrocardiography (ECG), Holter ECG monitoring and echocardiography. The mean age was 58.9 years. At 12-month follow-up, AVCDs were diagnosed in 21.4% of subjects, with AV first-degree block in 16.7% and sinoatrial arrest in 3.7%. ELA serum concentration at index MI correlated positively with the occurrence of AVCD (p = 0.003) and heart rate (p = 0.005) at 12-month follow-up. The apelin-13 serum concentration at index MI correlated negatively with the Q/QRS ratio. The apelin peptide concentration during an acute phase of MI impacts the development of AVCD and the value of Q/QRS ratio in MI survivors.

Abstract 13784: Impact of the Variation of Aortomitral Positional Anatomy for the Atrioventricular Conduction Disorder in the Mitral Valve Surgery

Introduction: Advances in cardiac imaging have provided detailed anatomical information, including the variation of the aortic root rotation. This variation affected the distance between membranous septum and right fibrous trigone, that might be synonymous with variation of the conduction system location. However, clinical significance has been unknown. We aimed to analyze the variation of the aorto-mitral position and its relationship of conduction disorder in the mitral valve surgery. Methods: This study included 180 patients underwent simple mitral valve surgery (valve repair: n=159, replacement: n=21). The anatomical variations were classified by preoperative three-dimensional transesophageal echocardiography (3D-TEE), and postoperative occurrence of new conduction disorder was analyzed. Results: As in the image, the variations in the aorto-mitral position were classified into Lateral (14%) or Center appearance (86%) groups, which was further classified to Center (83%), Lateral (14%), or Medial rotation (3%) groups. Atrioventricular conduction disorder was observed as first-degree block (n=24 (13%)) including complete right bundle branch block (n=1 (0.6%)). This disorder newly occurred more in the Lateral appearance compared to the Center (36% vs 10%, p=0.0003). The prolongation of the PR interval (msec) between the pre and postoperative period (ΔPR) was greater in the Lateral appearance than the Center (+17 vs +14, p=0.02). Regarding the aortic root rotation, the conduction disorder occurred in 6%, 27% and 20% patients, and each ΔPR was +2, +16 and +22 of the Center , Lateral , and Medial rotation respectively. Conduction disorder occurred more in the Lateral rotation than the Center (p=0.0017), persisting one year after the surgery (19% vs 2%, p=0.0059). Conclusion: The variation of the aorto-mitral position could be classified by 3D-TEE. The Lateral rotation would be a risk of atrioventricular conduction disorder in the mitral valve surgery.

Prophylactic epicardial pacemaker implantation in tricuspid valve replacement.

Patients undergoing surgical tricuspid valve replacement (TVR) are at high risk of atrioventricular conduction disorders. Because implanting a lead through the tricuspid bioprosthesis is discouraged, the patients who undergo TVR in our centre are usually given a prophylactic epicardial pacemaker. Our aim was to assess the benefits and risks of this strategy. Among the patients who underwent TVR with prophylactic epicardial pacemaker implantation, clinical evaluations and pacemaker reports were analysed retrospectively after surgery. The need for cardiac pacing were assessed by characterizing the atrioventricular conduction, while the risks were evaluated by listing and adjudicating post-operative events. A total of 80 patients were analysed (mean age was 57 ± 16 years old, 30% males). TVR was isolated in 28 (35%) patients, but most often associated with another valve surgery. In the postoperative period, heart rhythm was analysed in 59/80 patients during a median follow-up of 35 months. Cardiac pacing was needed in 46% patients: 14% had complete pacing dependency, 17% had high degree AV block, while 15% had a high ventricular pacing rate (>80%). No pre- or per-operative variables could predict cardiac pacing requirement. Post-operatively, a spontaneous heart rate >70bpm (P = 0.02) and the presence of narrow QRS (P = 0.03) were significantly associated with a lower risk of cardiac pacing requirement. Complications related to epicardial pacemaker were documented in 2 (2.5%) patients. After TVR, cardiac pacing was needed in 46% of patients for post-operative atrioventricular conduction disorders. This high incidence associated with an acceptable safety profile supports a prophylactic epicardial pacing strategy for the patients undergoing TVR.

