First-degree Block Research Articles

Biallelic truncating variants in children with titinopathy represent a recognizable condition with distinctive muscular and cardiac characteristics: a report on five patients.

Monoallelic and biallelic TTN truncating variants (TTNtv) may be responsible for a wide spectrum of musculoskeletal and cardiac disorders with different age at onset. Although the prevalence of heterozygous TTNtv is relatively high in the general population, cardiac phenotyping (mainly cardiomyopathies, CMPs) in biallelic titinopathy has rarely been described in children. We reviewed the medical records of pediatric patients with biallelic TTNtv and cardiac involvement. Clinical exome sequencing excluded pathogenic/likely pathogenic variants in major CMP genes. Five pediatric patients (four male) with biallelic TTNtv were included. Major arthrogryposis multiplex was observed in four patients; no patient showed intellectual disability. At a cardiac level, congenital heart defects (atrial and ventricular septal defects, n = 3) and left ventricular non-compaction (n = 1) were reported. All patients had dilated cardiomyopathy (DCM) diagnosed at birth in one patient and at the age of 10, 13, 14, and 17 years in the other four patients. Heart rhythm monitoring showed tachyarrhythmias (premature ventricular contractions, n = 2; non-sustained ventricular tachycardia, n = 2) and nocturnal first-degree atrio-ventricular block (n = 2). Cardiac magnetic resonance (CMR) imaging was performed in all patients and revealed a peculiar late gadolinium enhancement distribution in three patients. HyperCKemia was present in two patients and end-stage heart failure in four. End-organ damage requiring heart transplantation (HT) was indicated in two patients, who were operated on successfully. Biallelic TTNtv should be considered when evaluating children with severe and early-onset DCM, particularly if skeletal and muscular abnormalities are present, e.g., arthrogryposis multiplex and congenital progressive myopathy. End-stage heart failure is common and may require HT.

Pseudo-pacemaker syndrome with prolonged PR interval: A narrative review.

Pseudo-pacemaker syndrome (PPMS) is a rare complication of first-degree atrio-ventricular (AV) block in which a very prolonged PR interval causes AV dyssynchrony and subsequent symptoms of hemodynamic instability in the absence of an implanted pacemaker. The aim of this manuscript was to describe a unique case of PPMS and to provide a comprehensive review of the topic to help clinicians in the diagnosis and management of this condition. Through systematic research on PubMed, Google Scholar, EBSCO, and Ovid MEDLINE and using the search strings "pseudo-pacemaker syndrome" and "symptomatic first-degree AV block," we identified 14 articles accounting for 17 cases of PPMS, including our case report. The most common age group for PPMS was middle-aged and young adults, with an average age of 47 years. Palpitations were the most common presenting symptom and four main etiologies of PPMS were identified, as follows: (1) Idiopathic PPMS with evidence of impaired conduction over the AV node (20% of cases), (2) PPMS associated with reversable inflammatory causes (13%) or (3) associated with iatrogenic surgical or interventional procedures leading to the permanent damage of the normal AV conduction system (20%), and, finally, (4) PPM related to dual AV nodal physiology (DAVNP) as a primary finding (27%) or occurring after fast or slow pathway ablation for treatment of AV nodal re-entrant tachycardia (AVNRT) (20%). Treatment should be patient-tailored and based on the specific etiology once identified. However, the treatment of PPMS due to DAVNP without AVNRT presentation is yet to be clarified.

Prediction of atrioventricular conduction disturbance after ablation of persistent atrial fibrillation.

The prevalence of atrioventricular conduction disturbance (AVCD) in patients with persistent atrial fibrillation (AF) has not yet been fully investigated. We sought to identify the predictors of AVCD in patients with AF by analyzing the relationship between pre-ablation heart rate during AF and the PR interval in sinus rhythm after ablation. We analyzed pre-ablation 24-h Holter electrocardiogram (ECG) and 12 lead ECG 12months after ablation of 121 consecutive patients with persistent AF who underwent their first ablation procedure and maintained sinus rhythm at 12months. AVCD was defined as a first-degree atrioventricular block (AVB), second-degree AVB, high-degree AVB, or third-degree AVB observed on ECG at 12months after ablation. Seventeen out of 121 patients (14.0%) had AVCD at 12months. In the group with AVCD, total heartbeat (THB) and maximum heart rate (Max HR) were significantly lower, and the prevalence of concomitant Cavo-tricuspid isthmus-dependent atrial flutter before ablation and the appearance of macro reentrant atrial tachycardia (AT) during the procedure were significantly higher than those in the group without AVCD. Multiple regression analysis revealed that maximum HR and macro reentrant AT were significant predictors of AVCD. Receiver operating characteristic curve analysis revealed that Max HR of <165.0bpm predicts AVCD with a sensitivity of 76.47% and a specificity of 74.00%. In patients with persistent AF, low Max HR and the presence of macro reentrant AT during the ablation procedure were predictors of AVCD.

