Rhythm Monitoring Research Articles

Left atrial strain is associated with atrial fibrillation recurrence after catheter ablation: Data from the ISOLATION registry

Abstract Funding Acknowledgements Type of funding sources: None. Background Catheter ablation (CA) has been established as an effective therapeutic option to achieve rhythm control in patients with atrial fibrillation (AF). However, AF recurrence occurs in approximately 45% of the patients undergoing CA. The association between AF recurrence after CA and left atrial (LA) strain, which is a surrogate marker of LA mechanical dysfunction already appearing before the enlargement of the LA, remains less clear. Aim The purpose of this study was to evaluate the association between LA function assessed by strain echocardiography and AF recurrence after CA. Methods This sub-study of ISOLATION (NCT04342312), involved consecutive patients with paroxysmal or persistent AF scheduled for first cryoballoon or radiofrequency CA. Clinical characteristics and echocardiography examination were collected at baseline visit before CA. Patients were followed for 12 months. Follow-up consisted of outpatient visits and heart rhythm monitoring (48 day Holter, 12-lead electrocardiogram, 7 day photoplethysmography-based rhythm app) at 3, 6, and 12 months. Results We analyzed 312 patients (median age 65, 36% women). More than half (52%; n=162) underwent radiofrequency CA and 84 (27 %) had AF recurrence within one year follow-up. No statistically significant differences in baseline characteristic were observed between patients with and without recurrent AF, expect higher prevalence of persistent AF prior to CA in patients with recurrence of AF (75% vs. 46%, p<0.001). LA reservoir strain (22 [14-33]% vs 29 [19-37]%, p=0.002), LA conduit strain (15 [9.6-19]% vs 17 [12-22]%, p=0.038) and LA contraction strain (7.5 [2.2-15]% vs 12 [5.8-16]%, p<0.001), were significantly lower, and mildly-to-severe LA dilatation (≥39mm in women and ≥41–in men) was more frequently observed (77% vs 64%, p=0.039) in patients with (vs without) recurrence of AF. Based on multiple logistic regression, LA contraction strain was an independent predictor for AF recurrence (OR 0.94, 95%CI 0.90-0.98) in all study group. LA contraction strain of ≤9.4% had a sensitivity of 61% and specificity of 58% for recurrence of AF after CA. In the group with normal LA (<39mm in women and <41–in men), LA reservoir strain was significantly associated with the risk for recurrence of AF (OR 0.94 [0.90–0.99]). Overall, LA reservoir strain of ≤29% in this group had a negative predictive value of 90% and sensitivity of 74% for recurrence of AF after CA (Figure 1). AF type was not predictive in this subgroup. In the group with mildly-to-severe enlarged LA, AF type remained strongly predictive for recurrence of AF (OR 3.38[1.82-6.25]), whereas LA strains did not. Conclusions LA function assessed by LA strain is associated with AF recurrence after CA, even in patients with non-dilated LA. Whether integration of results derived from systematic preprocedural LA strain analysis into patients’ selection strategies may help to identify patients profiting from CA required further study.

Comparison of amplified P-wave analysis to artificial intelligence-derived analysis for diagnosis of atrial cardiomyopathy and outcome prediction following pvi for persistent atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Left atrial cardiomyopathy (ACM) is invasively diagnosed by presence of low voltage substrate (LVS) in electro-anatomical mapping. ACM is associated with high (50%) AF recurrence rates after PVI, but also with increased risk for de-novo AF and ischemic stroke. Aims We establish and compare ACM-diagnosis based on 12-lead-ECG analysis, using (A) digital amplified p-wave analysis during SR versus (B) a neural network trained to diagnose ACM using automatically determined sinus-p-wave features (duration, morphology) in 12-lead-ECG as inputs. Methods Left atrial (LA) voltage mapping was acquired during SR in 270 AF (50% paroxysmal; 43% female; age: 64+/-11years) prior to PVI. ACM was defined as presence of left atrial LVS<0.5mV at >2cm2 during SR, and was detected in 95/270 (35.2%) of patients. P-wave-analysis was assessed for outcome prediction in a prospective cohort of persistent AF patients undergoing rhythm monitoring using 7-day Holter at 6 and 12 months post PVI-only approach. Results The duration of amplified sinus-p-wave (APWD) >151ms (left top panel) enabled to diagnose ACM with an AUC 0.87 (sensitivity: 78% and specificity: 76%, left bottom panel). The accuracy of the AI-neural-network-derived ECG-analysis (using automatically determined APWD and p-morphology criteria) for ACM diagnosis was: AUC 0.85, sensitivity 74%, specificity 78%, accuracy: 77% (see right panel top and bottom). Application of AI-derived ACM-diagnosis on a prospective cohort of persistent AF patients undergoing PVI-only approach (n=58) enabled arrhythmia outcome prediction: Patients with vs. without ACM (based on AI-derived p-wave-analysis) had significantly higher arrhythmia recurrences at 12 months following PVI (46% vs. 23%, p=0.017). Conclusion Both the measurement of the APWD and the automatic neural network-based p-wave-analysis enable diagnosis of individuals with left atrial cardiomyopathy with high accuracy in a large cohort of patients with paroxysmal and persistent AF. Diagnosis of ACM based on automatic neural-network-based P-wave analysis enables identification of patients at high risk for arrhythmia recurrence post PVI-only ablation approach.

