Cardiac Arrhythmias Automated Screening Using Discrete Fractional-Order Integration Process and Meta Learning Based Intelligent Classifier

The long-term outcome of athletes with frequent ventricular premature complexes (VPCs) and apparently normal heart has not been fully clarified. To evaluate the clinical and prognostic significance of VPCs and the influence of continuing sports activity during follow-up, we studied 120 healthy athletes (96 men; median age 16 years) in whom frequent VPCs (>100 VPCs/24 hours) were discovered by chance during preparticipation screening. All athletes were followed up for a median of 84 months. During follow-up, 96 underwent serial 24-hour Holter recording and 62 underwent serial echocardiography. The median number of VPCs/24 hours on basal Holter was 3,760. During follow-up, 81 athletes continued sports activity, whereas 39 did not. No athlete died or developed overt heart disease. The median number of VPCs/24 hours decreased in both athletes who continued sports activity and those who did not (from 3,805 to 1,124, p <0.0001 and from 5,787 to 1,298, p <0.0001, respectively). During follow-up, left ventricular ejection fraction slightly decreased to <55% in 9 of 62 athletes who, in respect to the remaining 53, had more VPCs/24 hours both in the basal state (12,000 vs 3,880) and during follow-up (10,702 vs 1,368), and a longer follow-up (95 vs 36 months). In conclusion, (1) frequent VPCs in athletes without heart disease have a long-term benign prognostic significance, (2) sporting activity does not modify this benign outcome, (3) during follow-up, the burden of VPCs decreases whether or not subjects continue sports activity, and (4) in 14.5% of athletes, ejection fraction slightly decreases over time.

Premature ventricular contraction (PVC), a common arrhythmia affecting 1–2% of the general population, has been considered to have a benign clinical course. However, people with PVC often develop heart failure and ventricular arrhythmias such as ventricular tachycardia. We aimed to clarify the risk of heart failure and lethal ventricular arrhythmias in people with PVC. The Korean National Health Insurance Service database was used for this study. People who underwent nationwide health check-ups in 2009 were enrolled in this study and clinical follow-up data until December 2018 were analyzed. Newly diagnosed PVC in 2009 (≥ 1 inpatient or outpatient claim) were identified and cumulative incidence of heart failure (≥ 1 inpatient claim) and ventricular arrhythmias (≥ 1 inpatient or outpatient claim) were compared. A total of 4515 people were first diagnosed with PVC in 2009 among 9,743,582 people without prior history of PVC, heart failure, or ventricular arrhythmias. People with newly diagnosed PVC in 2009 had a significantly higher incidence of heart failure compared to those without PVC [adjusted hazard ratio (HR) 1.371; 95% confidence interval (CI) 1.177–1.598; p < 0.001]. Significant interaction was observed between age and PVC with young age people at greater risk of developing heart failure for having PVC. The incidence of ventricular arrhythmia was also significantly increased in people with PVC (HR 5.588; 95% CI 4.553–6.859; p < 0.001). Age and chronic kidney disease had significant interactions with PVC. In conclusion, the incidence of heart failure and ventricular arrhythmia was significantly increased in people with PVC. Outpatient follow-up of people with PVC can be helpful to detect early signs of heart failure or advanced forms of ventricular arrhythmia.

This study evaluates four databases from PhysioNet: The American Heart Association database (AHADB), Creighton University Ventricular Tachyarrhythmia database (CUDB), MIT-BIH Arrhythmia database (MITDB), and MIT-BIH Noise Stress Test database (NSTDB). The ANSI/AAMI EC57:2012 is used for the evaluation of the algorithms for the supraventricular ectopic beat (SVEB), ventricular ectopic beat (VEB), atrial fibrillation (AF), and ventricular fibrillation (VF) via the evaluation of the sensitivity, positive predictivity and false positive rate. Sample entropy, fast Fourier transform (FFT), and multilayer perceptron neural network with backpropagation training algorithm are selected for the integrated detection algorithms. For this study, the result for SVEB has some improvements compared to a previous study that also utilized ANSI/AAMI EC57. In further, VEB sensitivity and positive predictivity gross evaluations have greater than 80%, except for the positive predictivity of the NSTDB database. For AF gross evaluation of MITDB database, the results show very good classification, excluding the episode sensitivity. In advanced, for VF gross evaluation, the episode sensitivity and positive predictivity for the AHADB, MITDB, and CUDB, have greater than 80%, except for MITDB episode positive predictivity, which is 75%. The achieved results show that the proposed integrated SVEB, VEB, AF, and VF detection algorithm has an accurate classification according to ANSI/AAMI EC57:2012. In conclusion, the proposed integrated detection algorithm can achieve good accuracy in comparison with other previous studies. Furthermore, more advanced algorithms and hardware devices should be performed in future for arrhythmia detection and evaluation.