The Pacemaker and Implantable Cardioverter-Defibrillator Registry of the Italian Association of Arrhythmology and Cardiac Pacing - Report 2022

The Pacemaker (PM) and Implantable Cardioverter-Defibrillator (ICD) Registry of the Italian Association of Arrhythmology and Cardiac Pacing (AIAC) collects information about demographics, clinical characteristics, main indications for PM/ICD therapy and device types from the voluntary Italian collaborating centers. For the year 2022 main data about national PM and ICD implantation activity were obtained on the basis of European Cards and subsequently analyzed to create a standard report. PM Registry: data about 17 800 PM implantations were collected (14 191 first implants and 3609 replacements). The number of collaborating centers was 152. Median age of treated patients was 81 years (75 quartile I; 86 quartile III). Main ECG indications included atrioventricular conduction disorders in 46.0% of first PM implants, sick sinus syndrome in 17.7%, atrial fibrillation plus bradycardia in 7.7%, other unspecified ECG and electrophysiological abnormalities in 43.0%. For first PM implants, pacing in DDDR mode was reported in 42.2%, followed by DDD mode (20.6%), VVIR mode (25.1%), VVI mode (11.1%) and finally VDD-VDDR (5.1%). Median value of longevity of explanted PMs was 8.3 years. ICD Registry: data about 5210 ICD implantations were obtained (3656 first implants and 1554 replacements). The number of collaborating centers was 301. Median age of treated patients was 72 years (63 quartile I; 79 quartile III). Primary prevention indication was reported in 72.4% of first implants, secondary prevention in 27.6% (cardiac arrest in 4.6% of records). A single-chamber ICD was used in 30.3% of first implants, dual-chamber ICD in 30.0% and biventricular ICD in 39.7%. Median value of longevity of explanted ICDs was 7.0 years. In the calendar year 2022, the Italian PM Registry showed stable electrocardiographic and symptom indications, with an important prevalence of dual-chamber pacing. The ICD Registry documented a large use of prophylactic and biventricular ICDs, reflecting a favorable adherence in clinical practice to trials and guidelines. The ICD longevity and the number of recalls demonstrated a favorable trend.

Rationale and Design of the Randomized Bayesian Multicenter COME-TAVI Trial in Patients With a New Onset Left Bundle Branch Block

Patients with new-onset left bundle branch block (LBBB) after transcatheter aortic valve implantation (TAVI) are at risk of developing delayed high-degree atrioventricular block. Management of new-onset LBBB post-TAVI remains controversial. In the Comparison of a Clinical Monitoring Strategy Versus Electrophysiology-Guided Algorithmic Approach in Patients With a New LBBB After TAVI (COME-TAVI) trial, consenting patients with new-onset LBBB that persists on day 2 after TAVI, meeting exclusion/inclusion criteria, are randomized to an electrophysiological study (EPS)-guided approach or 30-day electrocardiographic monitoring. In the EPS-guided approach, patients with a His to ventricle (HV) interval ≥ 65 ms undergo permanent pacemaker implantation. Patients randomized to noninvasive monitoring receive a wearable continuous electrocardiographic recording and transmitting device for 30 days. Follow-up will be performed at 3, 6, and 12 months. The primary endpoint is a composite outcome designed to capture net clinical benefit. The endpoint incorporates major consequences of both strategies in patients with new-onset LBBB after TAVI, as follows: (i) sudden cardiac death; (ii) syncope; (iii) atrioventricular conduction disorder requiring a pacemaker (for a class I or IIa indication); and (iv) complications related to the pacemaker or EPS. The trial incorporates a Bayesian design with a noninformative prior, outcome-adaptive randomization (initially 1:1), and 2 prespecified interim analyses once 25% and 50% of the anticipated number of primary endpoints are reached. The trial is event-driven, with an anticipated upper limit of 452 patients required to reach 77 primary outcome events over 12 months of follow-up. In summary, the aim of this Bayesian multicentre randomized trial is to compare 2 management strategies in patients with new-onset LBBB post-TAVI—an EPS-guided approach vs noninvasive 30-day monitoring. Trial registration number: NCT03303612.