Endomyocardial fibrosis in a 12-year-old boy

Abstract Endomyocardial fibrosis (EMF) is characterized by the abnormal scarring of the endocardium with deposition of fibrous tissues in the apices and inflow tracts of the right ventricle, left ventricle, or both, leading to symptoms such as heart failure, arrhythmias, and intracardiac thrombosis. EMF is a rare cause of cardiac morbidity and mortality in children of the tropics including Nigeria, hence the presentation of this case report. A 12-year-old male presented to Children emergency ward with abdominal swelling from infancy, which worsened 3 months before presentation, leg swelling and weight loss of 3 months, cough of 1 month, and fast breathing of 1 week. Physical examination revealed dyspnea, pedal and leg edema, absent breath sounds in the right middle and lower lung zone, tachycardia, irregular pulse, elevated jugular venous pressure, and a grossly distended abdomen. Echocardiography demonstrated dilated atria, thickened AV valves, small, thickened ventricular cavities, intra-atrial thrombus, fibrous tissue in the apices and inlets of left and right ventricles, and pericardial effusion. Electrocardiography revealed first-degree AV block, left anterior fascicular block, and left atrial enlargement. Chest radiograph revealed right lobar pneumonia, pleural effusion, and cardiomegaly. The abdominopelvic scan revealed congestive hepatomegaly and ascites. He received diuretics, beta-blockers, aspirin, and antibiotics. Repeated abdominal paracentesis, thoracocentesis, and pericardiocentesis drained 14.2 L, 1.5 L, and 2.1 L of serosanguineous fluid, respectively. EMF is an enigmatic disease which requires further research to unravel its underlying mechanisms and develop more targeted therapeutic strategies.

Frequency of Cardiac Arrhythmias Detection on 24 Hours Holter Monitoring

To determine the clinical outcomes and assess the diagnostic yield of Holter monitoring and its potential use in diagnosing and managing abnormal rhythms, along with identifying patterns or trends in the prevalence of different arrhythmias, which could modify and design future research and clinical practice. It was a descriptive cross sectional study carried out at MMC Mardan on around 1000 patients, from June 2017 to December 2022. Three trained Cardiologists having more than 03 years of experience reviewed the 24-hour monitor data through the system. Among these 1000 patients, 31% had at least one arrhythmia detected on 24-hour Holter monitoring. The most common arrhythmias detected were premature ventricular contractions (54%), followed by Atrial fibrillation (18%) and supraventricular tachycardia (15%) while 2.3% had first-degree AV block, 4.5% had second-degree AV block, and 0.8% had third-degree AV block. In conclusion, our study showed that Holter monitoring for 24 hours is a useful tool for detecting a range of cardiac arrhythmias, with premature ventricular contractions being on the top, with some forms of AV block also being detected in a small group of patients, having first-degree AV block being the most common type.

#4771 PROGNOSTIC RELEVANCE OF ELECTROCARDIOGRAPHIC ABNORMALITIES ACCORDING TO EGFR CATEGORIES

Abstract Background and Aims Electrocardiogram (ECG) abnormalities are associated with adverse cardiovascular outcomes in patients with chronic kidney disease (CKD), but their prognostic relevance according to estimated glomerular filtration rate (eGFR) categories remains unexplored. This study investigated the associations between no, minor, and major ECG abnormalities and fatal cardiovascular disease (CVD) according to different strata of renal function. Method This was a retrospective cohort study including 310.060 individuals aged ≥16 years from the Copenhagen General Practitioners' Laboratory that had an available digital ECG and creatinine measurement within 7 days from 2001–2015. eGFR was calculated using The Chronic Kidney Disease Epidemiology Collaboration equation, and data were cross-linked with Danish nation-wide healthcare registries to gain information on medication, comorbidity, and fatal CVD. ECG abnormalities were categorized as either no abnormalities, minor (first-degree atrioventricular block, incomplete bundle branch block or corrected QT prolongation) or major (left ventricular hypertrophy, atrial fibrillation/flutter, bundle branch block, Q waves, or ST-T deviations), as done previously [1]. Patients with both minor and major ECG abnormalities were assigned as major ECG abnormalities. ECG abnormalities and their association with fatal CVD were compared across strata of renal function [eGFR (ml/min/1.73m2) &amp;gt;90, 61–90, 46–60, 31–45, 16–30 and ≤15] based on multivariable Cox-regression analysis adjusted for age, sex, and comorbidities. Counterfactual G-estimation of Hazard Ratios (HRs) standardized to age and sex was performed to estimate 5-year absolute risk of fatal CVD. Results The median age was 55 [IQR, 41-69] years and 46% were male. Median study follow-up time was 10.3 [IQR, 6.7-14.4] years. A total of 47,249 (17.9%) of the included patients had an eGFR &amp;lt;60. The rate of fatal CVD according to ECG abnormalities and their adjusted HRs is shown in Fig. 1, while 5-year standardized risk of fatal CVD is depicted in Fig. 2. Generally, having minor or major ECG abnormalities, conferred a worse prognosis across all eGFR strata, with the highest 5-year absolute risk of fatal CVD being observed among patients with major ECG abnormalities and an eGFR between 31–45 [19% (95% CI, 18–20%)], eGFR 16–30 [25% (95% CI, 24–26%)] or an eGFR ≤15 [27.5% (95% CI, 24–31%)], Fig. 1–2. Conclusion In a population-based setting, having minor or major ECG abnormalities were associated with an increased risk of fatal CVD across all strata of renal function. Patients with an eGFR ≤45 and major ECG abnormalities represent a high-risk population, that might benefit from careful monitoring and cardiovascular risk management.

