Significant Arrhythmias Research Articles

Association of Autonomic Balance With Phone Call Duration in Healthy Individuals.

Background This study aimed to estimate the association of autonomic balance with the duration of phone calls in healthy individuals. Methodology A total of 30 subjects aged between 18 and 30 years without any established systemic disease and using mobile phones for more than five years with minimum daily usage of 30 minutes were included in this analytical study. Heart rate variability (HRV) was recorded using a three-channel physiograph (AD Instruments South Asia (India) Pvt. Ltd., New Delhi, India) with the software LabChart PROV8.1.8 with HRV Module version 2.0.3 for 10 minutes. Time domain parameters were recorded in terms of the standard deviation of normal to normal interval (SDNN), root mean square of successive differencesbetween normal heartbeats (RMSSD), R-R intervals greater than 50 ms (pRR50), and mean heart rate (MHR), and frequency domain parameters were total power,low-frequency power (LF), high-frequency power (HF), and the ratio of low-frequency to high-frequency power (LF/HF). HRV was recorded three times in each subject that included baseline HRV, HRV during the use of a mobile phone, and HRV after the use of a mobile phone. Results A total of 30 subjects (14 males and 16 females) participated in this study. The mean age of participants was 31.93 ± 8.59 years (32.07 ± 9.87 years for males, and 31.81 ± 7.64 years for females). There were no findings of significant arrhythmiain any of the participants. There was a significant difference in pRR50 on comparing all three phases (p = 0.036). However, there was no significant variation in other parameters such as very low frequency (VLF, ms2), VLF (%), LF (ms2), LF (%), HF (ms2), HF (%), LF/HF, SDNN (ms), RMSSD (ms), Poincare plot standard deviation perpendicular to the line of identity (ms), Poincare plot standard deviation along the line of identity (ms), systolic blood pressure (mmHg), and diabolic blood pressure (mmHg) during, before, and after exposure to mobile phone calls. There was no significant difference in the value of all parameters between males and females (p < 0.05). Conclusions Mobile phone calls may influence HRV and autonomic balance. This change may be affected by the electromagnetic field and by speaking as well.

Changes of ECG parameters after BNT162b2 vaccine in the senior high school students.

The purpose of this study is to determine the ECG parameter change and the efficacy of ECG screening for cardiac adverse effect after the second dose of BNT162b2 vaccine in young population. In December 2021, in cooperation with the school vaccination system of Taipei City government, we performed a ECG screening study during the second dose of BNT162b2 vaccines. Serial comparisons of ECGs and questionnaire survey were performed before and after vaccine in four male-predominant senior high schools. Among 7934 eligible students, 4928 (62.1%) were included in the study. The male/female ratio was 4576/352. In total, 763 students (17.1%) had at least one cardiac symptom after the second vaccine dose, mostly chest pain and palpitations. The depolarization and repolarization parameters (QRS duration and QT interval) decreased significantly after the vaccine with increasing heart rate. Abnormal ECGs were obtained in 51 (1.0%) of the students, of which 1 was diagnosed with mild myocarditis and another 4 were judged to have significant arrhythmia. None of the patients needed to be admitted to hospital and all of these symptoms improved spontaneously. Using these five students as a positive outcome, the sensitivity and specificity of this screening method were 100% and 99.1%, respectively. Conclusion: Cardiac symptoms are common after the second dose of BNT162b2 vaccine, but the incidences of significant arrhythmias and myocarditis are only 0.1%. The serial ECG screening method has high sensitivity and specificity for significant cardiac adverse effect but cost effect needs further discussed. What is Known: • The incidence of cardiac adverse effects was reported to be as high as 1.5 per 10 000 persons after the second dose BNT162b2 COVID-19 vaccine in the young male population based on the reporting system. What is New: • Through this mass ECG screening study after the second dose of BNT162b2 vaccine we found: (1) The depolarization and repolarization parameters (QRS duration and QT interval) decreased significantly after the vaccine with increasing heart rate; (2) the incidence of post-vaccine myocarditis and significant arrhythmia are 0.02% and 0.08%; (3) The serial ECG screening method has high sensitivity and specificity for significant cardiac adverse effect.

Heart Rate Estimation from Incomplete Electrocardiography Signals.

As one of the most remarkable indicators of physiological health, heart rate (HR) has become an unfailing investigation for researchers. Unlike many existing methods, this article proposes an approach to implement short-time HR estimation from electrocardiography in time series missing patterns. Benefiting from the rapid development of deep learning, we adopted a bidirectional long short-term memory model (Bi-LSTM) and temporal convolution network (TCN) to recover complete heartbeat signals from those with durations are less than one cardiac cycle, and the estimated HR from recovered segment combining the input and the predicted output. We also compared the performance of Bi-LSTM and TCN in PhysioNet dataset. Validating the method over a resting heart rate range of 60−120 bpm in the database without significant arrhythmias and a corresponding range of 30−150 bpm in the database with arrhythmias, we found that networks provide an estimated approach for incomplete signals in a fixed format. These results are consistent with real heartbeats in the normal heartbeat dataset (γ > 0.7, RMSE < 10) and in the arrhythmia database (γ > 0.6, RMSE < 30), verifying that HR could be estimated by models in advance. We also discussed the short-time limits for the predictive model. It could be used for physiological purposes such as mobile sensing in time-constrained scenarios, and providing useful insights for better time series analyses in missing data patterns.

