PVCs, PVC-Induced Cardiomyopathy, and the Role of Catheter Ablation

Effects of contemporary hard- and software mapping and ablation features on acute and long-term success in premature ventricular complex ablation

BACKGROUND

Current standards of ablation of premature ventricular complexes (PVC) combine modern hard- and software mapping and ablation features like multielectrode mapping catheters (MEC), contact force (CF) guided ablation catheters and pattern matching filters (PMF). Benefits of these individual tools were described for selected patients with PVC, but data on combination of these features in the real world setting is sparse.

METHODS

Between 2015 and 2021 we retrospectively enrolled 172 consecutive patients undergoing PVC ablation in our center. The utilization of MEC, CF guided ablation catheters and PMF software was analyzed in terms of procedural data, acute and long-term success after 12 months.

RESULTS

Acute ablation success was reached in 71% of patients (n = 118) with an overall recurrence rate of 34% after 12 months. PMF software was used in 130 patients (78%), MEC in 131 patients (79%) and ablation was guided using CF in 99 patients (60%). PMF significantly reduced procedural duration and time of radiofrequency application (RF, 150 vs. 185 min, p 0.04 and 325 vs. 556 min, p 0.01). CF enabled significantly shorter radiation time (7.9 vs. 12.3 min, p 0.01), whereas MEC did not influence procedural data. Acute and long-term outcomes were not affected by these modern mapping and ablation features, yet, multivariable regression analysis revealed an underlying cardiomyopathy and the respective focus as independent predictors for recurrence.

CONCLUSION

Contemporary hard- and software mapping and ablation features could reduce procedural, radiation and RF time in PVC ablation. Furthermore, patient characteristics rather than technical factors alter outcome of this all-comer collective.

Developing a Mechanistic Approach to Sudden Death Prevention in Mitral Valve Prolapse

Sudden cardiac death (SCD) from ventricular fibrillation (VF) can occur in mitral valve prolapse (MVP) in the absence of other comorbidities including mitral regurgitation, heart failure or coronary disease. Although only a small proportion with MVP are at risk, it can affect young, otherwise healthy adults, most commonly premenopausal women, often as the first presentation of MVP. In this review, we discuss arrhythmic mechanisms in MVP and mechanistic approaches for sudden death risk assessment and prevention. We define arrhythmogenic or arrhythmic MVP (AMVP) as MVP associated with complex and frequent ventricular ectopy, and malignant MVP (MMVP) as MVP with high risk of SCD. Factors predisposing to AMVP are myxomatous, bileaflet MVP and mitral annular disjunction (MAD). Data from autopsy, cardiac imaging and electrophysiological studies suggest that ectopy in AMVP is due to inflammation, fibrosis and scarring within the left ventricular (LV) base, LV papillary muscles and Purkinje tissue. Postulated mechanisms include repetitive injury to these regions from systolic papillary muscle stretch and abrupt mitral annular dysmotility (excursion and curling) and diastolic endocardial interaction of redundant mitral leaflets and chordae. Whereas AMVP is seen relatively commonly (up to 30%) in those with MVP, MVP-related SCD is rare (2-4%). However, the proportion at risk (i.e., with MMVP) is unknown. The clustering of cardiac morphological and electrophysiological characteristics similar to AMVP in otherwise idiopathic SCD suggests that MMVP arises when specific arrhythmia modulators allow for VF initiation and perpetuation through action potential prolongation, repolarization heterogeneity and Purkinje triggering. Adequately powered prospective studies are needed to assess strategies for identifying MMVP and the primary prevention of SCD, including ICD implantation, sympathetic modulation and early surgical mitral valve repair. Given the low event rate, a collaborative multicenter approach is essential.

Premature ventricular contractions cause a position shift in 3D mapping systems: analysis, quantification, and correction by hybrid activation mapping

Aims

Using a modified CARTO 3D mapping system, we studied if premature ventricular contractions (PVCs) cause position shifts within the 3D co-ordinate system. We quantified magnitude of the phenomenon and corrected for it, by creating both an activation map that represents the conventional local activation time (LAT) and one corrected for this position shift (hybrid LAT map).