FREQUENCY OF HIGH DEGREE ATRIOVENTRICULAR BLOCK IN PATIENTS WITH ACUTE ANTERIOR WALL MYOCARDIAL INFARCTION

Atrioventricular (AV) block is an AV conduction disorder that can manifest in various settings, with varying symptomaticity and severity. Complications of acute ST-elevation myocardial infarction (STEMI) as AV blocks are often observed. The first degree of atrioventricular block is the most common and requires no treatment. The second-degree block is sub-classified in Mobitz type I and Mobitz type II. This study aimed to determine the frequency of high-degree atrioventricular block in acute anterior wall myocardial infarction cases. The current cross-sectional analysis was conducted at the Department of Cardiology, Rehmat-ul-Lil-Alameen Institute of Cardiology, Lahore, from 19-02-2021 to 18-08-2021. A total of 311 patients were enrolled in the study. Cases underwent an electrocardiogram, and high degree AV Block was labeled per operational definitions. The results were noted and recorded on the same proforma. The overall mean age of the patients was 55.6±8.4 years. Gender distribution of patients shows a higher frequency of 57.9% males compared to 42.1% females with a female-to-male ratio of 1:1.4. High degree of atrioventricular block was found among 5.8% of the total patients. Around 5.8% of AWMI patients presented with high-grade AV block in this study are in-concomitant with other studies. No association of risk factors (p-value &gt;0.05) was presented regarding age, gender, DM, hypertension, dyslipidemia, family history of CAD, and smoking in this study.

The Pacemaker and Implantable Cardioverter-Defibrillator Registry of the Italian Association of Arrhythmology and Cardiac Pacing - Report 2021

The Pacemaker (PM) and Implantable Cardioverter-Defibrillator (ICD) Registry of the Italian Association of Arrhythmology and Cardiac Pacing (AIAC) collects information about demographics, clinical characteristics, main indications for PM/ICD therapy and device types from the voluntary Italian collaborating centers. For the year 2021 main data about national PM and ICD implantation activity were obtained on the basis of European Cards and subsequently analyzed to create a standard report. PM Registry: data about 18 631 PM implantations were collected (15879 first implants and 2752 replacements). The number of collaborating centers was 121. Median age of treated patients was 82 years (76 quartile I; 87 quartile III). Main ECG indications included atrioventricular conduction disorders in 26.8% of first PM implants, sick sinus syndrome in 12.2%, atrial fibrillation plus bradycardia in 9.6%, other unspecified ECG and electrophysiological abnormalities in 43.0%. For first PM implants, pacing in DDDR mode was reported in 46.5%, followed by DDD mode (20.6%), VVIR mode (15.0%), VVI mode (9.0%) and finally VDD-VDDR (5.8%). Median value of longevity of explanted PMs was 8.9 years. ICD Registry: data about 6878 ICD implantations were obtained (4708 first implants and 2170 replacements). The number of collaborating centers was 345. Median age of treated patients was 72 years (70 quartile I; 75 quartile III). Primary prevention indication was reported in 86.3% of first implants, secondary prevention in 13.7% (cardiac arrest in 4.4% of records). A single-chamber ICD was used in 32.1% of first implants, dual-chamber ICD in 30.3% and biventricular ICD in 37.6%. Median value of longevity of explanted ICDs was 6.9 years. In the calendar year 2021, the Italian PM Registry showed stable electrocardiographic and symptom indications, with an important prevalence of dual-chamber pacing. The ICD Registry documented a large use of prophylactic and biventricular ICDs, reflecting a favorable adherence in the clinical practice to trials and guidelines. The ICD longevity and the number of recalls demonstrated a favorable trend. In order to increase and optimize the cooperation of Italian PM and ICD implanting centers, the online data entry (https://www.aiac.it/riprid) should be adopted at large scale.

Post-Dilatation of New-Generation Self-Expandable Transcatheter Aortic Valves Does Not Increase Atrioventricular Conduction Abnormalities.