Фибрилляция предсердий и инфаркт миокарда: клинико-патогенетические взаимосвязи и влияние на прогноз

Aim. To summarize the contemporary literature data on the clinical and pathogenic correlations between atrial fibrillation (AF) and myocardial infarction (MI). Key points. AF is one of the most common and clinically significant arrhythmias. In patients with MI, this type of arrhythmia is recorded for the first time in 6 % to 21 % of cases. The review discusses the incidence of AF in patients with various forms of coronary heart disease, mechanisms of arrhythmogenesis, and the ways to predict poor outcomes in a group of patients with AF who had a history of MI. Conclusion. The mechanisms of AF development in patients with MI need better understanding. AF impact on the short-term and long-term prognosis for patients with MI should be studied better, and modern tools for the classification of poor outcome risks should be developed. Keywords: atrial fibrillation, myocardial infarction, predictive significance.

Arrhythmia and Heart Rate Variability during Long Interdialytic Periods in Patients on Maintenance Hemodialysis: Prospective Observational Cohort Study.

Sudden cardiac death among hemodialysis patients is related to the hemodialysis schedule. Mortality is highest within 12 h before and after the first hemodialysis sessions of a week. We investigated the association of arrhythmia occurrence and heart rate variability (HRV) using an electrocardiogram (ECG) monitoring patch during the long interdialytic interval in hemodialysis patients. This was a prospective observational study with 55 participants on maintenance hemodialysis for at least six months. A patch-type ECG monitoring device was applied to record arrhythmia events and HRV during 72 h of a long interdialytic period. Forty-nine participants with sufficient ECG data out of 55 participants were suitable for the analysis. The incidence of supraventricular tachycardia and ventricular tachycardia did not significantly change over time. The square root of the mean squared differences of successive NN intervals (RMSSD), the proportion of adjacent NN intervals differing by >50 ms (pNN50), and high-frequency (HF) increased during the long interdialytic interval. The gap in RMSSD, pNN50, HF, and the low-frequency/high-frequency (LF/HF) ratio between patients with and without significant arrhythmias increased significantly over time during the long interdialytic interval. The daily changes in RMSSD, pNN50, HF, and the LF/HF ratio were more prominent in patients without significant arrhythmias than in those with significant arrhythmias. The electrolyte fluctuation between post-hemodialysis and subsequent pre-hemodialysis was not considered in this study. The study results suggest that the decreased autonomic response during interdialytic periods in dialysis patients is associated with poor cardiac arrhythmia events.

In-Hospital Outcome of Patients with ST - T Changes in Non ST Segment Elevation Myocardial Infarction

Background: This cross sectional observational study was carried out with an aim to find out in-hospital outcome in patients with ST-T changes in non-STsegment elevation myocardial infarction (NSTEMI). Methods: This cross sectional observational study was carried out in the department of cardiology, National Institute of Cardiovascular Diseases, Dhaka, Bangladesh from January 2014 to December 2014. A total of 120 patients with NSTEMI were the study population. Patients were divided into two groups on the basis of ST-T changes, 60 patients with ST-T changes were in group I and 60 patients without ST-T changes were in group II. Result: In this study, the mean age was 54.2 ±14.2 years. Male female ratio was 2.75:1 among the study population. There was no statistically significant difference in mean BMI among the two groups. Smoking was the most common risk factor present (47.5%). Smoking was found significantly more in Group I than patients of group II (p=0.02). Serum troponin I was found significantly raised in group I (42.8±5.5 vs 10.5±8.3, p=0.002). The mean left ventricular ejection fraction (LVEF) of patients in group I was significantly lower than group II (52.1±9.1% vs 61.7±6.9%. p=0.001). Adverse in-hospital outcome was significantly more in group I than group II (48.3% vs 26.7%, p=0.01). Recurrent angina pectoris, STEMI, significant arrhythmia, acute LVF and cardiogenic shock were also more in group I than in group II. In-hospital mortality was noted in group I patients with both ST segment depression and T wave inversion (6.7%). Emergency revascularization was done more commonly in patients of group I (6.7%). The mean duration of hospital stay was statistically significant between the groups (6.24±2.58 vs 4.44±1.71 days. p&lt;0.05)). Multivariate logistic regression analysis revealed that ST-T changes are an independent predictor for developing adverse inhospital outcome in patients with non-ST-segment elevation myocardial infarction. Conclusion: The ST-segment depression and T-wave inversion on admission ECG are important predictors of outcome in patients with NSTEMI. The ST-segment depression on admission ECG of patients with NSTEMI is associated with higher adverse in hospital outcome and mortality. Bangladesh Heart Journal 2022; 37(2): 99-106

Implantable Loop Recorder with Long Sensing Vector: Safety, Acceptability, and Sensing Performance in Pediatric Patients

