Premature Ventricular Complex-induced Cardiomyopathy

Peripartum ventricular tachycardia and PVC-induced cardiomyopathy: delivering optimal care when it's time to deliver

Ventricular tachycardia (VT) is a rare but potentially fatal complication in pregnancy. We present a case of a pregnant woman with cardiomyopathy due to frequent premature ventricular complexes (PVCs) and VT originating from the left ventricular outflow tract. After presenting late in the third trimester, the decision was made to deliver the fetus after 4 days of medication titration due to continued sustained episodes of VT. After delivery, the patient continued to have frequent PVCs and VT several months after discharge, and she ultimately underwent a PVC ablation with dramatic reduction in PVC burden and improvement in cardiomyopathy. Multidisciplinary planning with a pregnancy heart team led to appropriate contingency planning and a successful delivery. This case highlights how multidisciplinary management is best practice in pregnancy complicated by VT and the need for better diagnostic guidelines for PVC-induced cardiomyopathy in the setting of pregnancy.

Arrhythmia-Induced Cardiomyopathy: JACC State-of-the-Art Review

Arrhythmias frequently accompany heart failure and left ventricular dysfunction. Tachycardias, atrial fibrillation, and premature ventricular contractions can induce a reversible form of dilated cardiomyopathy (CM) known as arrhythmia-induced CM (AiCM). The intriguing question is why certain individuals are more susceptible to AiCM, despite similar arrhythmia burdens. The primary challenge is determining the extent of arrhythmias' contribution to left ventricular systolic dysfunction. AiCM should be considered in patients with a mean heart rate of >100 beats/min, atrial fibrillation, or a PVC burden of >10%. Confirmation of AiCM occurs when CM reverses upon eliminating the responsible arrhythmia. Therapy choice depends on the specific arrhythmia, patient comorbidities, and preferences. After left ventricular function is restored, ongoing follow-up is essential if an abnormal myocardial substrate persists. Accurate diagnosis and treatment of AiCM have the potential to enhance patients' quality of life, improve clinical outcomes, and reduce hospital admissions and overall health care costs.

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.

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.

Systems of care for ambulatory management of decompensated heart failure

Heart failure (HF) represents a worldwide health burden and the annual per patient cost to treat HF in the US is estimated at $24,383, with most of this expense driven by HF related hospitalizations. Decompensated HF is a leading cause for hospital admissions and is associated with an increased risk of subsequent morbidity and mortality. Many hospital admissions for decompensated HF are considered preventable with timely recognition and effective intervention.Systems of care that include interventions to facilitate early recognition, timely and appropriate intervention, intensification of care, and optimization to prevent recurrence can help successfully manage decompensated HF in the ambulatory setting and avoid hospitalization.

Left ventricular remodeling in premature ventricular contraction-induced cardiomyopathy: Effect of coupling intervals and atrioventricular dissociation

Background

Left ventricular dyssynchrony (LVD) and postextrasystolic potentiation (PESP) associated with premature ventricular contractions (PVCs) may play a role in the development of premature ventricular contraction-induced cardiomyopathy (PVC-CM). Long-coupled (LC) PVCs have a greater LVD than short-coupled (SC) PVCs, whereas SC-PVCs have a stronger PESP than LC-PVCs.

Objective

The purpose of this study was to compare SC-PVCs and LC-PVCs to evaluate the roles of LVD, PESP, and atrioventricular dissociation (AVD) in the development of PVC-CM.

Methods

Thirty-six canines underwent pacemaker implantation to induce bigeminal right ventricular apical epicardial PVCs (50% burden) for 12 weeks. Telemetry assessed PVC burden and AVD. Animals were grouped as SC-PVC (coupling interval [CI] 200-220ms), LC-PVC (CI 330 ms), or sham (control). Echocardiographic changes, AVD, and hemodynamics were monitored for 12 weeks.