#2803 ECG ABNORMALITIES AND MORTALITY IN HEMODIALYSIS PATIENTS

Abstract Background and Aims Hemodialysis patients undergo electrocardiogram (ECG) testing for acute events or as a part of the regular workup. It is still unknown whether chronic ECG abnormalities could be considered as a prognostic factor in dialysis patients. This study aims to analyze the association between mortality and ECG abnormalities of the last two years of follow-up of hemodialysis patients. Method This is a retrospective study that included all patients treated with chronic hemodialysis in a single center between January 2002 and December 2021. Patients who had no ECG in their medical file during the last two years of follow-up were excluded. ECGs were interpreted by two physicians. Logistic regression analysis evaluated the association between ECG signs and mortality. The study was approved by the institutional ethics committee and was conducted in accordance with Helsinki Declaration. Results A total of 298 medical files were reviewed, 149 files included an ECG in the last two years of follow-up. Mean age of patients was 67.1 ±13.2 years, 64.4% were males, 54.4% had diabetes, 44.2% had documented coronary artery disease (CAD), 14.8% had chronic or paroxysmal atrial fibrillation. The median left ventricular ejection fraction (LVEF) was 60% [55.5, 64.5]. 55% percent died after a median follow-up of 47 [25, 87] months. Table 1 summarizes the ECG characteristics found among all patients. In the univariate analysis, age, CAD, LVEF, left axis deviation, large QRS, ST depression and first-degree AV block were significantly associated with mortality. After adjustment to age, dialysis vintage, sex, diabetes, CAD and LVEF, we found a significant association between all-cause death and left axis deviation (Table 2). The poor R wave progression was associated with increased sudden cardiac arrest after adjustment to age, dialysis vintage, sex, diabetes and CAD (OR = 2.65, 95%CI 1.01-6.94, p = 0.048). Conclusion This study showed that left axis deviation on ECG of patients treated with chronic hemodialysis is an independent factor associated with increased all-cause mortality after adjustment to demographic and medical factors. Poor R wave progression was associated with sudden cardiac arrest.

Novel compound heterozygous variants in the RPL3L gene causing dilated cardiomyopathy type-2D: a case report and literature review

BackgroundDilated cardiomyopathy type-2D (CMD2D) is a rare heart disease causing a severe cardiomyopathy with neonatal onset and rapid progression to cardiac decompensation and death in untreated patients. CMD2D is an autosomal recessive disease resulting from variants in the RPL3L gene, which encodes the 60 S ribosomal protein exclusively expressed in skeletal and cardiac muscle and plays an essential role in myoblast growth and fusion. Previous reports have only associated CMD2D with a small duplication and seven nucleotide substitution in the RPL3L gene.Case presentationIn this study, we report the case of a 31 days old Chinese infant patient with severe dilated cardiomyopathy (DCM) and rapid decompensation along with other cardiac malformations. In addition to previously reported clinical features, the patient showed the previously unreported complication of occasional premature atrial contractions and a first-degree atrioventricular block. Whole-exome sequencing (WES) revealed compound heterozygous variants (c.80G > A (p.Gly27Asp) and c.1074dupA (p.Ala359fs*6)) in RPL3L (NM_005061.3). The latter novel variant may result in the absence of protein production with a significant decrease in mRNA level, suggesting it is a loss-of-function mutation.ConclusionsThis is the first case report of RPL3L-associated neonatal dilated cardiomyopathy in China. The molecular confirmation of the patient expands the genetic spectrum of CMD2D, and the clinical manifestation of CMD2D in the patient provides additional clinical information regarding this disease.

