Premature Ventricular Complex–Induced Cardiomyopathy

Management of Heart Failure With Improved Ejection Fraction: Current Evidence and Controversies

Heart failure with improved ejection fraction (HFimpEF) is defined by improved left ventricular ejection fraction (LVEF) among patients who previously had reduced LVEF. HFimpEF is associated with improved prognosis, albeit with persistent risk of relapse and adverse events in some patients. Current guidelines thus recommend sustained and indefinite guideline-directed medical therapy (GDMT) for all patients with HFimpEF. Emerging clinical experience suggests that heart failure arising from acute etiologies that fully resolve along with complete LVEF recovery may have a favorable prognosis with lower risk of relapse. Indeed, cohort and case series studies have demonstrated the feasibility of safe de-escalation of GDMT in select patients with specific etiologies, with multiple small trials ongoing. Future studies should investigate whether advanced imaging or blood biomarkers could aid in risk stratifying patients with recovered LVEF, whether partial de-escalation of GDMT could be safe and feasible, and whether implantable cardioverter-defibrillator therapy can be safely discontinued.

Electrocardiographic Characteristics and Ablation Outcomes Associated With Para-Hisian Ventricular Arrhythmias

BACKGROUND

Ventricular arrhythmias (VAs) near the His-bundle comprise 9% of unexplained VAs and present challenges for ablation caused by the risk of atrioventricular block.

OBJECTIVES

The authors studied the electrocardiographic (ECG) and electrophysiological characteristics of Para-Hisian (PH) VAs, comparing them with septal right ventricular outflow tract VAs.

METHODS

From 210 patients with VAs between 2018 and 2024, 31 (14.7%) with PH-VAs and 23 (10.9%) with septal right ventricular outflow tract VAs were included. ECG characteristics of both were compared, and features differentiating left and right PH and supra- and infra-Hisian VAs were identified.

RESULTS

Of 31 patients, 15 had VAs from the right PH site and 16 from the left. Median follow-up was 15 months (Q1-Q3: 14-21 months) for left infra-Hisian, 16 months (Q1-Q3: 14-20 months) for left supra-Hisian, and 14 months (Q1-Q3: 14-16 months) for right infra-Hisian and right supra-Hisian VAs (Q1-Q3: 14-15 months). PH-VAs had narrower QRS complexes (134 ± 19.6 ms vs 169 ± 24 ms; P < 0.05), R-wave in lead aVL (100% [31 of 31] vs 4.3% [1 of 23]; P < 0.001), and earlier R-wave transition at or before lead V3 (80.6% [25 of 31] vs 47.8% [11 of 23]; P < 0.05). Left PH-VAs had earlier R-wave transition at lead V2 (50% [8 of 16] vs 20% [3 of 15]; P = 0.036). Right PH VAs had deeper S-wave relative to the preceding sinus beat in lead V1 (73.3% [11 of 15] vs 37.5% [6 of 16]; P = 0.04) and lead aVR (80% [12 of 15] vs 56.3% [9 of 16]; P = 0.01). Postprocedure heart block occurred in 1 patient.

CONCLUSIONS

PH-VAs exhibit unique ECG features based on their origins, and can be effectively treated without affecting atrioventricular conduction.

Initial Holter Electrocardiogram Index to Predict the Burden of Subsequent Persistent Premature Ventricular Complex in Childhood

BACKGROUND

Asymptomatic premature ventricular complex (PVC) in childhood often disappears over time. However, predictive factors for persistent PVC are unknown. We examined predictive factors for persistent PVCs on initial Holter electrocardiogram (ECG) in pediatric patients with asymptomatic PVC.

METHODS AND RESULTS

The initial Holter ECG findings of untreated PVC patients (n=216) between 2010 and 2021 were examined. Multivariable analysis was performed to clarify predictive factors for subsequent persistent PVC burden for each index (age, sex, PVC burden, PVC origin, minimum and maximum mean RR intervals [RRmin and RRmax, respectively]) of the 3 heartbeats of baseline sinus rhythm immediately before the PVC. The median age at initial Holter ECG was 11.6 years (range 5.8-18.8 years), the PVC burden was 5.22% (range 0.01-44.21%), RRmin was 660 ms, RRmax was 936 ms, RRrange (=RRmax-RRmin) was 273 ms, and 15 (7%) PVC runs were identified. The median follow-up period was 5.1 years (range 0.8-9.4 years), and the final Holter PVC burden was 3.99% (range 0-36.38%). In multivariate analysis, RRrange was the only independent risk factor for predicting a final Holter PVC burden >10%, with an area under the curve of 0.920 using an RRrange of 600 ms as the cut-off value.

CONCLUSIONS

A wide RRrange at the initial Holter ECG may be a predictive indicator for persistent PVC in childhood.

Ventricular premature beats in a pregnant woman originating from trabeculae carneae in the right ventricle treated with radiofrequency ablation without X-ray guidance: a case report

BACKGROUND

Premature ventricular beats increase the cardiac load in pregnant women, leading to symptoms, such as palpitations. In severe instances, they may reduce placental perfusion, potentially causing intrauterine distress and developmental delays in the fetus, which could result in miscarriage or stillbirth. Fluoroscopy-less ablation offers significant advantages for pregnant women, including reduced radiation exposure, enhanced treatment precision, and a lower incidence of postprocedure complications.

CASE PRESENTATION

This case describes how radiofrequency catheter ablation was used on a pregnant Chinese woman who was identified with frequent ventricular premature beats originating from the high septal margin trabeculae carneae of the right ventricle. The rarity of this premature beat focus poses challenges for electrophysiology mapping and ablation; however, the ablation ultimately succeeded. In this case report, the clinical manifestations, electrocardiogram, ablation procedure, and patient prognosis are reported and discussed.

CONCLUSION

X-ray free ablation clearly reduces radiation exposure while maintaining a high success rate and safety of the ablation procedure.