Baseline pr internal prolongation and elevated diastolic blood pressure are predictors of new-onset atrial fibrillation in hypertensive patients

Abstract Funding Acknowledgements Type of funding sources: None. Introduction One of the most significant risk factors for atrial fibrillation is hypertension (HTN) (AF). Although the PR interval is a factor in the Framingham risk score for AF, it has been linked to an elevated risk of incident AF. However, there is a lack of consistency in the findings identifying PR prolongation as a risk factor for AF. Purpose In a large cohort of HTN patients, we seek to assess the predictive value of the PR interval for the emergence of AF. Methods The average follow-up time for consecutive individuals with essential hypertension and no known AF at baseline was 5.3 years. Each patient underwent a 12-lead ECG, an echocardiogram examination, and a 24-hour Holter rhythm monitoring in the event of arrhythmia complaints. These tests were done at baseline and once a year. The European Society of Cardiology/European Society of Hypertension guidelines for HTN therapy were followed during the follow-up period, including routine clinical and paraclinical assessments and drug administration. The baseline ECG was used to determine the PR interval and P wave length. Results We included 1807 hypertensives (mean age 57±11 years; 49% men) with office systolic/diastolic blood pressure of 144±17/89±11 mmHg. A total of 65 occurrences of new-onset AF (3%) were reported during the follow-up period. P wave duration and PR internal time were longer at baseline in patients with new-onset AF (n=67) compared to those without AF (n=1740) (P wave, 115 vs 110 ms) (PR interval, 174 vs 157 ms). A multivariate Cox regression analysis showed that baseline P wave duration had no significant prognostic value for the occurrence of new-onset AF, but baseline PR internal was substantially linked with the development of AF (HR = 1.01, 95% CI = 1.01-1.02; p = 0.01). A greater incidence of AF was linked to baseline elevated diastolic blood pressure (HR 1.05, 95% 1.003-1.091; p=0.037). Conclusions Baseline PR internal and elevated diastolic blood pressure were significant predictors of new-onset AF in hypertensive patients. PR prolongation may be a marker for cardiovascular degenerative aging caused by vascular inflammation and myocardial fibrosis.

Association of ivabradin use with ventricular arrhythmias in heart failure patients

Abstract Funding Acknowledgements Type of funding sources: None. Background/Introduction Heart failure patients with reduced left ventricular function are at high risk for ventricular arrhythmias and sudden cardiac death. Ivabradine, a specific inhibitor of the If current in the sinoatrial node, provides heart rate reduction in sinus rhythm and angina control in chronic coronary syndromes. Purpose The effect of ivabradine on ventricular arrhythmias in heart failure patients has not been fully elucidated. In this study, we aimed to investigate the effect of ivabradine use on life-threatening arrhythmias and long-term mortality in heart failure patients. Methods In this retrospective study, 1639 patients with heart failure were included. Patients were divided into two groups as ivabradine users and non-users. Patients presenting with ventricular tachycardia, presence of ventricular extra systole and ventricular tachycardia in 24-hour rhythm monitoring, appropriate ICD shocks and long-term mortality outcomes were evaluated according to ivabradine use. Results After adjustment for clinical variables, admission with ventricular tachycardia had 3.0 higher rates in ivabradine non-users (95% CI: 1.5 – 10.2). According to the adjusted model for all variables, approximately 4.1 times more appropriate ICD shocks were observed in the ivabradine non-users than the users (95% CI: 1.8 – 9.6). Long-term mortality did not differ between these groups after adjustment for all covariates. Conclusion The use of ivabradine reduced the appropriate ICD discharge in heart failure patients with low ejection fraction. Ivabradine has a potential in the treatment of ventricular arrhythmias in heart failure patients.

Atrial contractile and electrical remodeling is associated with more complex conduction patterns in patients without history of atrial fibrillation: a high-density epicardial mapping study