The Success of a New Protocol for Early Diagnosis and Management of Congenital Atrioventricular Block: A Follow-up Study of 15 Fetuses from November 2007 to August 2022

Background: Congenital atrioventricular heart block (CAVB) is a relatively rare condition that can lead to long-term complications. Early diagnosis and management of CAVB is currently the ideal goal, particularly in high-risk pregnancies. Methods: The Fetal Heart Center at Kurdistan University serves as the primary referral center for pregnant mothers residing in the western region of Iran. Fifteen fetuses with CAVB were admitted between November 2007 and August 2022. They were referred for one or more of the following reasons: Fetal bradycardia or arrhythmia, abnormal ultrasound findings, and previous maternal or fetal risk factors. After obtaining a complete medical history, we conducted fetal echocardiography and ordered testing for maternal Lo/Ra autoantibodies. Our therapeutic approach was based on the type of atrioventricular block (AVB), serum titer of Lo/Ra antibodies, and specific risk factors associated with each type of AVB. Consequently, we used a combination of different medications, including dexamethasone, Hydroxychloroquine (HCQ), IVIG, beta-agonists, and inotropes. Results: We admitted 15 fetuses with CAVB, including seven females (47%) and eight males (53%). Most of our cases had positive tests for Lo and Ra autoantibodies, with varying degrees of AVB. A previous fetal death was common in our case series, accounting for 47% of cases. Moderate and high antibody titers were present in 80% of our cases. Mild bradycardia was a relatively common finding in our cases of first and second-degree atrioventricular block (AVB), occurring in 33% of patients. All of the above-mentioned findings, commonly referred to as major risk factors, were used for either early evaluation or therapeutic goals. No cases with first-degree AVB developed a higher grade of AVB after our therapeutic approach. One fetus with second-degree AVB developed CCHB, and another with mixed second/third-degree AVB reverted to second-degree AVB with the use of appropriate medications. Conclusions: Our therapeutic approach for the current cases yielded satisfactory results. Subsequently, we attempted to develop a rudimentary approach for early managing and treating fetuses with various types of CAVB. We are looking forward to future multicenter studies.

Marked first-degree AV block may lead to complete AV block development

Abstract Funding Acknowledgements Type of funding sources: None. Background First-degree atrioventricular (AV) block (PR interval &amp;gt;200 ms) is considered a benign condition with rare progression to a higher degree AV block. The site of block is determined with electrophysiological (EP) study and measurement of His-ventricular (HV) interval, with normal values below 55 ms. Prolonged HV interval &amp;gt; 70 ms is predictive of higher-grade AV block development. Marked first-degree AV block with a PR &amp;gt; 300 ms may lead to symptoms such as fatigue, poor exercise tolerance and palpitations. When symptoms are correlated to the conduction delay, permanent pacemaker (PPM) implantation to restore AV synchrony should be considered. In the Framingham heart study, patients with first-degree AV block had a threefold higher risk of PPM implantation. However, there is no data on the HV intervals and the rate of progression of conduction disorder in patients with marked first-degree AV block. Purpose To assess the predictive value of HV interval measurement in patients with marked first-degree AV block for progression to a higher-degree conduction disorder. Methods We prospectively evaluated consecutive patients with symptomatic marked first-degree AV block that underwent a PPM implantation. His electrograms were recorded during the implantation, and HV intervals were measured from the first deflection of the His signal to the earliest onset of ventricular activation on a 12-lead surface ECG. Patients were followed for 6 months with three out-patient visits, during which the PPM was temporarily inhibited to check for intrinsic AV conduction. Results Seventeen patients were evaluated between January 2020 and September 2022. Ten patients (59%) were male, and 7 (41%) were female, with an average age of 61 ± 19 years. All patients had markedly prolonged PR interval (383 ± 47 ms) and narrow QRS complex (100 ± 16 ms). Three patients (17%) had intermittent type 1 second-degree AV block, right bundle branch block was recorded in two (12%) and left anterior fascicular block in four (24%) patients. Except for one patient with a corrected atrial septal defect, there were no echocardiographic signs of structural heart disease with a left ventricular ejection fraction of 61 ± 5%. The HV intervals were on the upper limit of normal values at 54 ± 6ms and no patient had an HV interval above 70 ms. Two patients (12%) developed complete AV block during follow-up: one female, and one male, 28 and 83 years old, respectively, with a PR interval 392 and 363 ms, QRS 104 and 94 ms, and HV 57 and 48 ms. None of the two had any additional conduction blocks at the time of PPM implant. Conclusion In our cohort of patients with symptomatic first-degree AV block (PR&amp;gt;300 ms), two patients (12%) developed complete AV block despite normal HV intervals at the time of implant. Closer monitoring, beyond only EP measurements, of patients with markedly prolonged PR intervals is warranted for the potential progression of conduction disorder.