Diving Deep into Arrhythmias: Unravelling the Impact of Underwater Environments on Premature Ventricular Complexes in Divers

This review examines the relationship between the physiological demands of diving and premature ventricular complexes (PVCs) in divers. In the general population, some individuals have a greater tendency to experience PVCs, often without awareness or a clear understanding of the triggering factors. With the increasing availability and popularity of both scuba and apnoea diving, more people, including those with a predisposition to PVCs, are engaging in these activities. The underwater environment, with its unique stressors, may increase the risk of arrhythmogenic events, particularly PVCs. Here, we review the prevalence, pathophysiology, and aggravating factors of PVCs in divers, emphasising the need for a comprehensive cardiovascular assessment. Evidence suggests a higher prevalence of PVCs in divers compared with the general population, influenced by factors such as age, dive depth, gas bubbles, cold water immersion, pre-existing cardiovascular diseases, and lifestyle factors. The change in environment during diving could potentially trigger an increased frequency of PVCs, especially in individuals with a pre-existing tendency. We discuss diagnostic strategies, management approaches, and preventive measures for divers with PVCs, noting that although guidelines for athletes can be adapted, individual assessment is crucial. Significant knowledge gaps are identified, highlighting the need for future research to develop evidence-based guidelines and understand the long-term significance of PVCs in divers. This work aims to evaluate potential contributing factors to PVCs in divers and identify individuals who may be at higher risk of experiencing major adverse cardiovascular events (MACEs). This work aims to improve diver safety by promoting collaboration between cardiologists and diving medicine specialists and by identifying key areas for future investigation in this field. This work aims to improve the safety and well-being of divers by understanding the cardiovascular challenges they face, including pressure changes, cold water immersion, and hypoxia. We seek to elucidate the relationship between these challenges and the occurrence of PVCs. By synthesising current evidence, identifying knowledge gaps, and proposing preliminary recommendations, we aim to encourage collaboration between cardiologists and diving medicine specialists to optimise the screening, management, and risk stratification of PVCs in the diving population.

Premature Ventricular Contraction-Induced Cardiomyopathy: Contemporary Evidence from Risk Stratification, Pathophysiology, and Management

Premature ventricular complexes (PVCs) are commonly encountered problems in clinical settings. The range of symptoms can be from asymptomatic to palpitations, fatigue, or heart failure symptoms. A higher burden of PVCs is a risk factor for development of PVC-induced cardiomyopathy (PIC). Rhythm evaluation by 12-lead ECG and an ambulatory monitoring device are essential. Currently, several imaging modalities, such as echocardiography and cardiac magnetic resonance imaging, are utilized to evaluate the underlying structure that may be related to PIC. Beta blockers and antiarrhythmic drugs are typically part of the initial management strategy. If these fail, catheter ablation of PVCs is typically the next step. The purpose of this article is to summarize the current evidence/knowledge about PIC.

Unlocking the enigma: decoding premature ventricular complexes for effective clinical assessment and risk management

The identification of ventricular premature complexes during a cardiological evaluation necessitates the implementation of diagnostic processes aimed at discerning the clinical context that may predispose individuals to a high risk of sudden cardiac death. Epidemiological studies reveal that ventricular premature beats occur in approximately 75% of healthy (or seemingly healthy) individuals, as long as there is no evidence of underlying structural heart disease, such as benign idiopathic ventricular extrasystole originating from the right and left ventricular outflow tracts. In the real world, however, ventricular ectopic beats with morphologies very similar to seemingly benign occurrences are not uncommon. They are notable in subjects exhibiting rapid and complex repetitive forms during exercise testing and Holter electrocardiogram. Additionally, these subjects may display more or less extensive scarring signs on cardiac magnetic resonance and may have a family history of cardiomyopathy and/or sudden cardiac death. Therefore, the purpose of this review is to critically analyse the process of evaluating premature ventricular complexes, which is crucial for accurate risk stratification. The latter cannot overlook some inevitable elements, including morphology, origin, complexity, and the associated clinical setting (absence or presence of structural heart disease).

Three-Day Monitoring of Adhesive Single-Lead Electrocardiogram Patch for Premature Ventricular Complex: Prospective Study for Diagnosis Validation and Evaluation of Burden Fluctuation

BACKGROUND

Wearable electrocardiogram (ECG) monitoring devices are used worldwide. However, data on the diagnostic yield of an adhesive single-lead ECG patch (SEP) to detect premature ventricular complex (PVC) and the optimal duration of wearing an SEP for PVC burden assessment are limited.

OBJECTIVE

We aimed to validate the diagnostic yield of an SEP (mobiCARE MC-100, Seers Technology) for PVC detection and evaluate the PVC burden variation recorded by the SEP over a 3-day monitoring period.

METHODS

This is a prospective study of patients with documented PVC on a 12-lead ECG. Patients underwent simultaneous ECG monitoring with the 24-hour Holter monitor and SEP on the first day. On the subsequent second and third days, ECG monitoring was continued using only SEP, and a 3-day extended monitoring was completed. The diagnostic yield of SEP for PVC detection was evaluated by comparison with the results obtained on the first day of Holter monitoring. The PVC burden monitored by SEP for 3 days was used to assess the daily and 6-hour PVC burden variations. The number of patients additionally identified to reach PVC thresholds of 10%, 15%, and 20% during the 3-day extended monitoring by SEP and the clinical factors associated with the higher PVC burden variations were explored.

RESULTS

The recruited data of 134 monitored patients (mean age, 54.6 years; males, 45/134, 33.6%) were analyzed. The median daily PVC burden of these patients was 2.4% (IQR 0.2%-10.9%), as measured by the Holter monitor, and 3.3% (IQR 0.3%-11.7%), as measured in the 3-day monitoring by SEP. The daily PVC burden detected on the first day of SEP was in agreement with that of the Holter monitor: the mean difference was -0.07%, with 95% limits of agreement of -1.44% to 1.30%. A higher PVC burden on the first day was correlated with a higher daily (R2=0.34) and 6-hour burden variation (R2=0.48). Three-day monitoring by SEP identified 29% (12/42), 18% (10/56), and 7% (4/60) more patients reaching 10%, 15%, and 20% of daily PVC burden, respectively. Younger age was additionally associated with the identification of clinically significant PVC burden during the extended monitoring period (P=.02).

CONCLUSIONS

We found that the mobiCARE MC-100 SEP accurately detects PVC with comparable diagnostic yield to the 24-hour Holter monitor. Performing 3-day PVC monitoring with SEP, especially among younger patients, may offer a pragmatic alternative for identifying more individuals exceeding the clinically significant PVC burden threshold.

Predictors and possible mechanisms of premature ventricular contraction induced cardiomyopathy

Premature ventricular complexes (PVCs) are encountered frequently in clinical practice. While PVCs may have various causes, a small number of individuals with PVCs develop cardiomyopathy in the absence of other potential etiologies. When correctly identified, patients with PVC-incuded cardiomyopathy can have dramatic improvement of their cardiomyopathy with treatment of their PVCs. In this focused review, we discuss potential predictors of PVC-induced cardiomyopathy, including PVC frequency, PVC characteristics, and modifiable patient risk factors. We also review some proposed mechanisms of PVC-induced cardiomyopathy and conclude with future directions for research and clinical practice.

Are antiarrhythmic agents indicated in premature ventricular complex-induced cardiomyopathy and when?