Methods and results

We prospectively enrolled patients planned for PVC ablation. Distances between the earliest LAT, the earliest hybrid-LAT, and the best pacemap positions were calculated in a 3D model. Ablation was performed at the best hybrid-LAT location. Efficacy was evaluated by acute response to ablation as well as clinical outcome on 24-h Holter at 1 year. One hundred and twenty-seven LAT-hybrid pairs were studied in 18 patients (age 48.3 ± 18.0 years, 12 female). Baseline PVC burden was 16 ± 12%. The mean position shift between LAT-hybrid and its associated LAT position was 8.9 ± 5.5 mm. The mean position shift between best LAT-hybrid and best pacemap was 6.2 ± 5.0 mm and the mean shift between best conventional LAT and best pacemap was 13.5 ± 7.0 mm (P < 0.0001 for all pairwise comparisons). Exclusive targeting of best LAT-hybrid position resulted in acute abolition of PVC activity in all patients. After 1-year follow-up, mean PVC burden reduction was 16% (baseline) to <1%.

Conclusion

Premature ventricular contractions cause a position shift in 3D mapping systems compared with the same endocardial position in sinus rhythm. An approach to account for this phenomenon, correct it and target exclusively the adjusted 3D position is feasible and highly efficient in terms of acute and 1-year clinical outcome after radiofrequency ablation.

Premature ventricular contraction-induced dilated cardiomyopathy: a case report

Background

Premature ventricular complexes (PVCs) are ectopic heartbeats caused by early myocardial depolarizations, previously thought to be benign. Recent studies found high PVC burden above 24% can induce or contribute to cardiomyopathy and heart failure. We present a case of PVC-induced dilated cardiomyopathy (DCM).

Case summary

A 68-year-old woman was admitted with pneumonia after an overseas trip with a preceding viral respiratory tract infection. An initial chest X-ray was suggestive of cardiomegaly. A transthoracic echocardiogram (TTE) revealed DCM with global systolic dysfunction (left ventricular ejection fraction <30%) without valvular lesions. Biochemistry and coronary angiography were normal. Clinical deterioration occurred despite medical therapy. A 24-h Holter monitoring detected 27% PVCs, which was thought to have caused DCM. As an alternative to cardiac resynchronization therapy and an implantable cardiac defibrillator for primary prevention, ablation of the PVC focus led to complete suppression of ectopy. Post-procedure TTEs and Holter monitoring showed normalized systolic function and low PVC burden.

Discussion

Because high PVC burden can lead to cardiomyopathy and heart failure, suppression of PVC should be considered to restore ventricular function for patients with structural heart disease and frequent symptomatic PVCs. This case highlights that PVCs may be a modifiable risk factor for heart failure that can be successfully treated with pharmacological therapies or catheter ablation.

Recommendations for the use of electrophysiological study: Update 2018

The field of cardiac electrophysiology has greatly developed during the past decades. Consequently, the use of electrophysiological studies (EPSs) in clinical practice has also significantly augmented, with a progressively increasing number of certified electrophysiology centers and specialists. Since Zipes et al published the Guidelines for Clinical Intracardiac Electrophysiology and Catheter Ablation Procedures in 1995, no official document summarizing current EPS indications has been published. The current paper focuses on summarizing all relevant data of the role of EPS in patients with different types of cardiac pathologies and provides up-to-date recommendations on this topic. For this purpose, the PubMed database was screened for relevant articles in English up to December 2018 and ESC and ACC/AHA Clinical Practice Guidelines, and EHRA/HRS/APHRS position statements related to the current topic were analyzed. Current recommendations for the use of EPS in clinical practice are discussed and presented in 17 distinct cardiac pathologies. A short rationale, evidence, and indications are provided for each cardiac disease/group of diseases. In conclusion, because of its capability to establish a diagnosis in patients with a variety of cardiac pathologies, the EPS remains a useful tool in the evaluation of patients with cardiac arrhythmias and conduction disorders and is capable of establishing indications for cardiac device implantation and guide catheter ablation procedures.