Catheter ablation of symptomatic idiopathic ventricular arrhythmias : A five-year single-centre experience

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.

Ventricular tachycardia ablation in children

INTRODUCTION

The ablation of ventricular tachycardia, including premature ventricular contractions, is an approved, albeit infrequent procedure in pediatric patients. Data are scarce regarding the outcomes of this procedure. The purpose of this study was to share a high-volume center experience and patient outcomes for catheter ablation of ventricular ectopy and ventricular tachycardia in pediatric population.

METHODS

Data were retrieved from the institutional data bank. Outcomes over time were evaluated, and procedural details were compared.

RESULTS

A total of 116 procedures were performed on 102 pediatric patients between July 2009 and May 2021 at the Rajaie Cardiovascular Medical and Research Center in Tehran, Iran. Ablation was not performed in 4 procedures (3.4%) due to high-risk substrates. Of the remaining 112 ablations performed, 99 (88.4%) were successful. However, one patient died due to a coronary complication. There were no significant differences observed in early ablation results based on patients' age, sex, cardiac anatomy, or ablation substrates (P > 0.05). Follow-up records were available for 80 procedures, and 13 (16.3%) of those experienced recurrence. During long-term follow-up, none of the variables mentioned above were statistically different between patients with or without arrhythmia recurrence.

CONCLUSION

The overall success rate of pediatric ventricular arrhythmia ablation is favorable. We found no significant predictor for the procedural success rate concerning acute and late outcomes. Larger multicenter studies are needed to elucidate the predictors and outcomes of the procedure.

The R-S difference index: A new electrocardiographic method for differentiating idiopathic premature ventricular contractions originating from the left and right ventricular outflow tracts presenting a left bundle branch block pattern

Introduction: Differentiating idiopathic premature ventricular contractions (PVCs) originating from the right and left ventricular outflow tracts with a left bundle branch block (LBBB) morphology is relevant to catheter ablation planning and important for lowering the risk of complications. This study established a novel electrocardiographic (ECG) criterion to discriminate PVCs originating from the septum of the right ventricular outflow tract (s-RVOT) and those originating from the aortic sinus cusp of the left ventricular outflow tract (LVOT-ASC).

Methods: A total of 259 patients with idiopathic PVCs originating from ventricular outflow tract with a LBBB pattern who underwent successful catheter ablation were retrospectively included. Among them, the PVCs originated from the s-RVOT in 183 patients and from the LVOT-ASC in 76 patients. The surface ECGs of the PVCs and sinus beats were analyzed using an electronic caliper. The R-S difference index in the precordial leads was calculated as V2R + V3R + V4R − V1S.

Results: PVCs originating from both the s-RVOT and LVOT-ASC displayed an inferior axis (dominant R waves in leads II, III, and aVF). Compared with the s-RVOT group, the R-wave amplitudes on leads II, III, and aVF were significantly larger in the LVOT-ASC group (p < 0.001, p < 0.003, and p < 0.001, respectively). Compared to the LVOT-ASC group, the s-RVOT group showed smaller R-wave amplitudes on leads V1–V6 (p = 0.021, p < 0.001, p < 0.001, p < 0.001, p < 0.001, and p < 0.001, respectively) and larger S-wave amplitudes on leads V1–V3 (p < 0.001, p < 0.001, and p < 0.001, respectively). Lead V3 was the most common transitional lead in both groups. Analysis of the receiver operating characteristic curve showed that the R-wave amplitude on lead V3 had the largest area under the curve (AUC) of 0.856 followed by the R-wave amplitudes on leads V4 (0.834) and V2 (0.806). The AUC of the R-S difference index was 0.867. An R-S difference index greater than 20.9 predicted an LVOT-ASC origin with 73.7% sensitivity and 86.3% specificity. This index is superior to previous criteria in differentiating PVCs with LBBB morphology and inferior axis originating from s-RVOT vs. LVOT-ASC.

Conclusions: The R-S difference index in precordial leads is a useful new ECG criterion for distinguishing LVOT-PVCs from RVOT-PVCs with LBBB morphology.

