First-degree Block Research Articles

Histopathology and prognosis of new-onset atrio-ventricular block after coronary artery bypass graft surgery

Abstract Background Atrio-ventricular block (AVB) can often be seen in patients undergoing cardiac procedures. Nevertheless, little is known about the histopathological features of new-onset postoperative AVB prior to the clinical manifestation and its prognostic impact. Purpose This study explores the association of first-degree AVB in ECG and postoperative outcome of patients with either preoperative or a new-onset AVB. Furthermore, histopathological features were analyzed to distinguish the characteristics between preoperative and postoperative AVBs compared to no AVB. Methods CAREBANK is a prospective study with atrial biopsies obtained at the time of open-heart cardiac surgery and long-term follow-up focusing on the adverse events. We analyzed preoperative as well as postoperative ECGs derived after index hospitalization (1-18mo) in patients undergoing CABG. The definition of first-degree AVB was PR-interval ≥200ms. The main outcome of interest was follow-up mortality. Histopathological analysis was used to assess the amount of fibrosis, cardiomyocytes, number of nuclei and macrophages. Results Median follow up time was 4.0 (IQR 2.7 – 5.0) years. First-degree AVB was found in 84/373 (22.5%) preoperative ECGs. Altogether 25/289 (8.7%) cases where ECG was available (after excluding preop AVB, atrial fibrillation) developed first-degree AVB after index hospitalization. New-onset first-degree AVB was associated with increased mortality (aHR 4.033 (95-CI% 1.019–15.965, p=0.047). In atrial histopathological analysis, area covered by cardiomyocytes (p=0.033) as well as area covered by nuclei (p=0.047) were smaller in those with new-onset AVB after surgery, but not in those with preoperative first-degree AVB (p=0.692 and p=0.384) as compared with controls, respectively. Similarly, the total area of fibrosis was greater in those with preoperative first-degree AVB (p<0.001), but not in those with postoperative new-onset AVB (p=0.244). When compared with controls, share of CD68 positive macrophages was similar (p=0.073), but anti-inflammatory CD206 positive M2 macrophages were absent in patients with new-onset AVB (p=0.042). Conclusion Patients with new-onset AVB after CABG have increased mortality in the long-term compared to those without. Histopathology identifies marked differences in macrophage populations between those with and without new-onset AVB.

Dual-chamber CRT-D using ICD lead implantation in the LBBAP position

Abstract Background Interest in conduction system pacing (CSP) has increased in recent years. For left bundle branch area pacing (LBBAP), 4F and 6F pacing leads have been shown to be effective and safe. No information is available on the potential use of ICD leads for LBBAP. Aim The objective of the study was to demonstrate the feasibility of implanting an ICD lead in the LBBAP position to reduce the number of leads for CRT-D therapy. Patients and Methods We implanted the 7F ICD lead in the LBBAP position through a new 10F CSP delivery sheath in ten consecutive patients. Periprocedural data, QRS morphology and degree of QRS reduction were analyzed. Results Ten consecutive patients (one female) aged 69.5±9.2 years were treated with the above-mentioned method. Eight patients had ischemic cardiomyopathy and two patients had nonischemic cardiomyopathy. All patients had a CRT-D indication. Eight patients had a wide QRS complex with complete LBB and a QRS complex of 184.8±25.8 ms. Two patients had a narrow QRS complex but first-degree AV block with a PR interval greater than 240 ms. Left ventricular ejection fraction was 31.8±8.6%. Operative and fluoroscopy times were 103.6±30.3 minutes and 10.5±6.1 minutes, respectively. On average, 1.7 ± 0.6 screwing attempts were required per patient. The intraprocedural LBBAP threshold was 0.78±0.6V/1.0ms, the impedance was 530.8±86.5 ohm, and the R-wave amplitude was 9±3.3mV. The unipolar paced QRS complex was 123.6±15.9ms, the bipolar paced QRS complex was 129.5±12.8ms, and the bipolar paced QRS complex on the next day was 133.3±11.7. The mean duration from stimulus to R-wave peak in lead V6 was 82.9 ± 19.7 ms. The R-wave interpeak interval between leads V6 and V1 was 43.4 ± 9.7 ms. All but one patient received an effective defibrillation threshold test at 30J (n=8) and 36J (n=1). One patient was not tested during the procedure due to high risk. Conclusion This first-in-human study of ICD lead implantation in the LBBAP position demonstrated its feasibility and efficacy in achieving conduction system stimulation. This approach may lead to a reduction in the number of leads implanted for cardiac resynchronization therapy. Figure 1. A- RAO view, angiography of the RV for verification of the TVA-summit. B- LAO view, angiography from the CSP- sheath after reaching final position of the LBBAP lead (right sided interventricular septum - yellow dotted line). C – 12 lead ECG (speed 50mm/sec) demonstrating paced and native QRS complexes. D – Fluoroscopy in RAO view, final result. E – Fluoroscopy in LAO view, final result. F – Transthoracic echocardiography the next day (4Ch view) demonstrates optimal LBBAP lead position.. RAO – right anterior oblique; LAO – left anterior oblique; TVA – tricuspid valve anulus; CSP – conduction system pacing; LBBAP – left bundle branch area pacing.Figure 1.