The impact that post-dilatation has on the risk of experiencing conduction disorders after post-transcatheter aortic valve replacement with self-expanding valves (SE-TAVR) is unclear. We compared the rate of developing an atrioventricular (AV) high-grade conduction disorder and permanent pacemaker implantation (PPI) in post-TAVR patients undergoing post-dilatation. We enrolled patients with severe symptomatic calcified aortic stenosis (CAS) who were undergoing SE-TAVR between 1 January 2016, and 19 April 2019 at a single French center. Of the 532 patients treated with SE-TAVR, 417 subjects (78.4%) received Corevalve Evolute R and 115 subjects (21.6%) received the latest-generation Corevalve Evolute Pro valve. In total, 104/532 patients (19.5%; 21.6% with Evolute R vs. 12.2% with Evolute Pro, p = 0.024) required post-dilatation. Evolut R was associated with an increased risk of post-dilatation (odds ratio 2.1 (1.01-4.33, p = 0.046)). We did not observe any post-dilatation increases in AV or in intra- and interventricular conduction disorders. In total, 26.1% of participants needed PPI within the first 30 post-procedure days (p = 0.449). Post-dilatation was not associated with a higher PPI risk (subdistribution hazard ratio 1.033 (0.726-1.471); p = 0.857). No significant differences existed between the groups in terms of one-year mortality (10.3%; p = 0.507). Post-dilatation in SE-TAVR did not increase the rate of electrical conduction disorders and PPI in the early implantation phase. The latest generation of SE-TAVR valves was associated with less need for post-dilatation.

Incidence and management of atrioventricular conduction disorders in new-onset left bundle branch block after TAVI: A prospective multicenter study

New-onset left bundle branch block (LBBB) is one of the most frequent complications after transcatheter aortic valve implantation (TAVI) and is associated with delayed high degree atrioventricular (AV) block. The objectives of this study were to determine the incidence of AV block in such a population and to assess the performance and safety of a risk stratification algorithm on the basis of electrophysiology study (EPS) followed by implantation of a pacemaker or implantable loop recorder (ILR). This was a prospective open-label study with 12-month follow-up. From June 8, 2015, to November 8, 2018, 183 TAVI recipients (mean age 82.3 ± 5.9 years) were included at 10 centers. New-onset LBBB after TAVI persisting for >24 hours was assessed by electrophysiology study during initial hospitalization. High-risk patients (His-ventricle interval ≥70 ms) were implanted with a dual-chamber pacemaker recording AV conduction disturbance episodes. Patients at lower risk were implanted with an ILR with automatic remote monitoring. A high-grade AV conduction disorder was identified in 56 patients (30.6%) at 12 months. Four subjects were symptomatic, all in the ILR group. No complications were associated with the stratification procedure. Patients with His-ventricle interval ≥70 ms displayed more high-grade AV conduction disorders (53.2% [25 of 47] vs 22.8% [31 of 136]; P < .001). In a multivariate analysis, His-ventricle interval ≥70 ms was independently associated with the occurrence of a high-grade conduction disorder (subdistribution hazard ratio 2.4; 95% confidence interval 1.2-4.8; P = .010). New-onset LBBB after TAVI was associated with high rates of high-grade AV conduction disturbances. The stratification algorithm provided safe and valuable aid to management decisions and reliable guidance on pacemaker implantation.

Abstract 14956: Extensive Cardiac Involvement in Laminopathies Diagnosed in Pediatric-Aged Patients: A Single Center Study