Results

PVC burden was similar between SC-PVC and LC-PVC groups but was statistically higher in the SC-PVC group (50% vs 47.5%; P = .028). After 12 weeks, left ventricular ejection fraction (LVEF) significantly decreased in both SC-PVC and LC-PVC groups (47.1% ± 1.4% and 45.5% ± 2%, respectively) compared to sham group (61% ± 1.6%; P <.001). Overall AVD was similar between SC-PVC and LC-PVC groups, and there was no significant correlation between AVD and reduction in LVEF at 12 weeks (r = 0.09, P = .5; and r = 0.06, P = .8, respectively). Additionally, both SC-PVC and LC-PVC groups experienced substantial declines in max and min dP/dt after 12 weeks compared to baseline.

Conclusion

Neither PVC CI nor AVD played an independent role in the development or severity of PVC-CM. LVD and PESP make equal relative contributions to the development of PVC-CM.

Yield of Cardiac Investigations in Patients Presenting with Acute Ischaemic Stroke: A single tertiary centre experience

Objectives

Strokes are a major cause of morbidity and mortality. This study aimed to evaluate the effectiveness of routine cardiac investigations in identifying a cardioembolic aetiology for ischaemic strokes.

Methods

This retrospective study involved patients who presented with a stroke to the Sultan Qaboos University Hospital, Muscat, Oman, between January and December 2019.

Results

A total of 183 patients (mean age = 66.2 ± 13.5 years), the majority of which were male (n = 109, 59.6%), were included. The common risk factors included hypertension (74.9%), diabetes (61.7%) and hyperlipidaemia (54.6%). The middle cerebral artery was the most common artery affected, in 44 patients (24.0%). On admission, 14 (7.6%) patients were in atrial fibrillation (AF), while the rest were in sinus rhythm. The 24-hour electrocardiogram (ECG) Holter monitoring revealed no abnormalities in 135 patients. AF was observed in 15 (8.1%) patients (inclusive of the 14 who had AF on resting ECG). Furthermore, 32 (17.4%) patients had evidence of non-sustained atrial arrhythmia, and nine (4.9%) had non-sustained ventricular tachycardia. Frequent supraventricular ectopics (>30/hour) was noted on 30 patients (16.3%), while five (2.7%) patients had a high ventricular ectopic burden (>10% burden). No significant abnormalities were noted in the echocardiograms of the patients; however, 10 out of 132 (7.5%) patients presented a positive bubble echo. Enlarged left atria were found in 24 (13.1%) patients.

Conclusion

The overall diagnostic yield of the abnormalities from routine cardiac testing for patients with stroke appears to be low. Targeted screening of patients with cryptogenic stroke, as suggested by newer guidelines, is recommended.

May myocardial work predict the risk of cardiomyopathy in patients with premature ventricular complex?

BACKGROUND

An increased premature ventricular complex (PVC) frequency is related to an increased risk of cardiomyopathy. Changes in myocardial work (MW) parameters in patients with PVC may be a predictor of the development of cardiomyopathy.

METHODS

The study included 56 patients with PVC and 50 healthy volunteers as a control group. A comprehensive echocardiographic examination was done. A speckle tracking echocardiography was used to obtain the left ventricle (LV) global longitudinal strain (GLS). A bull's eye plot of the global MW index and the global work efficiency of 17 left ventricle segments with MW component values were generated.

RESULTS

Global work index (GWI), global constructive work (GCW), and global work efficiency (GWE) were significantly lower in the patient group (2377.84 ± 216.52 vs.1818.30 ± 283.73, 2734.00 ± 208.90 vs. 2283.73 ± 321.65, 92.48 ± 2.85 vs. 87.75 ± 3.87, respectively, all p values <0.001). Global wasted work (GWW) was significantly higher in the patient group (216.80 ± 26.86 vs. 302.13 ± 41.81, p < 0.001) Patients were compared according to the origin of PVCs. GWI, GCW, GWE were significantly lower and GWW was significantly higher in patients with PVC originating from the right ventricle or the epicardial region (p < 0.001).

CONCLUSIONS

Compared to healthy individuals, patients with PVC had lower GCW, GWI, GWE values and a higher GWW value than healthy individuals, similar to cardiomyopathy patients. Therefore, the detoriation in MW parameter in patients with PVC may be a predictor of cardiomyopathy development.