Ethnic differences in normal electrocardiographic findings in elite brazilian football players: b-pro foot ECG pilot study

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): CNPq, CAPES, FIPE-HCPA. Introduction The 12-lead electrocardiogram (ECG-12) is a useful tool in the assessment of athletes. The prevalence of normal electrocardiographic findings in elite Brazilian football players (EBFP) of different ethnicities is not well described. Purpose To compare the prevalence of normal ECG-12 findings in Caucasian, Mixed-race (MR), and Afro-Brazilian (AB) EBFP. Methods A multicenter cross-sectional descriptive study was conducted with exams performed on EBFP as a pre-participation assessment from February 18, 2002, through October 20, 2022. Results 4,363 EBFP from 51 professional clubs (from all five regions of Brazil; 15 states, and 21 cities), aged 15-35 years (median: 19 years; IQR: 16-23) were evaluated. 2,027 were Caucasians, 1,324 were MRs, and 1,012 were ABs. In general, we recorded 4,155 ECG-12 with normal variations (95.2%). Positive Sokolow-Lyon criteria for left ventricular hypertrophy was more prevalent in ABs (41.8%) than in Caucasians (33.4%), or MRs (32.7%). The prevalence of early repolarization in ABs (41.5%) was higher than in Caucasians (34.6%), or MRs (35.5%). The PR interval was longer in ABs (157.1 ms) than in Caucasians (151.4 ms), or MRs (153.3 ms), and the first-degree atrioventricular block was more frequent in ABs compared to MRs (4.2% vs. 2.3%, respectively). On the other hand, Caucasians had a higher prevalence of incomplete right bundle branch block (14.2%) than MRs (11.2%), or ABs (9.7%). In our sample, only three EBFP showed second-degree atrioventricular block Mobitz type I (0.07%; one Caucasian and two AB athletes). Conclusions This is the first large study to compare the prevalence of ECG-12 findings in EBFP from different ethnic groups. Those of AB origin have a significantly higher prevalence of ECG-12 findings compatible with the athlete's heart than Caucasians and MRs.

Usefulness of parahisian pacing for risk prediction of pacemaker implantation after TAVI

Abstract Funding Acknowledgements Type of funding sources: None. Background Conduction disturbances determining pacemaker implantation are a significant concern in patients undergoing Transcatheter Aortic Valve Implantation (TAVI), a procedure that is nowadays spreading even in the low-risk population. OBJECTIVE The aim of the study was to evaluate the role of the parahisian pacing, a method to directly identify the conduction system anatomical variability, in predicting the iatrogenic damage risk conditioning pacemaker implantation after TAVI. Methods Between October 2021 and November 2022 we prospectively collected clinical features, ECG, procedural and imaging data (cardiac CT and echocardiography) of every patient who underwent electrophysiological study for pre-existing or worsening conduction disorders within 48 hours after TAVI procedures in our centre. After having recorded the HV interval, parahisian stimulation at decreasing energy output was performed (CL 600 ms, 25V to 0.5V x 2 ms) with definition of the loss of capture pattern related to the three anatomical variations of His bundle described by Kawashima (1). Fisher’s exact test was used for statistical analysis; p-value &amp;lt;0.05 was considered statistically significant. Results Out of 110 TAVI performed, a total of 31 patients with conduction disorders have been studied. Patients who developed permanent 3rd degree AV block after the procedure were excluded. Mean age was 82.6±4.4 years; 21 patients (67.7%) were males. 11 patients (35.5%) had a pre-existing conduction disorder worsened after TAVI, 13 patients (41.9%) developed newly-onset LBBB; 8 (25.8%) also developed 1st degree AV block. The total number of patients who underwent PM implantation was 16 (51.6%). The anatomical variables (membranous septum &amp;lt;3mm and/or septal cusps calcifications) and type of valve implanted were not significantly associated with PM implantation (p = NS). An HV interval &amp;lt;70 ms was registered in 20 (64.5%) patients (Fig. 1); 7 of them underwent PM implantation as they developed paroxysmal 3rd degree AV block. These 7 patients all had type 2 or type 3 pattern during parahisian stimulation. None of the patients undergoing PM implantation presented a type 1 pattern during parahisian stimulation. A significant protective value (p = 0.02) for PM implantation in patients with type 1 pattern was observed (Fig. 2). Conclusions Parahisian stimulation can be a useful tool to define the conduction system anatomical variability. It can also be helpful to predict the conduction system damage risk during TAVI, conditioning PM implantation. Our data need to be confirmed in a larger population.