Implantable loop recorders (ILRs) are effective tools for detecting arrhythmias by long-term continuous heart rhythm monitoring. Benefits have been demonstrated even in pediatric patients. ILR with a long sensing vector has recently been designed to improve signal quality in terms of P wave visibility and R wave amplitude. However, there are no data on its use in pediatric patients. We considered a series of pediatric patients implanted with a long sensing vector ILR. Sensing performance, including R wave amplitude and P wave visibility, device-related complications, and diagnostic yield were collected. During follow-up, each patient guided by his/her parents/guardians was also asked to complete a brief questionnaire to assess patient acceptability of the device. Twenty-five consecutive pediatric patients (mean age 11.3 ± 3.5years, 72% male) were enrolled. The insertion success rate was 100% on the first attempt with no complications. The median amplitude of the R wave was 1.15mV (interquartile range, 1.01-1.42) with no significant differences between patients aged ≤ or > 10years (p = 0.726) and between female and male (p = 0.483). P wave was classified as 'always visible' in 24/25 patients (96%). ILR was generally well accepted and tolerated by all involved patients. During a median follow-up of 297days (117-317), we achieved in 5 patients a correlation between symptoms and rhythm disorders (20%)and ruled out significant arrhythmias in 6 symptomatic children (24%). Long sensing vector ILR showed to be well accepted, with good signal quality and an excellent safety profile even in pediatric patients.

Investigation of proarrhythmic effect of high sugammadex doses: an experimental animal study

BackgroundStudies on higher doses of sugammadex effect on QT interval and leading arrhythmia have been limited. In this study, we aimed to investigate possible proarrhythmic effect of higher doses of sugammadex in conditions that required urgent reversal of neuromuscular blockade during general anesthesia in an experimental animal model.MethodsIt was experimental animal study. Total of 15 male New Zealand rabbits were randomly divided into three groups for low (4 mg/kg, n = 5), moderate (16 mg/kg, n = 5), and high dose of sugammadex (32 mg/kg, n = 5). All rabbits were premedicated by intramuscular ketamine 10 mg/kg, and general anesthesia was inducted by intravenous injection of 2 mg/kg of a propofol, 1 mcg/kg fentanyl, and 0.6 mg/kg rocuronium injection. Airway was provided by V-gel rabbit and connected to anesthetic device and ventilated at about 40 cycle/min and 10 ml/kg; oxygen 50% plus air 50% mixture was used with 1 MAC isoflurane to maintain anesthesia. Electrocardiographic monitorization and arterial cannulation were provided to follow-up mean arterial pressure and for arterial blood gas analyses. Intravenous sugammadex in three different doses were injected at 25th min of induction. After observing adequate respiration of all rabbits, V-gel rabbit was removed. Parameters and ECG recordings were taken basal value before induction and at the 5th, 10th, 20th, 25th, 30th, and 40th min to measure corrected QT intervals and were stored on digital media. QT interval was calculated as the time from the beginning of the Q wave to the end of the T wave. Corrected QT interval was calculated according to the Bazett’s formula. Possible adverse effects were observed and recorded.ResultsIn all three groups, there was no significant statistical difference in mean arterial blood gases parameters, arterial pressures, heart rates, and Bazett QTc values, and no serious arrhythmia was recorded.ConclusionWe found in animal study that low, moderate, and high doses of sugammadex did not significantly altered corrected QT intervals and did not cause any significant arrhythmia.

A service evaluation of Zio XT: the Liverpool experience

Abstract Introduction The Zio XT is an adhesive, ambulatory heart rhythm monitoring device that can be worn for up to 14 days. It can be fitted by patients and utilises an Artificial Intelligence-based algorithm for rhythm analysis, offering potential convenience, accuracy and efficiency compared to Holter monitors. However, there is a lack of data regarding its efficacy and long-term impact. Thus, until further evidence ensues, NICE guidelines recommend Zio XT as a potential option for those requiring prolonged rhythm monitoring. Purpose We evaluated the efficacy of Zio XT for heart rhythm monitoring compared to Holter monitors. Methods 200 sequential patients that had Holter monitors and 204 that had Zio XT were included. Zio cases were randomly selected over 6 months to avoid the learning curve effect. Primary outcomes included time to results and the arrhythmia detection rate. Secondary outcomes included the proportion of patients that had heart rhythm monitoring in the 12 months preceding their investigation, those who required further tests as well as rates of outpatient appointments (OPAs) for device fitting and follow-up, and procedures such as device implantation and ablations. Results Data from 22 (10.8%) Zio patches was unavailable due to these being lost/not returned/unwearable, thus post-investigation outcomes were analysed for 182 Zio and 200 Holter cases. Zio XT was associated with a significantly shorter time to results compared to Holter monitors (median time: 21 days (interquartile range (IQR) 18–25) vs. 46 days (IQR 37.3–87.8), p&amp;lt;0.001), and a higher significant arrhythmia detection rate (55.4% vs. 17.5%, p&amp;lt;0.001). 26.5% of Zio patients had heart-rhythm monitoring in the preceding 12 months, compared to the 14.5% in the Holter group, p=0.003, with 55.8% having Holters and 28.8% having Zios previously, in the Zio group. A higher proportion of Zio recipients also required repeat tests (19.4 vs. 8.5%, p=0.002). Reasons for this included post-intervention monitoring (44.1%), lack of results due to devices being lost/faulty/not returned (41.2%) and a lack of diagnosis (14.7%). Zio monitoring was associated with a significant reduction in the need for OPAs for fitting (0.5% vs. 96%, p&amp;lt;0.001) and follow-up (70.1% vs. 87.0, p&amp;lt;0.001), and resulted in a significant increase in ablations (5.9% vs. 1.0%, p=0.005) but not device implantations (5.9% vs. 3.9, p=0.209). Conclusion Our findings indicate that Zio XT is associated with a statistically significant reduction in time to results, higher arrhythmia detection rate and a reduced need for OPAs. We demonstrated a higher rate of both Holter and Zio testing before and Zio testing after these investigations. We postulate that this has partly been due to a learning curve effect with the introduction of a new technology compared to the Holter which has been in use for many decades. Further large-scale evaluation is recommended to yield vital information on management pathways and cost efficacy. Funding Acknowledgement Type of funding sources: None.