[Quality of life in patients with idiopathic ventricular arrhythmias treated at the Instituto Nacional Cardiovascular - INCOR]

Objective

To describe the quality of life in patients with idiopathic ventricular arrhythmias treated at the Instituto Nacional Cardiovascular INCOR in Lima -Peru.

Materials and methods

. Analytical and cross-sectional study of patients with idiopathic ventricular arrhythmias treated by 3D ablation or antiarrhythmic therapy between July 2017 and December 2019 to whom the SF-36 health questionnaire was applied to assess quality of life related to health.

Results

Fifty-two patients with idiopathic ventricular arrhythmias were included (34 underwent 3D ablation, and 18 underwent antiarrhythmic therapy only). The percentage of recurrence (14.7% vs. 50%, p=0.01) and adverse effects (0% vs. 22.2%, p=0.011) were lower in the 3D ablation group compared to the antiarrhythmic group. The mean standardized scores obtained from the Spanish version of the Health Survey SF-36v2, applied to the 3D ablation and antiarrhythmic groups were 85.1 vs 68.4 (p<0.001), respectively. Were found statistically significant differences in 6 of the eight components that evaluate health-related quality of life: physical function (96.0 vs. 76.0, p<0.001), physical role (93.4 vs. 61.1, p<0.001), general health (74.5 vs. 47.4, p<0.001), vitality (69.9 vs 54.7, p=0.008), emotional role (92.2 vs. 77.8, p=0.006) and mental health (73.8 vs. 60, p<0.001).

Conclusions

Patients with idiopathic ventricular arrhythmias who underwent 3D ablation have a higher mean standardized score for health-related quality of life.

12-lead ECG signal processing and atrial fibrillation prediction in clinical practice

BACKGROUND

Because clinically used 12-lead electrocardiography (ECG) devices have high falsepositive errors in automatic interpretations of atrial fibrillation (AF), they require substantial improvements before use.

OBJECTIVE

A clinical 12-lead ECG pre-processing method with a parallel convolutional neural network (CNN) model for 12-lead ECG automatic AF recognition is introduced.

METHODS

Raw AF diagnosis data from a 12-lead ECG device were collected and analyzed by two cardiologists to differentiate between true- and false-positives. Using a stationary wavelet transform (SWT) and independent component analysis (ICA) noise reduction was conducted and baseline wandering was corrected for the raw signals. AF patterns were learned and predicted using a parallel CNN deep learning (DL) model. (1) The proposed method alleviates the decreased ECG QRS amplitude enhances the signal-to-noise ratio and clearly shows atrial and ventricular activities. (2) After training, the CNNbased AF detector significantly reduced false-positive errors. The precision of AF diagnosis increased from 77.3% to 94.0 ± 1.5% as compared to ECG device interpretation. For AF screening, the model showed an average sensitivity of 96.8 ± 2.2%, specificity of 79.0 ± 5.8%, precision of 94.0 ± 1.5%, F1-measure of 95.2 ± 1.0%, and overall accuracy of 92.7 ± 1.5%.

CONCLUSIONS

The method can bridge the gap between the research and clinical practice The ECG signal pre-processing and DL-based AF interpretation can be rapidly implemented clinically.

Revisiting exercise-induced premature ventricular complexes as a prognostic factor for mortality in asymptomatic patients: A systematic review and meta-analysis

Background

Recent investigations suggest that premature ventricular complexes (PVCs) during an exercise test are associated with an elevated risk of mortality in asymptomatic individuals. However, given the small number of studies included, the association between these two entities in the asymptomatic population remains obscure. Our aim was to evaluate this matter.

Methods

A comprehensive literature search was conducted utilizing several online databases up to April 2022. The study comprised cohort studies examining the relationship between exercise-induced premature ventricular complexes (EI-PVCs) and all-cause mortality (ACM) as well as cardiovascular mortality (CVM) in asymptomatic populations. To provide diagnostic values across the statistically significant parameters, we additionally calculated sensitivity, specificity, and area under the curve (AUC).

