24-h ECG Research Articles

Heart Rate Asymmetry in Healthy Children.

Heart rate asymmetry (HRA) is a physiological phenomenon characterized by an unequal contribution of heart rate decelerations and accelerations to different heart rate variability (HRV) features. While HRA has been demonstrated in adults' ECGs of different duration, a similar investigation in healthy children has not been conducted. This study investigated the variance- and number-based HRA features in 96 healthy children (50 girls and 46 boys, aged 3-18 years) using 24-h ECGs. Additionally, we studied sex differences in HRA. To quantify HRA, variance-based and relative contributions of heart rate decelerations to short-term (C1d), long-term (C2d), and total (CTd) HRV, and the number of all heartbeats (Nd) were computed. Heart rate decelerations contributed more to C1d, but less to C2d and CTd, and were less frequent than heart rate accelerations. Short-term HRA was better expressed in boys. The majority of children (93.7%) had short-term HRA, 88.5% had long-term HRA, 88.5% had total HRA, and 99.0% had more accelerations than decelerations. No sex differences were observed for the rate of various HRA features. Heart rate asymmetry is a common phenomenon in healthy children, as observed in 24-h ECGs. Our findings can be used as reference data for future clinical studies on HRA in children.

Incidence and Outcome of Newly Diagnosed Atrial Fibrillation in Medical ICU Patients: An Observational-Descriptive Study

Abstract Introduction: Cardiac arrhythmias frequently occur in critically ill patients in the intensive care unit (ICU), significantly impacting their health outcomes. Among these arrhythmias, supraventricular cardiac arrhythmic tachycardia, particularly atrial fibrillation (AF), is increasing in incidence and spans various medical and surgical contexts. In medical patients, the incidence ranges from 1%–46%. In patients with sepsis, the incidence of acute AF varies with the severity of sepsis, with an incidence of 8–10% in sepsis, 6–22% in severe sepsis, and 23–44% in septic shock. The development of cardiac arrhythmias in critically ill patients poses a substantial risk to both morbidity and mortality. Aim: To study the incidence and outcome of new-onset AF (NOAF) in medical ICU patients. Materials and Methods: NOAF was identified in patients with documented sinus rhythm ECG upon admission to the medical ICU who later developed AF. Results: Four hundred and twenty patients underwent 24-h continuous ECG monitoring, with 68 developing new-onset arrhythmias. Among them, 21 developed AF (5%). AF predominated in patients with preexisting cardiac illness (76.1%), with pneumonia being the primary non-cardiac cause. Notably, among 21 patients with AF, 12 individuals (57.1%) experienced mortality, while 9 patients (42.8%) were discharged from medical care. Notably, among the discharged patients, 5 individuals (45.4%) continued to exhibit persistent AF. Conclusion: It has been observed that there is an increased incidence of AF among critically ill patients, correlating with heightened rates of mortality and morbidity. Early detection and treatment hold promise in altering disease trajectories. Hence, the implementation of 24-h ECG monitoring is advocated for critically ill patients. Furthermore, a significant fraction of acute illness survivors experience new-onset AF after being discharged, which raises their long-term risks of heart failure, ischemic stroke, and death. However, the lack of expert consensus documents or evidence-based guidelines for managing NOAF highlights the need for carefully planned multicenter, prospective randomized trials to address these clinical uncertainties.

Multimodality strategy for cardiac damage assessment in falciparum malaria: A preliminary study

Malaria caused by the Plasmodium falciparum (P.f) parasite can result in life-threatening complications. Traditionally, cardiac involvement has not been included as a frequent cause of morbidity and mortality. Cardiac damage in P.f infection is probably underdiagnosed. To analyze the hypothesis of cardiac damage in apparently uncomplicated P.f infection with a multimodality strategy unavailable in most endemic countries. Cardiac biomarkers, ECG and 24 h ECG recording, transthoracic echocardiography with global strain analysis, and complete CMR analysis, including T2 (Fig. 1) and T1 mapping and extracellular volume quantification (ECV), were performed in patients hospitalized for malaria in a French tertiary center. Ten cases (sex ratio: 1 – mean age: 45 ± 13 years) imported from sub-Saharan Africa were prospectively included. Mean P.f parasitemia was 1.6 ± 1.7%. Hs-c Troponin T and NT pro BNP were mildly increased respectively in 1 and 2 patients. 24-h ECG recording revealed > 500 ventricular premature beats in 2 patients. Imaging revealed normal left and right ventricular systolic function, diastolic function and longitudinal global strain in all but one patient. CMR revealed 2 cases of focal late gadolinium enhancement consistent with the diagnosis of acute myocarditis in 1 case. ECV value was increased in 1 case (dilated cardiomyopathy). All patients were treated with piperaquine + dihydroartemisine and had a favorable outcome. Multimodality strategy reveals some cardiac abnormalities (ventricular ectopy, myocarditis) in patients hospitalized for falciparum malaria. Specificity of such findings remains questionable in this preliminary study. Further investigation is required to conclude about the hypothesis of a significant malaria-induced cardiac.

