Surveillance of arrhythmia in post-myocardial infarction patients using wearable ECG patch devices: a prospective cohort study (Preprint)

BACKGROUND Acute myocardial infarction may be associated with new-onset arrhythmias. Myocardial infarction patients may manifest with serious arrhythmias such as ventricular tachyarrhythmias or atrial fibrillation. Frequent, prolonged electrocardiogram (ECG) monitoring can prevent devastating outcomes by these arrhythmias. OBJECTIVE We investigated the incidence of arrhythmias in post-myocardial infarction patients using a patch-type device: ATP-C120. METHODS This study is a non-randomized, single-center, prospective cohort study. We evaluated 71 patients with post-myocardial infarction who had been admitted to our hospital. The ATP-C120 device was attached for 11 days and analyzed by two cardiologists for new-onset arrhythmic events. RESULTS One participant was concordantly diagnosed with atrial fibrillation. Atrial premature beats occurred in 91.5% and 84.5% of participants, and ventricular premature beats occurred in 53.5% and 62.0%, respectively. Interestingly, 56.3% of the patients showed less than 2 minutes of sustained paroxysmal atrial tachycardia. Among participants with atrial tachycardia, the use of beta blockers was significantly lower (70.0% vs. 90.3%, p=0.037). However, different dosages of beta blockers did not show significant differences. CONCLUSIONS Wearable patch ECG monitoring devices are easy to apply and can correlate symptoms and ECG rhythm disturbances among post-myocardial infarction patients. Further study is necessary regarding clinical implications and appropriate therapies for arrhythmias detected early, post-myocardial infarction, to prevent adverse outcomes.

Characteristics of the Dynamic Electrocardiogram in the Elderly with Nonvalvular Atrial Fibrillation Combined with Long R-R Intervals

Objective. To investigate the characteristics of dynamic electrocardiogram and their clinical implications in elderly patients with nonvalvular atrial fibrillation combined with long R-R intervals. Methods. Elderly patients diagnosed with nonvalvular atrial fibrillation who were admitted as an inpatient or attended the outpatient department from January 2015 to January 2020 were selected. Patients were divided into two groups based on the presence of a long R-R interval. The characteristics and therapeutic significance of dynamic electrocardiogram between the two groups were compared. Results. A total of 532 patients were included in our analyses. Of these, 399 patients were in the long R-R interval group and 133 in the nonlong R-R interval group. In 399 patients, there were 48,840 long R-R intervals manifested within 24 hours. The average, slowest, and fastest ventricular rates during sleep time were higher than those in nonsleep time, while the number of long R-R intervals in sleep time was significantly smaller than that in nonsleep time ( P < 0.05 ). Clinical parameters including dizziness/syncope, cerebral infarction, ST-segment changes, platelet count, average hematocrit, prothrombin time (PT), left ventricular systolic function, end-diastolic diameter, pulmonary artery pressure, and left ventricular ejection fraction were comparable between the groups ( P > 0.05 ). When compared with the nonlong R-R interval group, the level of C-reactive protein was slightly lower in the long R-R interval group ( P < 0.05 ). In addition, the long R-R interval group had a higher incidence of atrial premature beats but a lower incidence of ventricular premature beats. Furthermore, the probability of long R-R interval combined with paroxysmal atrial tachycardia, transient ventricular arrest, second-degree atrioventricular block, and complete or incomplete right bundle branch block was higher than that of nonlong R-R interval ( P < 0.05 ). In patients with long R-R interval >3 s, the risk of having second-degree atrioventricular block and complete or incomplete right bundle branch block was significantly lower, while the risk of having transient ventricular arrest was higher when compared to patients with long R-R intervals of 2-3 s ( P < 0.05 P). Conclusions. Long R-R interval is a common electrocardiographic phenomenon among the elderly with nonvalvular atrial fibrillation. The long R-R interval mostly occurs in nonsleeping time. The average ventricular rate, slowest ventricular rate, and fastest ventricular rate of sleep time are higher than nonsleeping time. Analysis of the characteristics of the dynamic electrocardiogram of these patients may shed light on the mechanisms for long R-R intervals, including the likelihood of concealed conduction and physiological interference in the atrioventricular node, overspeed inhibition, increased vagus nerve tension, or pathological atrioventricular block.