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – EU funding. Main funding source(s): This work was supported by the Netherlands Heart Foundation (CVON2014-09, RACE V Reappraisal of Atrial Fibrillation: Interaction between hyperCoagulability, Electrical remodelling, and Vascular Destabilisation in the Progression of AF), the European Union (ITN Network Personalized Therapies for Atrial Fibrillation: a translational network: PersonalizeAF, grant 860974, CATCH ME: Characterizing Atrial fibrillation by Translating its Causes into Health Modifiers in the Elderly, No. 633196). Background Early atrial remodeling refers to a concept where atrial structural, functional, and electrophysiological changes may be present without clinical manifestation of atrial arrhythmias. (1) However, it is currently unknown how electrophysiological and functional atrial properties are related, especially in the early stages of atrial remodeling. Purpose To investigate the relationship between electrophysiological properties of the atria, determined by intraoperative high-density epicardial mapping after AF-induction, and echocardiographic and electrocardiographic parameters in patients without a history of AF undergoing cardiac surgery. Methods All patients underwent functional and electrophysiological analysis of both atria using preoperative transthoracic echocardiography, electrocardiography, and intraoperative biatrial high-density epicardial mapping. Postoperatively, all patients were continuously monitored for occurrence of new-onset postoperative AF (POAF). In addition to univariable and multivariable analysis, cluster analysis was performed to identify distinct clusters of subjects for epicardial mapping parameters. Results The study population consisted of 38 patients undergoing coronary artery bypass grafting, isolated aortic valve replacement, or the combination of both. All patients completed 1-year continuous rhythm monitoring and 19 patients (50%) developed POAF. There was a greater number of waves/cycle (4.57±1.55 vs. 3.98±1.63, p=0.04) and breakthrough (BT) waves/cycle (1.16±0.58 vs. 0.88±0.60, p=0.01) in the RA compared to the LA (Figure 1). Also, there was a lower conduction velocity (CV) in the RA than in the LA (0.71±0.10m/s vs 1.19±0.36m/s, p<0.01) (Figure 1). Average waves/cycle were significantly correlated with reduced P-wave duration and P-wave amplitude (Spearman’s rho=-0.32, p=0.04, and Spearman’s rho=-0.32, p=0.04, respectively). Also, there was significant negative correlation between LA booster function and LA waves/cycle (Spearman’s rho=-0.55, p<0.01). Survival analysis revealed that older age, lower P-wave amplitude, reduced LA booster function, and increased RA waves/cycle were associated with increased occurrence of POAF (Figure 2). Cluster analysis was performed for RA and LA epicardial mapping parameters, which identified 2 distinct clusters: cluster 1 consisted of patients with more complex atrial electrical conduction patterns, and cluster 2 less complex atrial electrical conduction patterns. Multivariable analysis showed that reduced LA booster function was independently associated with a cluster representing more complex atrial electrical conduction patterns in the LA (OR=1.13, 95% CI: 1.02-1.25, p=0.02). Conclusion In patients without a history of AF, reduced LA contractile function and lower P-wave amplitude are associated with more complex electrical conduction patterns in acutely induced AF, potentially representing an early step in the atrial remodeling process.

P323 WELLENS PATTERN, MYOCARDIAL BRIDGING, AND BIVENTRICULAR ARRHYTHMOGENIC CARDIOMYOPATHY: A SINGLE "TRIPLE" DIAGNOSIS

Abstract Wellens‘ syndrome describes an electrocardiographic pattern characterized by T–wave changes in the antero–septal leads that make this finding highly suggestive of a lesion of the proximal segment of the anterior interventricular artery. Case report. A 58–year–old patient from China with a silent medical history presented to the emergency department with angor, dizziness, asthenia, and blurred vision. The electrocardiogram shows a Wellens type A pattern, and blood chemistry tests collected in the emergency department show liver, kidney function and blood count within normal limits. High–sensitivity troponin T values stand at 34 ng/mL. The echocardiogram shows preserved biventricular systolic function in the absence of major regional wall motion abnormality. Given the symptoms, troponin values, and electrocardiographic pattern, the patient underwent coronary angiopgraphy, which showed lesion–free epicardial coronary arteries but with a muscular bridge in the mid–proximal section of the anterior interventricular artery, with no obvious significant systolic–diastolic caliber changes at subsequent coronary CT analysis. To better assess possible myocardial ischemic damage, the patient underwent MRI (magnetic resonance), which showed an entirely unexpected result. In fact, T1 sequences revealed biventricular adipose infiltration at the anterolateral and inferolateral walls of the left ventricle, with homosedial enhancement to nonischemic pattern on late post–contrast images: this picture was considered suggestive of biventricular arrhythmogenic cardiomyopathy. In the absence of history of syncope and documented arrhythmias on prolonged rhythm monitoring during hospitalization, no indication was made for further diagnostic and therapeutic investigations from the arrhythmological point of view. Thus, beta blocker and ace inhibitor therapy was set, and the patient was started on an outpatient cardiology follow–up course and genetic counseling for him and first–degree family members was scheduled. Selecting the correct imaging method becomes crucial for a correct diagnosis, especially in cases in which symptomatology is inconclusive.

Reduced Left Atrial Appendage Flow Is Associated With Future Atrial Fibrillation After Cryptogenic Stroke

Hemostasis within the left atrial appendage (LAA) is a common cause of stroke, especially in patients with atrial fibrillation (AF). Although LAA flow provides insights into LAA function, its potential for predicting AF has yet to be established. The aim of this study was to explore whether LAA peak flow velocities early after cryptogenic stroke are associated with future AF on prolonged rhythm monitoring. A total of 110 patients with cryptogenic stroke were consecutively enrolled and underwent LAA pulsed-wave Doppler flow assessment using transesophageal echocardiography within the early poststroke period. Velocity measurements were analyzed offline by an investigator blinded to the results. Prolonged rhythm monitoring was conducted on all participants via 7-day Holter and implantable cardiac monitoring devices, with follow-up conducted over a period of 1.5years to determine the incidence of AF. The end point of AF was defined as irregular supraventricular rhythm with variable RR interval and no detectable P waves lasting ≥30sec during rhythm monitoring. During a median follow-up period of 539 days (interquartile range, 169-857 days), 42 patients (38%) developed AF, with a median time to AF diagnosis of 94 days (interquartile range, 51-487 days). Both LAA filling velocity and LAA emptying velocity (LAAev) were lower in patients with AF (44.3±14.2 and 50.7± 13.3cm/s, respectively) compared with patients without AF (59.8±14.0 and 76.8±17.3cm/sec, respectively; P<.001 for both). LAAev was most strongly associated with future AF, with an area under the receiver operating characteristic curve of 0.88 and an optimal cutoff value of 55cm/sec. Age and mitral regurgitation were independent determinants of reduced LAAev. Impaired LAA peak flow velocities (LAAev<55cm/sec) in patients with cryptogenic stroke are associated with future AF. This may facilitate the selection of appropriate candidates for prolonged rhythm monitoring to improve its diagnostic accuracy and implementation.