Transcatheter aortic valve implantation (TAVI) is a therapeutic treatment for patients with severe aortic stenosis (AS) at high surgical risk. Although the procedure is associated with a reduction in total mortality, there are no data regarding changing in the incidence of premature ventricular contractions (PVCs) and ventricular arrhythmias (VAs) after TAVI. The aim of this study was to assess the incidence of VAs before and after TAVI. We enrolled 237 patients who underwent TAVI at our centre. Ninety-one patients were excluded for the following reasons: presence of prior permanent pacemaker (PPM) (n = 20), new PPM implant after TAVI (n = 48), death during the follow-up period (n = 16), and lost at follow-up (n = 7). Finally, 146 patients were included in our analysis. The presence of VAs was evaluated in all patients recording a 24 h Holter monitoring before the procedure and after 1 and 12 months. Ventricular arrhythmias were classified according to a modified Lown grading system. Before the procedure, isolates PVCs (grade 1-2 of Lown grading system) were present in 34.9% of patients (n = 51). Complex PVCs (grade 3-4a-4b of Lown grading system) were present in 48.6% of the population (multifocal PVCs in 32 patients, 21.9%; pairs in 25 patients, 17.1%; ventricular tachycardia in 14 patients, 9.6%). One month after the procedure, we observed statistically significant incidence decrease of arrhythmias of grade 3 (from 21.9 to 17.1%) and grade 4 (pairs from 17.1 to 12.3%; ventricular tachycardia from 9.6 to 4.8%). After 12 months, there was a further significant reduction in the frequency and severity of PVCs. In particular, 45.8% of patients had isolates PVCs (<30 in all given hours of monitoring in 45 patients, 30.8%; higher than 30 in any hour of monitoring in 22 patients, 15%) while the frequency of complex arrhythmias was reduced to 16.4% (multifocal PVCs in 13 patients, 9%; couplets 8 patients, 5.5% and ventricular tachycardia in 3 patients, 2.0%). The difference was statistically significant (P < 0.01). This study indicates that VAs are common in patients with AS. We observed a significant decrease in the incidence and severity of PVCs since the first month after TAVI. Furthermore, after 1 year follow-up there was a further and significant reduction in the frequency of complex PVCs. This may be related to the benefits determined by valve replacement on left ventricular function.

Background A subset of patients with mitral valve prolapse (MVP) are at risk of life-threatening ventricular arrhythmias (VAs), and a high burden of premature ventricular contractions (PVCs) is associated with increased mortality in patients with MVP. Previous studies indicate that PVC burden could either increase with increasing heart rate (HR), decrease with increasing HR, or with no relationship to HR. The association between PVC burden and HR in MVP is not known, nor if there is an association with VAs. Purpose We aimed to explore the relationship between PVC burden and HR in patients with MVP. Furthermore, we aimed to explore whether the different PVC profiles were associated with severe VA. Methods In this cross-sectional ambispective outcome study, we included patients with MVP and available Holter monitorings with &amp;gt;100 PVCs per 24-hours seen at our tertiary centre. The Holter monitoring with the highest PVC burden was used in case of multiple recordings. We investigated the relationship between hourly PVC burden and hourly mean HR by univariable mixed linear regression. We defined PVC profiles as (1) fast-HR-dependent-PVC (F-HR-PVC) when there was a significant positive correlation, (2) slow-HR-dependent-PVC (S-HR-PVC) when there was a significant negative correlation, and (3) independent-HR-PVC (I-HR-PVC) when no correlation between PVC and HR was found. The significance was set to 0.05. Severe VA was defined as sustained ventricular tachycardia, non-sustained ventricular tachycardia with haemodynamic instability, ventricular fibrillation, aborted cardiac arrest, or appropriate shock by a primary preventive implantable cardioverterefibrillator. Severe VA was recorded from retrospective medical history, prospective ICD interrogation or monitoring with implantable loop recorder. Results We included 75 patients with &amp;gt;100 PVCs at Holter monitoring (median age 48 years [IQR 35-58], 58% female). The median PVC burden was 1.9% per 24-hours (IQR 0.4-7.2). We found F-HR-PVC in 49 patients (65%), S-HR-PVC in 1 (1%), and I-HR-PVC in 25 (33%). Twelve (16%) patients had severe VA and these had higher PVC burden compared to those without severe VA (7.3% per 24-hours [IQR 4.2-10.4] vs 1.1% per 24-hours [IQR 0.3-5.3], p=0.004). The median PVC burden was 1.5% (IQR 0.3-8.0) for F-HR-PVC, 5.7% for S-HR-PVC and 1.5% (IQR 0.3-8.0) for I-HR-PVC. We found no association between different PVC profiles and the presence of severe VA (F-HR-PVC 65% vs 67%, S-HR-PVC 2% vs 0%, I-HR-PVC 33% vs 33%, p&amp;gt;0.05 for all groups). Conclusion Fast-HR-dependent-PVC was most common in MVP patients, and slow-HR-dependent-PVC were rare. A higher PVC burden was associated with severe VA. However, different PVC profiles did not infer higher risk of severe VA in our study. Further studies are needed to explore whether distinct PVC profiles can predict severe VA in larger patient populations.