INTRODUCTION

Premature ventricular complexes (PVCs) are the most common ventricular arrhythmia that are encountered in the clinical practice. Recent data suggests that high PVC burden may lead to the development of PVC-induced cardiomyopathy (PVC-CM) even in patients without structural heart disease. Treatment for effective suppression of PVCs, can reverse PVC-CM. Both antiarrhythmic drugs (AADs) and catheter ablation (CA) are recognized treatment modalities for any cardiac arrhythmias. However, with increasing preference of CA, the role of AADs needs further defining regarding their efficacy, safety, indications and patient selection to treat PVC-CM.

METHODS

To ascertain the role of AADs to treat PVC-CM; whether they are indicated to treat PVC-CM, and if so, when, we interrogated PubMed and other search engines for English language publications with key words premature ventricular complexes (PVCs), cardiomyopathy, anti-arrhythmic drugs, catheter ablation, and pharmacological agents. All publications were carefully reviewed and scrutinized by the authors for their inclusion in the review paper. For illustration of cases, ethical standard was observed as per the 1975 Declaration of Helsinki, and the patient was treated as per the prevailing standard of care. Informed consent was obtained from the patient for conducting the ablation procedure.

RESULTS

Our literature search specifically the pharmacological treatment of PVC-CM with AADs revealed significant paradigm shift in treatment approach for PVCs and PVC-induced cardiomyopathy. No major large, randomized control trials of AADs versus CA for PVC-CM were found. We found that beta-blockers and calcium channel blockers are particularly effective in the treatment of PVCs originating from right ventricular outflow tract. For Class Ic AADs - flecainide and propafenone, small clinical studies showed Class Ic AADs to be effective in PVC suppression, but their usage was not recommended in patients with significant coronary artery disease. Mexiletine was found to have modest effect on PVC suppression. Studies showed sotalol to significantly reduce PVCs frequency in patients receiving both low and high doses. Studies also showed amiodarone to have higher successful PVC suppression, but not recommended as a first-line treatment for patients with idiopathic PVCs in the absence of symptoms and left ventricular dysfunction. For dronedarone, no major clinical data were available.

CONCLUSIONS

Based on the available data in the literature, we conclude that AADs play important role in the treatment of PVC-induced cardiomyopathy. However, appropriate patient selection criteria are vitally important, and in general terms AADs are indicated or polymorphic PVCs, epicardial PVCs; and when CA procedure is contraindicated, or not feasible or failed.

Effect of ivabradine on ventricular arrhythmias in heart failure patients with reduced ejection fraction

BACKGROUND/INTRODUCTION

Heart failure patients with reduced ejection fraction 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.

OBJECTIVE

The effect of ivabradine on ventricular arrhythmias in heart failure patients with reduced ejection fraction patients has not been fully elucidated. The aim of this study was to investigate the effect of ivabradine use on life-threatening arrhythmias and long-term mortality in heart failure patients with reduced ejection fraction patients.

METHODS

In this retrospective study, 1,639 patients with heart failure patients with reduced ejection fraction were included. Patients were divided into two groups: ivabradine users and nonusers. Patients presenting with ventricular tachycardia, the presence of ventricular extrasystole, and ventricular tachycardia in 24-h rhythm monitoring, appropriate implantable cardioverter-defibrillator shocks, and long-term mortality outcomes were evaluated according to ivabradine use.

RESULTS

After adjustment for all possible variables, admission with ventricular tachycardia was three times higher in ivabradine nonusers (95% confidence interval 1.5-10.2). The presence of premature ventricular contractions and ventricular tachycardias in 24-h rhythm Holter monitoring was notably higher in ivabradine nonusers. According to the adjusted model for all variables, 4.1 times more appropriate implantable cardioverter-defibrillator shocks were observed in the ivabradine nonusers 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 implantable cardioverter-defibrillator discharge in heart failure patients with reduced ejection fraction patients. Ivabradine has potential in the treatment of ventricular arrhythmias in heart failure patients with reduced ejection fraction patients.

An Early Indicator in Evaluating Cardiac Dysfunction Related to Premature Ventricular Complexes: Cardiorespiratory Capacity

Cardiac dysfunction induced by premature ventricular complexes (PVCs) is relatively controversial and challenging to detect in the early stage. In this observational study, we retrospectively analyzed the cardiopulmonary exercise test (CPET) data of 94 patients with frequent premature ventricular beats (47 males, 49.83 ± 13.63 years) and 98 participants (55 males, 50.84 ± 9.41 years) whose age and gender were matched with the patient with PVCs. The baseline information and routine echocardiography detection were recorded on admission. PVCs were diagnosed by 24 h Holter monitoring, and cardiorespiratory capacity was assessed using peak oxygen uptake (V'O2peak), anaerobic threshold (AT), and other CPET parameters with an individualized bicycle ramp protocol according to the predicted workload and exercise situation of each participant. There were no statistically significant differences in most baseline characteristics between the two groups. Indicators that reflect cardiopulmonary capacity, such as V'O2peak, AT, and ΔO2 pulse/Δwork rate(ΔV'O2/ΔWR), were all significantly lower in the PVC group (p = 0.031, 0.021, and 0.013, respectively) despite normal and nondiscriminatory left ventricular ejection fractions between the two groups. However, there was no statistically significant difference among subgroups based on the frequency of PVCs, which was <10,000 beats/24 h, 10,000-20,000 beats/24 h, and >20,000 beats/24 h. The cardiorespiratory capacity was lower in patients with frequent PVCs, indicating that CPET could detect early signs of impaired cardiac function induced by PVCs.

Transcutaneous electrical vagus nerve stimulation to suppress premature ventricular complexes (TREAT PVC): study protocol for a multi-center, double-blind, randomized controlled trial

BACKGROUND

The autonomic nervous system can be responsible for the initiation and maintenance of arrhythmias. Low-level tragus stimulation (LLTS), a noninvasive form of autonomic neuromodulation, has been shown to be effective in treating atrial fibrillation. We intended to treat frequent premature ventricular complexes (PVCs) with LLTS.

METHODS AND DESIGN

The present study will be a prospective multicenter, double-blind, randomized, controlled trial to assess the antiarrhythmic effects of LLTS on frequent PVCs in patients without structured heart disease (SHD). A total of 100 patients with PVC burden > 10% will be randomly assigned to the active or sham LLTS in 1:1 fashion and receive the proposed intervention for 6 months. The primary outcome is PVC burden at 6 months as assessed by 10 days of continuous ambulatory electrocardiographic monitoring. Secondary outcomes include heart rate variability (HRV), quality of life, skin sympathetic nerve activity, and inflammatory markers. Adverse events will also be recorded.

DISCUSSION

The present trial will be the first to evaluate the effect of LLTS on frequent PVCs on patients without SHD. LLTS may serve as a low-cost, minimal-risk, and non-invasive alternative to conventional antiarrhythmic therapy.