P326 FALSE POSITIVE BONE–SCINTIGRAPHY IN ELDERLY HYPERTROPHIC CARDIOMYOPATHY

Abstract Differential diagnosis of cardiomyopathies with hypertrophic phenotype is crucial because some secondary forms of cardiac hypertrophy can be susceptible of specific treatment aimed to revert and/or stabilize the increase in wall thickness.A positive nuclear scintigraphy with hydroxy bisphosphonate bone tracer (99mTc–HPD)is believed to have high sensitivity and specificity for the diagnosis of transthyretin (TTR) amyloid cardiomyopathy. An 85–year–old man with systemic arterial hypertension was admitted because of pre–syncope associated to evidence at Holter monitoring of both bradiarrhythmias(1st degree AV block with PR interval of 300 ms and several episodes of 2nd degree Mobitz type 1 AV block with electrical pause &amp;gt;3 s) and tachyarrhythmias.He suffered from a bilateral carpal tunnel syndrome that underwent surgery 2 years earlier.Routine laboratory tests were normal except for elevated cardiac troponin HS(0.295 mcg/L,nv &amp;lt; 0.014 mcg/L) and N–terminal pro–BNP (384.3 pg/mL,nv = 0–254 pg/mL).Because of clinical suspicion of senile amyloidosis,nuclear scintigraphy with hydroxy bisphosphonate bone tracer(99mTc–HPD)was performed,that revealed a grade 3 myocardial uptake.Serum–urine immunofixation and immunoglobulin free light–chain was negative for monoclonal gammopathy.Neurological examination was unremarkable Genetic test did not show TTR mutation.Thus,a diagnosis of wild–type TTR cardiac amyloidosis was suggested.The patient,in view of Tafamidis treatment,underwent a LV endomyocardial biopsy.Six specimens were drawn from the LV,cut and processed for histology,immunohistochemistry,and transmission electron microscopy. Unexpectedly,histology failed to confirm amyloid deposition but revealed the presence of severely hypertrophied disarrayed cardiomyocytes fragmented in short runs by interstitial and replacement fibrosis,denoting a sarcomeric hypertrophic cardiomyopathy.Congo red staining at polarized light scored negative for areas of apple–green florescence.Immunohistochemistry form transthyretin,kappa/lambda light chain and SAA was negative.Transmission electron microscopy failed to demonstrate the presence of rigid unbranched amyloid fibrils.Thus,a final diagnosis of hypertrophic cardiomyopathy was reached. Coclusion:A positive cardiac signal of bone scintigraphy can occur in other pathologic settings.Future studies are needed to investigate the incidence of false–positive TTR cardiac amyloidosis to bone scintigraphy compared with endomyocardial biopsy.

P351 FATAL RECURRING SYSTEMIC THROMBOEMBOLYSM IN A PATIENT WITH CARDIAC AL AMYLOIDOSIS WITHOUT EVIDENCE OF ATRIAL FIBRILLATION

Abstract Backgound: Cardiac amyloidosis is associated with an increased thromboembolic risk. While the need to anticoagulate patients in atrial fibrillation regardless of the CHA2DS2–VASc score is evident, it is not clear whether and which patients in sinus rhythm should be treated with anticoagulant drugs Case Presentation A 51–year–old man presented with repeated episodes of chest pain and exertional dyspnea. The ECG showed synus rhythm, left–axis deviation, 1st degree AV–block, left anterior hemiblock and no significant anomalies of ventricular repolarisation. Transthoracic echocardiography revealed markedly thickened left ventricular (IN) walls (maximum interventricular septum dimension 18 mm) with a granular–sparkling appearance of the myocardium, bi–atrial enlargement, preserved LV ejection fraction (EF 52%), restrictive mitral flow pattern with a very small A–wave, thickened interatrial septum and atrio– ventricular valves; circumferential pericardial effusion ( maximum 11mm). Laboratory tests showed an increase in troponin and NTproBNP levels and serum and urine immunoelectrophoresis showed a monoclonal component in zone kappa. A periumbilical fat biopsy was negative for amyloidosis so the patient underwent an endomyocardial biopsy which showed positive Congo red, and immunohistochemistry positive for kappa light chains and negative for transthyretin. A diagnosis of cardiac amyloidosis AL was then made and the patient was referred to the hematologist to perform specific therapy. One week after discharge he was hospitalized for acute pain in the lower limbs due to acute thrombosis of the left common femoral artery treated with Fogarty embolectomy. Discharged in therapy with low molecular weight heparin after a few days he was again symptomatic for pain in the lower limbs and went to the emergency room where he died of electromechanical dissociation. Conclusions Our case demonstrates that cardiac AL amyloidosis is associated with an increased thromboembolic risk, irrespective of the presence of atrial fibrillation, for the hematological disease itself and for the infiltration of the atrium by the amyloid substance. This suggests that in selected cases, with reduced A–wave amplitude and evidence of impaired atrial mechanics, empirical anticoagulation should be considered even in sinus rhythm.