1102 ARRYTHMOGENIC CARDIOMYOPATHY: LESSONS FROM A LARGE FAMILY

Abstract Background Arrhythmogenic cardiomyopathy is a genetically-inherited cardiomyopathy. PKP2 mutations are the most common cause of the disease, associated with conventional ARVC phenotype. Case presentation We presented a 14 years old sportswoman admitted to our emergency department for cardiac arrest-related to ventricular fibrillation. The patient was asymptomatic leading up to cardiac arrest. At admission, she met the diagnosis of AC with bi-ventricular involvement (T negative waves in V1-V6 and inferior leads; severe biventricular dysfunction with fibrofatty replacement involving both ventricles). Family history revealed that her cousin, a 15 years competitive athlete, received a recent diagnosis of ARVC, wherein pathogenetic variant p.Tyr857_Lys859 in heterozygosity in the PKP2 gene was found. As expected, the index case presented the same mutations in PKP2 gene, and no other mutations were found. Implanted cardioverter defibrillator (ICD) and strength follow-up, including heart failure management, was performed. Cascade screening of family members allowed us to identify 19 mutations carriers. Of these, 5 patients were identified to have disease expression. The first to be studied was her 9 years old sister, who involved in high level of sport activities. She presented abnormal ECG with negative T waves in V2-V4, significance burden of premature ventricular complex (PVC &amp;gt;500/24 h) with mild right ventricle dilatation. Of others family members, four patients presented early signs of myocardial disease and significant arrhythmias burden. Except for one patient, all these members were involved in amateur sport activities. Two members had signs of left ventricle (LV) involvement (inverted T waves in leads V4–V6 and inferior leads, LV wall motion abnormalities and late enhancement), whereas one patient (P3) showed a fulfilled ARVD. Three patients presented significant PVC on 24-hour ambulatory ECG monitoring (PVC &amp;gt;500/24 h) (P2, P3 and P5). The arrhythmic burden was more pronounced in two young patients having a sports activity (P2 and P3). This trend was also confirmed at exercise testing. Except for one patient, these findings appear to be related to sport activity, even if this is no high-intensity activity. Among other carriers of pathogenic mutation, three patients showed ECG abnormalities in infero-lateral leads and significance PVC at 24-hour ECG monitoring in absence of other findings related-cardiomyopathy. All family members carried PKP2 mutation were restricted in sports activities, and, in patients presented early disease and arrhythmogenic burden, treatment with beta-blockers was started. Conclusion In this family presenting PKP2 mutation, heterogenicity of disease expression and a close relationship with sport activity was found. This large family case encourages future ACM studies to better understand disease expression and their relationship with sports activity across the entire ACM phenotypic spectrum and ages. Also, this case underscores the importance of early familiar screening, including children involved high-level of sports activity.

198 ROLE OF CARDIAC MAGNETIC RESONANCE IMAGING IN ARRHYTMICH RISK STRATIFICATION

Abstract Introduction Danon disease (DD) is a rare multi-systemic disorder firstly described by Danon et al. in 1981 and characterized by a triad consisting with hypertrophic cardiomyopathy, skeletal myopathy, and intellectual disability. It is an inherited dominant X-linked condition, due to mutations in the lysosome-associated membrane protein 2 (LAMP2) gene. Typically, males present a more severe phenotype with earlier onset and rapid heart failure progression with extracardiac manifestations; female patients manifest a milder phenotype with later onset and isolated cardiac involvement. Female carriers may develop dilated cardiomyopathy (DCM). In recent years, it has been described a severe arrhythmogenic phenotype, particularly in women, with a high risk of sudden cardiac death (SCD). Case presentation Case 1 is a 16 y.o. woman referred to our outpatient cardiomyopathies clinic, diagnosed with left ventricle (LV) hypertrophy on the basis of ECG and echocardiography, performed in 2016, in view of cutaneous nevus surgical exeresis. At echocardiographic evaluation we found an asymmetric LV hypertrophy with preserved LV ejection fraction (LVEF 65%). A cMRI was performed, showing mild LV thickening and left ventricular hypertrabeculation morphology, mainly in the LV lateral wall, but not all criteria for LV noncompaction (NC) were satisfied. There was no late gadolinium enhancement (LGE) accumulation. She underwent a genetic screening with inconclusive results, so we started a clinical outpatient follow-up showing no significant arrhythmias at ECG Holter and no limitation of physical activities. In 2021, when she was 21 yo, her father died suddenly and no autoptic examination was performed. A genetic exam was repeated, highlighting a LAMP2 gene mutation. In 2016 her 3 years older sister, Case 2, underwent a familiar screening. She had a long history of mild dyspnea occurring during exertion. Echocardiography showed asymmetric hypertrophy with marked thickening of infero-lateral wall (25 mm,) with normal systolic function (EF 70%). She underwent a cMRI, highlighting diffuse asymmetric hypertrophy (max 24 mm) with LGE in lateral wall and lower septum. First genetic test was nonconclusive but after her father's death another test was performed, demonstrating LAMP2 gene mutation. In 2021 a follow-up cMRI showed markedly reduced myocardial thickness of the apex, with a pattern of noncompaction myocardial. We found a LVEF at lower limits, depressed longitudinal function (MAPSE 8 mm) and manly severe progression of fibrotic degeneration. ECG Holter revealed premature ventricular complex, in absence of nonsustained ventricular tachycardia. Following the evolution of fibrosis, cardioverter defibrillator (ICD) implantation was performed. Case 1 was clinically stable during strict follow-up. Conclusion Cardiac magnetic resonance imaging (cMRI) may be useful in arrhythmic risk stratification, accurate systolic dysfunction evaluation, and proper timing and indication for ICD implantation.

