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.

Catheter Ablation of Idiopathic Epicardial Outflow Tract Premature Ventricular Contractions: A Case Report and Review of the Literature.

The epicardial outflow tract can be a site of origin of idiopathic ventricular arrhythmias. These arrhythmias are most commonly perivalvular and can be targeted from within the coronary venous system or from other adjacent structures, such as the right ventricular and left ventricular outflow tracts or the coronary cusp region. The authors report a case of an epicardial idiopathic outflow tract premature ventricular contraction originating from the midseptal epicardial left ventricle. In this case, direct epicardial access was crucial to identify early local activation and achieve successful catheter ablation.

Alterations of Myocardial Mitochondrial Morphology and Function in a Canine Model of Premature Ventricular Contractions-Induced Cardiomyopathy.

AIMS: Changes in myocardial mitochondrial morphology and function in premature ventricular contractions (PVCs)-induced cardiomyopathy (PVCCM) remain poorly studied. Here, we investigated the effects of PVCs with different coupling intervals (CIs) on myocardial mitochondrial remodelling in a canine model of PVCCM. METHODS AND RESULTS: Twenty-one beagles underwent pacemaker implantation and were randomised into the sham (n = 7), short-coupled PVCs (SCP, n = 7), and long-coupled PVCs (LCP, n = 7) groups. Right ventricular (RV) apical bigeminy was produced for 12-week to induce PVCCM in the SCP (CI, 250 ms) and LCP (CI, 350 ms) groups. Echocardiography was performed at baseline and biweekly thereafter to evaluate cardiac function. Masson's trichrome staining measured ventricular interstitial fibrosis. The ultrastructural morphology of the myocardial mitochondria was analysed using transmission electron microscopy. Mitochondrial Ca2+ concentration, reactive oxygen species (ROS) levels, adenosine triphosphate (ATP) content, membrane potential, and electron transport chain (ETC) complex activity were measured to assess myocardial mitochondrial function. Twelve-week-PVCs led to left ventricular (LV) enlargement with systolic dysfunction, disrupted mitochondrial morphology, increased mitochondrial Ca2+ concentration and ROS levels, decreased mitochondrial ATP content and membrane potential, and impaired ETC complex activity in both the SCP and LCP groups (all p < 0.01 vs the sham group). Ventricular fibrosis was observed only in canines with LCP. Worse cardiac function and more pronounced abnormalities in mitochondrial morphology and function were observed in the LCP group than to the SCP group (all p < 0.05). CONCLUSION: We demonstrated myocardial mitochondrial abnormalities in dogs with PVCCM, characterised by abnormal mitochondrial morphology, mitochondrial Ca2+ overload, oxidative stress, and impaired mitochondrial energy metabolism. Compared to SCP, long-term LCP exposure resulted in more severe mitochondrial remodelling and cardiac dysfunction in dogs.

The diagnostic efficiency of artificial intelligence based 2 hours Holter monitoring in premature ventricular and supraventricular contractions detection.

BACKGROUND: Electrocardiography (ECG) and 24 hours Holter monitoring (24 h-Holter) provided valuable information for premature ventricular and supraventricular contractions (PVC and PSVC). Currently, artificial intelligence (AI) based 2 hours single-lead Holter (2 h-Holter) monitoring may provide an improved strategy for PSVC/PVC diagnosis. HYPOTHESIS: AI combined with single-lead Holter monitoring improves PSVC/PVC detection. METHODS: In total, 170 patients were enrolled between August 2022 and 2023. All patients wore both devices simultaneously; then, we compared diagnostic efficiency, including the sensitivity/specificity/positive predictive-value (PPV) and negative predictive-value (NPV) in detecting PSVC/PVC by 24 h-Holter and 2 h-Holter. RESULTS: The PPV and NPV in patients underwent 2 h-Holter were 76.00%/87.50% and 96.35%/98.55, respectively, and the sensitivity and specificity were 79.17%/91.30%, and 95.65%/97.84% in PSVC/PVC detection compared with 24 h-Holter. The areas under the ROC curves (AUCs) for PSVC and PVC were 0.885 and 0.741, respectively (p < .0001). CONCLUSIONS: The potential advantages of the 2 h-Holter were shortened wearing period, improved convenience, and excellent consistency of diagnosis.