Potential impact of cold water immersion on arrhythmogenesis: a pilot exploratory study surrounding the Geneva christmas cup

Abstract Background Cold-water immersion (CWI) is gaining popularity and is regulated by sports federations with guidelines for various cold temperature ranges. Small studies suggest cardiovascular and stress reduction benefits from regular CWI, yet acute effects and cardiac risks remain underexplored. Purpose This study aimed to assess the impact of CWI on arrhythmogenesis among participants of the 2023 Geneva Christmas Cup, the world's largest cold-water swimming event. Methods Volunteers aged 45 and older were recruited through the organizing committee. Each underwent baseline cardiovascular risk assessment 10 days prior to the event, including medical interviews, physical exams, blood tests, and 12-lead ECGs. A waterproof ECG recorder (BodyGuardian Mini®) was attached to participants, monitoring them for 10 days up to the end of the race. An activity diary recorded training sessions, CWI exposure, and any symptoms. Data from BodyGuardian Mini® were analyzed for CWI-induced arrhythmias and conduction disturbances. The local ethics committee approved the study. Results Twenty volunteers (11 women, mean age 56 ± 6.4 years) participated. Their mean SCORE2/SCORE2-OP was 4 ± 1.8%, with 60% at low to moderate and 40% at high cardiovascular risk. Average weekly training was 5.5 ± 2.9 hours. Lake temperature was 7.0 degrees. One participant could not race but all completed CWI training and wore ECG recorders for an average of 226 ± 32 hours. Sixteen participants (80%) exhibited non-sustained atrial tachycardia (average 12.4 ± 8.8 events), and four (20%) had non-sustained ventricular tachycardia events (average 1.2 ± 0.5), with no significant pauses or >1st degree AV block observed. No arrhythmic events were directly linked to CWI. Conclusion This exploratory study of active, middle-aged participants with moderate cardiovascular risk found no association between CWI and arrhythmias. Further, larger-scale studies are necessary to conclusively determine CWI's safety.

Impact of dapagliflozin on supraventricular and ventricular arrhythmias, assessed by Holter ECG, in patients with heart failure with reduced ejection fraction

Abstract Background & Introduction Dapagliflozin has significantly reduced morbidity & mortality in patients with heart failure with reduced ejection fraction (HFrEF) (1). Some studies reported supraventricular & ventricular arrhythmia suppression, but Holter ECG was underused, hindering precise assessment of arrhythmia burden. Purpose We aim to assess the impact of dapagliflozin on reduction of arrhythmia in HFrEF at 1 year follow-up (FU) by Holter ECG. Methods This is a single center, prospective study. We have screened 219 HFrEF patients, but only 156 patients were enrolled with LVEF <40% in sinus rhythm from December 2021 to July 2023. All patients had dapagliflozin 10 mg once/day tablet with the standard HF therapy. Clinical evaluation, NYHA evaluation, 6-minute walking test (6MWT), echocardiogram, 24-hours Holter ECG and laboratory work-up were done at baseline, and FU at 6 months and 12 months. Results Males constituted 61.5% of study population; mean± SD participants’ age was 56.8 ± 8.6 years. The most common comorbidities were: ischemic etiology (63.3%), dilated cardiomyopathy (28.1%), hypertension (27.3%), smokers (14.7%), and type II diabetes (31.4%). LVEF was ≤ 35% in 85.9% of patients. We have reported (7.69%) deaths during 1-year FU, and 4 patients (2.56%) didn't complete 1-year FU. Main clinical and echocardiographic findings (baseline vs. 1-year FU): NYHA FC III& ambulant IV dropped from (42.9 to 32.9%), P value<0.05. Distance walked in 6MWT improved from 191.52 ± 75.37 to 219.35 ± 71.51 mean± SD meters, P value<0.05. E/e improved (9.4 to 8.3 cm/s, P value <0.01), LVEF improved (31.3 to 36.4%, P value<0.05). HF emergency: [HF visits dropped (23.7 to 19.2%) and HF hospitalization dropped (11.1 to 7.8%)], P value<0.05. Holter ECG (baseline vs. 1-year FU): Supraventricular Arrhythmia: [Paroxysmal AF reduced (56.2 to 47.6%), frequent PACs (≥ 10%) dropped (3.8 to 1.4%) & Intermittent 1st degree heart block dropped (12.5 to 7.3%)] P value <0.01. Ventricular Arrhythmia: [PVCs >5%-<10% dropped (16% to 9.3%), Frequent PVCs >10% dropped (3.2 to 1.4%), and NSVT dropped (7.8 to 3.1%)], P value <0.01. Stepwise logistic regression multivariable model aiming to predict the occurrence of ventricular and supraventricular arrhythmias has indicated a direct linear correlation with male gender, smoking, body mass index, left atrial volume, and a history of myocardial infarction. Conversely, there is an inverse relationship with systolic blood pressure, 6MWT distance, LVEF, and the administration of dapagliflozin (OR 0.72 [0.61 - 1.07], P value <0.01) concerning the likelihood of supraventricular and ventricular arrhythmias. Conclusions Dapagliflozin has demonstrated significant improvement in functional and echocardiographic parameters in HFrEF patients. Furthermore, it has effectively decreased the incidence of supraventricular and ventricular arrhythmias, identified through 24-hour Holter ECG monitoring during 1-year follow-up.