TRIAL REGISTRATION

ClinicalTrial.gov NCT04909528. Registered on 17 June 2021. World health organization trial registration data set was shown in Supplementary Table 1.

NT-proBNP-Possible Prognostic Marker in Pregnant Patients with Associated Cardiovascular Risk Factors and SARS-CoV-2 Infection

BACKGROUND

N-terminal pro brain-type natriuretic peptide (NT-proBNP) is a practical biomarker in the clinical pathologies where the ventricle is under stress and particularly stretched in the general population. The study aims to compare the value of NT-proBNP and its importance in the prognosis and severity of the cases involving pregnant patients with SARS-CoV-2 infection and cardiovascular risk factors to those of low-risk pregnant patients, mainly by analysing their symptoms, administered medication, days of hospitalization and severity of the viral disease.

METHODS

The study included a total of eighty-three pregnant patients who underwent natural birth or caesarean section at out hospital. NT-proBNP levels were analyzed at hospital admission as a potential cardiovascular marker. A comparative analysis was performed between pregnant patients with cardiovascular risk factors and pregnant patients without cardiovascular risk factors regarding NT-proBNP values.

RESULTS

Pregnant patients with SARS-CoV-2 infection and cardiovascular risk factors had higher values of NT-proBNP in comparison to pregnant patients without cardiovascular risk factors.

CONCLUSIONS

NT-proBNP testing in pregnant patients with SARS-CoV-2 infection can be a relatively important marker to be taken into consideration when it comes to the management, treatment and outcome of the cases, especially when it comes to women with associated cardiovascular risk factors.

Natural products as the calcium channel blockers for the treatment of arrhythmia: Advance and prospect

Arrhythmia is one of the commonly heart diseases with observed abnormal heart-beat rhythm that caused by the obstacles of cardiac activity and conduction. The arrhythmic pathogenesis is complex and capricious and related with other cardiovascular diseases that may lead to heart failure and sudden death. In particular, calcium overload is recognized as the main reason causing arrhythmia through inducing apoptosis in cardiomyocytes. Moreover, calcium channel blockers have been widely used as the routine drugs for the treatment of arrhythmia, but the different arrhythmic complications and adverse effects limit their further applications and demand new drug discovery. Natural products have always been the rich minerals for the development of new drugs that could be employed as the versatile player for the discovery of safe and effective anti-arrhythmia drugs with new mechanisms. In this review, we summarized natural products with the activity against calcium signaling and the relevant mechanism of actions. We are expected to provide an inspiration for the pharmaceutical chemists to develop more potent calcium channel blockers for the treatment of arrhythmia.

Successful radiofrequency catheter ablation of idiopathic premature ventricular complexes originating from the outflow tract improves heart failure-related quality of life

BACKGROUND

To investigate the effect of successful RFCA in patients with idiopathic outflow tract PVCs (OT-PVC) on left heart functions, neurohormonal activation, functional status, and heart failure-related quality of life (HFQoL), with an integrated approach.

METHODS

Patients with frequent OT-PVCs, determined by 12-lead surface ECG who underwent radiofrequency catheter ablation (RFCA) with an acute success, were prospectivelly enrolled. Left heart functions were evaluated with the use of transthoracic echocardiography, neurohormonal activation with N-terminal Pro-brain natriuretic peptide (BNP), functional class with New York Heart Association (NYHA) and 6-min walking distance (6MWD), and HFQoL with Minnesota Living with Heart Failure Questionnaire (MLHFQ), at baseline and at 6 months.

RESULTS

A total of 108 patients were included in this study (43 ± 12 years old, 56% male). Majority of the OT-PVCs originated from aortic valve and right ventricle outflow tract (44% and 37%, respectively). Total RF time was 216 ± 87 s. Major complication rate was 0.9%. Left ventricle (LV) ejection fraction increased from 47 ± 8 to 53 ± 6% at 6 months (p < 0.001). Neurohormonal activation was suppressed significantly (104 ± 69 to 83 ± 42, p < 0.001). Functional class improved with %NYHA-I patients increasing from 54 to 89% (p < 0.001) and 6MWD from 293 ± 73 to 335 ± 59 m (p < 0.001). MLHFQ score improved from 32 ± 9 to 23 ± 5 p < 0.001. In multivariable analysis, LV end-systolic diameter (LVESD) and 6MWD were independent predictors of improvement in MLHFQ (for LVESD Uβ: - 0.26, 95%CI [0.44-0.09], p < 0.004 and for 6MWD: 0.04, 95%CI [0.03-0.06], p < 0.001).

CONCLUSIONS

RFCA of OT-PVCs is associated with improved well-being of patients, determined by left heart functions, neurohormonal activation, functional class, and HFQoL.

ECGNet: An Efficient Network for Detecting Premature Ventricular Complexes Based on ECG Images

BACKGROUND

Preoperative prediction of the origin site of premature ventricular complexes (PVCs) is critical for the success of operations. However, current methods are not efficient or accurate enough. In addition, among the proposed strategies, there are few good prediction methods for electrocardiogram (ECG) images combined with deep learning aspects.

METHODS

We propose ECGNet, a new neural network for the classification of 12-lead ECG images. In ECGNet, 609 ECG images from 310 patients who had undergone successful surgery in the Division of Cardiology, the First Affiliated Hospital of Soochow University, are utilized to construct the dataset. We adopt dense blocks, special convolution kernels and divergent paths to improve the performance of ECGNet. In addition, a new loss function is designed to address the sample imbalance situation, whose cause is the uneven distribution of cases themselves, which often occurs in the medical field. We also conduct extensive experiments in terms of network prediction accuracy to compare ECGNet with other networks, such as ResNet and DarkNet.

RESULTS

Our ECGNet achieves extremely high prediction accuracy (91.74%) and efficiency with very small datasets. Our newly proposed loss function can solve the problem of sample imbalance during the training process.

CONCLUSION

The proposed ECGNet can quickly and accurately realize the multiclassification of PVCs after training with little data. Our network has the potential to be helpful to doctors with a preoperative diagnosis of PVCs. We will continue to collect similar cases and perfect our network structure to further improve the accuracy of our network's prediction.

Prevalence of atrial fibrillation and procedural outcome in patients undergoing catheter ablation for premature ventricular complexes

INTRODUCTION

Atrial fibrillation (AF) and premature ventricular complexes (PVC) are common arrhythmias. We aimed to investigate AF prevalence in patients with PVC and its impact on PVC ablation outcomes.