[Evidence mapping of Chinese patent medicines in treatment of premature ventricular contractions].

This study employed evidence mapping to systematically sort out the clinical studies about the treatment of premature ventricular contractions with Chinese patent medicines and to reveal the distribution of evidence in this field. The articles about the treatment of premature ventricular contractions with Chinese patent medicines were searched against PubMed, Cochrane Library, Web of Science, CNKI, Wanfang, and VIP with the time interval from January 2016 to December 2022. Evidence was analyzed and presented by charts and graphs combined with text. According to the inclusion and exclusion criteria, 164 papers were included, including 147 interventional studies, 4 observational studies, and 13 systematic reviews. A total of 27 Chinese patent medicines were involved, in which Shensong Yangxin Capsules and Wenxin Granules had high frequency. There were off-label uses in clinical practice. In recent years, the number of articles published in this field showed a decreasing trend. Eight types of outcome indicators were used in interventional studies. Ambulatory electrocardiography, clinical response rate, safety, and echocardiography had high frequency, while the rate of ß-blocker decompensation, major cardiovascular events, and pharmaceutical economic indicators were rarely reported. The evaluation was one-sided. The low quality of the included articles reduced the reliability of the findings. In the future, the clinical use of medicines should be standardized, and the quality of clinical studies should be improved. Comprehensive clinical evaluation should be carried out to provide a sound scientific basis for the treatment of premature ventricular contractions with Chinese patent medicines.

Ventricular bigeminy associated with myocardial ischemia in a dog with a colonic torsion: a case report.

BACKGROUND: Ventricular bigeminy due to myocardial ischemia has been reported in humans as well as in canine patients with obstructive gastrointestinal diseases. This is the first case report of ventricular bigeminy in a dog with a colonic torsion that resolved after fluid resuscitation and restoration of myocardial perfusion. CASE PRESENTATION: An 11-year-old, male neutered mixed breed dog presented with a one day history of vomiting, tenesmus, and lethargy. Physical examination identified an irregular heart rhythm and intermittent pulse deficits. A ventricular arrhythmia represented by ventricular premature complexes (VPCs) organized in bigeminy, was appreciated on a 3-lead electrocardiogram (ECG) with a single lead (II) view. Abdominal radiographs confirmed a colonic torsion. Prior to anesthetic induction, ventricular bigeminy was non responsive to fentanyl or lidocaine. The patient was anesthetized and intravascular volume deficit was identified by dampened plethysmographic wave amplitude (plethysomographic variability), audible softening of the Doppler sound, and more pronounced pulse deficits. Fluid resuscitation was achieved with a combination of intravenous crystalloid and colloid fluid therapy comprising 7.2% hypertonic saline and 6% hetastarch. The patient's cardiac rhythm converted to normal sinus after fluid resuscitation. The colonic torsion was surgically corrected. The patient recovered well from anesthesia and was ultimately discharged from the hospital 5 days later. CONCLUSIONS: The present case report highlights that myocardial ischemia can lead to ventricular arrythmias, such as ventricular bigeminy. This is the first documented case of ventricular bigeminy in the canine patient with a colonic torsion. Assessment of patient volume status and appropriate fluid resuscitation along with continuous electrocardiogram (ECG) monitoring are vital to patient stability under general anesthesia.

Temporal association of ventricular arrhythmias and respiratory events in heart failure patients with central sleep apnoea.

In contrast to obstructive sleep apnoea, the peak of sympathetic tone in central sleep apnoea occurs during the hyperventilation phase. To explore the temporal association of premature ventricular complex (PVC) burden in the context of the apnoea/hypopnoea-hyperpnoea cycle, the duration of apnoea/hypopnoea was defined as 100 %. We assessed the PVC burden throughout the apnoea/hypopnoea-hyperpnoea cycle during the periods of ±150 % in 50 % increments before and after the apnoea/hypopnoea phase. In this subanalysis of 54 SERVE-HF patients, PVC burden was 32 % higher in the late hyperventilation period (50-100 % after apnoea/hypopnoea) compared to the apnoea/hypopnoea phase.