Occurrence of Severe Arrhythmias in Patients with Non-ST Elevation Acute Coronary Syndrome (NSTE-ACS): A Retrospective Study.

Non-ST elevation acute coronary syndrome (NSTE-ACS) is one of the most frequent manifestations of coronary artery disease. The occurrence of serious heart rhythm disorders (SHRDs) in NSTE-ACS is not well documented. However, continuous heart rhythm monitoring is recommended during the initial management of NSTE-ACS. The targeted monitoring of patients at greater risk for SHRDs could facilitate patients' care in emergency departments (EDs) where the flow of patients is continuously increasing. This retrospective single-center study included 480 patients from emergency and cardiology departments within the Strasbourg University Hospital between 1 January 2019 and 31 December 2020. The objective was to estimate the frequency of the occurrence of SHRDs among patients with NSTE-ACS. The secondary objective was to highlight the factors associated with a higher risk of SHRDs. The proportion of SHRDs during the first 48 h of hospital care was 2.3% (CI95%: 1.2-4.1%, n = 11). Two time periods were considered: before coronary angiography (1.0%), and during, or after coronary angiography (1.3%). In the first group, two patients required immediate treatment (0.4% of the patients) and no death occurred. In the univariate analysis, the variables significantly associated with SHRDs were age, anticoagulant medication, a decrease in glomerular filtration rate, plasmatic hemoglobin, and left ventricle ejection fraction (LVEF), and an increase in plasmatic troponin, BNP, and CRP levels. In the multivariable analysis, plasmatic hemoglobin > 12 g/dL seemed to be a protective factor for SHRDs. In this study, SHRDs were rare and, most often, spontaneously resolved. These data challenge the relevance of systematic rhythm monitoring during the initial management of patients with NSTE-ACS.

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.

Reduced Exercise Capacity, Chronotropic Incompetence, and Early Systemic Inflammation in Cardiopulmonary Phenotype Long Coronavirus Disease 2019.

Mechanisms underlying persistent cardiopulmonary symptoms after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (postacute sequelae of coronavirus disease 2019 [COVID-19; PASC] or "long COVID") remain unclear. This study sought to elucidate mechanisms of cardiopulmonary symptoms and reduced exercise capacity. We conducted cardiopulmonary exercise testing (CPET), cardiac magnetic resonance imaging (CMR) and ambulatory rhythm monitoring among adults >1 year after SARS-CoV-2 infection, compared those with and those without symptoms, and correlated findings with previously measured biomarkers. Sixty participants (median age, 53 years; 42% female; 87% nonhospitalized; median 17.6 months after infection) were studied. At CPET, 18/37 (49%) with symptoms had reduced exercise capacity (<85% predicted), compared with 3/19 (16%) without symptoms (P = .02). The adjusted peak oxygen consumption (VO2) was 5.2 mL/kg/min lower (95% confidence interval, 2.1-8.3; P = .001) or 16.9% lower percent predicted (4.3%-29.6%; P = .02) among those with symptoms. Chronotropic incompetence was common. Inflammatory markers and antibody levels early in PASC were negatively correlated with peak VO2. Late-gadolinium enhancement on CMR and arrhythmias were absent. Cardiopulmonary symptoms >1 year after COVID-19 were associated with reduced exercise capacity, which was associated with earlier inflammatory markers. Chronotropic incompetence may explain exercise intolerance among some with "long COVID."

Atrial strain and occult atrial fibrillation in cryptogenic stroke patients: a systematic review and meta-analysis.

Cryptogenic stroke (CS) remains a significant cause of morbidity. Failure to identify the underlying pathology increases the rate of recurrence. Atrial fibrillation (AF) seems to be responsible for a substantial proportion of CS. Thus, there is an unmet need to identify and properly treat those with silent AF. To investigate the association between left atrial strain and newly diagnosed AF in CS patients. We searched major electronic databases for articles assessing the relationship between either peak left atrial longitudinal (PALS) or peak contractile (PACS) strain-quantified using speckle tracking echocardiography-and the incidence of occult AF during the diagnostic work-up of CS patients. Eleven studies (two thousand and eighty-one patients) were analyzed. Incidence of occult AF was 19%. Both PALS and PACS were significantly lower in patients with newly diagnosed AF (MD -8.6%, 95%CI -10.7 to -6.4, I2 86.4% and MD -5.5, 95%CI -6.8 to -4.2, I2 80.8%). According to the diagnostic accuracy meta-analysis, PALS < 20% present 71% (95%CI 47-87%) sensitivity and 71% (95%CI 60-81%) specificity for the diagnosis of occult AF, assuming a prevalence of 20%. The corresponding values for PACS < 11% are 83% (95%CI 57-94%) and 78% (95%CI 56-91%). Both PALS and PACS are significantly lower in patients with CS and silent AF. It seems that the cut-off values mentioned above could help physicians in identifying patients who may benefit more from prolonged rhythm monitoring. More studies are needed to confirm these findings.