Asymptomatic cardiac tumour with premature ventricular contraction in an athlete: case report

Cardiac fibromas are the second most common benign primary tumour of the heart in the children; the clinical features include chest pain, arrhythmia, low cardiac output due to outflow tract obstruction, and sudden cardiac death. Sports are associated with an increased risk for sudden death in athletes who are affected by cardiovascular conditions predisposing to life-threatening arrhythmias. We present a case report of 10-year-old asymptomatic boy who was referred to the paediatric cardiology department by his general practitioner for cardiac examination before participation in competitive sports. The electrocardiogram showed premature ventricular contractions originated from inferior of left ventricle. A mass was detected by 2D transthoracic echocardiography, and it was found to be compatible with fibroma on MRI. In some cases, cardiac tumours are asymptomatic as in our patient. Electrocardiogram abnormalities require detailed cardiac imaging with echocardiogram, and if necessary CT/MRI. In this article, we emphasise that detailed cardiac examination of individuals before participating in competitive sports is vital.

Assessment of functional and structural echocardiography parameters in patients with frequent premature ventricular contractions without structural heart disease

BACKGROUND

Premature ventricular contractions (PVCs) are early depolarizations of the myocardium which originate from the ventricle. PVCs have previously been considered a benign condition. The clinical significance of PVCs in patients without structural heart disease is controversial.

METHODS

In this cross-sectional study, patients with a palpitation complaint who underwent electrocardiography (ECG) Holter recording for 48 hours were analyzed. Patients with frequent PVCs (more than ten times in 1 hour) were identified and enrolled in the study. 26 patients were in the PVC group, and 26 patients were in the control group without PVC. The identified patients underwent an echocardiographic examination with strain modality.

RESULTS

There were 15 women (57.7%) in the PVC group and 17 women (65.4%) in the control group (P = 0.57). Two patients in the PVC group and three patients in the control group were hypertensive (P > 0.99). There was only one patient with diabetes in PVC and control group (P > 0.99). There were two smokers in the PVC group, whereas there was no smoker in the control group (P = 0.49). In comparison between two groups, patients with frequent PVCs had significantly larger left ventricular end-diastolic volume index (LVEDVI) (P = 0.048) along with lower left ventricular ejection fraction (LVEF) (P = 0.011), lower (more positive) left ventricular global longitudinal strain (LVGLS) (P = 0.001), and lower peak systolic mitral annular velocity (S') (P = 0.045). The left atrial volume index (LAVI) was significantly larger in the PVC group (P = 0.001). In speckle tracking echocardiography (STE) parameters, global peak atrial longitudinal strain (PALS) (P = 0.001) and peak atrial contraction strain (PACS) (P = 0.001) were significantly lower and time to peak longitudinal strain (TPLS) (P = 0.002) was significantly higher in the PVC group.

CONCLUSION

In this study, left atrial (LA) and left ventricular (LV) function and geometry were adversely affected by frequent PVCs. Early diagnosis of these effects is possible with echocardiography along with strain analysis. It can guide the timely treatment of PVC to avoid the harmful effects of frequent PVCs on the heart.

Impact of age on catheter ablation of premature ventricular contractions

INTRODUCTION

Catheter ablation (CA) of frequent premature ventricular contractions (PVC) is increasingly performed in older patients as the population ages. The aim of this study was to assess the impact of age on procedural characteristics, safety and efficacy on PVC ablations.

METHODS

Consecutive patients with symptomatic PVCs undergoing CA between 2015 and 2020 were evaluated. Acute ablation success was defined as the elimination of PVCs at the end of the procedure. Sustained success was defined as an elimination of symptoms, and ≥80% reduction of PVC burden determined by Holter-electrocardiogram during long-term follow. Patients were sub-grouped based on age (<65 vs. ≥65 years).