An improved method to detect arrhythmia using ensemble learning-based model in multi lead electrocardiogram (ECG).

Arrhythmia is a life-threatening cardiac condition characterized by irregular heart rhythm. Early and accurate detection is crucial for effective treatment. However, single-lead electrocardiogram (ECG) methods have limited sensitivity and specificity. This study propose an improved ensemble learning approach for arrhythmia detection using multi-lead ECG data. Proposed method, based on a boosting algorithm, namely Fine Tuned Boosting (FTBO) model detects multiple arrhythmia classes. For the feature extraction, introduce a new technique that utilizes a sliding window with a window size of 5 R-peaks. This study compared it with other models, including bagging and stacking, and assessed the impact of parameter tuning. Rigorous experiments on the MIT-BIH arrhythmia database focused on Premature Ventricular Contraction (PVC), Atrial Premature Contraction (PAC), and Atrial Fibrillation (AF) have been performed. The results showed that the proposed method achieved high sensitivity, specificity, and accuracy for all three classes of arrhythmia. It accurately detected Atrial Fibrillation (AF) with 100% sensitivity and specificity. For Premature Ventricular Contraction (PVC) detection, it achieved 99% sensitivity and specificity in both leads. Similarly, for Atrial Premature Contraction (PAC) detection, proposed method achieved almost 96% sensitivity and specificity in both leads. The proposed method shows great potential for early arrhythmia detection using multi-lead ECG data.

Prognostic implications of premature ventricular contractions and non-sustained ventricular tachycardia in light-chain cardiac amyloidosis.

AIMS: Premature ventricular contractions (PVC) and non-sustained ventricular tachycardia (NSVT) are commonly observed in light chain cardiac amyloidosis (AL-CA), but their association with prognosis is still unclear. We aimed to evaluate the prognostic value of PVCs and NSVT in patients with moderate-to-advanced AL-CA. METHODS AND RESULTS: We retrospectively included patients with AL-CA at modified 2004 Mayo stages II-IIIb between February 2014 and December 2020. Twenty-four-hour Holter recordings were assessed on admission. The outcomes included (i) new onset of adverse ventricular arrhythmia (VA) or sudden cardiac death (SCD) and (ii) cardiac death during follow-up. Of the 143 patients studied (60.41 ± 11.06 years, male 64.34%), 132 (92.31%) had presence of PVC, and 50 (34.97%) had NSVT on Holter. Twelve (8.4%) patients died in hospital and 131 patients were followed up (median 24.4 months), among whom 71 patients had cardiac death, and 15 underwent adverse VA/SCD. NSVT [hazard ratio (HR): 13.57, 95% confidence interval (CI): 3.06-60.18, P < 0.001], log-transformed PVC counts (HR: 1.46, 95%CI: 1.15-1.86, P = 0.002) and PVC burden (HR: 1.43 95%CI:1.14-1.80, P = 0.002) were predictive of new onset of adverse VA/SCD. The highest tertile of PVC counts (HR: 2.33, 95%CI: 1.27-4.28, P = 0.006) and PVC burden (HR: 2.58, 95%CI: 1.42-4.69, P = 0.002), rather than NSVT (HR: 1.16, 95%CI: 0.67-1.98, P = 0.603), was associated with cardiac death. Higher PVC counts/burden provided incremental value on modified 2004 Mayo stage in predicting cardiac death, with C index increasing from 0.681 to 0.712 and 0.717, respectively (P values <0.05). CONCLUSION: PVC count, burden, and NSVT significantly correlated with adverse VA/SCD during follow-up in patients with AL-CA. Higher PVC counts/burdens added incremental value for predicting cardiac death.

Cardiac atrial pathology in Duchenne muscular dystrophy.