Anxiety, patient activation, and quality of life among stroke survivors prescribed smartwatches for atrial fibrillation monitoring

The detection of atrial fibrillation (AF) in stroke survivors is critical to decreasing the risk of recurrent stroke. Smartwatches have emerged as a convenient and accurate means of AF diagnosis; however, the impact on critical patient-reported outcomes, including anxiety, engagement, and quality of life, remains ill defined. To examine the association between smartwatch prescription for AF detection and the patient-reported outcomes of anxiety, patient activation, and self-reported health. We used data from the Pulsewatch trial, a 2-phase randomized controlled trial that included participants aged 50 years or older with a history of ischemic stroke. Participants were randomized to use either a proprietary smartphone-smartwatch app for 30 days of AF monitoring or no cardiac rhythm monitoring. Validated surveys were deployed before and after the 30-day study period to assess anxiety, patient activation, and self-rated physical and mental health. Logistic regression and generalized estimation equations were used to examine the association between smartwatch prescription for AF monitoring and changes in the patient-reported outcomes. A total of 110 participants (mean age 64 years, 41% female, 91% non-Hispanic White) were studied. Seventy percent of intervention participants were novice smartwatch users, as opposed to 84% of controls, and there was no significant difference in baseline rates of anxiety, activation, or self-rated health between the 2 groups. The incidence of new AF among smartwatch users was 6%. Participants who were prescribed smartwatches did not have a statistically significant change in anxiety, activation, or self-reported health as compared to those who were not prescribed smartwatches. The results held even after removing participants who received an AF alert on the watch. The prescription of smartwatches to stroke survivors for AF monitoring does not adversely affect key patient-reported outcomes. Further research is needed to better inform the successful deployment of smartwatches in clinical practice.

Prevalence of ventricular extrasystoles among smokers and individuals with risk factors for cardiovascular diseases

Abstract Funding Acknowledgements Type of funding sources: None. Main funding source(s): no. The purpose of the work to establish the prevalence of life-threatening arrhythmias and the risk of sudden death among people with a high and very high risk of cardiovascular diseases. Materials and methods During the period 2007-2013 years, we examined 4,214 patients, ages 35 to 85 years, who underwent Holter heart rhythm monitoring. Patients were divided into 4 groups. The 1st group: patients with coronary heart disease (stable angina), but without concomitant risk factors for cardiovascular diseases, such as smoking and obesity. The 2nd group - people who smoke 5 or more cigarettes per day for more than 2 years. The 3rd group - obese people without concomitant ischemic heart disease and arterial hypertension. The 4th group - people with obesity and hypertension. The control group included 149 practically healthy people. The groups were identical in age and sex. The highest prevalence of ventricular extrasystoles was recorded in group 2 (among smokers) and was 44,8% (p&amp;lt;0.01), and 9,02% of people from this group had class V ventricular extrasystoles according to V. Lown and M. Wolf classification, and the result was higher among people with stable angina, where this figure was 7,69%. The lowest prevalence of this arrhythmia was found among people with stable angina and was 30,34%. This can be explained by patients being more thoroughly supervised by doctors and medicine intake. Another reason was that groups 2-4 included people with only risk factors, and group 1 - people with the disease. Among obese people with and without hypertension, the prevalence of this arrhythmia was almost the same – 35,1% and 36,7%, respectively, and was not significantly different from the control group (33,6%). The next step was to determine the prevalence of polytopic (supraventricular + ventricular extrasystole) and ectopic foci among these individuals. And again, smokers had the highest prevalence of polytopic extrasystoles, which was 69,57%. Among people with stable angina, this figure was 55% (p&amp;lt;0.01). In people with obesity, which were included in the 3rd and 4th groups, polytopy was observed in less than half of the patients – 47,83% and 43,48%, respectively. Therefore, analyzing the data presented above, we can say that people who smoke tobacco have higher prevalence of both individual ventricular arrhythmia and ventricular and supraventricular extrasystoles than healthy individuals and people with obesity and hypertension. There is no significant difference in the prevalence of ventricular extrasystoles in individuals with only obesity or plus hypertension.

Multidisciplinary Center Care for Long COVID Syndrome–A Retrospective Cohort Study