METHODS

Consecutive patients undergoing PVC ablation at a single institution between 2016 and 2019 were included and prospectively followed for 2 years. Patients with severe valvular heart disease, hyperthyroidism, malignancy, alcohol use disorder and advanced renal/hepatic diseases were excluded. Twelve-lead electrocardiograms were used to diagnose AF and assess PVC morphology. All PVCs were targeted for ablation using 4-mm irrigated-tip catheters at standardized radiofrequency power guided by 3-D mapping and intracardiac echocardiography. Patients were followed with remote monitoring, device interrogations and office visits every 6 months for 2 years. Detection of any PVCs in follow-up was considered as recurrence.

RESULTS

A total of 394 patients underwent PVC ablation and 96 (24%) had concurrent AF. Patients with PVC and AF were significantly older (68.2 ± 10.8 vs. 58.3 ± 15.8 years, p < .001), had lower LV ejection fraction (43.3 ± 13.3% vs. 49.6 ± 12.4%, p < .001), higher CHA₂ DS₂ -VASc (2.8 ± 1.3 vs. 2.0 ± 1.3, p < .001) than those without. PVCs with ≥2 morphologies were detected in 60.4% and 13.7% patients with vs without AF (p < .001). At 2-year follow-up, PVC recurrence rate was significantly higher in patients with vs without AF (17.7% vs. 9.4%, p = .02).

CONCLUSION

AF was documented in 1/4 of patients undergoing PVC ablation and was associated with lower procedural success at long-term follow-up. This was likely attributed to older age, worse LV function and higher prevalence of multiple PVC morphologies in patients with concurrent AF.

Effects of radiofrequency catheter ablation for premature ventricular complexes originating from the right ventricular outflow tract on right ventricular function

INTRODUCTION

This study aimed to elucidate the relationship between premature ventricular complexes (PVCs) and right ventricular (RV) dysfunction, and the effects of radiofrequency catheter ablation (RFCA) on RV function.

METHODS

A total of 110 patients (age, 50.8 ± 14.4 years; 30 men) without structural heart disease who had undergone RFCA for RV outflow tract (RVOT) PVCs were retrospectively included. RV function was assessed using fractional area change (FAC) and global longitudinal strain (GLS) before and after RFCA. Clinical data were compared between the RV dysfunction (n = 63) and preserved RV function (n = 47) groups. The relationship between PVC burden and RV function was analyzed. Change in RV function before and after RFCA was compared between patients with successful and failed RFCA.

RESULTS

PVC burden was significantly higher in the RV dysfunction group than in the preserved RV function group (p < .001). FAC and GLS were significantly worse in proportion to PVC burden (p < .001 and p < .001, respectively). The risk factor associated with RV dysfunction was PVC burden [odds ratio (95% confidence interval), 1.092 (1.052-1.134); p < .001]. Improvement in FAC (13.0 ± 8.7% and -2.5 ± 5.6%, respectively; p < .001) and GLS (-6.8 ± 5.7% and 2.1 ± 4.2%, respectively; p < .001) was significant in the patients with successful RFCA, compared to the patients in whom RFCA failed.

CONCLUSIONS

Frequent RVOT PVCs are associated with RV dysfunction. RV dysfunction is reversible by successful RFCA.

Risk factors for the development of premature ventricular complex-induced cardiomyopathy: a systematic review and meta-analysis

Background

Premature ventricular complexes (PVCs) are a potentially reversible cause of heart failure. However, the characteristics of patients most likely to develop impaired left ventricular function are unclear. Hence, the objective of this study is to systematically assess risk factors for the development of PVC-induced cardiomyopathy.

Methods

We performed a structured database search of the scientific literature for studies investigating risk factors for the development of PVC-induced cardiomyopathy (PVC-CM). We investigated the reporting of PVC-CM risk factors (RF) and assessed the comparative association of the different RF using random-effect meta-analysis.

Results

A total of 26 studies (9 prospective and 17 retrospective studies) involving 16,764,641 patients were analyzed (mean age 55 years, 58% women, mean PVC burden 17%). Eleven RF were suitable for quantitative analysis (≥ 3 occurrences in multivariable model assessing a binary change in left ventricular (LV) function). Among these, age (OR 1.02 per increase in the year of age, 95% CI [1.01, 1.02]), the presence of symptoms (OR 0.18, 95% CI [0.05, 0.64]), non-sustained ventricular tachycardias (VT) (OR 3.01, 95% CI [1.39, 6.50]), LV origin (OR 2.20, 95% CI [1.14, 4.23]), epicardial origin (OR 4.72, 95% CI [1.81, 12.34]), the presence of interpolation (OR 4.93, 95% CI [1.66, 14.69]), PVC duration (OR 1.05 per ms increase in QRS-PVC duration [1.004; 1.096]), and PVC burden (OR 1.06, 95% CI [1.04, 1.08]) were all significantly associated with PVC-CM.

Conclusions

In this meta-analysis, the most consistent risk factors for PVC-CM were age, non-sustained VT, LV, epicardial origin, interpolation, and PVC burden, whereas the presence of symptoms significantly reduced the risk. These findings help tailor stringent follow-up of patients presenting with frequent PVCs and normal LV function.

Sustained Suppression of Premature Ventricular Contractions by a Three-Month Pacing Adjustment

Premature ventricular contractions (PVCs) that comprise more than 15% of total heartbeats can induce cardiomyopathy in patients with systolic dysfunction, and cardiac ablation is frequently used to reduce PVCs in this patient group. However, cardiac ablation is not entirely without hazards. We report a noninvasive method that dramatically reduced PVCs in a cardiac pacemaker patient from 31% to 3% in seven days by increasing the lower limit pacing rate from 50 beats per minute (bpm) to 60 bpm. Not only were our patient's PVCs reduced by the initial pacing elevation, but PVC levels were maintained below 5% even after the pacemaker's lower limit was returned to its original value of 50 bpm. This irreversible suppression of PVC activity following a three-month pacing elevation is a novel result that might be caused by ventricular remodeling of the original ectopic focus.

A case report of an improvement in premature ventricular complex–induced cardiomyopathy following continuous positive airway pressure therapy in a patient with severe obstructive sleep apnoea

Background

Premature ventricular complexes (PVCs) are the most common arrhythmias observed in patients without structural heart disease (SHD). Frequent PVCs cause left ventricular dilation and dysfunction without SHD, the so-called PVC-induced cardiomyopathy (PIC). Obstructive sleep apnoea (OSA) is a highly prevalent disease worldwide and is strongly associated with arrhythmias including PVCs. PVCs have been reported in up to two-thirds of patients with OSA. Continuous positive airway pressure (CPAP) is a well-established primary treatment modality in patients with moderate-to-severe OSA.

Case summary

We present a 69-year-old male case with severe OSA and an improvement in his PIC following CPAP therapy. He has remained well without any symptoms or arrhythmias for 2 years after the introduction of the CPAP therapy for his OSA.