INTRODUCTION/AIMS: Duchenne muscular dystrophy (DMD) is characterized by fibrofatty replacement of muscle. This has been documented in the ventricular myocardium of DMD patients, but there is limited description of atrial involvement. The purpose of this study is to examine the arrhythmia and ectopy burden in patients with DMD and non-DMD dilated cardiomyopathy (DCM) and to characterize the cardiac histopathologic changes in DMD patients across the disease spectrum. METHODS: This was a retrospective analysis of age-matched patients with DMD and non-DMD DCM who received a Holter monitor and cardiac imaging within 100 days of each other between 2010 and 2020. Twenty-four-hour Holter monitors were classified based on the most recent left ventricular ejection fraction at the time of monitoring. Cardiac histopathologic specimens from whole-heart examinations at the time of autopsy from three DMD patients and one DCM patient were reviewed. RESULTS: A total of 367 patients with 1299 Holter monitor recordings were included over the study period, with 94% representing DMD patients and 6% non-DMD DCM. Patients with DMD had more atrial ectopy across the cardiac function spectrum (p < 0.05). There was no difference in ventricular ectopy. Four DMD patients developed symptomatic atrial arrhythmias. Autopsy specimens from DMD patients demonstrated fibrofatty infiltration of both atrial and ventricular myocardium. DISCUSSION: The atrial myocardium in patients with DMD is unique. Autopsy specimens reveal fibofatty replacement of the atrial myocardium, which may be a nidus for both ectopy and arrhythmias in DMD patients.

Class 1C Antiarrhythmics for Premature Ventricular Complex Suppression in Nonischemic Cardiomyopathy With Implantable Cardioverter-Defibrillators.

BACKGROUND: Premature ventricular complexes (PVCs) are common and associated with worse outcomes in patients with heart failure. Class 1C antiarrhythmic drugs (AADs) effectively suppress PVCs, but guidelines currently restrict their use in structural heart disease. OBJECTIVES: This study aimed to assess the safety and efficacy of class 1C AADs in patients with nonischemic cardiomyopathy (NICM) and implantable cardioverter-defibrillators (ICDs). METHODS: All patients with NICM and an ICD treated with flecainide or propafenone at the Hospital of the University of Pennsylvania between 2014 and 2022 were identified. PVC burden, left ventricular ejection fraction (LVEF), and biventricular pacing percentage were compared before and during class 1C AAD treatment. Safety outcomes included sustained atrial and ventricular arrhythmias, heart failure admissions, and death. RESULTS: We identified 34 patients, 23 receiving flecainide and 11 propafenone. Most patients (62%) had failed other AADs or catheter ablation (68%) prior to class 1C AAD initiation. PVC burden decreased from 20% ± 13% to 6% ± 7% (P < 0.001), LVEF increased from 33% ± 9% to 37% ± 10% (P = 0.01), and biventricular pacing percentage increased from 85% ± 9% to 93% ± 7% (P = 0.01). Sustained ventricular tachycardia (2 vs 9 patients) and admissions for decompensated heart failure (2 vs 3 patients) decreased compared with the 12 months prior to class 1C AAD initiation. CONCLUSIONS: Class 1C AADs effectively suppressed PVCs in patients with NICM and ICDs, leading to increases in LVEF and biventricular pacing percentage. In this limited sample, their use was safe. Larger studies are needed to confirm the safety of this approach.

Curvature-mediated source and sink effects on the genesis of premature ventricular complexes in long QT syndrome.

Premature ventricular complexes (PVCs) are spontaneous excitations occurring in the ventricles of the heart that are associated with ventricular arrhythmias and sudden cardiac death. Under long QT conditions, PVCs can be mediated by repolarization gradient (RG) and early afterdepolarizations (EADs), yet the effects of heterogeneities or geometry of the RG or EAD regions on PVC genesis remain incompletely understood. In this study, we use computer simulation to systematically investigate the effects of the curvature of the RG border region on PVC genesis under long QT conditions. We show that PVCs can be either promoted or suppressed by negative or positive RG border curvature depending on the source and sink conditions. When the origin of oscillation is in the source region and the source is too strong, a positive RG border curvature can promote PVCs by causing the source area to oscillate. When the origin of oscillation is in the sink region, a negative RG border curvature can promote PVCs by causing the sink area to oscillate. Furthermore, EAD-mediated PVCs are also promoted by negative border curvature. We also investigate the effects of wavefront curvature and show that PVCs are promoted by convex but suppressed by concave wavefronts; however, the effect of wavefront curvature is much smaller than that of RG border curvature. In conclusion, besides the increase of RG and occurrence of EADs caused by QT prolongation, the geometry of the RG border plays important roles in PVC genesis, which can greatly increase the risk of arrhythmias in cardiac diseases.NEW & NOTEWORTHY The effects of the curvature or geometry of the repolarization gradient region and wavefront curvature on the genesis of premature ventricular complexes are systematically investigated using computer modeling and simulation. Premature ventricular complexes can be promoted by either positive or negative curvature of the gradient region depending on the source and sink conditions. The underlying mechanisms of the curvature effects are revealed, which provides mechanistic insights into arrhythmogenesis in cardiac diseases.