A multilabel deep learning model for the detection of conduction and rhythm disorders from PDF outputs of a widely available portable ECG Device

Abstract Background Wearable and portable devices with ECG capabilities can provide broad access to screening for cardiovascular disorders. However, most are approved for the detection of only atrial fibrillation. Most algorithms for detecting rhythm and conduction disorders are trained and tested on 12-lead ECGs or the lead I of clinical ECGs, with an unclear role for extending the diagnostic range of wearable and portable devices. Moreover, no current algorithms enable cardiovascular diagnosis on data available to end users, who largely have access to the PDF outputs of their data. Purpose To validate a novel artificial intelligence (AI) model trained to identify conduction disorders and arrhythmias on synthetic ECG outputs from lead I data of clinical ECGs, to detect the same disorders on cardiologist-annotated PDF outputs from the Alivecor KardiaMobile single-lead ECGs (Kardia ECGs). Methods We extracted lead I data from 3,076,352 clinical ECGs across 5 hospitals of a large U.S.-based hospital system from 2000-2024 and simulated wearable PDF outputs from commercial devices using a novel plotting approach that replicated the variations in plotted formats. Gold-standard cardiologist written diagnosis statements were processed to generate 8 clinical labels spanning conduction and rhythm disorders, and we developed a multilabel model to predict these labels using an EfficientNet-B3 convolutional neural network. We examined the performance of the model on 24,808 Kardia ECGs annotated by cardiologists. Results The model achieved a high performance on clinical ECGs in a held-out subset of the synthetic lead I ECG printouts resembling wearable outputs (AUC > 0.9 for all 8 labels). In the independent 24,808 Kardia ECGs, annotated by experts, the model achieved high performance across all labels. For the rhythm disorders atrial fibrillation or atrial flutter, premature atrial contraction, and premature ventricular contraction, the model had AUROCs of 0.99, 0.91, and 0.95, respectively. For the conduction disorders 1st-degree AV block and 2nd or 3rd-degree AV blocks, the model had AUROCs of 0.94 and 0.99, respectively. Finally, for supraventricular tachycardias, wide QRS, and paced ECGs, the model had AUROCs of 0.998, 0.98, and 0.98, respectively. Conclusions We demonstrate that a deep learning model trained to identify rhythm and conduction disorders based on synthetic ECGs where lead I data from clinical 12 lead ECGs are used to replicate real-world PDF outputs of wearable ECGs, generalizes to real-world wearable and handheld single-lead devices.

Electrocardiographic abnormalities are frequently detected in healthy adult Borzoi with a normal echocardiogram.

Borzoi reportedly experience sudden death. The objective of this study was to report ECG intervals, amplitudes, and frequency of ECG abnormalities in clinically healthy Borzoi. 98 clinically healthy Borzoi were prospectively recruited and underwent echocardiogram, ECG, and cardiac troponin I testing between October 2020 and December 2022. Standard ECG measurements were obtained. Early repolarization notches and slurs were recorded. Of 82 Borzoi with a structurally normal echocardiogram, ventricular arrhythmias were documented in 8 (10%) dogs, all of which had normal cardiac troponin I concentrations. Median P wave duration was 55 milliseconds (range, 45 to 70 milliseconds). Median PR interval was 125 milliseconds (range, 80 to 175 milliseconds). Thirty-one (38%) Borzoi had first-degree atrioventricular block (PR interval > 130 milliseconds). Median QRS duration was 65 milliseconds (range, 48 to 90 milliseconds). Median QT interval was 235 milliseconds (range, 185 to 275 milliseconds). Twenty-nine (35%) and 15 (18%) of 82 Borzoi had QT intervals > 240 or > 250 milliseconds, respectively. Sixty-seven of 82 (82%) Borzoi had early repolarization notches or slurs. Seventeen of 82 (21%) Borzoi had an abnormality of the ST segment, most commonly convexity/doming. Convexity of the ST segment was intermittent (n = 9) or persistent (4). Ventricular arrhythmias, early repolarization, prolonged QT intervals, and ST segment abnormalities are not infrequent in clinically healthy Borzoi. P, PR, and QRS durations are commonly prolonged compared to general canine reference intervals. Future study into heritable channelopathies in Borzoi is warranted given the frequency of ventricular arrhythmias, repolarization abnormalities, and sudden death in the breed. Breed-specific ECG reference intervals are needed.