Results

A total of 13 studies consisting of 82,161 patients with a mean age of 49.3 years were included. EI-PVCs were linked to an increased risk of ACM (risk ratio (RR) = 1.30 (95% confidence interval (CI) = 1.18–1.42); p &lt; 0.001; I2 = 59.6%, p-heterogeneity &lt; 0.001) and CVM (RR = 1.67 (95% CI = 1.40–1.99); p &lt; 0.001; I2 = 7.5%, p-heterogeneity = 0.373). Subgroup analysis based on the frequency of PVCs revealed that frequent PVCs were similarly related to a higher risk of ACM and CVM, but not infrequent PVCs. Moreover, diagnostic test accuracy meta-analysis showed that recovery phase EI-PVCs have a higher overall specificity than exercise phase EI-PVCs regarding our outcomes of interest.

Conclusion

EI-PVCs are correlated with a higher risk of ACM and CVM. When compared to the exercise phase, the specificity of PVCs generated during the recovery period in predicting interest outcomes is higher. As a result, we propose that the exercise ECG be utilized on a regular basis in middle-aged asymptomatic individuals to measure the frequency of PVCs and stratify the risk of mortality.

Systematic review registration

[https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=328852], identifier [CRD42022328852].

Mechanisms, time course and predictability of premature ventricular contractions cardiomyopathy-an update on its development and resolution

Frequent premature ventricular contractions (PVCs) associated left ventricular systolic dysfunction (LVSD) is a well-known clinical scenario and numerous predictors for cardiomyopathy (CMP) development have been already thoroughly described. It may present as a "pure" form of dissynchrony-induced cardiomyopathy or it may be an aggravating component of a multifactorial structural heart disease. However, the precise risk to develop PVC-induced CMP (which would allow for tailored-patient monitoring and/or early treatment) and the degree of CMP reversibility after PVC suppression/elimination (which may permit appropriate candidate selection for therapy) are unclear. Moreover, there is limited data regarding the time course of CMP development and resolution after arrhythmia suppression. Even less known are the other components of PVC-induced CMP, such as right ventricular (RV) and atrial myopathies. This review targets to synthetize the most recent information in this regard and bring a deeper understanding of this heart failure scenario. The mechanisms, time course (both in experimental models and clinical experiences) and predictors of reverse-remodelling after arrhythmia suppression are described. The novel experience hereby presented may aid everyday clinical practice, promoting a new paradigm involving more complex, multi-level and multi-modality evaluation and possible earlier intervention at least in some patient subsets.

The effects of catheter ablation of outflow tract premature ventricular complexes on atrial electromechanical delay

BACKGROUND

Consistent data from several studies have shown that catheter ablation of frequent premature ventricular complexes (PVCs) results in substantial improvement in left ventricular ejection fraction (LVEF), left ventricular diastolic function, and left atrial volume and mechanics. However, the effects of catheter ablation of PVCs on atrial electromechanical properties have not been documented yet.

AIMS

In the present study, we investigated the short-term effects of radiofrequency catheter ablation (RFCA) of outflow tract PVCs on atrial electromechanical delay (EMD).

METHODS

A total of 71 subjects with idiopathic outflow tract PVCs who underwent RFCA were included. Interatrial and intra-atrial EMDs were measured by tissue Doppler imaging before and 3 months after catheter ablation.

RESULTS

The study population was divided into normal ejection fraction (EF) and low-EF subgroups according to their LVEF. In all study groups, substantial improvement was found in lateral electromechanical coupling time (PA), septal PA, right ventricular PA, interatrial EMD, left-sided intra-atrial EMD, and right-sided intra-atrial EMD. No treatment heterogeneity was observed when comparing low-EF and normal-EF subgroups with respect to atrial EMDs (interatrial EMD, interaction p = .29; left-sided intra-atrial EMD, interaction p = .13; right-sided intra-atrial EMD, interaction p = .88).

CONCLUSION

RFCA of outflow tract PVC has a favorable early effect on intra- and inter-atrial EMDs irrespective of preprocedural LVEF.

Left Ventricular Remodeling in Non-syndromic Mitral Valve Prolapse: Volume Overload or Concomitant Cardiomyopathy?