Low prevalence of cardiac abnormalities in competitive athletes at return-to-play after COVID-19.

to evaluate the prevalence of cardiac involvement after COVID-19 in competitive athletes at return-to-play (RTP) evaluation, following the recommended Italian protocol including cardiopulmonary exercise test (CPET) and 24-Hour Holter monitoring. this is a single centre observational, cross-sectional study. Since October 2020, all competitive athletes (age ≥ 14 years) evaluated in our Institute after COVID-19, prior RTP were enrolled. The protocol dictated by the Italian governing bodies included: 12‑lead ECG, blood test, CPET, 24-h ECG monitoring, spirometry. Cardiovascular Magnetic Resonance (CMR) was performed based on clinical indication. 219 consecutive athletes were examined (59% male), age 23 years (IQR 19-27), 21% asymptomatic, 77% mildly symptomatic, 2% with previous pneumonia. The evaluation was performed after a median of 10 (6-17) days from negative SARS-CoV-2 swab. All athletes showed a good exercise capacity at CPET without cardiovascular and respiratory limitations. Uncommon premature ventricular contractions (PVCs) were found in 9.5% (n = 21) at CPET/Holter ECG monitoring. Two athletes (0.9%) were diagnosed with acute myocarditis (by CMR) and another one with new pericardial effusion. All the three athletes were temporally restricted from sport participation. Myocarditis in competitive athletes screened after COVID-19 resolution was detected in a low minority of the cases (0.9%). However, a non-negligible prevalence of uncommon PVCs (9%) was observed, either at CPET and/or Holter ECG monitoring, including all athletes with COVID-19 related cardiovascular abnormalities.

594 HIDDEN CAUSES FOR UNEXPLAINED SINCOPE

Abstract Bicuspid aortic valve (BAV) is a congenital cardiac abnormality, affecting approximately 1%-2% of the general population (male > female). A 33-year-old man was admitted to emergency department (ED) for syncope during exertion. He had a history of cigarette smoking with a known previously discovered BAV with mild stenosis. TTE showed a severely calcified bicuspid aortic valve with severe stenosis and regurgitation. ECGs showed frequent asymptomatic complete hearth block (CHB), unresponsive to isoprenaline infusion. He underwent ministernotomy aortic valve replacement (AVR) with mechanical valve. During hospital stay, the 24h ECG telemetric monitoring did not show any A-V disturbance and TTE demonstrated normal prosthesis function. Pacemaker implantation was delayed, Follow-up was performed at 1, 6 and 10 months after surgery: 24h-ECG recordings were performed showing no A-V conduction disturbances. At 1 year, during routine medical screening, cardiac frequency of 38 bpm was detected (ECG revealed sinus rhythm with CHB and junctional escape rhythm of 38 bpm). ICCU echocardiogram showed good ventricular and prosthesis function. Therefore, a dual-chamber MRI compatible pacemaker was implanted. Few cases are reported in literature of young patients presenting with A-V block having a severely calcified aortic bicuspid valve. Their management is poorly explored, and therapies (medical therapy, aortic valve replacement and pacemaker implantation) are not fully evidence based. In literature, 3 cases of possible reversibility of conducting system disorders after severe stenotic aortic valve surgery are described. Noninvasive strategy was initially successful as demonstrated by both the post-operative absence of any AV conduction disturbance and/or symptoms and the close follow-up monitoring. Despite of previous evidence, our experience demonstrates that a complete heart block can recur following aortic valve surgery, even in young patients. Initial presentation of CHB was intermittent, suggesting that the structural damage to the conducting system could not be irreversible; thus, it could positively respond to valve surgery. Unfortunately, in CHB with calcific aortic stenosis patients should be considered for PM implantation at the time of aortic surgery. When a waiting strategy prevails, especially for young patients, close monitoring and follow-up must be warranted to early detect A-V disturbances recurrence.