Introduction: Lamin A/C ( LMNA ) gene mutations result in a heterogeneous group of inherited conditions termed laminopathies. Cardiac manifestations of laminopathies include atrial and ventricular arrhythmias, atrioventricular conduction disorders, and cardiomyopathy, with or without skeletal muscle involvement. Because this disease is rare and typically presents in adulthood, pediatric data is limited. Methods: We identified patients &lt; 18 years with genetically confirmed mutations in LMNA followed at our center between 2003 and 2021. Clinical phenotypes along with cardiac test results were retrospectively catalogued. Results: We identified 12 patients with a median age of 5 years at diagnosis (IQR 4-11 years) with a LMNA mutation. Nine (75%) patients were male and 10 (83%) had associated skeletal muscle involvement. Of the 12 patients, 10 (83%) developed cardiac manifestations over a median follow up period of 111 months (IQR 91-116 months). Seven patients (58%) had documented arrhythmias (AV block, ventricular/atrial tachycardias) and 3 (25%) underwent pacemaker and/or implantable cardiac defibrillator placement. Three (25%) patients were diagnosed with cardiomyopathy with 1 (8%) requiring a ventricular assist device and 1 (8%) requiring continuous intravenous inotropes and subsequent transplant. Three (25%) patients died during the study period, one awaiting transplant, one from complications post-transplant, and one from non-cardiac causes. Conclusions: Cardiac involvement, specifically cardiomyopathy and progressive conduction system abnormalities, were common in pediatric patients with LMNA mutations. Early genetic diagnosis of laminopathies followed by frequent surveillance for dysrhythmia and dysfunction is necessary for more timely initiation of advanced cardiac therapies to prevent adverse events. More comprehensive phenotype-genotype correlation is strongly needed.

High-risk ECG patterns in ST elevation myocardial infarction for mortality prediction

AimWe explored the pre-intervention (first medical contact) electrocardiographic (ECG) patterns and their relation to survival among patients with acute myocardial infarction, who presented either with ST elevation (ST elevation myocardial infarction, STEMI) or LBBB, and who underwent emergent coronary angiography in a region with a 24/7/365 STEMI network. MethodsThis is a retrospective analysis of 1363 consecutive patients hospitalized for first STEMI between the years 2014 and 2018. We assessed the prognostic significance of a variety of ECG categories, including location of ST elevation, severity of ischemia, intraventricular and atrioventricular conduction disorders, atrial fibrillation or flutter, junctional rhythms, heart rate, left ventricular hypertrophy and Q waves. The primary outcome was all-cause mortality between January 2014 and the end of 2020. ResultsThe mean age of the patients was 67.9 (SD 12.8) years. The majority were treated by percutaneous coronary intervention (93.8%, n = 1278). Median follow-up time was 3.7 years (IQR 2.5–5.1 years) during which 22.5% (n = 307) of the patients died. According to Cox regression analysis, adjusted for pre-existing conditions and age, the ECG variables with statistically significant association with survival were elevated heart rate (>100 bpm) (HR 2.34, 95% CI 1.75–3.12), atrial fibrillation or flutter (HR 1.94, 95% CI 1.41–2.67), left bundle branch block (LBBB) (HR 2.62, 95% CI 1.49–4.63) and non-specific intraventricular conduction delay (NIVCD) (HR 1.85, 95% CI 1.22–2.89). ConclusionHigher heart rate, atrial fibrillation or flutter, LBBB and NIVCD are associated with worse outcome in all-comers with STEMI. Ischemia severity was not associated with impaired prognosis.

Theophylline Use to Prevent Permanent Pacing in the Contemporary Era of Heart Transplantation: The Rotterdam Experience.

IntroductionSinus node dysfunction and atrioventricular conduction disorders occur increasingly after orthotopic heart transplantation (HTX) due to aging donors and may require permanent pacemaker (PM) implantation. Theophylline has been used in the past in selected cases as an alternative to PM implantation.PurposeThe aim of this study was to investigate the rate and success of oral theophylline administration after orthotopic heart transplantation preventing permanent PM implantation.MethodsWe included all patients treated with theophylline post HTX due to bradyarrhythmia's in our center from January 1985 to January 2020. Data was obtained retrospectively through electronic patient files. Re-transplants and patients who died within 1 month post HTX were excluded from the analysis.ResultsOf the total of 751 heart transplant recipients, 73 (9,7%) patients (mean age 46 ± 15.2 years; 73% male) were treated with theophylline for bradyarrhythmia's early post HTX. Of these patients, 14 (19%) patients needed a permanent PM during hospitalization and 10(14%) patients stopped using theophylline because of adequate heart rhythm. In the end, 49 (6.5% of the total) patients were discharged with a theophylline (mean maintenance doses of 354 ± 143 mg). At the outpatient clinics, additional 6 (12%) patients needed a PM within 7 months after discharge, with the rest stable sinus rhythm.ConclusionIn this retrospective data analyses oral theophylline remained a viable alternative to permanent PM implantations in patients post HTX with increased heart rates, facilitating the withdrawal of chronotropic support and avoiding the need of permanent PM implantation.