941 SARCOIDOSIS: THE IMPORTANCE OF MULTIMODALITY IMAGING

Abstract A 55-years old sporty man, without any cardiovascular risk factors nor previously known cardiological history, presented for a cardiological evaluation due to extra-systolic palpitations and dyspnea. The ECG documented a new onset of right bundle branch block, left anterior fascicular block and first degree of atrio-ventricular block. Echocardiography revealed severe left ventricular (LV) systolic dysfunction (LV ejection fraction -EF- 34%), showing also right ventricular (RV) dilatation and disfunction. A 24-hour Holter monitoring did not show any significant arrhythmias and maximal stress test did not reveal any ECG changes nor arrhythmias. Cardiac magnetic resonance (CMR) confirmed the presence of severe biventricular dysfunction; multiple areas of edema and late gadolinium enhancement (LGE) were observed, with ischemic and nonischemic pattern and extensive involvement of the RV and the interventricular septum. In the suspicion of cardiac sarcoidosis a 18-fluorodeoxyglucose positron emission tomography (PET) was performed, confirming the presence of an inflammatory cardiomyopathy in an active phase. A subsequent endomyocardial biopsy was performed, which demonstrated the presence of non-caseating granulomas, signs of inflammation and fibrosis, consistent with the diagnosis of cardiac sarcoidosis. No signs of extra-cardiac involvement were present. The patient started anti-inflammatory therapy with Prednisone and Metotrexate, along with anti-neurohormonal therapy. However, due to a significant increase in ventricular arrhythmic burden, an implantable cardioverter defibrillator was placed during early follow-up, and Amiodarone therapy was started. After 5 months of medical therapy, PET scan showed a marked reduction of cardiac inflammation and echocardiography showed a significant LVEF improvement (from 34% to 43%). After slow tapering of steroid therapy Prednisone was stopped, whereas Metotrexate, Amiodarone and anti-neurohormonal therapy were maintained. Follow-up is still ongoing without clinical events. Sarcoidosis is a systemic inflammatory disease characterized by the presence of non-caseating granulomas in multiple organs. Cardiac involvement is associated with higher incidence of heart failure, ventricular arrhythmias and all-cause mortality. Isolated cardiac involvement is rare but associated with worse prognosis. Multimodality imaging is of paramount importance for the diagnosis and monitoring therapy.

Clinical Outcomes of a Non-Compliant Balloon Dilatation Catheter: MOZEC™ NC Study

The present study sought to assess the clinical outcomes of the Mozec™ Non-compliant (NC) Rx PTCA balloon dilatation catheter (BDC) (Meril Life Sciences Pvt. Ltd., Vapi, India) for dilatation of coronary lesions. This was a post-marketing, single-centre, single-arm, retrospective study. In total, 57 patients who had undergone post-dilatation with the Mozec™ NC Rx PTCA balloon dilatation catheter were evaluated. The primary endpoint was procedural success defined as (i) successful delivery of the investigational device to and across the target lesion; (ii) successful inflation, deflation, and withdrawal of the investigational device; (iii) absence of vessel perforation, flow-limiting vessel dissection, increase in thrombolysis in myocardial infarction (TIMI) flow from baseline, clinically significant arrhythmia requiring medical treatment; and (iv) achievement of final TIMI flow grade 3 after percutaneous coronary intervention of the target lesion after single or multiple attempts to cross the target lesion. Procedural success was achieved in 57 (100%) patients. There were no incidences of major adverse cardiac events (MACE)/target lesion failure (TLF). Mozec™ NC Rx PTCA balloon dilatation catheter has demonstrated favourable outcomes for the dilatation of routine and complex coronary lesions in a small cohort, as evidenced by its 100% procedural success rate and absence of MACE.

Arrhythmogenic cardiomyopathy is under-recognized in end-stage pediatric heart failure: A 36-year single-center experience.