Perioperative management of severe head injury in a patient with arrhythmogenic right ventricular dysplasia.

In this study, we evaluated the relationship between beat-to-beat changes in high frequency components of the QRS complex and ventricular arrhythmias by using a newly developed event-related (ER) signal averaging technique. The study involved 82 patients with premature ventricular contractions (PVC), 56 of whom, including 16 with ventricular tachycardia (VT), were enrolled in Analysis I. In Analysis I, averaged sinus beats were classified into three patterns: 1) the sinus beat immediately before PVC (BEF); 2) that immediately after PVC (AFT); and 3) all sinus beats (ALL). Analysis II covered the remaining 26 patients, and involved five modes of event-related signal averaging, using: 1) the second beat preceding PVC (2-B); 2) the beat immediately preceding PVC (1-B); 3) the beat immediately after PVC (1-A); 4) the second beat after PVC (2-A); and 5) the beat isolated (ISO) from PVC. The filtered QRS duration (F-QRS) and the integral voltage of the terminal 40 msec (RMS 40-I) were measured using these averaging patterns. F-QRS in the VT group was longer than that in the non-VT group, but RMS 40-I was shorter. The F-QRS of BEF (1-B) was significantly longer than that of AFT (1-A). The transient difference in the F-QRS was observed in both VT and non-VT groups. This difference was almost eliminated at AFT (1-A) in the non-VT group, but was stable at AFT (1-A) in the VT group. Simultaneousely, RMS 40-I in BEF was significantly shorter than that in AFT. This transient decrease of RMS 40-I was observed in both VT and non-VT groups. Although RMS 40-I after this decrease showed a return almost to the control level at AFT in the non-VT group, it tended to remain even at AFT in the VT group. The sudden prolongation of F-QRS that occurred with the RMS 40-I decrease in BEF was related to the appearance of PVCs. We attributed the fact that these changes in F-QRS and RMS 40-I were observed even at AFT in the VT group to electrophysiologically preferable conditions for reentry.

Hospital discharge diagnoses of ventricular arrhythmias and cardiac arrest were useful for epidemiologic research