A multicenter study of clinical predictors of positive pyrophosphate scintigraphy findings in the diagnosis of transthyretin amyloidosis

BackgroundThe prevalence of wild-type transthyretin (ATTR) amyloidosis is increasing with advancements in diagnostic techniques and growing awareness of the disease worldwide. 99mTc-labeled pyrophosphate (99mTc-PYP) scintigraphy exhibits high performance in diagnosing ATTR cardiac amyloidosis. This study aimed to validate the characteristics of patients with positive 99mTc-PYP scintigraphy results in a multicenter setting to provide more accurate case selection criteria. Methods and resultsIn total, 180 patients with suspected ATTR amyloidosis underwent 99mTc-PYP scintigraphy in participating institutions in Japan between January 2018 and July 2022. Of 135 patients included in the analysis, 62 were 99mTc-PYP-positive. Logistic regression analysis was performed, and the following five factors were adopted to create a scoring system, with each weighted according to its odds ratio value; 1 point was scored for the absence of hypertension, existence of peripheral entrapment neuropathy (carpal tunnel syndrome or spinal canal stenosis), conduction disturbance (the presence of QRS complex ≥120 ms, first-degree atrioventricular block, higher degree of atrioventricular block, or presence of pacemaker implantation), and left ventricular hypertrophy and 2 points for troponin I/T ≥ 0.06 ng/mL. 99mTc-PYP scintigraphy positivity rate in the 0-point group was 0 %, whereas that in the 6-point group was 100 %. The area under the curve of the criteria was 0.820 (95 % confidence interval, 0.752–0.888; P < 0.001). ConclusionsThe combination of clinical information, which is easily available in local clinics, can provide accurate pretest prediction of positive 99mTc-PYP scintigraphy results. This will help clinicians to make an early diagnosis of ATTR amyloidosis.

Dilated cardiomyopathy revealing Refsum disease: a case report

BackgroundRefsum disease is a rare autosomal recessive hereditary disorder of lipid metabolism that results in the accumulation of phytanic acid. This syndrome is characterized with a range of classic symptoms including ataxia, peripheral neuropathy, amyotrophy, retinopathy, ichthyosis, and hearing loss. Later in life, individuals with Refsum disease may present cardiac manifestations, such as arrhythmias or conduction defects (first-degree atrioventricular block and bundle branch block) and hypertrophic or dilated cardiomyopathy, leading to heart failure and sudden death. To the best of our knowledge, this is the first case revealed by cardiac manifestations described in literature.Case presentation: We report the case of 38-year-old white Moroccan male who was admitted in our department for an acute decompensated heart failure episode. Transthoracic echocardiography found a dilated cardiomyopathy with a reduced ejection fraction at 15%. Further evaluation showed different features of Refsum disease. High plasma level of phytanic acid confirmed the diagnosis. Cardiac manifestations are frequent in the late course of the adult Refsum disease and include, cardiomyopathy, electrical abnormalities, and sudden cardiac death. Moreover, arrhythmias remain one of the main causes of death in these patients.ConclusionRefsum’s disease is an autosomal recessive disorder. It presents as retinitis pigmentosa with anosmia, deafness ataxia, and cardiac defects. Current interventions for individuals with Refsum disease consist of dietary phytanic acid restriction and lipid apheresis to control symptoms and enhance quality of life.

Phenome-Wide Association of APOE Alleles in the All of Us Research Program.

Genetic variation in APOE is associated with altered lipid metabolism, as well as cardiovascular and neurodegenerative disease risk. However, prior studies are largely limited to European ancestry populations and differential risk by sex and ancestry has not been widely evaluated. We utilized a phenome-wide association study (PheWAS) approach to explore APOE-associated phenotypes in the All of Us Research Program. We determined APOE alleles for 181,880 All of Us participants with whole genome sequencing and electronic health record (EHR) data, representing seven gnomAD ancestry groups. We tested association of APOE variants, ordered based on Alzheimer's disease risk hierarchy (ε2/ε2<ε2/ε3<ε3/ε3<ε2/ε4<ε3/ε4<ε4/ε4), with 2,318 EHR-derived phenotypes. Bonferroni-adjusted analyses were performed overall, by ancestry, by sex, and with adjustment for social determinants of health (SDOH). In the overall cohort, PheWAS identified 17 significant associations, including an increased odds of hyperlipidemia (OR 1.15 [1.14-1.16] per APOE genotype group; P=1.8×10-129), dementia, and Alzheimer's disease (OR 1.55 [1.40-1.70]; P=5×10-19), and a reduced odds of fatty liver disease (OR 0.93 [0.90-0.95]; P=1.6×10-9) and chronic liver disease. ORs were similar after SDOH adjustment and by sex, except for an increased number of cardiovascular associations in males, and decreased odds of noninflammatory disorders of vulva and perineum in females (OR 0.89 [0.84-0.94]; P=1.1×10-5). Significant heterogeneity was observed for hyperlipidemia and mild cognitive impairment across ancestry. Unique associations by ancestry included transient retinal arterial occlusion in the European ancestry group, and first-degree atrioventricular block in the American Admixed/Latino ancestry group. We replicate extensive phenotypic associations with APOE alleles in a large, diverse cohort, despite limitations in accuracy for EHR-derived phenotypes. We provide a comprehensive catalog of APOE-associated phenotypes and present evidence of unique phenotypic associations by sex and ancestry, as well as heterogeneity in effect size across ancestry.