Although ventricular failure is a late finding in adults with AC, we hypothesize that this is a presenting symptom in pediatric heart failure patients who undergo HT and that their ventricular arrhythmia burden could differentiate AC from other cardiomyopathies. We performed a single-center retrospective cohort study reviewing 457 consecutive pediatric (≤18 years) HT recipients at our institution. Explanted hearts were examined to establish the primary diagnosis, based on pathologic findings. Demographic and clinical variables were compared between AC versus non-HCM cardiomyopathy cases. Forty-five percent (n= 205/457) had non-HCM cardiomyopathies as the underlying primary diagnosis. Ten cases (10/205=4.9%) were diagnosed with AC. All 10 had biventricular disease. In 8/10 patients (80%), AC diagnosis was unrecognized pre-HT. Compared with non-AC cardiomyopathies, the AC group was older at diagnosis (9.3 years vs. 4.3 years, p= .012) and transplant (11.1 years vs. 6.5 years, p= .010), had more ventricular arrhythmias (80.0% vs 32.8%, p= .003), and required more anti-arrhythmic use (80.0% vs 32.3%, p= .001). Genetic testing yielded causative pathogenic variants in all tested individuals (n= 5/5, 100%). AC is often an unrecognized cardiomyopathy pretransplant in children who undergo HT. Pediatric non-HCM phenotypes with heart failure who have a significant ventricular arrhythmia burden should be investigated for AC.

Influence of the levels of thyroid hormones on the result of radiofrequency ablation for atrial fibrillation: literature review

Introduction. Atrial fibrillation is one of the most common, clinically significant cardiac arrhythmias and is associated with an increased risk of mortality, hospitalization, and deterioration in the quality of life. The prevalence of atrial fibrillation averages 1% and tends to increase with age. It is well known that aberrations of thyroid hormones have a proarrhythmogenic effect and increase the risk of cardiovascular disease. Currently, radiofrequency ablation is actively used to treat atrial fibrillation, which in most cases has high efficiency and lasting effect. However, recurrence of atrial fibrillation may occur in some patients even after radiofrequency ablation. It is known that thyroid function is closely related to the success of radiofrequency ablation and risk of relapse of atrial fibrillation after the procedure. The aim of this literature review is to determine what is already known about the effect of thyroid and thyroid-stimulating hormones levels on the outcome of radiofrequency ablation of atrial fibrillation and to analyze previous studies. Materials and methods. A complete review of the literature on atrial fibrillation and the relationship between thyroid and thyroid hormones and recurrence of atrial fibrillation after radiofrequency ablation was conducted to examine the effect of hormone levels on the success of radiofrequency ablation and recurrence of atrial fibrillation after the procedure. Results. Data from a significant number of studies suggest that the incidence of atrial fibrillation recurrence remains high after radiofrequency ablation and that thyroid hormones affect the success of radiofrequency ablation even within normal ranges. Evidence may also suggest that patients with thyroid dysfunction, even in the presence of subclinical forms, may require better monitoring of thyroid function prior to the procedure, which may reduce the incidence of atrial fibrillation recurrence. Conclusions. It should be noted that the assessment and correction of all modifying risk factors before radiofrequency ablation can prevent recurrence of supraventricular paroxysmal arrhythmias, improve the prognosis and overall quality of life in patients in this group.

Prevalence of cardiac arrhythmias among patients undergoing chronic hemodialysis

Aim. To evaluate the prevalence of arrhythmias in patients undergoing chronic hemodialysis, to characterize the arrhythmia types in relation to the dialysis procedure and to determine their relationship with clinical findings and echocardiographic characteristics.Material and methods. The study involved 152 patients with kidney failure undergoing chronic hemodialysis. All patients underwent an assessment of dialysis parameters, collection of clinical data, and 48-hour Holter monitoring. In addition, 93 patients underwent an echocardiography with an assessment of left ventricular (LV) mass index, LV ejection fraction, left atrial (LA) volume index, E/e’, cardiac output and preload, which was defined as increased LV filling pressure (E/e’ &gt;12) and LA enlargement (LA volume index &gt;30 ml/m2).Results. Among the 152 examined patients, premature supraventricular and ventricular contractions (PVCs) were observed in almost all patients, while 41% had paroxysmal supraventricular tachycardia. Clinically significant arrhythmias included persistent atrial fibrillation (AF) in 8,6% of patients, paroxysmal AF in 3,9%, nonsustained ventricular tachycardia in 19,7%, bradycardia in 4,6%, second-degree atrioventricular block in 1,3% and third-degree atrioventricular block among 2,6%. PVCs were more common on dialysis days, while tachyarrhythmias were more common during dialysis and in the immediate post- dialysis period. Older age (odds ratio (OR) 10 years older, 1,53; 95% confidence interval (CI): 1,15-2,03; P=0,003), lower cardiac output (OR 1 L/min more, 0,66; 95% CI: 0,44-1,00; P=0,05) were independently associated with clinically relevant arrhythmias.Conclusion. In patients on chronic hemodialysis, older age, increased preload and lower cardiac output are independently associated with clinically relevant arrhythmias. In addition, a positive association between increased LV mass index and AF episodes has been demonstrated. Lower cardiac output had positive correlation with AF and ventricular arrhythmias.