Cardiac arrhythmias are frequently detected in patients with mitral valve prolapse (MVP) The proper mechanisms causing ventricular arrhythmias in patients with MVP have not been fully investigated. In the current issue of the International Journal of Cardiovascular Imaging, Turker et al. [1] evaluated the clinical, echocardiographic and heart rate variability (HRV) parameters, and plasma concentrations of electrolytes and inflammatory markers in predicting ventricular arrhythmias in 58 consecutive patients with MVP. Ventricular arrhythmias were defined as the occurrence of ventricular premature contractions (VPCs), VPC couplets, and ventricular tachycardias documented by Holter analysis, continuous monitoring or by electrocardiography. Twenty patients (34%) showed ventricular arrhythmias, and 38 (66%) patients did not have ventricular arrhythmias. Seventeen patients had VPC, 2 patients had VPC couplets and one patient had ventricular tachycardia. Univariable predictors of ventricular arrhythmias included echocardiography-determined isovolumetric relaxation time and the presence of moderate to severe mitral regurgitation. Interestingly, multivariable logistic regression analysis showed that occurrence of moderate to severe mitral regurgitation was the only independent predictor of ventricular arrhythmias. Several recent studies did already address the relation between cardiac arrhythmias and the presence of MVP. Chen et al. [2] showed that improper autonomic tone is to be considered the etiology of arrhythmias in conjunction with MVP. Heart rate turbulence (HRT) and HRV are methods assessed for autonomic dysfunction. The authors studied the relationship of HRT, HRV and the number of ventricular premature beats in patients with MVP and non-significant mitral regurgitation. No significant correlation was found between the number of VPCs and HRT/HRV parameters. Markiewicz-Łoskot et al. [3] studied electrocardiographic abnormalities in ten young athletes with MVP. Abnormal ECG repolarization was found in seven athletes. Young athletes with MVP are therefore often predisposed to electrocardiographic abnormalities of ventricular repolarization. Cetinkaya et al. [4] evaluated the risk of vasovagal syncope and cardiac arrhythmias in 37 children with MVP. Arrhythmias and the risk of vasovagal syncope, indicated by a positive tilt test, were found to be increased in children with MVP. Similar to echocardiography [5–13], cardiovascular magnetic resonance (CMR) imaging can identify MVP by similar anatomic and functional criteria [13–30]. In addition, CMR allows tissue characterization in various cardiac diseases using hyperenhancement techniques [31–38]. In this way, CMR can identify myocardial fibrosis involving the papillary muscle in MVP patients. Delayed contrast enhancement (DCE) of papillary muscles is often present in a subgroup of patients with complex ventricular arrhythmias [39]. This tissue hyperenhancement is indicative of fibrosis which may act as a focus for arrhythmias. Kwon et al. [40, 41] using delayed contrast enhancement CMR, showed a clear association of myocardial fibrosis, electrocardiography and ventricular tachyarrhythmia in hypertrophic cardiomyopathy (HCM). HCM subjects with ventricular tachycardias showed a higher percentage of myocardial scarring on DCE-CMR. As a consequence, the presence of fibrotic papillary muscles in patients with MVP might give rise to both cardiac arrhythmias and mitral regurgitation. In addition to echocardiography and CMR, multislice computed tomography (MSCT) has recently been shown to evaluate the functional status of the mitral valve in patients with MVP [42–45]. MSCT may therefore have a major role in preoperative assessment of the mitral valve apparatus before mitral valve surgery. To summarize, nowadays the diagnosis of MVP can be made by several imaging techniques. Apart from echocardiography, CMR and MSCT are capable of accurately delineating the structure and function of the mitral valve. Next, there is a clear association between the level of incompetence of the mitral valve and the presence of cardiac arrhythmias, in particular in case of MVP. These findings have been proven both by echocardiography and DCE-CMR. The study by Turker et al. [1], using echocardiography, add to these results by showing that the occurrence of moderate to severe mitral regurgitation was the only independent predictor of ventricular arrhythmias in patients with MVP.

Ventricular arrhythmias (VAs) are rare in pediatric patients, especially in absence of structural heart disease (SHD). Few data are available regarding the invasive VAs treatment with catheter ablation (CA) in pediatric patients and predictors of outcomes have not been fully investigated. To describe the clinical presentation, procedural characteristics, and outcomes in pediatric patients undergoing CA for VAs. Eighty-one consecutive pediatric patients (58 male [72%], 15.5 ± 2.2 years) treated by CA for ventricular tachycardia (VT) or premature ventricular beats (PVBs) were retrospectively evaluated. Study endpoints were VAs recurrence and mortality for any cause. Ninety-five procedures were performed in 81 patients, 52 (55%) PVBs and 43 (45%) VT ablations. During a follow-up of 35.0 months (interquartile range = 13.0-71.0), 14 patients (14.7%) had a VA recurrence: 11 (33.3%) patients treated with CA for VT and 3 (6.2%) patients treated for PVBs (p < .001). One patient (1%) died 26 months after the procedure during an electrical storm. Patients with SHD had higher VAs recurrence rate, as compared with idiopathic VAs (pairwise log-rank p < .001). Patients treated with CA for VT had higher VA recurrence rate, as compared with PVB patients (pairwise log-rank p = .002). At Cox multivariate analysis only SHD was an independent predictor of VAs recurrence (hazard ratio = 5.56, 95% confidence interval = 2.68-11.54, p < .001). CA of VAs is effective and safe in a pediatric population. CA of idiopathic and fascicular VAs are associated with lower recurrence rate, than VAs in the setting of SHD.