Electrocardiogram Abnormalities in Children With Lyme Arthritis.

Classically, Lyme disease follows a staged illness pattern with carditis occurring in early disseminated disease and arthritis in late-stage disease. A more comprehensive understanding of Lyme suggests that clinical stages may intersect. Little is known regarding the overlap of electrocardiogram (ECG) abnormalities in children with Lyme arthritis. This study aimed to estimate the prevalence of ECG changes in pediatric patients presenting with Lyme arthritis. In this retrospective, cross-sectional study was conducted at a tertiary care children's hospital in a Lyme endemic area; patients were identified based on Lyme testing performed from January 2012 to August 2022. Children diagnosed with Lyme arthritis by 2-tiered serology with ECGs obtained within 2 days of antibiotic initiation were included. A study cardiologist reviewed all ECGs for evidence of carditis defined as atrioventricular block, ST-T wave changes, QTc interval prolongation, accelerated junctional rhythm or right bundle branch block. Two hundred thirty-three patients were diagnosed with Lyme arthritis; 90 (38.6%) had ECGs completed. Five patients (5.6%) had ECG abnormalities: 3 were diagnosed with first-degree atrioventricular block, 1 with QTc prolongation, and 1 with ST-T wave changes. No clinical or laboratory features in patients with Lyme arthritis were associated with an increased likelihood of having an abnormal ECG. All patients with ECG abnormalities were treated with oral antibiotics, and none had clinically significant cardiac disease. ECG abnormalities in children with Lyme arthritis rarely occur and, when present, are not reflective of clinically significant cardiac disease. These results do not support routine screening ECGs on asymptomatic pediatric patients with Lyme arthritis.

Two Cases of Acute Myocarditis with Suspected Acute Myocardial Infarction

Case 1: The patient is a 19-year-old male who was admitted to the hospital with a cough for three days and chest pain for a day, aggravated for two hours. Electrocardiogram showed 1. Sinus tachycardia 2. First-degree atrioventricular block 3. ST-T changes, not excluding acute extensive anterior wall myocardial infarction. Case 2: The patient was a 47-year-old woman admitted to the hospital with a fever for three days. Electrocardiogram showed: 1. Sinus tachycardia, 2. Complete block of the right bundle branch, 3. ST-T changes, not excluding acute extensive anterior myocardial infarction. The study of these two cases strengthened the departmental staff’s knowledge of ECG in acute myocarditis and provided a rapid and accurate ECG diagnosis in the clinic.

Prevalence of cardiac ARRHYTHMIAs in patients recovering from COVID-19

Abstract Background The family of seven known human coronaviruses are known for their impact on the respiratory tract, not the heart. However, the most recent coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has marked tropism for the heart and can lead to myocarditis (inflammation of the heart), necrosis of its cells, mimicking of a heart attack, arrhythmias, and heart failure. These complications, which at times are the only features of coronavirus disease 2019 (COVID-19) clinical presentation, have occurred even in cases with mild symptoms and in people who did not experience any symptoms. Recent findings of heart involvement in young athletes, including sudden death, have raised concerns about the current limits of our knowledge and potentially high risk and occult prevalence of COVID-19 heart manifestations. Aim of the Work was to detect the prevalence of cardiac arrhythmias in patients recovering from COVID-19 and to find out if it is related to COVID infection. Patients and Methods This cross sectional study was to detect the prevalence of cardiac arrhythmias in patients recovered from COVID-19 and to find out its relation to COVID infection. It was carried out on one hundred patients who had been diagnosed as COVID-19 and came after recovery from one to six months Post COVID at Ain Shams University Hospitals .This study was carried out during a period of six months between November 2021 and May 2022. Results that among these 100 patients recovering from COVID-19, 17 % of them developed cardiac arrhythmias as follow; 7 (7%) were diagnosed as Inappropriate Sinus Tachycardia, 3 (3%) had PVCs arising from RVOT, 3 (3%) were diagnosed as PACs, 2 (2%) were diagnosed as Paroxysmal AF, 1 (1%) was diagnosed as SVT (AVRT) and 1 (1%) was diagnosed as 1st degree heart block. Conclusion we found that Inappropriate sinus tachycardia was the most prevalent Cardiac Arrhythmia in these patients recovering from COVID-19 (7%) while other arrhythmias had lower prevalence with RVOT PVCS found in 3 % of the studied group, PACs in 3%, Paroxysmal AF in 2%, SVT (AVRT) in 1% and 1st degree heart block in 1% of this studied population. Absolute Lymphopenia during the course of COVID-19 illness had an effect on the prevalence of Cardiac Arrhythmias in patients recovering from COVID-19. Correlation among these arrhythmias and symptoms of these patients was called Post COVID syndrome.