A Phase II Study of the Combination of Decitabine, Venetoclax and Ponatinib in Patients with Chronic Myeloid Leukemia (CML) in Myeloid Blast Phase (MBP) or Philadelphia-Chromosome Positive (Ph+) Acute Myeloid Leukemia (AML)

Background: Advanced phases of CML and Ph+ AML are therapeutic challenges. Preclinical and early clinical data have shown that combining venetoclax (VEN) with a tyrosine kinase inhibitor (TKI) works synergistically in Ph+ myeloid leukemias (Leonard et. al., Sci Transl Med 2016 and Maiti et. al., Acta Haematologica 2020). We hypothesized that combining a potent TKI (ponatinib) with a hypomethylating agent plus VEN backbone might lead to high rates of response that could facilitate potentially curative allogeneic stem cell transplantation (SCT). Methods: This is a single-arm phase II study (NCT04188405) that enrolled patients (pts) ≥ 18 years (yrs) of age with newly diagnosed or relapsed/refractory advanced phase CML [CML in accelerated phase (CML-AP) or CML-MBP] or Ph+ AML. Pts were required to have an ECOG PS ≤ 3 and adequate liver and renal function. Pts with clinically significant cardiovascular comorbidities, including recent or active myocardial infarction, heart failure, clinically significant arrhythmias, cerebrovascular accident, venous thromboembolism or uncontrolled hypertension were excluded. Pts were treated with a combination of decitabine (DAC) (20 mg/m2/day) x 5 days, VEN (400 mg equivalent dose/day) x 21 days, and ponatinib (45mg/day) x 21 days in cycle 1 and then continuously in cycle 2+ (Fig. 1A). Ponatinib was reduced to 30mg/day for pts in CR/CRi and to 15 mg/day for pts in CMR. For C1 only, pts who had not received ponatinib prior to trial initiation had a lead-in phase of ponatinib monotherapy for 7 days before the initiation of DAC and VEN. Cycles were repeated every 28 days, as permitted by peripheral blood count recovery, and pts could receive a maximum of 24 cycles. Intrathecal prophylaxis with 4 doses of cytarabine was recommended. The primary objective was to determine the overall response rate of the regimen. Results: From July 2020 to May 2022, 12 pts were treated, 1 pt with de novo Ph+ AML and 11 pts with advanced phase CML (2 pts with CML-AP and 9 pts with CML-MBP). The median age of the pts was 45 yrs (range, 28-71 yrs). Three pts (25%) had received no prior therapy (1 each with Ph+ AML, CML-AP and CML-MBP). Nine pts (75%) had prior TKI exposure (including prior ponatinib exposure in 4 pts) and 3 pts (25%) had received prior chemotherapy. Eleven pts (92%) had the p210 transcript of BCR::ABL1. Eight pts (67%) had additional cytogenetic abnormalities, including 5 pts with complex karyotype and 2 pts with a MECOM rearrangement. 4 of 11 tested pts (36%) had an ABL1 kinase domain mutation detected at enrollment (T315I, Q252H, L384M and E255K in 1 pt each). The median number of cycles received was 2 (range, 1-7). Nine pts (75%) responded, including 1 with CR, 3 with CRi and 5 with MLFS as best response. The CR/CRi rate was 33%. Best response was achieved after cycle 1 in 7 of 9 responders. Both pts with CML-AP responded, and 2 of 3 pts without prior TKI exposure responded. One of the responders achieved an MMR. After a median follow-up of 9.1 months, the median overall survival (OS) is 9.5 months, and the estimated 9-month OS is 64%. The median relapse-free survival 5.1 months. Among the 9 responders, 3 pts are in continuous response without SCT, 1 pt proceeded to SCT and is still alive, 3 pts did not undergo SCT and relapsed (2 of whom had a complex karyotype), 1 pt died in MLFS, and 1 pt was lost to follow-up (Fig. 1B). The one pt who proceeded to SCT achieved MLFS as best response pre-SCT and remains in MRD-negative CR 22 months post-SCT. The toxicity profile of the regimen was similar to historical expectations with DAC plus VEN. One pt developed grade 3 mucositis, which was considered related to study therapy. No grade 4-5 related non-hematological adverse events were observed. Related grade 1-2 non-hematological adverse events included rash in 2 pts, and transaminitis, creatinine elevation and mucositis in 1 pt each. Of the 8 pts who received > 1 cycle of study therapy, 4 pts had delay (>1 week) in initiation of a subsequent treatment cycle due to cytopenias; for 2 of these pts the duration of VEN was reduced. The 60-day mortality rate was 0%. Two pts died on the study, one from leukemia and one from infection while in MLFS. Conclusion: The triplet combination of DAC, VEN and ponatinib was well-tolerated in pts with advanced Ph+ myeloid leukemias. In this poor-risk population, a marrow remission rate of 75% was achieved, although durations of remission were modest in the absence of consolidative SCT. This study continues to accrue pts. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Abstract 13630: Association Between Arrhythmia Burden During Clinical Exercise Testing and All-Cause Mortality