Epidemiological profile of PLWH aged 50 and over at the Ahala district medical center, Yaounde

People living with HIV aged 50 years and over (P50+) represent a growing population in HIV care units in Cameroon. The objective of this study was to determine the epidemiological profile of this population in order to better target their management in HIV care units in Cameroon. It was found that the prevalence of P50+ was 13.3% and the median age was 58 [52-61] years. The sector of professional activity was dominated by the informal sector (45%), followed by unemployment (30%). The level of education was predominantly represented by secondary (52.5%) and primary (30%) education. The status of the partner was known in 67.5% of cases and 25% of partners were HIV positive. The median duration of HIV disease since discovery was 4 [3- 6] years. The circumstances of discovery were mainly clinical suspicion (67.5%). The most common type of HIV was type 1 (90%). The median CD4 count was 181 [9-319] cells/mm3 and 85.2% of patients had an undetectable viral load after at least 6 months of ART. The median duration of treatment was 48 [27-60] months and the 1st line of ART was used. The prevalences of hypertension, diabetes and renal failure were 24.3%, 7.5% and 23.1%, respectively. Other cardiovascular risk factors identified were physical inactivity (22.5%), excessive alcohol consumption (7.5%), and active smoking (5%). Electrocardiographic examination revealed the prevalence of rhythm, depolarisation, and atrioventricular conduction disorders in 11.4%, 5.7%, and 25.7% of patients, respectively. The prevalences of atrial and ventricular hypertrophy, repolarisation disorders, and myocardial ischemia were 37.1%, 5.7%, 8.6%, and 22.9%, respectively. The P50+ represent a distinct population within the PLWH with varied sociodemographic and clinical characteristics.

The Pacemaker and Implantable Cardioverter-Defibrillator Registry of the Italian Association of Arrhythmology and Cardiac Pacing - Report 2020

The Pacemaker (PM) and Implantable Cardioverter-Defibrillator (ICD) Registry of the Italian Association of Arrhythmology and Cardiac Pacing (AIAC) collects information about demographics, clinical characteristics, main indications for PM/ICD therapy and device types from the Italian collaborating centers. For the year 2020, the main data about national PM and ICD implantation activity were obtained on the basis of European Cards and subsequently analyzed to create a standard report. PM Registry: data about 22 080 PM implantations were collected (18 027 first implants and 3803 replacements). The number of collaborating centers was 142. Median age of treated patients was 82 years (75 quartile I; 87 quartile III). ECG indications included atrioventricular conduction disorders in 31.0% of first PM implants, sick sinus syndrome in 13.8%, atrial fibrillation plus bradycardia in 9.9%, other unspecified ECG and electrophysiological abnormalities in 36.6%. Use of single-chamber PMs was reported in 29.0% of first implants, of dual-chamber PMs in 68.2%, of PM with cardiac resynchronization therapy (CRT) in 2.7%. ICD Registry: data about 11 931 ICD implantations were obtained (8266 first implants and 3665 replacements). The number of collaborating centers was 330. Median age of treated patients was 72 years [63 quartile I; 79 quartile III]. Primary prevention indication was reported in 85.0% of first implants, secondary prevention in 15.0% (cardiac arrest in 4.2%). A single-chamber ICD was used in 30.2% of first implants, dual-chamber ICD in 31.2% and biventricular ICD in 38.6%. In the calendar year 2020, the Italian PM Registry showed stable ECG and symptom indications, with an important prevalence of dual-chamber pacing. The ICD Registry documented a large use of prophylactic and biventricular ICDs, reflecting a favorable adherence in clinical practice to trials and guidelines. The ICD longevity and the number of recalls demonstrated a favorable trend. In order to increase and optimize the cooperation of Italian PM and ICD implanting centers, the online data entry (https://www.aiac.it/riprid) should be adopted at large scale.