Uncut Gemella Haemolysans: A Case of Bacteremia with No Clear Entry Site

Background: Gemella haemolysans is a gram-positive coccus that colonizes the genitourinary system, gastrointestinal system, and upper respiratory tract as an opportunistic pathogen. Berge et al. found that the frequency of Gemella species bacteremia was 4.5 and infective endocarditis was 0.31 per 1,000,000 inhabitants yearly. We report the first case of G. haemolysans bacteremia presenting as new-onset atrial fibrillation with rapid ventricular response (RVR) and acute respiratory failure and present a case series on G. haemolysans bacteremia and infective endocarditis. Case Presentation: A 58-year-old male with a past medical history including aortic valve bioprosthetic replacement, type 2 diabetes, hypertension, and coronary artery stenting and bypass surgery presented with shortness of breath and confusion. Examination and testing revealed a 40.4°C fever, acute respiratory failure, atrial fibrillation with RVR, congestive heart failure, lactic acidosis, and acute renal failure, with no drug use, dental wounds, or pneumonia. Diltiazem, metoprolol, aspirin, atorvastatin, insulin, heparin, and ceftriaxone were started. TTE and TEE revealed no clear vegetations. Blood cultures revealed Gemella haemolysans. He became stable after 4 days, was electrically cardioverted to sinus rhythm with first-degree AV block, progressed to complete heart block, then had a temporary pacer placed. A repeat TEE demonstrated an aortic root abscess. He underwent redo sternotomy and homograft placement with no complications and was discharged with instructions to complete a six-week course of ceftriaxone. Discussion: Our patient presented with multiple comorbidities at a younger age compared to the mean (66) and median (70) age of the 4 bacteremia cases in our 8-case series. Preemptive antibiotic treatment may be warranted for prosthetic heart valve patients, with the possibility of urgent valve replacement surgery. Several antibiotics were previously reported in case studies with varying results. The shortest course was 16 days, with most courses lasting 4 to 7 weeks. With no standard treatment, this case series suggests G. haemolysans tends to be susceptible to beta-lactam agents. Conclusion: Our case highlights the importance of a multidisciplinary approach in the diagnosis and management of Gemella haemolysans bacteremia, particularly in patients with complex medical histories and prosthetic heart valves.

Characterization of patients with extensive left atrial myopathy referred for atrial fibrillation ablation: incidence, predictors, and outcomes.

Although atrial fibrosis has a relevant impact on ablation success rate, experimental studies have reported that extensive fibrosis may be accompanied by a reduced burden secondary to a prominent depression of atrial excitability. We aimed to identify clinical and echocardiographic factors associated with extensive left atrial myopathy (ELAM), to analyze the predictive ability of established scores (AF score, APPLE, and DR-FLASH) and assess outcomes in terms of AF recurrence, left atrial flutter, and post-procedural heart failure admissions. A total of 950 consecutive patients undergoing the first AF ablation were included. A 3D electroanatomical mapping system (CARTO3, Biosense Webster) was created using a multipolar mapping catheter (PentaRay, Biosense Webster). ELAM was defined as ≥ 50% low voltage area. A subanalysis with four groups was also created (< 10%; 10-20%; 10-20%; and > 30%). Logistic regressions, Cox proportional hazards models, and log-rank test were used to test the predictors independently associated with the presence of ELAM and AF recurrence. The model was prospectively validated in a cohort of 150 patients obtaining an excellent ability for prediction AUC 0.90 (CI 95% 0.84-0.96). Overall, 78 (8.42%) presented ELAM. Age, female sex, persistent AF, first-degree AV block, and E/e' were significant predictors. The model incorporating these factors outperformed the existing scores (AUC = 0.87). During a mean follow-up of 20months (IQR 9 to 36), patients with ELAM presented a higher rate of AF recurrence (42.02% vs 26.01%, p = 0.030), left atrial flutter (26.03% vs 8.02%, p < 0.001), and post-procedural heart failure admissions (12.01% vs 0.61%, p < 0.001) than non-ELAM patients. This study reveals the incidence and clinical factors associated with ELAM in AF, highlighting age, female, persistent AF, first-degree AV block, and E/e'. Importantly, the presence of ELAM is associated with poorer outcomes in terms of recurrence and HF admission.

Not too old to be treated: electrophysiological study and catheter ablation in eldery patients