Fingolimod-related atrioventricular block in paediatric age group with multiple sclerosis: two case reports.

Multiple sclerosis is a chronic inflammatory and demyelinating disease of the central nervous system, usually seen in young adults. Early onset of multiple sclerosis at age younger than 18 years is called paediatric multiple sclerosis. Unlike adult multiple sclerosis, paediatric multiple sclerosis causes morbidity at earlier ages and often progresses in a relapsing-remitting form. Although fingolimod is an effective drug used as a disease-modifiying therapy agent in relapsing-remitting paediatric multiple sclerosis patients, it can cause dysryhthmia in the early period after first dose. Our first case is a 14-year-old girl with relapsing-remitting paediatric multiple sclerosis patients who was started to take fingolimod treatment. In the fifth hour of the follow-up, asymptomatic bradycardia was seen and the electrocardiogram was consistent with first-degree atrioventricular block. Her rhythm got spontaneously normal after 12 hours. Second case was 13 years old girl. Steroid treatment was started after her first paediatric multiple sclerosis attack. Despite treatment, she had a second attack 2 weeks after the first attack. Therefore, the neurologist switched to fingolimod therapy. Second-degree atrioventriculer block developed after 4 hours from the initiation of therapy. After 8 hours, rhythm regressed to first-degree atrioventricular block then returned to normal up to 13th hours of follow up. The aim of this article is to draw attention to dysrhythmia side effect of fingolimod which can be fatal. Therefore, the clinician must take precautions. Close cardiac rhythm monitoring is mandatory after the initiation fingolimod theraphy.

Asymptomatische Bradykardien

The cardiac implantable electronic device (CIED) is the therapy of choice for management of symptomatic bradyarrhythmias. However, the indication for CIED implantation in the cases of asymptomatic bradycardias should be carefully individualized. Incidental electrocardiographic findings in asymptomatic patients (e.g., low baseline heart rates, higher than first-degree atrioventricular block or longer pauses) may complicate the physician's decision regarding the necessity of CIED implantation. The main reason is the inherit risk of short- and long-term complications with every CIED implantation, i.e., peri-operative complications, risk of CIED infection, lead fractures, and the necessity for lead extraction. Therefore, before opting for, or against, CIED implantation, several factors should be considered in the subset of asymptomatic patients.

Clinical, electrocardiographic, and echocardiographic parameters associated with the development of pacing and implantable cardioverter-defibrillator indication in patients with transthyretin amyloid cardiomyopathy.

This study aimed to identify factors for attention leading to future pacing device implantation (PDI) and reveal the necessity of prophylactic PDI or implantable cardioverter-defibrillator (ICD) implantation in transthyretin amyloid cardiomyopathy (ATTR-CM) patients. This retrospective single-center observational study included consecutive 114 wild-type ATTR-CM (ATTRwt-CM) and 50 hereditary ATTR-CM (ATTRv-CM) patients, neither implanted with a pacing device nor fulfilling indications for PDI at diagnosis. As a study outcome, patient backgrounds were compared with and without future PDI, and the incidence of PDI in each conduction disturbance was examined. Furthermore, appropriate ICD therapies were investigated in all 19 patients with ICD implantation. PR-interval ≥220 msec, interventricular septum (IVS) thickness ≥16.9 mm, and bifascicular block were significantly associated with future PDI in ATTRwt-CM patients, and brain natriuretic peptide ≥35.7 pg/mL, IVS thickness ≥11.3 mm, and bifascicular block in ATTRv-CM patients. The incidence of subsequent PDI in patients with bifascicular block at diagnosis was significantly higher than that of normal atrioventricular (AV) conduction in both ATTRwt-CM [hazard ratio (HR): 13.70, P = 0.019] and ATTRv-CM (HR: 12.94, P = 0.002), whereas that of patients with first-degree AV block was neither (ATTRwt-CM: HR: 2.14, P = 0.511, ATTRv-CM: HR: 1.57, P = 0.701). Regarding ICD, only 2 of 16 ATTRwt-CM and 1 of 3 ATTRv-CM patients received appropriate anti-tachycardia pacing or shock therapy, under the number of intervals to detect for ventricular tachycardia of 16-32. According to our retrospective single-center observational study, prophylactic PDI did not require first-degree AV block in both ATTRwt-CM and ATTRv-CM patients, and prophylactic ICD implantation was also controversial in both ATTR-CM. Larger prospective, multi-center studies are necessary to confirm these results.