Theophylline Post Heart Transplantation to Prevent Permanent Pacing: The Rotterdam Experience

<h3>Purpose</h3> Sinus node dysfunction and atrioventricular conduction disorders occur increasingly after orthotopic heart transplantation (HTX) due to aging donors and may require permanent pacemaker (PM) implantation. Theophylline has been used in the past in selected cases as an alternative to PM implantation. The aim of this study was to investigate the rate and success of oral theophylline administration after orthotopic heart transplantation preventing permanent PM implantation. <h3>Methods</h3> We included all patients treated with theophylline post HTX due to bradyarrhythmia's in our center from January 1985 to January 2020. Data was obtained retrospectively through electronic patient files. Re-transplants and patients who died within one month post HTX were excluded from the analysis. <h3>Results</h3> Of the total of 751 heart transplant recipients, 73 (9,7%) patients (mean age 46+-15.2 years; 73% male) were treated with theophylline for bradyarrhythmia's early post HTX. Of these patients, 14 (19%) patients needed a permanent PM during hospitalization and 10(14%) patients stopped using theophylline because of adequate heart rhythm. In the end, 49 (6.5% of the total) patients were discharged with a theophylline (mean maintenance doses of 354+-143 mg). At the outpatient clinics, additional 6 (12%) patients needed a PM within 7 months after discharge, with the rest stable sinus rhythm. <h3>Conclusion</h3> In this retrospective data analyses oral theophylline remained a viable alternative to permanent PM implantations in patients post HTX with increased heart rates, facilitating the withdrawal of chronotropic support and avoiding the need of permanent PM implantation.

Infra-Hisian atrioventricular conduction disorder in a patient with treated acromegaly

Severe atrioventricular (AV) conduction disorder in acromegalic patients is limited to rare case reports with pacemaker implantation. This is a report of a 49-years-old female patient with cure criteria for acromegaly for 24 years and a history of syncope and lipothymia. The electrocardiogram showed a first-degree AV block. 24-hour Holter recorded Mobitz I second-degree AV block. The bundle of His electrogram showed prolongation of the HV interval (conduction time between the location where the His bundle potential is recorded and the beginning of ventricular activation). Thus, an artificial pacemaker was implanted with symptomatic improvement. The objective is to highlight atrioventricular conduction disorders in acromegalic patients and cardiological monitoring importance.

Study of cardiac function in adults with dengue

Background: Medical literature has reports of isolated cases of atrioventricular conduction disorders, supraventricular arrhythmias, and myocarditis in dengue fever (DF). There is a paucity of data available in the published literature on the cardiac manifestations of DF from India. The aim of the present study was to assess the cardiac manifestations of DF. Methods: The 140 patients aged ≥18 years with DF confirmed with a serology-dengue non-structural protein 1 antigen-positive were included for this prospective observational study. Three serial ECGs were taken on day one, day three and day seven or day of discharge. All the patients were evaluated using 2D echo on day one, day seven or day of discharge. The primary outcome measures were to find the incidence and type of echocardiographic abnormalities and electrocardiographic changes in dengue.Results: The incidence of cardiac abnormalities on ECG and 2D echo was 30 (21.4%), and 5 (7.0%) respectively. On ECG, 14 (10%) 9 (6.4%) 3 (2.1%) 3 (2.1%) and 1 (0.7%) patients had sinus bradycardia, sinus tachycardia, non-specific ST-T changes, right bundle branch block and atrio-ventricular block on ECG respectively. On 2D echo, 7 (5.0%), 5 (3.6%) and 1 (0.7%) patient had systolic dysfunction, ejection fraction (&lt;45.0%) and diastolic dysfunction respectively.Conclusions: The incidence of cardiac abnormalities on ECG and 2D ECHO in dengue patients was considerable. ECG and 2 D echo should be undertaken in patients with DF.