Abstract Background The number of elderly patients referred for electrophysiological study (EPS) and catheter ablation (CA) is increasing. These patients are thought to have more complications due to age and comorbidity. Purpose The aim of our study was to evaluate the safety (EPS and CA) and acute success (CA) in a group of elderly patients (age ≥75 years old). Methods Between August 2020 and September 2023, consecutive elderly patients (32.7% older than 80 years) underwent EPS alone or EPS and CA at our center. Left atrial thrombus was ruled out performing transesophageal echocardiography when indicated. Anticoagulation (ACO) was not interrupted. Femoral veins, arteries and transeptal punctures were performed under ultrasound guidance. A navigation system was used for all CA procedures, except for pulmonary vein isolation, which was performed with a cryoballoon. We analysed procedural complications related to EPS and CA and the acute success of CA procedures. Results A total of 104 patients undergoing EPS±CA (79.9±4.6 years, 41.3% female, 75% HTA, 67.3% diabetes type 2, 19.4% COPD, 20.2% chronic renal disease, 25% structural heart disease, CHA2DS2VasC score 3.6±0.8, IMC 27.3±4.5 kg/m2, weight 72.3±13.6 kg, LVEF 52.7±10.8%, 31% history of atrial fibrillation (AF), 47.1% on ACO, 38.5% bundle-branch block, 34.6% first-degree atrioventricular block, 4.8% implanted pacemaker or ICD) were included. Indications for referral (Figure 1) were typical atrial flutter (TAF, 34.6%), atrioventricular nodal reentrant tachycardia (AVNRT, 26.9%), study of syncope (11.5%) atypical atrial flutter or atrial tachycardia (AAF/AT, 10.6%), AF (8.6%, 6 patients for AV node ablation, 3 for pulmonary vein isolation), ventricular tachycardia or ectopy (VT or VE, 5.7%), orthodromic reentrant tachycardia (ORT, 1.9%). 2 patients had TAF and AVNRT, treated in the same procedure. Acute success was achieved in 100% of AF, 94.6% of TAF, 89.6% of AVNRT, 66% of VT/VE, 50% of ORT, 45% of AAF/AT. There were 4 complications (2.9%) in 3 patients, all during the CA procedure: an AV block during an AVNRT ablation, another AV block during an ischaemic septal VT ablation, a femoral artery pseudoaneurism in the same patient (femoral artery approach), and a dislocation of the electrodes from a previous pacemaker during an AT ablation. None of the patients undergoing EPS alone had complications. Weight was the only variable associated with the development of complications (mean difference= -19.8, 95% CI(-38.9-0.7); p=0.04), being higher in those with than in those without complications (91.5±2.2 vs 71.6±13 Kg),(Table 1). Conclusions EPS and CA procedures in elderly patients with multiple comorbidities are safe and effective. Acute success and complication rates of CA procedures are substrate-dependent and similar to those reported in the literature for younger patients. We conclude that age is not a barrier to the study and treatment of arrhythmias.

Permanent pacemaker reduction using temporary-permanent pacemaker as a 1-month bridge after transcatheter aortic valve replacement: a prospective, multicentre, single-arm, observational study

The permanent pacemaker (PPM) implantation and pacemaker dependency rates after transcatheter aortic valve replacement (TAVR) are highly variable as some of the conduction disturbances are reversible. It remains poorly investigated how to optimise temporary pacing in these patients. This study aimed to explore the potential reduction in the PPM implantation rate using temporary-permanent pacemaker (TPPM) as a 1-month bridge. This is a prospective, multicentre, single-arm, observational study. Consecutive patients undergoing TAVR from March 1, 2022 to March 1, 2023 in 13 tertiary hospitals in China were screened. Patients who developed high-degree atrioventricular block, complete heart block, or first-degree atrioventricular block plus new onset left bundle branch block during the TAVR procedure or within 1 month after TAVR were included to receive TPPM. Patients with pre-existing PPM implantation or indications for PPM implantation before the TAVR procedure were excluded. Patients with TPPM were monitored to determine whether the conduction disturbances persisted or recovered. The primary endpoint was the rate of freedom from indications for PPM implantation 1 month after TAVR. This study is registered with ChiCTR, ChiCTR2200057931. Of 688 patients who have undergone TAVR, 71 developed conduction disturbance and met the inclusion criteria, 1 patient withdrew due to noncompliance, 70 patients received TPPM and completed follow-up. There were 41 (58.6%) men and 29 (41.4%) women in the study, with a mean age of 74.3±7.3 years. At 1 month follow-up, 75.7% (53/70) of the patients with TPPM did not require PPM implantation. For 688 patients who have undergone TAVR, the rate of PPM implantation at 1 month was 2.47% (17/688, 95% CI 1.55%-3.92%), representing a significant reduction in self-comparison with the rate at 48 h after TPPM (2.47% vs. 8.28% [95% CI 6.45%-10.58%], P<0.0001). Similar results were obtained in the subgroup analysis of patients with HAVB/CHB. Multivariate analysis revealed the baseline PR interval, difference between the membranous septum length and implantation depth, and timing of postprocedural conduction disturbance occurrence were independent predictors of freedom from indications for PPM implantation at 1 month after TAVR. Using TPPM as a 1-month bridge allows for a buffer period to distinguish whether conduction disturbances are reversible or persistent, resulting in a significant reduction in the PPM implantation rate after TAVR when compared with the current strategy. However, this is an observational study, the results need to be confirmed in a randomized trial. Beijing Science and Technology Plan 2022 from Beijing Municipal Science & Technology Commission.