378 VERY-LATE THROMBUS-RELATED STROKE AFTER PERCUTANEOUS PFO CLOSURE: MEDICAL MANAGEMENT OF A RARE COMPLICATION

Abstract In May 2020, a 45-years-old woman was admitted to the Emergency Department due to transient ischemic attack. The thrombophilia screening showed hemizygous prothrombin gene mutation (Factor II) and homozygous MTHFR mutation. The transthoracic echocardiography was normal, with a left ventricular ejection fraction of 60% and no morphological or functional valve disease. The 24-h Holter ECG and the past medical history did not show any specific cause of the neurologic manifestations. In the absence of a specific and plausible cause of the transient ischemic attack, a diagnosis of cryptogenic stroke was made. The patient then underwent transcranial Doppler, which showed a high-grade shunt (curtain effect), and transesophageal echocardiography with bubble test, which showed the presence of a massive right-to-left shunt through a patent foramen ovale (PFO) during the Valsalva maneuver. A therapy with warfarin (achieving a target INR between 2 and 3) was therefore started, and the indication for a percutaneous PFO closure was given. In January 2021 the patient underwent successful percutaneous PFO closure with the Gore Cardioform Septal Occluder 25/25 mm (W.L. Gore and Associates, Inc.) through intracardiac echocardiographic guidance with no complication and without any residual shunt. The patient was discharged on dual antiplatelet therapy with aspirin 100 mg daily plus clopidogrel 75 mg daily for six months, and pantoprazole 20 mg daily, followed by aspirin 100 mg daily chronically. After 6 months the patient underwent transcranial Doppler, which was negative for shunt. 12 months after the implantation the patient stopped aspirin by her own initiative. In August 2022, due to the diagnosis of an ovarian cyst, the gynecologist prescribed estro-progestogen pill: in that occasion, the patient did not mention her thrombophilia. After 10 days, sudden onset of weakness of the right upper limb and aphasia. The patient was then admitted to the Emergency Department, were the computer tomography showed two acute lesions on the left cerebral hemisphere. Therefore, the patient underwent intravenous thrombolysis, with complete regression of the neurological symptoms: a diagnosis of stroke was then formulated. To understand the origin of such stroke, the neurologist gave indication to cardiological evaluation. The patient did not have any palpitation in the previous months and the electrocardiogram showed normal sinus rhythm. However, the transthoracic echocardiographic evaluation showed a dubious image of a mass attached to the interatrial septum, for which the patient underwent transesophageal echocardiography, which showed a 10×9 mm fluctuating thrombus attached to the left side of the previously implanted PFO closure device. Therefore, an oral anticoagulation therapy with warfarin plus a subcutaneous therapy with enoxaparin 6000 UI twice daily (as bridge to obtain the desired INR between 2 and 3) was started. After ten days, the patient underwent a new transesophageal echocardiography, which showed a substantial reduction in the dimensions of the thrombus (4×3 mm). The patient was then discharged in warfarin therapy with no residual neurological symptoms.

1039 CARDIAC MRI EVALUATION FOR ATHLETES WITH NEGATIVE T WAVES AT ECG AND NORMAL TRANSTHORACIC ECHOCARDIOGRAPHY.

Abstract Introduction Negative T waves at ECG represent a common diagnostic dilemma in athletes. These subjects, often asymptomatic, undergo ECG screening every year before practicing competitive sports. The clinical meaning of these ECG abnormalities is often unclear and a comprehensive diagnostic evaluation is needed. Echocardiography is the first step test in all these cases, but the advent of cardiac MRI in the clinical field empowers the diagnostic capability for the identification of cardiovascular disease at a very early stage, even when transthoracic echocardiography is normal. The aim of the present study is to define the prevalence of positive cardiac MRI among athletes with negative T waves at ECG and normal echocardiography and to define the clinical predictors of pathological cardiac MRI or cardiac CT Material and Methods A consecutive cohort of athletes with negative T waves at ECG and normal findings at transthoracic echocardiography were enrolled. All athletes underwent 24h ECG monitoring, ECG exercise test and cardiac MRI; cardiac CT was performed only if clinically indicated and in all subjects with >35 years old of age. The type of sport practiced was recorded and stratified according to intensity into low- mid- and high-intensity. The site of negative T waves was recorded and T waves were defined as “deep” if wider than 2 mm. The presence of any arrhythmias during the 24-ECG monitor or exercise ECG test was recorded as well. The primary end-point of the study was the identification of diagnostic criteria for any structural heart disease at cardiac MRI or cardiac CT Results A total of 55 athletes (50 male, 90%) were enrolled with a mean age of 27 ± 14 years-old. Most of them practiced high-intensity sports activity (47 athletes, 85.4%). Anterior T waves were the most common type (29 athletes, 52.7%) and 8 athletes (14.5%) had more than isolated ventricular ectopic beats at 24-hours ECG monitoring. Among the entire cohort, 16 athletes (29.1%) had cardiac MRI or cardiac CT diagnostic for specific structural heart disease. Of interest, the presence of deep negative t waves (OR 8.1 95%CI 1.4–49.5, p<0.001) and arrhythmias more complex than isolated ventricular ectopic beats (OR 5.5 95%CI 1.1–26.6, p<0.001) were significative associated with structural heart disease even in the presence of normal transthoracic echocardiography. Conclusions Our results identified a prevalence of 29% of structural heart disease among athletes with negative T waves at ECG even when transthoracic echocardiography was normal. Of interest deep negative T waves and arrhythmias more complex than isolated ventricular ectopic beats were significative associated with structural heart disease. Thus, according to our results, advanced cardiovascular imaging techniques (cardiac MRI or cardiac CT) should be considered in athletes with negative T waves at ECG even in the presence of normal transthoracic echocardiography especially if complex ventricular arrhythmias of deep negative T waves are present.