BackgroundPersistent multi-organ symptoms after coronavirus disease 2019 (COVID-19) have been termed “long COVID” or “post-acute sequelae of SARS-CoV-2 infection.” The complexity of these clinical manifestations posed challenges early in the pandemic as different ambulatory models formed out of necessity to manage the influx of patients. Little is known about the characteristics and outcomes of patients seeking care at multidisciplinary post-COVID centers. MethodsWe performed a retrospective cohort study of patients evaluated at our multidisciplinary comprehensive COVID-19 center in Chicago, Ill, between May 2020 and February 2022. We analyzed specialty clinic utilization and clinical test results according to severity of acute COVID-19. ResultsWe evaluated 1802 patients a median of 8 months from acute COVID-19 onset, including 350 post-hospitalization and 1452 non-hospitalized patients. Patients were seen in 2361 initial visits in 12 specialty clinics, with 1151 (48.8%) in neurology, 591 (25%) in pulmonology, and 284 (12%) in cardiology. Among the patients tested, 742/916 (81%) reported decreased quality of life, 284/553 (51%) had cognitive impairment, 195/434 (44.9%) had alteration of lung function, 249/299 (83.3%) had abnormal computed tomography chest scans, and 14/116 (12.1%) had elevated heart rate on rhythm monitoring. Frequency of cognitive impairment and pulmonary dysfunction was associated with severity of acute COVID-19. Non-hospitalized patients with positive SARS-CoV-2 testing had findings similar to those with negative or no test results. ConclusionsThe experience at our multidisciplinary comprehensive COVID-19 center shows common utilization of multiple specialists by long COVID patients, who harbor frequent neurologic, pulmonary, and cardiologic abnormalities. Differences in post-hospitalization and non-hospitalized groups suggest distinct pathogenic mechanisms of long COVID in these populations.

PO-03-232 PROGNOSTIC IMPACT OF NON-SUSTAINED VENTRICULAR TACHYCARDIA IN WILD-TYPE TRANSTHYRETIN CARDIAC AMYLOIDOSIS

Non-sustained ventricular tachycardia (NSVT) detected on rhythm monitoring is common in AL amyloidosis, but data on its prevalence and prognostic impact in patients with wild-type transthyretin cardiac amyloidosis (ATTRwt-CA) are sparse. To investigate the prevalence of NSVT detected during clinically-indicated ambulatory Holter monitoring and its association with incident sustained VT and ventricular fibrillation (VF) in ATTRwt-CA patients. A single-center retrospective cohort of ATTRwt-CA patients without known history of sustained VT/VF was included (2011-2022). The presence and characteristics of NSVT (≥3 beats) at the first Holter after the ATTRwt-CA diagnosis at our institution were documented. The endpoint was the first occurrence of sustained VT or VF recorded by an implantable cardioverter-defibrillator (ICD) or other methods (in patients without ICD), and it was comparatively assessed in patients with and without NSVT with Kaplan-Meier analysis. Multivariate Cox regression analyses using stepwise variable selection were also performed to identify predictors of incident VT/VF. A total of 219 patients with ATTRwt-CA were included (mean age 74.9 years; 95% males; mean LVEF 52%). Of them, 8 had an ICD at baseline while 14 underwent ICD implantation within a 6-month window from baseline. Mean Holter monitoring duration was 25.6 hours and 53% of patients had at least one NSVT run at index Holter monitor with mean total ventricular ectopy burden 3.8%. After mean follow up 35.2 months, 17 patients experienced the primary outcome. Patients with NSVT had a lower survival free of VT/VF compared to those without NSVT (log-rank p=0.01; figure). In multivariable analysis, the presence of NSVT (HR 3.95, 95% CI 1.10-14.0) and the number of NSVT runs (HR 1.003, 95% 1.00-1.01, per run) were significant predictors of future VT/VF. NSVT is highly prevalent among patients with ATTRwt-CA and confers an increased risk of incident sustained ventricular arrhythmias. This finding has implications in the risk stratification and decision-making for the prevention of sudden cardiac death in these patients.

PO-04-144 IMPACT OF AGE ON ATRIAL ARRHYTHMIA OUTCOMES AFTER PERCUTANEOUS ASD CLOSURE

Atrial Septal Defects (ASD) are one of the most common congenital heart defects, and if unrepaired, increase the risk of atrial fibrillation (AF) and atrial flutter (AFL). AF/AFL are linked to an increased risk of stroke and heart failure yet, it is not clear from existing data whether percutaneous ASD closure reduces the overall burden of AF/AFL and whether AF/AFL prevalence is impacted by closure age. To determine the effect of age at ASD closure on the prevalence of late atrial arrhythmias. All patients who underwent percutaneous ASD closure at Cleveland Clinic from January 2010 to July 2021 were included. Patients without right-sided dilatation and Qp:Qs < 1.5, iatrogenic ASDs, and those with Eisenmenger syndrome were excluded. A non-linear logistic mixed model informed a temporal decomposition model used to analyze the association between age at ASD closure and prevalence of AF/AFL, adjusting for gender and presence of pre-closure AF/AFL. A total of 192 patients met inclusion criteria, 121 (63%) female with a median age of 41.5 years (IQR 19-61) at time of ASD closure. Median follow up time was 2.7 years (IQR 0.64-4.7). 170 (89%) patients had a total of 681 records including ECGs and ambulatory rhythm monitors. Pre-procedural AF/AFL was associated with higher likelihood of late (>6 months) AF/AFL. The prevalence of post-ASD closure AF/AFL was composed of two phases: an early peaking phase of 13% at week 1 with a gradual decrease to 3.2% by 6 months. There was a late rising prevalence from 6 months up to 6 years from 3.2% to 4.7% (Figure 1a). Age ≥ 40 years was associated with higher likelihood of early (≤ 6 months) and late (> 6 months) post procedural AF/AFL prevalence (Figure 1b). Post-device closure, only 7 (3.6%) patients required cardioversions at a median time of 2.6 months, and 5 (2.6%) required ablations at a median time of 7.4 months post ASD closure. There were only 10 arrhythmia related ER visits during the follow up period. There is an increased prevalence of AF/AFL immediately post ASD closure that declines by 6 months. Patients older than 40 years of age and those with pre-procedure AF/AFL have ongoing risk for late AF/AFL post ASD closure. Rhythm monitoring before ASD closure may be indicated in age ≥ 40 to identify those at higher risk of developing late AF/AFL. Parametric estimate of prevalence of AF or AFL after percutaneous ASD closureTime1 day1 week2 week1 month6 month1 year3 year5 year6 yearOverall (%)0.8813106.73.23.54.24.64.7Stratified by age (%)<4002.61.80.630.0130.002000≥401.34332154.656.26.97.1 Open table in a new tab