Assessment of Repeated Electrocardiogram Findings in Pediatric Multisystem Inflammatory Syndrome Associated with COVID-19

Background: Cardiac involvement, stemming from the novel multisystem inflammatory syndrome in children (MIS-C) associated with coronavirus disease-2019 (COVID-19), leads to common and severe complications. Objectives: The aim of this study is to compare and evaluate repetitive electrocardiogram (ECG) results and laboratory indicators in children diagnosed with MIS-C upon their initial hospital admission. Methods: This prospective, single-center study, conducted between December 2020 and October 2022, included repeated electrocardiographic and laboratory tests. Changes in the ECG over the course of the disease were regularly recorded for three months. Results: This study included 72 patients, 25 of whom were female. Mitral regurgitation and left ventricular systolic dysfunction were observed in 25% of the patients. Statistically significant differences (P &lt; 0.05) were detected among the serial measurements of absolute neutrophil-lymphocyte count, CRP, procalcitonin, ESR, D-dimer, troponin T, pro-BNP, ferritin, and interleukin-6. Significant differences were also observed in heart rate, PR interval, QRS duration, QT duration, Fredericia QTc, JT interval, presence of sinus tachycardia, presence of first-degree AV block, presence of wide QRS, abnormal QRS axis, abnormal T axis, long QTc, and ST-T changes (P &lt; 0.05). Additionally, significant differences were noted in the absolute lymphocyte count, troponin levels, and ferritin levels between patients with prolonged abnormal ECG findings and those whose ECG findings were normal or had returned to normal. Furthermore, statistically significant differences were observed in absolute lymphocyte count, ferritin, and fibrinogen levels among the other four groups (P &lt; 0.05). Conclusions: Electrocardiogram findings in patients measured serially appear to improve over time. Since patients with MIS-C may experience ECG abnormalities that could lead to arrhythmias, close monitoring and the establishment of standardized approaches are essential. Long-term ECG abnormalities were associated with a decrease in absolute lymphocyte count and elevated levels of troponin, ferritin, and fibrinogen.

Electrocardiographic Patterns and Ejection Fraction in Patients with Nonischemic Dilated Cardiomyopathy: A Cross-sectional Retrospective Study

Background:: The relationship between ECG changes in dilated nonischemic cardiomyopathy and ejection fraction (EF) is complex and poorly understood. Thus, this study aimed to identify the most common patterns of ECG associated with dilated nonischemic cardiomyopathy and their relationship to EF. Methods:: A retrospective cross-sectional study was conducted between 2019 and 2022, including 100 consecutive patients with nonischemic dilated cardiomyopathy. ECG data were rate, axis, left (LBBB) and right bundle branch block (RBBB), first-degree heart block, premature ventricular contractions, depth of S wave in leads V1 and V2, length of R wave in leads V2 and V6, the ratio of R/S in the lead V4, left ventricular hypertrophy (LVH), maximum R wave length in leads I, II, and III, poor R wave progression, ST-segment elevation, and T wave inversion. Results:: The most common ECG pattern associated with cardiomyopathy was T-wave inversion (47%). The EF was 23.9± 8.87% in patients with LBBB and 25.5± 8.07% in patients without LBBB (P= 0.361). In patients with T-wave inversion, the EF was 23.4± 8.21%, and it was 26.28± 8.35% in patients without T-wave inversion (P= 0.086). In patients with LVH, the EF was 23.89± 7.84%, and it was 25.5± 8.66% in patients without LVH (P= 0.354). A negative nonsignificant correlation existed between SV1, SV2, RV2, RV6, R/S V4, and maximum R in I, II, III, and EF. Conclusions:: The study showed that T-wave inversion was the most common pattern associated with dilated nonischemic cardiomyopathy. The study provided insight into the negative correlation between EF and SV1, SV2, RV2, RV6, R/S V4, and maximum R in I, II, and III, although it did not reach a significant level.

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

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. 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. 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. 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). AV-optimized CSP could improve symptoms, exercise capacity and LVSV in patients with severe first-degree AV block.

Associations of Atrioventricular Blocks and Other Arrhythmias in Patients with Lyme Carditis: A Systematic Review and Meta-Analysis.

Lyme disease often leads to cardiac injury and electrophysiological abnormalities. This study aimed to explore links between atrioventricular blocks and additional arrhythmias in Lyme carditis patients. This systematic review and meta-analysis of existing literature was performed from 1990 to 2023, and aimed to identify cases of Lyme carditis through serology or clinical diagnosis with concomitant arrhythmias. Pubmed and Web of Science were searched using appropriate MESH terms. Patients were divided into groups with atrioventricular blocks and other arrhythmias for cardiovascular (CV) outcome assessment. A total of 110 cases were analyzed. The majority (77.3%) were male, with mean age = 39.65 ± 14.80 years. Most patients presented within one week of symptom onset (30.9%). Men were more likely to have first-degree atrioventricular blocks (OR = 1.36 [95% CI 1.12-3.96], p = 0.01); these blocks tended to be reversible in nature (OR = 1.51 [95% CI 1.39-3.92], p = 0.01). Men exhibited a higher likelihood of experiencing variable arrhythmias (OR = 1.31 [95% CI 1.08-2.16], p < 0.001). Ventricular and supraventricular arrhythmias were more likely to exhibit instability (OR = 0.96 [95% CI 0.81-1.16] p = 0.01) and variability (OR = 1.99 [95% CI 0.47-8.31], p < 0.001). Men with Lyme carditis are likely to present with various atrioventricular blocks. These atrioventricular blocks are benign, and follow a predictable and stable clinical course. Further large-scale studies are warranted to confirm these associations.