962 CASE REPORT: ARRHYTHMIC MITRAL VALVE PROLAPSE - STATE OF THE ART AND WHAT'S NEW

Abstract Background Mitral valve prolapse (MVP) is a well-known pro-arrhythmic condition that involves 2-3% of the general population with an incidence of nonfatal arrhythmic events up to 30% and sudden cardiac death of 2-4% per year. It is assumed that the pro-arrhythmic substrate consists in myocardial fibrosis, secondary to steer-stretch due to the anomalous mobility of the mitral valve apparatus. We still have gaps in the evidences about the arrhythmic risk stratification of MVP and the most appropriate therapy and follow-up. Clinical case We present the case of a 40-years-old man with a known MVP due to Barlow disease, who underwent an at-home resuscitated cardiopulmonary arrest. In hospital, an echocardiogram found left ventricular dilatation with diffuse hypokinesia and severe mitral insufficiency. A coronary angiogram showed an undamaged coronary tree. The 24h ECG monitoring showed very frequent ventricular ectopies and non-sustained ventricular tachycardia. The patient underwent valvular surgery and he is now waiting for cardiac defibrillator (ICD) implantation. Conclusion We discuss the state of the art in risk stratification of “malignant” MVP; the actual and potential future role of the cardiac magnetic resonance, ICD implantation, sympathetic modulation, and early surgical mitral valve repair, in the primary prevention of sudden cardiac death.

Predictors of tachycardia-induced cardiomyopathy in patients with first-time decompensation of chro­nic heart failure with reduced left ventricular ejection fraction of nonischemic etiology and persistent atrial tachyarrhythmia

Aim To identify possible predictors of tachycardia-induced cardiomyopathy (TICMP) in patients with newly developed decompensated chronic heart failure (CHF) of nonischemic origin with reduced left ventricular ejection fraction (LV EF) and with persistent atrial tachyarrhythmias.Material and methods This study included 88 patients with newly developed decompensated CHF of nonischemic origin with reduced LV EF and persistent atrial tachyarrhythmias. Resting 12-lead electrocardiography (EGC) and transthoracic echocardiography (EchoCG) were performed upon admission and following the electrical impulse therapy for all patients. Also, 24-h ECG monitoring was performed to confirm sinus rhythm stability. After recovery of sinus rhythm, outpatient monitoring was performed for three months, including repeated EchoCG to evaluate the dynamics of heart chamber dimensions and LV EF.Results The patients were divided into two groups based on the increase in LV EF: 68 responders (TICMP patients with a LV EF increase by >10%) and 20 non-responders (patients with an increase in LV EF by <10% during 3 months following the sinus rhythm recovery). According to results of the baseline EchoCG, LV EF did not significantly differ in the two subgroups (TICMP, 40±8.3 %, 18-50 % and non-responders, 38.55±7.9 %, 24-50 %); moreover, the incidence of cases with LV EF <30% did not differ either (9 patients TICMP and 2 non-responders, р=1.0). TICMP patients compared to non-responders, had significantly smaller left atrial dimensions (4.53±1.14 (2-7) cm and 5.68±1.41 (4-8) cm, р=0.034; 80.8±28.9 (27-215) ml and 117.8±41.3 (46-230) ml, р=0.03, respectively) and left ventricular end-systolic volume (ESV) (67.7±33.1 (29-140) ml and 104.5±44.7 (26-172) ml, р=0.02, respectively). The effect of major EchoCG parameters on the probability of TICMP development was assessed by one-factor and multifactor regression analyses with adjustments for age and sex. The probability of TICMP increased with the following baseline EchoCG parameters: end-diastolic volume (EDV) <174 ml [odd ratio (OR), 0.115, 95 % confidence interval (CI): 0.035-0.371], ESV <127 ml [OR, 0.034, 95 % CI: 0.007-0.181], left atrial volume <96 ml [OR, 0.08 , 95 % CI: 0.023-0.274], right ventricular dimension <4 cm [OR, 0.042 , 95 % CI: 0.005-0.389].Conclusion Among patients with newly developed decompensation of CHF with reduced LV EF of non-ischemic origin and persistent atrial arrhythmias, TICMP was detected in 72 % of patients. The probability of TICMP did not depend on baseline EF and duration of arrhythmias, but increased with the following baseline EchoCG parameters: EDV< 174 ml, ESV< 127 ml, left atrial volume <96 ml, right ventricular dimension <4 cm. The multifactorial analysis showed that a right atrial volume <96 ml is an independent predictor for the development of TICMP.