Significance of Ectopic Beats in Post Aortic Valve Replacement Arrhythmia Patients

Objective: The incidence of new onset arrhythmia after conventional aortic valve replacement (AVR) is relatively high whereby atrial fibrillation (AF) in particular (30-40%). Arrhythmias increase postoperative morbidity, mortality and consequently health costs. The need for a reliable method for early detection and discrimination between low and high risk patients is therefore indispensable. For this reason this study examined the possible correlation between electrophysiological abnormalities on continuous ECG recordings and the initiation of arrhythmia directly after surgery. Methods and Results: Both ECG and clinical data was collected from the hospitals filing system for all patient (n=107) who underwent surgical Aortic Valve Replacement (AVR) for non-rheumatic aortic valve stenosis or insufficiency for the period from January 2010 to December 2018. Continuous ECG data was converted into ISHNE-format and analyzed by using Synescope™ software. Data showed that one minute prior to arrhythmia, AF in particular, an increase of both supraventricular premature beats (SVPB) and missed beats (MB) was detected (n=33; P<0,05). However there was no correlation between arrhythmia and the overall SVPB incidence (n=33). Twenty-one out of 33 AVR patients developed a de novo intraventricular conductance delay directly after cardioplegic arrest, which persisted in 7 cases. Conclusions: Although there is an increase of both SVPB and MB prior to arrhythmia startup, it is still questionable what is the true predictive value of these findings are. Additionally it appeared that a temporarily intraventricular conduction delay (IVCD) is a common finding after AVR.

Effects of chronic exposure to usual and high doses of Bisphenol A on cardiac arrhythmias, electrophysiology, and autonomic modulation

Background Bisphenol A (BPA) is a synthetic compound found in plastic bottles, sports equipment, or water pipes. The continuous and inevitable human exposure to BPA has been related to increased cardiovascular risk. In experimental studies, acute exposure to high BPA doses was associated with ventricular arrhythmias. However, the effects of chronic exposure to usual BPA doses (i.e., relevant for usual human exposure) on cardiac arrhythmogenicity have not been properly assessed. Purpose We aimed to assess the effects of chronic exposure to high and usual BPA doses on cardiac arrhythmias, electrophysiology, and autonomic modulation in rats. Methods Adult female Wistar rats were randomized into 3 groups: Control, BPA, and BPA-HD (n=7 each). BPA and BPA-HD rats received 50 μg/kg/day and 25 mg/kg/day of BPA, respectively, for 9 weeks. Rats were implanted with radiotelemetry ECG devices and 24-h ECG recordings were performed prior to and after application of transesophageal atrial burst pacing (4,000 stimuli/min for 20 s; 15 cycles). Heart rate variability (HRV) parameters and atrial and ventricular arrhythmias (i.e., atrial premature beats [APB], atrial fibrillation [AF], ventricular premature beats [VPB], ventricular tachycardia/fibrillation [VT/VF]) were assessed based on the 24-h ECG recordings. The left atrium was then collected and atrial depolarization velocity and action potential duration to 90% (APD90) and 50% (APD50) of complete repolarization were measured. Results Mean heart rate (p=0.48), the number of VPB (p=0.90), AF inducibility (p=0.68), and atrial action potential parameters (all p&gt;0.05) were all similar between the 3 groups. None of the animals presented VT/VF. There was no significant difference in the number of atrial or ventricular arrhythmic events nor in the HRV parameters between BPA and Control (all p&gt;0.05). However, BPA-HD presented a significantly higher number of APB both prior to (p=0.02) and after (p=0.04) atrial pacing, and a significantly higher number of post-pacing spontaneous AF episodes (p&lt;0.01) compared to Control. The parasympathetic indexes SDNN, RMSSD, pNN5, and the NHF of the HRV spectrum were all significantly higher (all p&lt;0.05), whereas the LF/HF ratio, an index of sympathetic and parasympathetic interactions, was significantly lower (p=0.01) in the BPA-HD compared with the Control rats. Conclusions In rats, chronic exposure to BPA doses relevant for usual human exposure was not associated in any significant change in cardiac arrhythmogenicity, electrophysiology, or autonomic modulation. However, high-dose BPA exposure, such as that occurring in workers in the plastics industry, led to significant increase in atrial arrhythmogenicity, including AF, that did not seem to be related to atrial electrophysiology changes. Instead, given the strong atrial proarrhythmic effects of vagal hyperactivity, this effect could be linked to the significant increase in vagal modulation induced by high-dose BPA exposure. FUNDunding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was supported by a grant of the Romanian Ministry of Education and Research, CNCS – UEFISCDI