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.

Single catheter approach for treatment of premature ventricular contractions.

BACKGROUND: Catheter ablation has become one of the main treatment strategies in patients with premature ventricular complexes (PVC). The successful mapping and ablation can be performed with an ablation catheter without additional diagnostic catheters. HYPOTHESIS: We hypothesize that using a single catheter for PVC ablation may decrease complications, procedure time, and fluoroscopy exposure while maintaining comparable success rates. METHODS: Sixty-nine consecutive patients with PVC were treated with a single catheter approach compared to a historical cohort, in which a conventional setup was used. Propensity score matching was conducted with a 1:1 ratio. Outcome parameters included acute procedural success with elimination of all premature ventricular contractions after catheter ablation, procedural data as well as complication rates. RESULTS: Patients treated with a single catheter approach had shorter total procedure (60 minutes [IQR: 47,5-69,0 minutes] vs. 90 minutes [IQR 60-120 minutes]; p = 0.001) and fluoroscopy times (218 seconds [IQR: 110,5-446 seconds] vs. 310 seconds [IQR 190-640 seconds]; p = 0.012), which consecutively leads to a reduction of radiation exposure signified by a lower dose area product (155 cGycm² [IQR 74.4-334.5 cGycm²] vs. 368.4 cGycm² [IQR: 126-905.4 cGycm²]; p value 0.009). Acute procedural success rates were comparable in both groups (54 [84.3%] in the single catheter approach group and 58 [90.6%] in the conventional group; p: 0.287). CONCLUSION: A single catheter approach for the treatment of PVC is associated with a reduction of procedure- and fluoroscopy time, as well as a lesser radiation exposure, while maintaining equivalent acute success and complication rates compared with a conventionally used catheter setup.

Outcomes of single-procedure radiofrequency catheter ablation for idiopathic ventricular arrhythmias: a single-centre retrospective cohort study.

OBJECTIVES: Radiofrequency catheter ablation is the first-line treatment for idiopathic premature ventricular complexes (PVCs) and ventricular tachycardias (VTs). However, the outcomes were less compared among the categories. The study aims to assess the effectiveness and safety of catheter ablation for idiopathic PVC/VTs in a single high-volume centre, using the right ventricular outflow tract (RVOT) as a reference. DESIGN: Retrospective cohort study. SETTING: Patient data were collected from a tertiary hospital in Guizhou, China. PARTICIPANTS: Between September 2013 and September 2022, 1028 patients (male: 41.3%; age: 46.5±15.6 years) who underwent the first catheter ablation for idiopathic monomorphic PVC/VTs were enrolled. OUTCOME MEASURES: Acute success, procedure-related complications, and long-term recurrence were assessed. Antiarrhythmic drugs (AADs) were not administrated after procedures unless recurrence was identified. RESULTS: The overall acute success rate was 90.3%, with 368 patients (35.8%) experiencing left ventricular PVC/VTs. No cases of third-degree atrioventricular block or death were reported. Complications were more common in patients with left ventricular PVC/VTs than those with right-sided ones (4.6% vs 0.1%, p<0.001). A total of 926 patients (90.1%) were followed up for an average of 9.7±3.7 months, and only the PVC/VTs category was found to be associated with long-term success rates. The RVOT, endocardial left ventricular outflow tract (endoLVOT), tricuspid annulus (TA) free wall, posterior septum and fascicular VT had long-term success rates exceeding 85%. Other types of PVC/VTs showed significantly higher risks of recurrence. CONCLUSIONS: Besides RVOT and fascicular VT, single-procedure catheter ablation without AADs is highly effective for endoLVOT, TA-free wall and posterior septum. Patients with left ventricular PVC/VTs have higher complication risks compared with right ones.