Discussion

Using CPAP therapy for the treatment of his OSA, we could improve his PIC in accordance with a reduction in frequent PVCs without ablation of the PVCs. Only ablation without CPAP therapy may not be able to completely treat PIC associated with OSA, as in the present case. Thus, physicians should be aware of the possibility of PVCs associated with OSA when examining patients with PVCs. To the best of our knowledge, this is the first report of a case of improvement in PIC following CPAP therapy in a patient with severe OSA. Future investigations should focus on whether CPAP therapy can improve PIC associated with OSA and prevent a progression to heart failure and also result in an improvement in the prognosis.

Premature ventricular complex site of origin and ablation outcomes in patients with diabetes mellitus

BACKGROUND

Premature ventricular complexes (PVCs) are frequent in patients with diabetes mellitus (DM). Still, the PVCs characteristics as well as the outcomes after catheter ablation in this population remain unknown. Aim of the study was to describe principal features of PVCs ablated in a wide DM-patients cohort and report postablation clinical outcomes in the follow-up of patients with DM and left ventricular dysfunction.

METHODS

From April 2012 to April 2020 data of 544 patients (315 [58%] men, 55±16 y), consecutive patients submitted for PVC ablation, were prospectively collected. Patients with left ventricle (LV) systolic disfunction (LVEF<50%) were included in a prospective protocol and followed at 6 and 12 months, and annually thereafter. Baseline characteristic as well ablation outcomes were analyzed based on the presence of DM.

RESULTS

Sixty (11%) patients had DM. Patients with DM more frequently had a PVC's site of origin (SOO) in the LV (45 [75%] vs. 229 [48%], P<0.001). The most frequent PVC's SOO in DM patients was the LV outflow tract (OT) (35 [58%] patients: 12 aortic cusps; 12 LV summit; 11 in the myocardium immediately inferior to the valvular plane). Fifty-five (92%) patients with DM had an acute successful ablation, without differences compared with patients without DM (55 [92%] vs. 437 [90%], P=0.9). Twenty-tree (38%) DM-patients had LV dysfunction at the ablation time. In these patients, mean PVC burden decreased from 26±11% at baseline to 4±5% (P<0.001); LVEF increased from 36±8% to 42±11% (P<0.01) and NYHA class improved from 2.2±0.6 to 1.8+0.5 (P<0.01), after a mean follow-up of 37±14 months.

CONCLUSIONS

Patients with DM frequently have PVC with a LV-SOO, being the LVOT the most frequent SOO in this population. Among DM patients with LV dysfunction, ablation persistently and significantly reduce the PVC burden improving functional status. Patients with DM have lower benefit in terms of LV function recovery after ablation compared with non-diabetic patients.

2021 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure: Developed by the Task Force for the diagnosis and treatment of acute and chronic heart failure of the European Society of Cardiology (ESC). With the special contribution of the Heart Failure Association (HFA) of the ESC

Document Reviewers: Rudolf A. de Boer (CPG Review Coordinator) (Netherlands), P. Christian Schulze (CPG Review Coordinator) (Germany), Magdy Abdelhamid (Egypt), Victor Aboyans (France), Stamatis Adamopoulos (Greece), Stefan D. Anker (Germany), Elena Arbelo (Spain), Riccardo Asteggiano (Italy), Johann Bauersachs (Germany), Antoni Bayes-Genis (Spain), Michael A. Borger (Germany), Werner Budts (Belgium), Maja Cikes (Croatia), Kevin Damman (Netherlands), Victoria Delgado (Netherlands), Paul Dendale (Belgium), Polychronis Dilaveris (Greece), Heinz Drexel (Austria), Justin Ezekowitz (Canada), Volkmar Falk (Germany), Laurent Fauchier (France), Gerasimos Filippatos (Greece), Alan Fraser (United Kingdom), Norbert Frey (Germany), Chris P. Gale (United Kingdom), Finn Gustafsson (Denmark), Julie Harris (United Kingdom), Bernard Iung (France), Stefan Janssens (Belgium), Mariell Jessup (United States of America), Aleksandra Konradi (Russia), Dipak Kotecha (United Kingdom), Ekaterini Lambrinou (Cyprus), Patrizio Lancellotti (Belgium), Ulf Landmesser (Germany), Christophe Leclercq (France), Basil S. Lewis (Israel), Francisco Leyva (United Kingdom), AleVs Linhart (Czech Republic), Maja-Lisa Løchen (Norway), Lars H. Lund (Sweden), Donna Mancini (United States of America), Josep Masip (Spain), Davor Milicic (Croatia), Christian Mueller (Switzerland), Holger Nef (Germany), Jens-Cosedis Nielsen (Denmark), Lis Neubeck (United Kingdom), Michel Noutsias (Germany), Steffen E. Petersen (United Kingdom), Anna Sonia Petronio (Italy), Piotr Ponikowski (Poland), Eva Prescott (Denmark), Amina Rakisheva (Kazakhstan), Dimitrios J. Richter (Greece), Evgeny Schlyakhto (Russia), Petar Seferovic (Serbia), Michele Senni (Italy), Marta Sitges (Spain), Miguel Sousa-Uva (Portugal), Carlo G. Tocchetti (Italy), Rhian M. Touyz (United Kingdom), Carsten Tschoepe (Germany), Johannes Waltenberger (Germany/Switzerland) All experts involved in the development of these guidelines have submitted declarations of interest. These have been compiled in a report and published in a supplementary document simultaneously to the guidelines. The report is also available on the ESC website www.escardio.org/guidelines For the Supplementary Data which include background information and detailed discussion of the data that have provided the basis for the guidelines see European Heart Journal online.

Effectiveness of medical therapy for treatment of idiopathic frequent premature ventricular complexes

INTRODUCTION

The relative effectiveness of medical therapy compared with a conservative approach of monitoring in patients with idiopathic frequent premature ventricular complexes (PVCs) is uncertain. We evaluated the effectiveness of medical versus conservative therapy for frequent PVCs.

METHODS

Patients with frequent PVCs (≥5%) were prospectively enrolled in this cohort study between 2016 and 2020. In patients with normal cardiac function and no structural heart disease, those receiving medical therapy were compared with controls without therapy. Patients were followed longitudinally for change in PVC burden and with serial echocardiography.