Chronic Exposure to High Doses of Bisphenol A Exhibits Significant Atrial Proarrhythmic Effects in Healthy Adult Rats

Objectives: We aimed to evaluate the effects of chronic exposure to bisphenol A (BPA) on atrial fibrillation (AF) occurrence in rats. Methods: Twenty-two healthy female Wistar rats were randomized into three groups: Control (no BPA; n=7), BPA (exposed to usual BPA doses; 50 μg/kg/day, 9 weeks; n=7), and hBPA (exposed to high BPA doses; 25 mg/kg/day, 9 weeks; n=8). 24-h ECG monitoring was performed using radiotelemetry ECG devices prior to and after transesophageal atrial pacing. Spontaneous and pacing-induced atrial arrhythmias, autonomic tone, and in vivo an in vitro atrial arrhythmogenicity-related parameters were evaluated. Results: All studied parameters were similar between Control and BPA (all p>0.05). However, compared to Control, hBPA presented more atrial premature beats both at baseline (p=0.04) and after pacing (p=0.03), more AF episodes (p<0.001) and of longer duration (p=0.02) following transesophageal stimulation, and significantly higher vagal tone (all p<0.05). Conclusions: Chronic exposure to high, but not usual BPA doses induced significant atrial proarrhythmic effects in healthy rats, and this may be at least partially due to BPA-induced vagal hyperactivation. Exposure to high BPA doses, such as that occurring in plastics industry workers, could favor AF occurrence even in the absence of underlying cardiovascular disease.

Cardiovascular consequences of COVID-19: pathogenesis, diagnosis and treatment

В статье представлен обзор научной литературы, содержащий данные о патогенезе, диагностике и лечении сердечно-сосудистых последствий перенесенной новой коронавирусной инфекции. Поражение сердца наблюдается у 7-28% госпитализированных пациентов с COVID-19. Поражение миокарда при воздействии коронавирусной инфекции может быть реализовано посредством двух патологических механизмов: прямое повреждение миокарда вследствие взаимодействия SARS-CoV-2 с миокардиальными рецепторами ангиотензинпревращающего фермента 2, а также косвенное повреждение миокарда, которое может быть вызвано цитокинами и другими провоспалительными факторами, нарушением микроциркуляции, гипоксическими изменениями кардиомиоцитов. Частыми аритмическими осложнениями COVID-19 бывают фибрилляция предсердий и желудочковая экстрасистолия. Несмотря на многочисленные публикации о поражении сердца в острой фазе этого заболевания, данные о сохраняющихся после выздоровления нарушениях недостаточны, клинические рекомендации по ведению таких пациентов отсутствуют. На основе приведенного клинического случая описаны механизмы комбинированной терапии бисопрололом и амлодипином частой желудочковой экстрасистолии, возникшей после перенесенного СОVID-19. The paper presents an overview of the scientific literature containing data on the pathogenesis, diagnosis and treatment of cardiovascular consequences of a new coronavirus infection. Heart damage is observed in 7-28% of hospitalized patients with COVID-19. Myocardial damage when exposed to coronavirus infection can be realized through two pathological mechanisms: direct myocardial damage due to the interaction of SARS-CoV-2 with myocardial ACE2 receptors, as well as indirect myocardial damage, which can be caused by cytokines and other pro-inflammatory factors, microcirculation disorders, hypoxic changes cardiomyocytes. Frequent arrhythmic complications of COVID-19 are atrial fibrillation and ventricular premature beats. Despite numerous publications on heart damage in the acute phase of this disease, data on disorders remaining after recovery are insufficient, there are no clinical recommendations for the management of such patients. Based on the given clinical case, mechanisms of combination therapy of bisoprolol and amlodipine of frequent ventricular extrasystolia, which arose after COVID-19, are described.