The Brugada syndrome: risk stratification.

Thirty years after its first description, the knowledge regarding Brugada syndrome has greatly increased. Spontaneous type 1 ECG pattern (BrECG) is a well-defined prognostic marker in asymptomatic patients and is associated with a double risk of arrhythmic events during follow-up as compared to drug-induced ECG pattern. Due to the extreme variability of the ECG pattern over time, the spontaneous type 1 BrECG must be carefully sought, not only through periodic ECGs but especially with repeated 12-lead 24-h Holter monitoring, with V1 and V2 electrodes placed also on the second and third intercostal space, in order to explore the right ventricular outflow tract. 12-lead 24-h Holter should also be performed in all the patients with a dubious BrECG pattern even before the drug challenge with sodium channel blockers, which carries a low but definite risk of complications. In addition to spontaneous type 1, other electrocardiographic markers of increased arrhythmic risk have been described, such as first-degree AV block, QRS fragmentation, S wave in lead I and II, and increased QRS duration. The electrophysiological study in asymptomatic patients with a spontaneous ECG Brugada pattern is still under jury and further studies need to clarify its precise role.

SYNCOPE: A RARE PRESENTATION OF LYME DISEASE

BackgroundLyme disease is one of the most common vector-borne illnesses in the United States. It is caused by Borrelia burgdorferi infection transmitted via the Ixodes tick. Rarely, it can progress to early disseminated Lyme disease with cardiac or neurologic manifestations, or both. Case ReportA 41-year-old previously healthy man presented to the emergency department (ED) by ambulance after an episode of syncope. Electrocardiogram revealed right bundle branch block with borderline first-degree atrioventricular nodal block. During his admission he was noted to have night sweats and elevated procalcitonin. Infectious workup revealed positive Borrelia enzyme-linked immunosorbent assay. Further testing revealed positive Borrelia immunoglobulin M with negative immunoglobulin G, indicating a recent infection.Why should an emergency physician be aware of this? Lyme disease should be on the differential for patients presenting with vague, flu-like symptoms in the summer months in endemic areas. Treatment of early Lyme disease with doxycycline can prevent progression to secondary Lyme, which can present as a true cardiac or neurologic emergency.

Evaluation of echocardiographic abnormalities in children with end-stage renal disease (CKD stage 5): A single-center experience

BackgroundChronic Kidney disease (CKD) stage V might gradually induce the occurrence of morphological and functional cardiac disturbances; these cardiac disturbances make up supplementary risk factors. ObjectiveThe study aimed to describe electrocardiographic (ECG) and Echocardiographic (Echo) findings in dialysis patients. Also, to define the correlation between Echo findings and dialysis modality. MethodsWe studied 27 dialysis patients aged 3 years and one month to 25 years (163 ± 77 months. Boys accounted for 59.3 % of the patients. The modality of dialysis was peritoneal dialysis (PD) in 33.3 % and hemodialysis (HD) in 51.9 % of cases. Four patients (14.8 %) had undergone both modalities at different times. All patients were taken ECG and Doppler 2D echocardiography (Echo). Assessment of LV systolic function was done according to ejection fraction (EF) and categorized as normal (≥55 %), mild systolic dysfunction (45–54 %), moderate systolic dysfunction (30–44 %), and severe systolic dysfunction (<30 %) . ResultsThe most common abnormalities in ECG were left ventricular hypertrophy (70.4 %), prolonged QTC interval (33.3 %), and first-degree atrioventricular block (25.9 %), respectively. Based on the ejection fraction, 40.7 %, 33.3 %, and 26 % of the patients had normal systolic function, mild systolic dysfunction, and moderate systolic dysfunction, respectively. Also, left ventricular (LV) volume in both diastole and systole were significantly lower in PD compared to HD cases (P = 0.006 and 0.004). ConclusionsWe found that abnormal findings in ECG are common among pediatric dialysis patients. Additionally, Echo's assessment noted that systolic dysfunction was common. Significantly lower LV volume in diastole and systole in PD compared to HD cases may suggest that PD patients encounter less pressure and volume loads. These findings can be considered a positive point of PD modality.