Effects of cardiac resynchronization therapy on incidence of arrhythmic events in responder and nonresponder patients

A rapid wide complex tachycardia

Restrictive cardiomyopathy (RCM) is the least common among cardiomyopathies. It can be idiopathic, familial, or secondary to systematic disorders. Marked increase in left and/or right ventricular filling pressures causes symptoms and signs of congestive heart failure. Electrocardiographic findings are nonspecific and include atrioventricular conduction and QRS complex abnormalities and supraventricular and ventricular arrhythmias. Echocardiography and cardiac magnetic resonance (CMR) play a major role in diagnosis. Echocardiography reveals normal or hypertrophied ventricles, preserved systolic function, marked biatrial enlargement, and impaired diastolic function, often with restrictive filling pattern. CMR offering a higher spatial resolution than echocardiography can provide detailed information about anatomic structures, perfusion, ventricular function, and tissue characterization. CMR with late gadolinium enhancement (LGE) and novel approaches (myocardial mapping) can direct the diagnosis to specific subtypes of RCM, depending on the pattern of scar formation. When noninvasive studies have failed, endomyocardial biopsy is required. Differentiation between RCM and constrictive pericarditis (CP), nowadays by echocardiography, is important since both present as heart failure with normal-sized ventricles and preserved ejection fraction but CP can be treated by means of anti-inflammatory and surgical treatment, while the treatment options of RCM are dictated by the underlying condition. Prognosis is generally poor despite optimal medical treatment.

The pattern of premature ventricular beats, as a clue to site of origin, may help identify underlying cardiac diseases. To assess the value of premature ventricular beat patterns in managing athletes with ventricular arrhythmias. Athletes with 50 or more isolated premature ventricular beats/24 hours, and/or multifocal and/or repetitive premature ventricular beats at baseline, and/or exercise, and/or 24-hour electrocardiograms were selected for this analysis. Premature ventricular beats were defined as 'common' (outflow tract or fascicular origin), or 'uncommon' (other morphologies and/or multifocal or repetitive). From 4595 athletes consecutively examined, 205 (4%, 24.6 ± 6.9 years, 67% men) were included, 118 (58%) with uncommon and 87 (42%) with common premature ventricular beats. In particular, 81 (39%) showed complex patterns; 63 (31%) right/left ventricular outflow tract origin; 24 (12%) fascicular origin; 20 (10%) right bundle branch block pattern, intermediate/superior axis, wide QRS; and 17 (8%) left bundle branch block pattern, intermediate/superior axis. Uncommon premature ventricular beat patterns were predominant among men (62% vs. 38%; P < 0.001) but not among women. Uncommon premature ventricular beats were equally prevalent in endurance, mixed and skill disciplines, but lower in power sports. Cardiac diseases were detected in 11 (5%), 10 with uncommon patterns. Over a 6-year follow-up, cardiac diseases occurred in four (0.6%/year), all with uncommon patterns. Overall, cardiac diseases at baseline and during follow-up were detected in 14/118 athletes with uncommon versus one/87 with common premature ventricular beats (P = 0.003). Evaluation of premature ventricular beat patterns in Olympic athletes identified cardiac diseases, requiring disqualification and/or follow-up, in 12% with uncommon versus 1% with common patterns. This result suggests that athletes with uncommon premature ventricular beat patterns should undergo comprehensive cardiac evaluation and/or serial follow-up, irrespective of gender or sporting discipline.

As a new complication, new-onset ventricular arrhythmias (VAs) post atrial fibrillation (AF) ablation have not been well defined. This prospective study aimed to describe the details of new-onset VAs post AF ablation in a large study cohort.One thousand fifty-three consecutive patients who underwent the first radiofrequency catheter ablation for AF were enrolled. All patients had no evidence of pre-ablation VAs. New-onset VAs were defined as new-onset ventricular tachycardia (VT) or premature ventricular contractions (PVC) ≥1000/24 h within 1 month post ablation.There were 46 patients (4.4%) who had 62 different new-onset VAs, among whom 42 were PVC alone, and 4 were PVC coexisting with nonsustained VT. Multivariate analysis showed that increased serum leukocyte counts ≥50% post ablation were independently associated with new-onset VAs (OR: 1.9; 95% CI: 1.0–3.5; P = 0.043). The median number of PVC was 3161 (1001–27,407) times/24 h. Outflow tract VAs were recorded in 35 (76.1%) patients. No significant differences were found in origin of VAs (P = 0.187). VAs disappeared without any treatment in 6 patients (13.0%). No VAs-related adverse cardiac event occurred.The study revealed a noticeable prevalence but relatively benign prognosis of new-onset VAs post AF ablation. Increased serum leukocyte counts ≥50% post ablation appeared to be associated with new-onset VAs, implying that inflammatory response caused by ablation might be the mechanism.