PO-02-200 CIRCADIAN OCCURENCE PATTERNS OF ATRIAL FIBRILLATION AFTER CARDIAC SURGERY DURING 2.5 YEARS OF CONTINUOUS RHYTHM MONITORING

Atrial fibrillation (AF) is a frequent complication after cardiac surgery and current theories suggest that autonomic nervous system plays a major role in early-POAF development, but its role in late-recurrences is still unknown. Previous studies in non-surgical patients have shown distinct preferential AF-occurrence patterns, such as adrenergic/daytime AF, or nocturnal AF. However, the circadian onset patterns for POAF episodes have never been studied before. To investigate POAF circadian onset patterns after cardiac surgery during 2.5 years of continuous rhythm monitoring. Patients with and without history of AF undergoing cardiac surgery were included. Continuous rhythm monitoring was performed over a period of 2.5 years. Circadian distribution of AF-episodes onset was presented in radial histograms for the whole FU period, early postoperative phase (first 90 days), and late postoperative phase (after first 90 days). In addition, Bayesian circular regression was performed to calculate the average episode onset, along with 95% credibility intervals, for different classes of episode duration. The study population consisted of 134 patients with a median follow-up of 2.7 years (IQR: 2.2-2.9 years). Eighty-one (60.4%) patients developed AF during the follow-up period. Early-POAF (first 90 days) occurred in 75 patients (56.0%) and late-POAF (after first 90 days) in 47 patients (35.1%). In patients without history of AF, there was a heterogenuous POAF-episode onset pattern with peak incidence at 4:18pm (95%CI: 6:53am to 2:16am) (Figure 1). Paroxysmal AF and persistent AF patients showed more homogenuous occurrence patterns with peak incidence at 10:07am (95%CI: 9:29am to 10:51am) for paroxysmal AF, and 9:16am (95%CI: 8:42am till 9:50am) for persistent AF (Figure 1). Peak incidence of early-POAF was at night and in the morning for all rhythm groups (Figure 1), whearas late-POAF also started during the afternoon in patients without history of AF (Figure 1). In patients without history of AF, shorter AF episodes started predominantly during the afternoon whereas longer episodes started at night and in the morning (Table 1). In paroxysmal and persistent AF patients, most episodes started in the morning hours (Table 1). In patients with history of AF, POAF starts mostly during the night and in the morning, wheras patients with new-onset AF show a more heterogeneuous daytime occurrence pattern.

PO-03-082 EFFECT OF IMPLANTABLE LOOP RECORDER INSERTION SITE ON P WAVE AMPLITUDE

Implantable loop recorders (ILRs) are increasingly utilised for rhythm monitoring, including in the diagnosis of atrial fibrillation and other atrial arrhythmias. A larger P wave amplitude may assist in improving arrhythmia diagnosis. Current manufacturer guidelines for ILR insertion suggest a left 4th intercostal space (ICS) insertion, without prior mapping of R waves or P waves. However, recent data using surface mapping suggests that P wave sensing may be improved by altering the implant site to a higher ICS. To determine the effect of ILR insertion in the 3rd or 4th ICS on ILR sensing parameters. We reviewed the medical records and remote monitoring transmissions of 117 patients who underwent Medtronic ILR insertion at our institution. Both LINQ I and LINQ II devices were included. All devices were implanted in the left parasternal 3rd or 4th ICS using surface anatomical landmarks, at a 45-60 degree angle to the sternum. The choice of ICS was at the discretion of the implanting physician. P wave, T wave, R wave (base to positive peak), S wave (base to negative peak) and peak-to-peak QRS amplitudes were measured on the using electronic calipers, which were calibrated using the included voltage marker. Patients were excluded if the presenting electrocardiogram showed atrial fibrillation. Of the 117 patients, 77 (66%) had LINQ II and 40 (34%) had LINQ I devices. The median age was 65 years (IQR 43-75 years) and 63 (54%) were male. Sixty-nine (59%) devices were inserted in the 3rd ICS. The majority of devices were inserted for investigation of syncope (61%). A 3rd ICS implant location was associated with a higher mean P wave amplitude (0.037±0.016 vs 0.026±0.012mV, p<0.001). Mean R wave amplitude was smaller (0.24±0.24 vs 0.38±0.37mV, p=0.009) but there was no difference in mean peak-to-peak QRS amplitude (0.58±0.35vs 0.60+0.39mV, p=0.74) or mean T wave amplitude (0.12±0.08 vs 0.12±0.10mV, p=0.82). The mean QRS / P amplitude ratio was significantly lower with 3rd ICS implants (16±8.5 vs 24±13.9, p<0.001). Two patients had undetectable P waves and both had devices in the 4th ICS. One patient with a 3rd ICS device had peak-to-peak QRS amplitude of 0.09mV and intermittent T wave oversensing was noted. Insertion of ILRs in the 3rd ICS as opposed to the 4th ICS resulted in significantly higher P wave amplitude without a reduction of overall QRS amplitude.