RESULTS

Overall, 120 patients met inclusion criteria (mean: 56.5 ± 14.6 years, 54.2% female) with 53 on beta-blockers or calcium channel blockers (BBs/CCBs), 27 on Class I or III antiarrhythmic drugs (AADs), and 40 patients treated conservatively. Median initial PVC burden ranged from 15.5% to 20.6%. The median relative reduction of PVCs was 32.7%, 30.5%, and 81.3%, in the conservative therapy, BBs/CCBs, and AADs cohorts, respectively. AADs had greater PVC reduction compared with BBs/CCBs (p = 0.017) and conservative therapy (p = 0.045). PVC reduction to <1% was comparable across groups at 35.0%, 17.0%, 33.3%, respectively. Four patients (4/120, 3.3%) developed left ventricular dysfunction. Rates of adverse drug reactions and medication discontinuation were similar between groups, with no serious adverse events noted.

CONCLUSION

In patients with idiopathic frequent PVCs, BB, and CCB have limited effectiveness in PVC reduction. Class I and III AADs have superior effectiveness for medical therapy in symptomatic patients, but only achieved complete PVC resolution suppression in one-third of patients.

Using Three-Dimensional Lorenz Scatter Plots to Detect Patients with Atrioventricular Node Double Path Caused by Interpolated Ventricular Premature Systoles: A Case Study

A series of related electrophysiology phenomena can be caused by the occurrence of interpolated ventricular premature contraction. In our recent three-dimensional Lorenz R-R scatter plot research, we found that atrioventricular node double path caused by interpolated ventricular premature contraction imprints a specific pattern on three-dimensional Lorenz plots generated from 24-hour Holter recordings. We found two independent subclusters separated from the interpolated premature beat precluster, the interpolated premature beat cluster, and the interpolated premature beat postcluster, respectively. Combined with use of the trajectory tracking function and the leap phenomenon, our results reveal the presence of the atrioventricular node double conduction path.

Cardiac afferent signaling partially underlies premature ventricular contraction-induced cardiomyopathy

BACKGROUND

The mechanisms underlying premature ventricular contraction (PVC)-induced cardiomyopathy (PIC) remain unknown. Transient receptor potential vanilloid-1 (TRPV1) afferent fibers are implicated in the reflex processing of cardiac stress.

OBJECTIVE

The purpose of this study was to determine whether cardiac TRPV1 afferent signaling promote PIC.

METHODS

A PIC swine model (50% PVC burden) was created via an implanted pacemaker. We selectively depleted cardiac TRPV1 afferent fibers using percutaneous epicardial application of resiniferatoxin (RTX). Animals were randomized to PVC only (n = 11), PVC+RTX (n = 11), or control (n = 6). We examined early-stage (4 weeks after implantation; n = 5) and late-stage PIC (8 weeks after implantation; n = 6). At terminal experimentation, animals underwent echocardiography, serum sampling, and physiological and autonomic reflex testing.

RESULTS

Depletion of cardiac TRPV1 afferents by RTX treatment was confirmed by absent sensory fibers and absent functional responses to TRPV1 activators. Left ventricular ejection fraction was worse in late-stage than early-stage PIC (P <.01). At 4 weeks (early stage), left ventricular ejection fraction was higher in PVC+RTX vs PVC animals (51.7% ± 1.6% vs 45.0% ± 2.1%; P = .030), whereas no significant difference between PVC and PVC+RTX was observed at 8 weeks (late stage). Histologic studies demonstrated reduced fibrosis in PVC+RTX vs PVC alone at 4 weeks (2.27% ± 0.14% vs 3.01% ± 0.21%; P = .020), suggesting that RTX mitigated profibrotic pathways induced by persistent PVCs.

CONCLUSION

TRPV1 afferent depletion alleviates left ventricular dysfunction in early- but not late-stage PIC. This temporal effect suggests that multiple pathways promote PIC, of which TRPV1 afferents are a part.

Clinical significance of myocardial scar in patients with frequent premature ventricular complexes undergoing catheter ablation

BACKGROUND

Frequent premature ventricular complexes (PVCs) can result in PVC-induced cardiomyopathy (PICM). Scarring has been described in patients with frequent PVCs in the absence of apparent heart disease and in patients with known cardiomyopathy.

OBJECTIVE

The purpose of this study was to determine the impact of focal myocardial scarring as detected by cardiac magnetic resonance imaging (CMR) on PICM, procedural outcomes, and recovery of left ventricular function in patients with frequent PVCs.

METHODS

A total of 351 consecutive patients (181 men; age 53 ± 15 years; ejection fraction [EF] 51% ± 12%) with frequent PVCs referred for ablation were included. CMR was performed in all patients before the ablation procedure. A ≥10% increase in EF or normalization of a previously abnormal EF was defined as evidence of PICM.

RESULTS

Myocardial scarring was present in 134 of 351 patients (38%); 66 of 134 patients (49%) with scarring and 54 of 217 patients (25%) without scarring had improvement or normalization of EF after ablation. The presence of myocardial scarring, PVC burden >22%, male sex, asymptomatic status, and PVC QRS width >150 ms were associated with PICM by univariate analysis (P <.01 for all). The presence of scar was independently associated with PICM (odds ratio 2.2; 95% confidence interval 1.3-3.7; P <.005). The success rate of PVC ablation was lower in patients with scarring than in patients without focal scarring (mean 70% vs 82%; P <.01).

CONCLUSION

Focal scar defined by CMR is independently associated with PICM. Although ablation outcomes are worse in the presence of scarring, EF recovery can occur in most of these patients after ablation.

Comparison of the Transdermal Bisoprolol Patch with Oral Bisoprolol Fumarate Administration as a Therapeutic Agent for Idiopathic Frequent Premature Ventricular Contractions

The transdermal bisoprolol patch (TB) was designed to maintain a sustained concentration of bisoprolol in plasma by a higher trough concentration than oral bisoporolol (OB). We compared the efficacy between TB and OB in patients with idiopathic premature ventricular contractions (PVCs) while considering their duration of action.A total of 78 patients with a PVC count of ≥ 3,000 beats/24 hours were divided into groups treated with TB 4 mg (n = 43) or OB 2.5 mg (n = 35). PVCs were divided into positive heart rate (HR) -dependent PVCs (P-PVCs) and non-positive HR-dependent PVCs (NP-PVCs) based on the relationship between the hourly PVC density and hourly mean HR. Twenty-four-hour Holter electrocardiograms were performed before and 1 to 3 months after the initiation of therapy.There were no significant between-group differences in the baseline characteristics. Both the TB (from 14.6 [9.9-19.2] to 7.6 [1.7-15.8]%, P < 0.001) and OB (from 13.2 [7.6-21.9] to 4.6 [0.5-17.0]%, P = 0.0041) significantly decreased the PVC density, and there was no significant difference between the two groups (P = 0.73). Compared to OB, the TB had similar effects in reducing the PVC density for P-PVCs (P = 0.96), and NP-PVCs (P = 0.71). The TB significantly decreased the P-PVC density from baseline not only during day-time (P < 0.001) but also night-time (P = 0.0017), while the OB did not significantly decrease the P-PVC density from baseline during night-time (P = 0.17).Compared to OB, the TB could be used with the same efficacy of reducing idiopathic PVCs. The TB may be a more useful therapeutic agent than OB for P-PVCs during a 24-hour period.