Mitral valve prolapse (MVP) is a common valvular disorder that can be associated with mitral regurgitation (MR), heart failure, ventricular arrhythmias and sudden cardiac death. Given the prognostic impact of these conditions, it is important to evaluate not only mitral valve morphology and regurgitation, but also the presence of left ventricular (LV) function and remodeling. To date, several possible hypotheses have been proposed regarding the underlying mechanisms of LV remodeling in the context of non-syndromic MVP, but the exact pathophysiological explanation remains elusive. Overall, volume overload related to severe MR is considered the main cause of LV dilatation in MVP. However, significant LV remodeling has been observed in patients with MVP and no/mild MR, particularly in patients with bileaflet MVP or Barlow’s disease, generating several new hypotheses. Recently, the concept of “prolapse volume” was introduced, adding a significant volume load to the LV on top of the transvalvular MR volume. Another possible hypothesis is the existence of a concomitant cardiomyopathy, supported by the link between MVP and myocardial fibrosis. The origin of this cardiomyopathy could be either genetic, a second hit (e.g., on top of genetic predisposition) and/or frequent ventricular ectopic beats. This review provides an overview of the different mechanisms and remaining questions regarding LV remodeling in non-syndromic MVP. Since technical specifications of imaging modalities impact the evaluation of MR severity and LV remodeling, and therefore might influence clinical decision making in these patients, this review will also discuss assessment of MVP using different imaging modalities.

Is it possible to expect left ventricular ejection fraction improvement in patients with known advanced heart diseases in the case of right atrial flutter treated by ablation?

BACKGROUND

Atrial flutter (AFL)-related tachycardia-induced cardiomyopathy (TICM) is a treatable cause of heart failure (HF). This study aims to explore the effect of AFL ablation on left ventricular (LV) function in right AFL patients with or without advanced heart diseases.

METHODS

Between January 2013 and December 2019, 149 patients underwent ablation for persistent AFL. Among them, 60 patients with persistent right atrial (RA) flutter had symptomatic HF and elevated natriuretic peptide levels. Group 1 consisted of 35 patients without advanced heart diseases, and group 2 consisted of 25 patients with prior history of ischemic cardiomyopathy (ICM), dilated cardiomyopathy (DCM) or surgery for valvular heart disease (VHD). Follow-up echocardiography was performed 6 months later. Improvement of LV performance was defined as LV ejection fraction (EF) increase ≥50% of baseline EF without clinical HF symptoms or LVEF recovery to ≥60%.

RESULTS

Group 2 had larger LV end-diastolic volume (LVEDV) and LV end-systolic volume than group 1. At follow-up, group 2 had larger LV end-systolic volume than group 1. Group 1 had more increase in LVEF than group 2 (21.7 ± 15.2% vs 4.1 ± 13.2%; P < .001). A receiver operating characteristic curve was constructed to determine the discrimination threshold of baseline LVEDV (137 mL) in the overall study group for improvement of LV performance after ablation (P = .005).

CONCLUSIONS

Successful ablation for right AFL could achieve more reversal of LV dysfunction in patients without advanced heart diseases. Pre-ablation LVEDV ≥ 137 mL was associated with no improvement of LV performance after ablation.

A case of premature ventricular contractions-related cardiomyopathy

Premature ventricular contractions (PVCs) are heart beats initiated in the ventricles instead of in the sinoatrial node. A high burden of PVCs can lead to a cardiomyopathy, characterised by reduced left ventricular (LV) systolic dysfunction. We present a case of PVC-related cardiomyopathy where the 65-year-old male was initially seen by his primary care provider for recent onset chest pain and dizziness. His transthoracic echocardiogram showed mild concentric LV hypertrophy and mildly reduced systolic function (LV ejection fraction 43%). There was also mild right ventricular (RV) systolic dysfunction. He was started on a beta-blocker and an angiotensin-converting enzyme inhibitor. A 24-hour Holter monitor showed a very high burden of PVCs (32% of all beats). He continued to have frequent PVCs and his echocardiogram did not improve. He was eventually referred for a PVC ablation. Following the ablation, a repeat Holter monitor showed a marked reduction in PVC burden (<1% of beats) and his echocardiogram had normalised.