PO-02-135 DOES LA SIZE PREDICT OUTCOMES IN AF AND SYSTOLIC HEART FAILURE?

Significant left atrial (LA) enlargement often accompanies heart failure with reduced ejection fraction (HFrEF) and may determine the success of AF ablation. However, the impact of LA size on long-term outcomes remains unclear. We aim to determine the relationship between LA size and AF recurrence in patients with normal LV function (NLV) and HFrEF following AF ablation. Consecutive patients undergoing index AF ablation across 11 centres were stratified according to baseline LVEF (<50% or >50%). The impact of baseline LA size on 12-month AF recurrence was determined utilising continuous remote rhythm monitoring to detect arrhythmia recurrence and quantify AF burden. 360 patients were included (NLV=237, HFrEF=123). The HFrEF group (mean LVEF 34.9±8.3%) were younger (62±10 vs 65 ± 9 years, p=0.020), with larger LA size (LAVI 54.6±16.5ml/m2 vs 45.4±14.1ml/m2, p<0.001). Despite differences in LA size, freedom from AF was similar in those with and without HF (56% vs 54% respectively, Log Rank p=0.621, figure 1a). Similarly, AF burden did not differ between groups (median burden HFrEF 0% (0-1.1); NLV 0 (0-2.5), p=0.195). An age-matched 1:1 comparison of NLV and HFrEF (N=246) demonstrated no impact of baseline LA size on arrhythmia recurrence (p=0.579), despite larger LA in those with HFrEF (LAVI 54.6±16.5 vs NLV 45.0±15.0, p=0.0002). LA enlargement did not predict arrhythmia recurrence (HR 1.400, 95% CI 0.952-2.057, p=0.086) regardless of HF status (figure 1b). At 12 months, LV function normalised in 80% (LVEF>50%) of those with HFrEF (ΔLVEF: +19±13%, p<0.001) with a significant reduction in LA size (54.6±16.5 to 44.7±14.6ml/m2, p<0.001), comparable in those with and without AF recurrence (p=0.819). Baseline LA enlargement did not influence AF recurrence in those with or without LV recovery (HR 1.622 95% CI 0.702-3.748, p=0.258). LA enlargement did not determine the outcome of AF ablation in those with and without HFrEF. LA size is less useful in guiding patient selection for AF ablation in HFrEF

PO-04-124 ARRHYTHMIAS INCLUDING ATRIAL FIBRILLATION IN KLEEFSTRA SYNDROME: A POSSIBLE EPIGENETIC LINK

Kleefstra syndrome (KS), often diagnosed in early childhood, is a rare genetic disorder (EHMT1 gene: an important epigenetic modulator) that is characterized by hypotonia, developmental delay and distinct facial features. Although congenital heart disease (CHD) is frequently reported, there is a paucity of data on the prevalence of CHD subtypes and arrhythmias in KS; no known reports of Atrial Fibrillation (AF). To systematically assess the prevalence of CHD and arrhythmias in KS. Cross-sectional analysis of the two largest known KS registries: Radboudumc (50 patients, median/IQR age: 13.5/13 years) based on health record review at Radboud University Medical Center in Netherlands, and GenIDA (163 patients, median/IQR age: 10/12 years) based on surveys of patient families from around the world. Case series of 3 additional patients with KS and atrial tachyarrhythmias. Both registries independently report 40% (20 patients in Radboudumc and 65 in GenIDA) prevalence of a cardiovascular system abnormality and 2-8% prevalence of arrhythmias (4 in Radboudumc and 3 in GenIDA). Radboudumc registry included 14% patients with atrial septal defect (ASD), 12% with ventricular septal defect (VSD), 4% patients each with Tetralogy of Fallot and pulmonary valve stenosis, and none with left ventricular dysfunction. The 8% patients with arrhythmias in this registry did not report significant CHD and included one patient with AF, two with supraventricular tachycardias (SVTs), and one with ventricular tachycardia (VT). GenIDA registry reported 1% patients with cardiomyopathy, 10% with VSD, 13% with ASD, 16% with valvular disease, and 9% with vascular malformations. This registry also included one patient with AF and another with chronic ectopic atrial tachycardia with neither patient reporting CHD. A case series of 3 additional KS patients not included in these registries with atrial tachyarrhythmias reveals two patients with AF and one with atrial tachycardia, in the absence of CHD. One patient with symptomatic AF refractory to medications underwent successful pulmonary vein isolation (first known report) at age 23 without recurrence at 16 months. The largest database of KS patients compiled to-date reveals a high prevalence of CHD and early-onset atrial tachyarrhythmias including AF, even in the absence of structural heart disease. These findings suggest a role for regular electrocardiograms and ambulatory rhythm monitoring as well as a possible novel epigenetic mechanism for AF.