Pregnancy in Women with Arrhythmogenic Left Ventricular Cardiomyopathy.

In the last few years, a phenotypic variant of arrhythmogenic cardiomyopathy (ACM) labeled arrhythmogenic left ventricular cardiomyopathy (ALVC) has been defined and researched. This type of cardiomyopathy is characterized by a predominant left ventricular (LV) involvement with no or minor right ventricular (RV) abnormalities. Data on the specific risk and management of pregnancy in women affected by ALVC are, thus far, not available. We have sought to characterize pregnancy course and outcomes in women affected by ALVC through the evaluation of a series of childbearing patients. A series of consecutive female ALVC patients were analyzed in a cross-sectional, retrospective study. Study protocol included 12-lead ECG assessments, 24-h Holter ECG evaluations, 2D-echocardiogram tests, cardiac magnetic resonance assessments, and genetic analysis. Furthermore, the long-term disease course of childbearing patients was compared with a group of nulliparous ALVC women. A total of 35 patients (mean age 45 ± 9 years, 51% probands) were analyzed. Sixteen women (46%) reported a pregnancy, for a total of 27 singleton viable pregnancies (mean age at first childbirth 30 ± 9 years). Before pregnancy, all patients were in the NYHA class I and none of the patients reported a previous heart failure (HF) episode. No significant differences were found between childbearing and nulliparous women regarding ECG features, LV dimensions, function, and extent of late enhancement. Overall, 7 patients (20%, 4 belonging to the childbearing group) experienced a sustained ventricular tachycardia and 2 (6%)-one for each group-showed heart failure (HF) episodes. The analysis of arrhythmia-free survival patients did not show significant differences between childbearing and nulliparous women. In a cohort of ALVC patients without previous episodes of HF, pregnancy was well tolerated, with no significant influence on disease progression and degree of electrical instability. Further studies on a larger cohort of women with different degrees of disease extent and genetic background are needed in order to achieve a more comprehensive knowledge regarding the outcome of pregnancy in ALVC patients.

Abstract 12325: Burden of Premature Ventricular Complex is Associated With New-Onset Atrial Fibrillation

Introduction: Large burden of premature ventricular complex (PVC)lead to more cardiovascular mortality. A recent nationwide population-based database demonstrated that presence of PVC is associated with increased risk of atrial fibrillation. The relationship between burden of PVC and new onset of atrial fibrillation (AF), however, has never been investigated. Hypothesis: The purpose of the study is to clarify whether burden of PVC is associated with more new-onset AF. Methods: We designed a single-center, retrospective, and large population-based cohort to clarify the role of PVC burden and new-onset atrial fibrillation in Taiwan. PVC patients without history of atrial fibrillation with were divided into low burden group (<1000/day) and moderate to high burden group (≥1000/day) based on the report of 24-h Holter ECG. New-onset AF was defined as new or first detectable events presenting as either persistent or paroxysmal AF. Results: A total of 16030 AF-naïve patients who underwent 24-h Holter ECG were enrolled in this study with a mean follow-up time of 973 days. A propensity-score matched analysis demonstrated moderate to high burden PVC group had a higher risk to have new-onset AF in comparison with low burden (4.96% vs 2.79%, p<0.001). Multivariate Cox regression analysis showed that moderate to high burden of PVC is an independent risk factor to develop new-onset AF. A Kaplan-Meier analysis also showed that patients with moderate to high burden of PVC is associated with more new-onset AF (log rank p<0.001). Conclusions: Burden of PVC is associated with new-onset atrial fibrillation. Patients with moderate to high burden PVC are at a higher risk to have new-onset atrial fibrillation.

Abstract 14985: Artificial Intelligence Based Heart Rate Variability Analysis for Sudden Cardiac Arrest Risk Prediction

Introduction: Sudden Cardiac Arrest (SCA) is an unexpected life-threatening loss of cardiac function potentially leading to sudden cardiac death (SCD). It accounts for a half of cardiac mortality, posing a major public health problem. While SCA can be treated with implantable cardioverter defibrillators (ICD), most (80%) SCDs occur in relatively low risk patients, for whom risk benefit ratio of an ICD is unfavorable. Therefore, novel methods to identify high risk individuals and the time on which their risk is high may facilitate prevention of SCD. Methods : Long (~24h) ECG recordings from individuals who had an SCA on record (n=20), patients with other arrhythmias (n=84) and from healthy individuals (n=17) from PhysioNet databases were analyzed to extract inter beat intervals (IBI). For each step in the IBI series, 120 last IBIs were used to calculate 19 indices that quantify short term heart rate variability (HRV). An artificial intelligence model named temporal convolutional network (TCN) was used to continuously assess the risk of a future VF event based on the current HRV estimate combined with few hours of history of previous HRV estimates. Training and testing of the TCN was done using Leave One Out testing done twice. Patients being classified at any point in the record as high risk were considered high risk. Results : Only patients from the SCA population, and none from the other arrythmia and healthy patients, were classified as high risk (PPV=100%). On average, sensitivity and specificity were 62.5% and 100% respectively Conclusions : In this preliminary retrospective analysis, artificial intelligence based HRV analysis identified risk for a SCA event in the following 24 hours with high specificity. Larger cohort and prospective testing are needed to assess the clinical utility of such systems.