Relatively Benign yet a Reversible Cause of Dilated Cardiomyopathy

Arrhythmia-induced cardiomyopathy secondary to frequent ventricular premature contractions is a well-studied phenomenon; however, there is a paucity of data showing a similar association with frequent atrial premature contractions (APCs). Early recognition and successful APC ablation can reverse left ventricular dysfunction in these patients. (Level of Difficulty: Beginner.).

Cardiac Magnetic Resonance to Detect the Underlying Substrate in Patients with Frequent Idiopathic Ventricular Arrhythmias

BACKGROUND

A routine diagnostic work-up does not identify structural abnormalities in a substantial proportion of patients with idiopathic ventricular arrhythmias (VAs). We investigated the added value of cardiac magnetic resonance (CMR) imaging in this group of patients.

METHODS

A single-centre prospective study was undertaken of 72 patients (mean age 46 ± 16 years; 53% females) with frequent premature ventricular contractions (PVCs ≥ 500/24 h) and/or non-sustained ventricular tachycardia (NSVT), an otherwise normal electrocardiogram, normal echocardiography and no coronary artery disease.

RESULTS

CMR provided an additional diagnostic yield in 54.2% of patients. The most prevalent diagnosis was previous myocarditis (23.6%) followed by possible PVC-related cardiomyopathy (20.8%), non-ischaemic cardiomyopathy (8.3%) and ischaemic heart disease (1.4%). The predictors of abnormal CMR findings were male gender, age and PVCs/NSVT non-outflow tract-related or with multiple morphologies. Patients with VAs had an impaired peak left ventricular (LV) global radial strain (GRS) compared with the controls (28.88% (IQR: 25.87% to 33.97%) vs. 36.65% (IQR: 33.19% to 40.2%), p < 0.001) and a global circumferential strain (GCS) (-17.66% (IQR: -19.62% to -16.23%) vs. -20.66% (IQR: -21.72% to -19.6%), p < 0.001).

CONCLUSION

CMR reveals abnormalities in a significant proportion of patients with frequent idiopathic VAs. Male gender, age and non-outflow tract PVC origin can be clinical indicators for CMR referral.

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.

Non-fluoroscopic radiofrequency catheter ablation of right- and left-sided ventricular arrhythmias

Introduction

Radiofrequency catheter ablation (RFCA) is an important method of treatment of ventricular arrhythmias (VAs). In the majority of RFCA, fluoroscopy is used, exposing patients and medical staff to all related side effects. Current experience of non-fluoroscopic (NF)-RFCA in VAs from the left side is limited.

Aim

Analysis of safety and effectiveness of NF-RFCA of VAs from left- and right-sided cardiac chambers.

Material and methods

From 2014 to 2018, a group of 128 patients who underwent RFCA of VAs were retrospectively divided into two groups: NF-RFCA and fluoroscopic (F)-RFCA. Patients in each group were then subsequently subdivided into two groups based on VAs localization - left- (LS-Va) and right-sided (RS-Va) VAs. In all patients the CARTO Biosense Webster mapping system was used.

Results

In group 1 (NF-RFCA n = 88) 66 (75%) patients underwent RFCA of RS-Va and 22 (25%) of LS-Va. Early success was achieved in 89.8% (n = 79) and long term success in 81.8% (n = 72). In group 2 (F-RFCA n = 40) 19 patients (47.5%) had RFCA of RS-Va and 21 (52.5%) patients of LS-Va. Acute procedural success rate was 80% (n = 32) and long-term success 72.5% (n = 29). There were 4 (4.6%) perioperative complications in NF-RFCA and 2 (5%) in F-RFCA. Success rate, procedure time and complications were not significantly different between groups and subgroups in follow-up.

Conclusions

NF-RFCA in VAs from the right and left cardiac chamber is safe and equally effective as F-RFCA, and it should be implemented as often as possible for protection of patients and electrophysiology staff.