Ventricular disturbance of rhythm as a symptom of cardiovascular disease

The questions of the differential diagnosis of diseases accompanied by ventricular premature beats (ischemic heart disease, myocarditis, arrhythmogenic right ventricular dysplasia) are thrusted into the spotlight.

A case of infra-nodal Wenckebach conduction block with alternating bundle branch block

Background Atrioventricular (AV) node normally has decremental conduction property and a longer refractory period than His-Purkinje system (HPS). This results in AV conduction delay or block at the level of AV node in response to short-coupled atrial premature beats. Prolonged refractoriness in HPS can produce unusual physiological patterns of AV conduction such as conduction delay or infra-nodal block in the distal elements of HPS. Case presentation We present a case in which atrial premature stimulation produces infra-nodal Wenckebach conduction block which initiates long-short cycle sequence within the bundle branches resulted in alternating bundle branch block and atypical pattern of Ashman phenomenon. Conclusions This case highlights the importance of recognizing the unusual physiological AV conduction patterns of HPS. The long-short cycle sequence in the bundle branches of distal HPS and linking phenomenon can result in alternating bundle branch block without the presence of HPS disease.

Genotype-phenotype association in patients with arrhythmic variant of non-compaction cardiomyopathy

Funding Acknowledgements Type of funding sources: None. Purpose. To evaluate the genotype-phenotype association in Belarusian patients with non-compaction cardiomyopathy (NCCM) and clinically significant ventricular arrhythmias. Methods. The study included 170 unrelated pts with NCCM prospectively observed in the RSPC "Cardiology", who underwent 24-hour Holter ECG monitoring for 12 months after entering the study. The median follow-up was 36 months [6; 152,0]. The median age of pts was 42 [18; 69] years, men – 63,2%. The arrhythmic phenotype of NCСM was diagnosed by the presence of unexplained syncope; nonsustained ventricular tachycardia, defined as ≥3 consecutive ventricular contractions lasting &lt;30 seconds with a frequency of ≥120 bpm; the presence of ≥ 500 ventricular premature beats (VPB) per day. The diagnosis of NCCM was established on the basis of the following criteria: 1) Echocardiography of the R. Jenni criteria; 2) CMR of the S. Petersen and A. Jaquier criteria. The mutations search in the coding sequences of 174 genes was performed in 30 unrelated pts with NCCM using next generation sequencing (NGS). Results. In 76 out of 170 (44,7%) pts, clinically significant arrhythmias were the leading manifestation of the disease. Nonsustained VT was recorded in 54 (71,1%) pts, sustained VT – in 15 (19,7%) pts, VPB more than 500 per day – in 50 (65,8%), chronic AF with episodes of nonsustained VT was noted in 34 (44,7%) pts. During the follow-up period (median follow-up of 36 months), devices (ICD/CRT-D) were implanted in 15 (19,7%) pts, appropriate shocks were observed in two of them; three pts died, among which SCD occurred in one patient with CRT-D therapy, which was ineffective in stopping sustained VT. NGS sequencing revealed 40 changes in the nucleotide sequence (5 pathogenic mutations, 30 variants with uncertain significance (VUS), 5 new substitutions) in 27 genes in 26 (86,7%) probands. The proportion of mutations in sarcomeric proteins genes was 26,9%, and in ion channel proteins genes was 23,1%. Nucleotide changes in genes encoding structural proteins accounted for 11,5%. In 38,5% of cases, not one, but two or more rare mutations were detected, and in 30,8% – amino acid replacements were found in proteins of different functional classes. Conclusions. The frequency of multiple mutations was higher (38,5%) in the group of pts with the arrhythmic NCCM phenotype. In the group of pts with implantable devices (ICD/CRT-D), mutations in the genes of sarcomeric proteins were observed more often. The genetic characteristics of pts, along with their clinical characteristics, are markers of a high risk of developing life-threatening arrhythmias and can be additionally used for predicting adverse events in pts with NCCM, as well as for early diagnosis of the disease in their relatives.