Cartilaginous Intrusion of the Atrioventricular Node in a Quarter Horse with a High Burden of Second-Degree AV Block and Collapse: A Case Report

Second-degree atrioventricular (AV) block is the most common cardiac arrhythmia in horses, affecting 40-90% depending on breed. Usually, the AV blocks occur while the horses are resting and disappear upon exercise and are, therefore, considered to be uneventful for horses. However, if the AV blocks occur frequently, this may result in syncope and collapse. Identifying the cause of second-degree AV block is difficult and often subscribed to high vagal tone. In this report, we present an eight-year-old Quarter horse with a high burden of second-degree AV blocks and multiple collapses. The clinical examination, including neurological examination, blood analysis, 24-h ECG recording and cardiac echocardiography, did not reveal any signs of general or cardiovascular disease besides a high burden of second-degree AV blocks (~300 blocks per hour) and a hyperechoic area in the AV nodal region. An implantable loop recorder (ILR) was inserted to monitor the cardiac rhythm. The ILR detected several consecutive second-degree AV blocks and pauses above 5 s. However, unfortunately, no recordings were available during the collapses. Eventually, the horse was euthanized and the heart inspected. The aortic root was severely cartilaginous and appeared to penetrate the AV node, especially in the His bundle region, possibly explaining the hampered AV conduction. Nevertheless, it is still uncertain if the AV nodal disruption caused the collapses and more knowledge on AV nodal diseases in horses is warranted.

Predictors of proarrhythmic effect in heart failure patients after 9-week hybrid comprehensive telerehabilitation and their influence on cardiovascular mortality in long-term follow-up: Subanalysis of the TELEREH-HF randomized clinical trial

BackgroundRegular exercise training is beneficial in heart failure (HF) patients. However, its potential proarrhythmic effect is possible but has not been sufficiently investigated. ObjectiveTo identify patients at risk for proarrhythmic effect after the 9-week of hybrid comprehensive telerehabilitation (HCTR) program vs the 9-week of usual care (UC) and to investigate its predictors and impact on cardiovascular mortality based on data from the TELEREH-HF RCT. MethodsProarrhythmic effect, strictly defined on the basis of available standards was evaluated by comparing 24-h Holter ECG before and after 9-week of HCTR or UC of 773 HF patients (The New York Heart Association class I-III, left ventricular ejection fraction ≤40%). ResultsThe proarrhytmic effect was found in 78 (20.4%) and in 61 (15.6%) patients in the HCTR and UC group respectively, and the difference between groups was not statistically significant (p = 0.081). However, univariate analysis identified several statistically significant predictors of proarrhythmia in HCTR only vs the UC group. After a multivariate analysis ischaemic aetiology of HF (OR = 2.27, p = 0.008), peak oxygen consumption at baseline <14 ml/kg/min (OR = 2.03, p = 0.012) and level of N-terminal-pro B-type natriuretic peptide (NT-proBNP) in the first and the second tercile (OR = 1.85, p = 0.043) were identified to be independent predictors of proarrhytmic effect of exercise training among the HF patients in HCTR group only. ConslusionsPatients who underwent a 9-week HCTR were not at a higher risk of proarrhythmic effect after its completion compared to UC. However, predictors of proarrhythmia such as ischemic aetiology of HF, poor physical capacity, lower NT-proBNP level were discovered in the HCTR group only, yet it does not cause a significant risk of cardiovascular mortality including sudden cardiac death in long-term follow-up.