Important tips reflected in our daily practice from the American College of Cardiology Electrophysiology Council report on premature ventricular contractions

Premature ventricular contractions (PVCs) is one of the most common situations in the current cardiology practice. Although PVCs are generally benign in people without any structural heart disease, they may be associated with left ventricular dysfunction, cardiomyopathy, and, rarely, sudden death. Recently, there has been a considerable research in the pathophysiology of PVC, several clinical presentations in different situations, new proposals of successful diagnostic methods, and treatment modalities. Finally, the American College of Cardiology Electrophysiology Council has published a special report that deals with all the aspects of PVC. We reviewed the important points from this report that can be reflected in our daily practice.

Premature ventricular contractions of the right ventricular outflow tract: is there an incipient underlying disease? New insights from a speckle tracking echocardiography study

Context

Premature ventricular contractions (PVCs) originating in the right ventricular outflow tract (RVOT) are traditionally considered idiopathic and benign. Echocardiographic conventional measurements are typically normal.

Aims

To assess whether right ventricle longitudinal strain, determined by two-dimensional speckle tracking echocardiography, differ between RVOT PVCs patients (treated with catheter ablation) and healthy controls.

Methods

We retrospectively selected patients with PVCs from the RVOT who underwent electrophysiological study and catheter ablation between 2016 and 2019. Patients with documented structural heart disease were excluded. Transthoracic echocardiography was performed and right ventricle global longitudinal strain (RV-GLS), free wall longitudinal strain (RVFW-LS) and left ventricle global longitudinal strain (LV-GLS) were determined as well as conventional ultrasound measurements of RV and LV function.

Results

We studied 21 patients with RVOT PVCs and 13 controls. Patients with PVCs from the RVOT had lower values of RV-GLS and RVFW-LS compared with the control group (−19.4% versus −22.5%, P = 0.015 and −22.1% versus −25.5, P = 0.041, respectively). They also had lower values of LV-GLS, although still within the normal range (−19.1% versus −20.9%, P = 0.047). Regarding RVOT PVCs patients only, RV-GLS and RVFW-LS had no correlation with the PVCs burden prior to catheter ablation and they did not differ between the patients in whom the catheter ablation was successful and those in whom it was not. RV-GLS also had a positive correlation with RVOT proximal diameter (r = 0.487, P = 0.025).

Conclusions

In this group of RVOT PVCs patients, we found worse RV longitudinal strain values (and therefore sub-clinical myocardial dysfunction) when compared to healthy controls.

Low-Level Radiofrequency Exposure Does Not Induce Changes in MSC Biology: An in vitro Study for the Prevention of NIR-Related Damage

Background

The ubiquitous diffusion of radiofrequency (RF) radiation across human living environments has attracted the attention of scientists. Though the adverse health effects of RF exposure remain debatable, it has been reported that the interaction of such radiation with biological macromolecular structures can be deleterious for stem cells, inducing impairment of their main functions involving self-renewal and differentiation.

Purpose

The purpose of this study was to determine whether exposure to RF of 169 megahertz (MHz) that is part of very high radiofrequency (VHF) range 30–300 MHz, could cause damage to stem cells by inducing senescence and loss of regenerative and DNA repair capacity.

Methods

The study was conducted on mesenchymal stromal cells (MSCs) containing a subpopulation of stem cells. The MSCs were exposed to RFs of 169 MHz administered via an open meter 2G “Smart Meter” for different durations of time.

Result

We did not observe modifications in MSC biology as a result of the RF exposure conducted in our experiments.

Conclusion

We concluded that MSCs are insensitive to RF radiation exposure at 169 MHz for various time intervals, including longer durations.