RESULTS

A total of 114 patients were enrolled (median age 64 years, 71% males) and followed up for a median duration of 228 days. Baseline and procedural data were similar in both age groups. A left-sided origin of PVCs was more frequently observed in the elderly patient group compared to younger patients (83% vs. 67%; p = .04). The median procedure time was significantly shorter in elderly patients (160 vs. 193 min; p = .02). The rates of both acute (86% vs. 92%; p = .32) and sustained success (70% vs. 71%; p = .90) were similar between groups. Complications rates (3.7%) did not differ between the two groups.

CONCLUSION

In a large series of patients with a variety of underlying arrhythmia substrates, similar rates of acute procedural success, complications, and ventricular arrhythmia-free-survival were observed after CA of PVCs. Older age alone should not be a reason to withhold CA of PVCs.

Pre-procedural arrhythmia burden and the outcome of catheter ablation of idiopathic premature ventricular complexes

BACKGROUND

Radiofrequency catheter ablation of idiopathic premature ventricular complexes (PVCs) is an effective method for eliminating symptoms and preventing/reversing arrhythmia-induced cardiomyopathy. One reason for procedural failure is low PVC frequency during the procedure. We aimed to investigate the relation between pre-procedural PVC burden and outcome of idiopathic PVC catheter ablation.

METHODS

Patients who underwent idiopathic PVC ablation between 2013 and 2019 at two tertiary referral centers were retrospectively included. All procedures were performed using irrigated-tip ablation catheters and a 3D electro-anatomical mapping system. Sustained ablation success was defined as a ≥80% reduction of pre-procedural PVC burden determined by 24h-Holter at follow-up.

RESULTS

Overall, 254 patients (median age 54 years [IQR 42-64]; 47% male) were enrolled. The median pre-ablation PVC-burden was 22% (IQR 11-31%), which was reduced to a post-ablation PVC burden of 0.3% (IQR 0-4%) after a median of 90 days. Sustained ablation success was achieved in 182 patients (72%). Pre-procedural PVC burden did not differ between patients with sustained ablation success and recurrence during follow-up (median 21% vs. 22%, p = .76). When assessed in pre-ablation PVC-burden groups of ≤5%, 6-15%, 16-30%, and ≥31%, sustained ablation success was achieved in 67%, 75%, 71%, and 72%, respectively, with no significant difference (p = .89). Sustained ablation outcome for PVC-burden ≤5% versus >5% showed no difference either (67% vs. 72%, p = .52).

CONCLUSIONS

Pre-procedural Holter-determined PVC burden does not predict the outcome of idiopathic PVC ablation. Thus, catheter ablation may be a reasonable first choice also for patients with symptomatic yet rare PVCs.

Left Ventricular Inflow Velocity Pattern in Patients With Symptomatic Premature Ventricular Contraction

BACKGROUND

Because premature ventricular contractions (PVCs) are one of the most common arrhythmias, but with unclear causative mechanisms, we studied the hemodynamic features that can cause symptomatic PVCs.Methods and Results:We studied 109 patients (48 males, age 60±19 years) with frequent monomorphic PVCs and no structural heart disease. The left ventricular inflow diastolic filling velocity was recorded by transthoracic echocardiography (TTE) at the time of PVCs in all patients. We assessed the PVC E wave flow (E wave velocity×duration at PVC). A total of 38 patients (35%) had PVC-related symptoms (19 palpitations, 12 pulse deficit, 6 shortness of breath, 6 malaise, 1 syncope). These patients showed reduced PVC E wave flow (9.3±6.0 vs. 14.6±6.5 cm, P<0.0001), and reduced PVC stroke volume (20.5±10.8 vs. 29.9±17.2 mL, P=0.0030). In the multivariate analysis, only reduced PVC E wave flow was independently associated with PVC-related symptoms (P=0.00349, odds ratio: 1.134029, each 1.0 cm increase in PVC E wave flow, 95% confidence interval: 1.040726-1.247544).

CONCLUSIONS

Decreased E wave flow at the time of PVC was independently related with PVC-related symptoms in patients with PVCs. The LV contraction at the time of inadequate filling might be a cause of PVC-related symptoms.

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.