Introduction: Arrhythmias commonly occur during clinical exercise stress testing (EST), however there are limited data on prognostic significance, particularly differences between individuals with minor versus significant arrhythmia burden. Hypothesis: We hypothesized that significant but not minor arrhythmia burden during EST would be predictive of future all-cause mortality. Methods: Adults who underwent clinically indicated EST at Mayo Clinic Rochester between September 1993 and April 2017 were included and followed-up until March 2021 using the National Death Index to ascertain survival status. Expert clinician coding pertaining to arrhythmia burden during EST were used to group individuals (see Table 1 ). Cox proportional hazard models adjusted for known predictors of exercise-induced arrhythmias, were used to test the association of arrhythmia burden with all-cause mortality. Results: A total of 30796 individuals were included (age: 55±14yrs; female: 36%; Table 1 ). Mean follow-up was 8.8±3.6yrs, with a total of 2516 deaths. Arrhythmia during EST was associated with all-cause mortality compared with no arrhythmia (HR: 1.72; 95% CI: 1.58-1.88; p&lt;0.001), however significant arrhythmia showed greater association compared with minor arrhythmia (HR: 2.07; 95% CI: 1.81-2.38; p&lt;0.001). Both minor and significant arrhythmia during EST were significant predictors of all-cause mortality compared with no arrhythmia ( Figure, Table 2 ), however, after model adjustments, only significant arrhythmia was associated with all-cause mortality (HR: 1.40; 95% CI: 1.21-1.63; p&lt;0.001) ( Table 2 ). Conclusions: After multivariate adjustment, significant arrhythmia burden during EST showed a 40% increased future risk of all-cause mortality, Conversely, adjusting for age and sex attenuated the effect of minor arrhythmia burden during EST on incidence of death. These results highlight the clinical significance of arrhythmia burden during exercise testing.

Abstract 15677: Comprehensive Physiological Phenotyping Reveals Deconditioning Among Individuals With Long-COVID-19

Introduction: Post-acute COVID-19 sequalae (PASC) is a poorly understood constellation of symptoms that persist or emerge following the post-viral convalescent period. We sought to comprehensively evaluate cardiac and autonomic function and deconditioning as possible contributors to PASC associated fatigue. Methods: Thirty individuals with PASC (20F:10M; 41±11yrs; 137-730 days post-infection) prospectively underwent measures of autonomic function (heart rate [HR] and muscle sympathetic nerve activity [MSNA] response to passive head-up tilt 60° [HUT]); cardiac function (echocardiogram); arrhythmia burden (24-hour Holter monitor); exercise capacity (cardiopulmonary exercise test); hemoglobin and inflammatory biomarkers (CRP, troponin, IL-6, TNFα, IL-10). Participants were stratified by ongoing fatigue and symptoms of breathlessness (SOB+ or SOB-). Individuals with pre-existing conditions associated with fatigue were excluded. Results: Sixteen individuals (53%) reported breathlessness. Other common symptoms were palpitations (n=9; 30%) and light-headedness (n=5; 17%). Exercise capacity normalised for age and gender was lower in breathless subjects (SOB+) than in non-breathless subjects (SOB-); 70±11% vs 85±15%, p =0.004. The SOB+ group tended to have a blunted MSNA response to HUT when compared to SOB- ( p =0.06), with similar prevalence of postural orthostatic tachycardia (SOB+ n=5 vs SOB- n=5). Echocardiography revealed that global longitudinal strain trended higher in the SOB+ group compared with SOB- ( p= 0.075), with similar prevalence of participants who fulfilled diastolic dysfunction criteria (SOB+ 5 vs SOB- 4). There were no significant sustained arrhythmias on 24-hour Holter monitoring. Hemoglobin, troponin and cytokines were all similar (p&gt;0.05), but CRP was higher in the breathless group ( p =0.016). Conclusions: This is the first comprehensive phenotyping of PASC with ongoing fatigue and breathlessness. We found that these symptoms were associated with reduced exercise capacity but without any associated cardiac impairment, arrhythmias, or autonomic dysfunction. These findings suggest that deconditioning may contribute to the pathophysiology of PASC.

Abstract 14471: Cardiac Sarcoidosis Presenting With Hiccups - A Case Report

Introduction: Sarcoidosis is a multi-system disorder of unknown etiology that is commonly associated with hilar lymphadenopathy and granulomas. Cardiac involvement is less common, however, sarcoidosis is a known cause of restrictive cardiomyopathy. It typically presents as new-onset arrhythmias or heart failure, although cases of sudden cardiac death have been reported. Case presentation: We present a case of a 56-year-old male with a known history of pulmonary sarcoidosis, not on any active treatment, who presented to the emergency department with one week of continuous hiccups every few seconds associated with non-exertional dyspnea. Initial CT scan of the chest showed multiple stellate-like ground-glass opacities and progression of bronchiectasis. Troponins were negative. On the initial EKG, he was found to be in atrial flutter and was admitted to the general medical floor. He was given baclofen and the hiccups resolved over the next 24 hours. Cardiology was consulted for suspected cardiac sarcoidosis and they recommended transferring the patient to the tertiary care center for further evaluation. Upon arrival, the patient underwent catheter ablation for atrial flutter and he returned to the sinus rhythm after the procedure. The initial nuclear scan with gallium was not suggestive of cardiac sarcoidosis, however, subsequent cardiac MRI showed cardiac involvement. Due to the high risk of arrhythmias, the patient was scheduled for implantable cardioverter defibrillator placement before discharge. Treatment with steroids was deferred until after the PET scan could be completed. The patient was discharged in stable condition and interrogation of the device found it to be well functioning and with no significant arrhythmias noted. Conclusions: Presentation of cardiac sarcoidosis can be variable and should be considered in any patient with a known history of sarcoidosis who presents with atypical symptoms at or above the level of the diaphragm, such as hiccups or with new-onset arrhythmias.