Premature ventricular complexes: diagnostic and therapeutic considerations in clinical practice : A state-of-the-art review by the American College of Cardiology Electrophysiology Council

Premature ventricular complexes (PVCs) are common arrhythmias in the clinical setting. PVCs in the structurally normal heart are usually benign, but in the presence of structural heart disease (SHD), they may indicate increased risk of sudden death. High PVC burden may induce cardiomyopathy and left ventricular (LV) dysfunction or worsen underlying cardiomyopathy. Sometimes PVCs may be a marker of underlying pathophysiologic process such as myocarditis. Identification of PVC burden is important, since cardiomyopathy and LV dysfunction can reverse after catheter ablation or pharmacological suppression. This state-of-the-art review discusses pathophysiology, clinical manifestations, how to differentiate benign and malignant PVCs, PVCs in the structurally normal heart, underlying SHD, diagnostic procedures (physical examination, electrocardiogram, ambulatory monitoring, exercise testing, echocardiography, cardiac magnetic resonance imaging, coronary angiography, electrophysiology study), and treatment (lifestyle modification, electrolyte imbalance, medical, and catheter ablation).

The effect of idiopathic premature ventricular complexes on left ventricular ejection fraction

Aim

Current literature lacks a definitive threshold of idiopathic premature ventricular complex (PVC) burden for predicting cardiomyopathy (CMP). The main objective of the present study was to evaluate relationship between the PVC burden and left ventricular ejection fraction (LVEF).

Method

This multicenter, cross‐sectional study included 341 consecutive patients with more than 1,000 idiopathic PVC in 24 hr of Holter monitoring admitted to the cardiology clinics between January 2019 and May 2019 in the nineteen different centers. The primary outcome was the LVEF measured during the echocardiographic examination.

Result

Overall, the median age was 50 (38–60) and 139 (49.4%) were female. Percentage of median PVC burden was 9% (IQR: 4%–17.4%). Median LVEF was found 60% (55–65). We used proportional odds logistic regression method to examine the relationship between continuous LVEF and candidate predictors. Increase in PVC burden (%) (regression coefficient (RE) −0.644 and 95% CI −1.063, –0.225, p < .001), PVC QRS duration (RE‐0.191 and 95% CI −0.529, 0.148, p = .049), and age (RE‐0.249 and 95% CI −0.442, −0.056, p = .018) were associated with decrease in LVEF. This inverse relationship between the PVC burden and LVEF become more prominent when PVC burden was above 5%. A nomogram developed to estimate the individual risk for decrease in LVEF.

Conclusion

Our study showed that increase in PVC burden %, age, and PVC QRS duration were independently associated with decrease in LVEF in patients with idiopathic PVC. Also, inverse relationship between PVC burden and LVEF was observed in lower PVC burden than previously known.

Left Atrial Function Is Improved in Short-Term Follow-Up after Catheter Ablation of Outflow Tract Premature Ventricular Complexes

Background: Association of premature ventricular complexes (PVC) with left ventricular systolic dysfunction (LVSD) and efficacy of catheter ablation treatment have been demonstrated in studies. The role of left atrial (LA) mechanics in the etiopathogenesis of PVC-induced cardiomyopathy (PVC-CMP) as well as changes in LA mechanics with catheter ablation have not been studied before. Methods: A total number of 61 patients (Mean Age 43 ± 3) with idiopathic outflow tract (OT) PVCs undergoing radiofrequency catheter ablation (RFCA) were enrolled. ECG, 24 h Holter, and echocardiographic evaluation with left ventricular (LV) diastolic functions and LA volumetric assessments were performed before and three months after RFCA. Results: Along with a marginal increase in left ventricle ejection fraction (LVEF), improvement in diastolic functions and left atrial mechanics were observed in the study (LVEF 53 ± 7 versus 57 ± 6, p < 0.01) in short-term follow-up. The frequency of LV diastolic dysfunction (LVDD) decreased with catheter ablation (n = 5 to 0, p = 0.02). The overall LA function improved. Left atrium passive and overall emptying fraction (LAEF) increased significantly (0.32 ± 0.04 to 0.41 ± 0.04, p < 0.05 and 0.62 ± 0.04 to 0.65 ± 0.004, p < 0.05, respectively). Active LAEF decreased significantly (0.29 ± 0.005 to 0.24 ± 0.006, p < 0.05). Conclusions: The results of this study are indicative of “PVC-induced atriomyopathy” which responds to RFCA in short-term follow-up. Atrial dysfunction might play a role in symptoms and etiopathogenesis of LVSD.