A prediction model for ventricular tachycardia events using 24h ambulatory ECG

Abstract Background Ventricular tachycardia (VT) is a potentially lethal condition that occurs intermittently. The aim of this study was to derive a risk prediction model for VT episodes detected on ≤30 day mobile cardiac telemetry using a 24 hour ambulatory ECG recording. Methods We included patients who were monitored for 2–30 full days in the USA using a full-disclosure mobile cardiac telemetry device in 2017. Patients with a VT episode ≥10 beats duration (VT≥10 beats) on the first full recording day were excluded. Arrhythmias were algorithmically detected and manually verified. A LASSO model was derived for the outcome of a VT≥10 beats detected on days 2–30. Potential predictors included age, sex, and ECG data from the first 24h: heart rate (max, min and mean), premature atrial and ventricular complexes occurring as singles, couplets, triplets, and runs ≥4 beats as well as the fastest rate for each event. The population was split into equal random training and testing samples. Results In a population of 19,789 patients (mean age 65.3, 43.4% men), and during a median recording time of 18 days there were 1,511 patients with at least one VT≥10 beats. The LASSO model had good discrimination in the testing sample, ROC-statistic 0.7586, 95% CI 0.7398–0.7774 (Figure 1a). A model excluding age and gender had similar discrimination (ROC 0.7528, 95% CI 0.7339–0.7717). In the testing sample the model was well calibrated (Figure 1b). In the top quintile more than one in five patients had a VT≥10 beats, enough to warrant extended monitoring. Conclusion A risk score based on variables easily derived from a standard 24h ECG can be used to predict high risk of VT episodes ≥10 beats within 30 days. In the top quintile VT events ≥10 beats were ten times more common than in the bottom quintile. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): Hjärt-LungfondenSwedish Society for Medical Research

A Case of Mitral Annular Disjunction Combined with Ventricular Arrhythmias

The article presents a clinical case of a combination of mitral valve prolapse (MVP), mitral annular disjunction (MAD), and ventricular arrhythmia. The presence of MAD worsens the prognosis in MVP and predisposes to life-threatening ventricular arrhythmias. In a 42-year-old patient, MAD was detected during echocardiography to determine the indications for surgical correction of mitral insufficiency in MVP. Severe myxomatous degeneration of the mitral valve leaflets, polysegmental prolapse, and typical auscultatory pattern (systolic click followed by systolic murmur in the second half of systole) were the indications for the targeted search for MAD. Multi-day (ECG) monitoring recorded nonsustained ventricular tachycardias and premature ventricular complexes (PVCs). Cardiac magnetic resonance imaging was performed for confirmation the diagnosis and searched for left ventricular myocardial fibrosis accompanying MAD. Finally, MAD was confirmed, but myocardial fibrotic changes were not detected. Owing to the absence of myocardial fibrosis, the patient was treated conservatively with a beta-adrenoblocker (25 mg/day slow-release metoprolol succinate) in combination with 25 mg/day allaforte. Repeated 24-h ECG monitoring did not detect ventricular tachycardias and nonsustained registered a significant decrease of number of PVCs. The patient is followed up prospectively due to high risk factors for fibrosis and worsening prognosis, which may require surgical correction of the existing disturbances and/or implantation of a cardioverter-defibrillator.

Transcatheter Atrial Septal Defect Closure Before Versus After Adulthood.

ObjectivesTo evaluate the long-term outcome of patients who underwent percutaneous transcatheter closure of secundum atrial septal defects during teenage life versus adulthood.MethodsThe study included 100 patients with secundum type ASD who were treated by transcatheter closure of their defects 2–5 years before enrollment. The study population was subdivided into 2 equal groups: group 1 who underwent transcatheter closure during teenage life (13–19 years) and group 2 who underwent transcatheter closure after the age of 30 years. The two groups were compared according to resting 12 lead ECG, 24-h Holter ECG and transthoracic echocardiographic findings (Right ventricular size and functions, right atrial size, etc.)ResultsThe study population showed female predominance. The average follow up period was similar in both groups. Adult patients had more frequent right bundle branch block morphology in their resting 12 lead ECG than teenagers (69% versus 45% respectively, p < 0.01). The incidence of arrhythmias encountered in Holter ECG was also significantly higher in the adult group. Premature atrial contractions (PAC) were present in 10 patients (20%) in adult group while 3 patients (6%) had PACs in teenagers’ group with p < 0.01. The mean PAC burden was also higher in the adult group (9% versus 1.3%, p < 0.001). Paroxysmal AF lasting more than 30 seconds was found in 6 patients (12%) in the adult group while 1 patient in teenagers developed AF, p < 0.01. Regarding transthoracic echocardiography, adult patients showed significantly larger RV diameter, indexed RA area, indexed LA volume and more LV diastolic dysfunction. RV systolic functions were better in the teenage group as measured by 2D echocardiography. Adult patients with higher age, bigger defect size and device size had more abnormal ECG and echocardiographic findings.ConclusionEarly trans-catheter closure of secundum ASD during teenage life yields better right ventricular systolic function, better right ventricular size and less incidence of atrial arrhythmia.

Evaluation of the Cardiac Conduction System in Fibromyalgia Patients With Complaints of Palpitations.