Ventricular arrhythmias and risk stratification of cardiac sudden death in athletes

Sudden cardiac death (SCD) of young athletes is an unexpected and tragic event that could occur during sport activities and is frequently related to ventricular arrhythmias. Identifying athletes at risk of SCD remains a major challenge. While specific characteristics of premature ventricular contractions are considered common and benign, other "uncommon" features should require more accurate investigations, in order to determine eligibility for competitive sports. The most common type of idiopathic premature ventricular contractions originates from ventricular outflow tract and is characterized by an ECG pattern with left bundle branch block and inferior QRS axis (infundibular pattern). Another pattern associated with a good prognosis is the "fascicular" morphology, characterized by a typical right bundle branch block, superior QRS axis morphology and QRS duration <130 ms. Conversely, other morphological features (such as left bundle branch block /intermediate or superior axis or right bundle branch block/intermediate or superior axis and wide QRS) correlate to an underlying substrate. In risk stratification setting, cardiac magnetic resonance plays a key role allowing an accurate identification of myocardial tissue abnormalities, which could affect athletes' prognosis. This review focuses on characteristics of premature ventricular contractions characteristics in terms of morphology, distribution, complexity and response to exercise and describes the possible underlying myocardial substrates. This review also critically analyzes the evaluation process of athletes with premature ventricular contractions necessary for an accurate risk stratification.

Premature ventricular contraction detection for long-term monitoring in an implantable cardiac monitor

BACKGROUND

Premature ventricular complexes (PVCs) are an important therapeutic target in symptomatic patients and in the setting of PVC-induced cardiomyopathy; however, measuring burden and therapeutic response is challenging. We developed and validated an algorithm for continuous long-term monitoring of PVC burden in an insertable cardiac monitor (ICM).

METHODS

A high-specificity PVC detection algorithm was developed using real-world ICM data and validated using simultaneous Holter data and real-world ICM data. The PVC algorithm uses long-short-long RR interval sequence and morphology characteristics for three consecutive beats to detect the occurrence of single PVC beats. Data are expressed as gross incidence, patient average, and generalized estimating equation estimates, which were used to determine sensitivity, specificity, positive and negative predictive value (PPV, NPV).

RESULTS

The PVC detection algorithm was developed on eighty-seven 2-min EGM strips recorded by an ICM to obtain a sensitivity and specificity of 75.9% and 98.8%. The ICM validation data cohort consisted of 787 ICM recorded ECG strips 7-16 min in duration from 134 patients, in which the algorithm detected PVC beats with a sensitivity, specificity, PPV, and NPV of 75.2%, 99.6%, 75.9%, and 99.5%, respectively. In the Holter validation dataset with continuous 2-h snippets from 20 patients, the algorithm sensitivity, specificity, PPV, and NPV were 74.4%, 99.6%, 68.8%, and 99.7%, respectively, for detecting PVC beats.

CONCLUSIONS

The PVC detection algorithm was able to achieve a high specificity with only 0.4% of the normal events being incorrectly identified as PVCs, while detecting around three of four PVCs on a continuous long-term basis in ICMs.

Frequent Ventricular Premature Beats in Children and Adolescents: Natural History and Relationship with Sport Activity in a Long-Term Follow-Up

Premature ventricular complexes (PVCs) are frequently documented in children. To date, few studies report long-term follow-up in pediatric cohorts presenting with frequent PVCs. The aim of this study is to assess the clinical relevance and long-term outcomes of frequent PVCs (≥ 500/24 h) in a large pediatric cohort. From 1996 to 2016, we enrolled all consecutive patients evaluated at Anna Meyer Children Hospital for frequent PVCs. Symptomatic children were excluded together with those patients with known underlying heart diseases; thus, our final cohort of study included 103 patients (male 66%; mean age 11 ± 3.4 years), with a mean follow-up of 9.5 ± 5.5 years. All patients were submitted to complete non-invasive cardiologic evaluation. The mean number of PVCs at Holter Monitoring (HM) was 11,479 ± 13,147/24 h; couplets and/or triplets were observed in 5/103 (4.8%) cases; 3 patients (2.9%) presented runs of non-sustained ventricular tachycardia (NSVT). High-burden PVCs (> 30,000/24 h) was confirmed in 11/103 (10.6%) patients. During the follow-up, only five patients (4.8%) developed clinical symptoms (3 for palpitations, 1 myocardial dysfunction due to frequent PVCs and NTSV; 1 arrhythmogenic cardiomyopathy); no deaths occurred. Basal PVCs were still present in 45/103 (43.7%) patients. Our data suggest that frequent PVCs may be addressed as a benign condition and should not preclude sport participation if not associated with cardiac malformations, heart dysfunction, or cardiomyopathy. This seems to be true also in presence of very frequent/high-burden PVCs. Otherwise, a careful follow-up is mandatory since sport eligibility should be reconsidered in case of onset of symptoms and/or ECG/echocardiographic changes.

A novel ECG criterion to differentiate left from right ventricular outflow tract premature complex

Objectives. Catheter ablation is an effective method in the treatment of idiopathic ventricular arrhythmias. The mapping methods used for predicting the original site of arrhythmias are difficult to use and time-consuming. Consequently, developing methods using surface ECG for guiding the location is important. Here, we have tested a new ECG criterion to differentiate the left from the right ventricular originated complexes (PVCs) or tachycardias (VTs). Designs. Sixty patients with idiopathic PVC or VT who had undergone a successful radiofrequency catheter ablation (RFA) of arrhythmia were enrolled. The surface ECG during sinus rhythm and arrhythmia was analyzed. Initial r wave Surface Area (ISA) index was measured by multiplying the R wave duration in milliseconds by the R wave amplitude in terms of millivolt in V1 or V2 leads. Results. Thirty-seven patients with right ventricular (RVOT) and 23 with left ventricular outflow tract (LVOT) originated VT or PVC were enrolled. The ISA index was significantly greater in LVOT-VT/PVC compared to RVOTs (63.6 ± 78.9 vs. 8.3 ± 7.3, p < .001). With a cut off value of ≥15, the index could differentiate a left from right arrhythmia with 94.6% specificity and 78.2% sensitivity (Area on the curve, 0.81; p < .001). Compared to other previously reported indices, ISA is the most specific one. Conclusion. ISA index can serve as a very useful ECG criterion for differentiating a LVOT- from RVOT-originated VTs or PVCs.