ObjectiveThis study aimed to investigate the influence of fibromyalgia syndrome (FMS) on the cardiac conduction system and assess patients’ palpitation complaints using 24-h ambulatory ECG (Holter {Maynard, MA: Northeast Monitoring, Inc.}) monitoring.MethodsNinety patients with FMS and 70 healthy controls were included in this research. ECG was performed on all participants, and ECG parameters were calculated. Holter monitoring was conducted, and the recordings were analyzed. The results of time-domain heart rate variability (HRV) were evaluated.ResultsThe patient group’s mean age was 38.3±6.3 years. There were no statistically significant differences in demographic or laboratory parameters across the groups (p>0.05). The findings of a 24-h Holter ECG recording did not vary significantly between the groups (p=0.182). In the study group, the values for the standard deviation of R-R intervals (SDNN), low frequency (LF), and low/high frequency (LF/HF), which are known as HRV indicators, were substantially different between the two groups (p<0.05).ConclusionsThe study indicated that the risk of arrhythmias did not increase even though FM patients complained of palpitations.

Predictors of Long COVID in Patients without Comorbidities: Data from the Polish Long-COVID Cardiovascular (PoLoCOV-CVD) Study.

Background: The SARS-CoV-2 pandemic has become an enormous worldwide challenge over the last two years. However, little is still known about the risk of Long COVID (LC) in patients without comorbidities. Thus, we aimed to assess the predictors of LC in patients without comorbidities. Methods: Patients’ information, the course of the disease with symptoms, and post-COVID-19 complaints were collected within 4–12 weeks after COVID-19 recovery. Next, the patients were followed for at least 3 months. ECG, 24-h ECG monitoring, 24-h blood pressure (BP) monitoring, echocardiography, and selected biochemical tests were performed. LC was recognized based on the WHO definition. Results: We identified 701 consecutive patients, 488 of whom completed a 3-month follow-up (63% women). Comparisons were made between the LC group (n = 218) and patients without any symptoms after SARS-CoV-2 recovery (non-LC group) (n = 270). Patients with a severe course of acute-phase COVID-19 developed LC complications more often (34% vs. 19%, p < 0.0001). The persistent symptoms were observed in 45% of LC patients. The LC group also had significantly more symptoms during the acute phase of COVID-19, and they suffered significantly more often from dyspnoea (48 vs. 33%), fatigue (72 vs. 63%), chest pain (50 vs. 36%), leg muscle pain (41 vs. 32%), headache (66 vs. 52%), arthralgia (44 vs. 25%), and chills (34 vs. 25%). In LC patients, significant differences regarding sex and body mass index were observed—woman: 69% vs. 56% (p = 0.003), and BMI: 28 [24–31] vs. 26 kg/m2 [23–30] (p < 0.001), respectively. The number of symptoms in the acute phase was significantly greater in the LC group than in the control group (5 [2–8] vs. 2 [1–5], p = 0.0001). The LC group also had a higher 24-h heart rate (77 [72–83] vs. 75 [70–81], p = 0.021) at admission to the outpatient clinic. Multivariate regression analysis showed that LC patients had a higher BMI (odds ratio (OR): 1.06, 95% confidence intervals [CI]: 1.02–1.10, p = 0.007), almost twice as often had a severe course of COVID-19 (OR: 1.74, CI: 1.07–2.81, p = 0.025), and presented with joint pain in the acute phase (OR: 1.90, CI: 1.23–2.95, p = 0.004). Conclusions: A severe course of COVID-19, BMI, and arthralgia are independently associated with the risk of Long COVID in healthy individuals.

Twelve-month efficacy of second-generation cryoballoon ablation for atrial fibrillation performed at community hospitals: results of the German register on cryoballoon ablation in local hospitals (regional).

The 12-month follow-up (F/U) efficacy of CBA PVI performed at community hospitals for treatment of symptomatic paroxysmal and persistent atrial fibrillation (AF) is unknown. This study determined the 12-month efficacy of pulmonary vein isolation (PVI) using cryoballoon ablation (CBA) performed at community hospitals with limited annual case numbers. This registry study included 983 consecutive patients (pts) from 19 hospitals, each with an annual procedural volume of < 100 PVI procedures/year. Pts underwent CBA PVI for paroxysmal AF (n = 520), persistent AF (n = 423), or redo PVI (n = 40). The primary endpoint was frequency of documented recurrent AF, the occurrence of atrial flutter or tachycardia following a 90-day period after the index ablation and up to 12months. The frequency of repeat ablation was determined. Isolation of all PVs was documented in 98% of pts at the end of the procedure. Twelve-month F/U data could be obtained in 916 pts. A 24-h ECG registration was performed in 641 pts (70.0%); in 107 pts (16.7%) of them, recurrent AF was documented. The primary endpoint was met in 193 F/U pts (21.1%). It occurred in 80/486 F/U pts with paroxysmal AF (16.4%), and in 107/390 F/U pts with persistent AF (27.4%). Redo PVI was performed in 71 pts (7.8%), and atrial flutter ablation was performed in 12 pts (1.4%). CBA PVI for paroxysmal or persistent AF can be performed at community hospitals with adequate rates of 12-month symptom freedom and arrhythmia recurrence. The study was registered at the German register of clinical studies (DRKS00016504).