Catheter ablation of left para-Hisian premature ventricular contractions: a challenge and a compromise between success and inadvertent atrioventricular block: a case report

BackgroundA short-coupled variant of torsade de pointes (ScTdP) is rare and resistant to medical treatment. There has not been a reported catheter ablation (CA) of a short-coupled premature ventricular contraction (PVC) triggering ScTdP in an infant.Case summaryA neonate was referred to our hospital on the day of birth for Wolff–Parkinson–White syndrome, repeated episodes of supraventricular tachycardia, and a left ventricular non-compaction. She underwent CA of an accessory pathway at 72 days of age. On the 5th day after ablation, she had recurrent TdP episodes resistant to various antiarrhythmic drugs and received extracorporeal membrane oxygenation at 86 days of age. She underwent CA of PVCs triggering TdP at 122 days of age and a weight of 3.4 kg. Two types of PVCs triggering TdP were successfully ablated, which originated from the right ventricle (RV). Pre-potentials were recorded at the earliest ventricular activation sites of the targeted PVCs. After the ablation, she had no TdP episodes and the cardiac assist device was removed. However, she died of uncontrolled heart failure at 6 months of age. The histological findings were compatible with histiocytoid cardiomyopathy and abnormal cells were distributed throughout both ventricles. At the ablation site, fibrotic transmural lesions were noted in the RV wall.DiscussionThe PVCs triggering TdP were successfully ablated in a 4-month-old girl with histiocytoid cardiomyopathy. The PVCs were likely caused by triggered activity and associated with abnormal Purkinje cells.

Background:Premature ventricular contractions (PVCs) originating from aortic sinus cusps is not infrequent and can be eliminated effectively by radiofrequency ablation with rare complications. However, after a review of the medical literature, and to our knowledge, this is the first case of successful idiopathic aortic sinus cusps–PVC–ablation using a 3-dimensional (3D) mapping system in an adult with dextrocardia.Methods:A 62-year-old male with dextrocardia and situs inversus underwent catheter ablation of frequent PVCs. The electrocardiograms (ECG) were recorded by placement of the electrodes in reversed positions. The PVCs exhibited left bundle branch block and inferior axis QRS morphology with transition at leads V2–V3. The activation mapping indicated the earliest site of ventricular activation between the left and right aortic sinus cusps, highlighting that catheter ablation was successful at this point.Results:The catheter ablation was successful between the left and right aortic sinus cusps, and the PVCs were not detected for the subsequent 30 min following the procedure as well as for the rest of the hospital stay.Conclusion:Combined with ECG electrodes in reversed positions and 3D electroanatomical mapping system, catheter ablation of PVCs originating from aortic sinus cusps in patients with dextrocardia can be safely and effectively performed.

An accurate local activation time (LAT) map is essential during premature ventricular contraction (PVC) ablation. The aim of this study was to evaluate whether the use of a novel octaspline multielectrode catheter, with and without the use of a catheter-embedded unipolar reference, improves LAT mapping during PVC ablation compared to a pre-existing pentaspline mapping catheter. This study prospectively assessed 10 consecutive patients referred for PVC ablation from January to June 2023. Three 12-min LAT maps were performed in each patient using three different strategies: pentaspline catheter + unipolar reference in the inferior vena cava (IVC) versus octaspline catheter + unipolar in the IVC versus octaspline catheter + unipolar embedded in the mapping catheter. Acute procedural and midterm endpoints were assessed. The use of an octaspline catheter increased the number of total LAT points (1010 ± 451 vs. 397 ± 213, p = 0.001), LAT points near the successful RF ablation site (118 ± 105 vs. 21 ± 19, p = 0.010) and electrograms (EGM) per PVC (23 ± 21 vs. 7 ± 3, p = 0.032), while reducing mapping duration (65 ± 41 EGM/min vs. 21 ± 8 EGM/min, p = 0.003). However, signal resolution was not superior to that obtained with the pentaspline catheter, with similar bipolar (p = 0.505) and unipolar (p = 0.176) voltages, an increased bipolar signal duration (p = 0.003) and a reduction in the unipolar signal duration (p = 0.013). Use of a catheter-embedded unipolar reference led to shorter unipolar signal duration (76 ± 34 ms vs. 142 ± 29 ms, p < 0.001), and provided an earlier unipolar signal deflection to QRS onset (-24 ± 16 ms vs. -19 ± 11 ms, p = 0.006) and earlier -dV/dT signal annotation (-12 ± 10 ms vs. -7 ± 9 ms, p < 0.001). This subsequently led to a shorter distance from the earliest LAT to successful RF site (p = 0.014). No significant differences between multielectrode mapping catheters were seen regarding catheter-induced ectopy rate (p = 0.703). The use of an octaspline catheter combined with an embedded unipolar reference may associate with faster, more detailed and accurate activation mapping in the setting of PVC ablation.

IntroductionWe previously reported the clinical benefits of radiofrequency catheter ablation (RFCA) of premature ventricular contractions (PVCs) from the right ventricular outflow tract or near the His‐bundle, which can often deteriorate the clinical status. PVCs from the mitral valve (MA‐PVCs) also often deteriorate the patients’ clinical status. This study aimed to evaluate the effect of ablating MA‐PVCs with RFCA from a trans‐interatrial septal approach on the clinical status in symptomatic patients with frequent MA‐PVCs without structural heart disease.MethodsThe frequency of PVCs per the total heart beats by 24‐hours Holter monitoring and New York Heart Association (NYHA) functional class in 22 patients with MA‐PVCs were evaluated before and 6 months after RFCA.ResultsProcedural success was achieved in 20 (91%) of 22 patients. Of the 22 patients, in 15 (68%) and 1 (5%) patient, a successful RFCA on the left ventricular side of the MA using the trans‐interatrial septal approach and trans‐coronary sinus approach was achieved. Interestingly, in four (18%) patients, a successful RFCA on the left atrial (LA) side of the MA using a trans‐interatrial septal approach was achieved. Ablating MA‐PVCs readily improved the NYHA functional class compared to that before. A ≥0.62 peak deflection index and ≤30 years old may be one of the important predictors of successfully ablated MA‐PVCs from the LA side of the MA.ConclusionsRFCA produces clinical benefits in patients with MA‐PVCs. Further, it may be necessary to initially consider a trans‐interatrial septal approach to ablate these PVCs.

We aimed to assess the acute and midterm efficacy of premature ventricular contraction (PVC) ablation guided by multielectrode and point-by-point (PbP) mapping. This is a retrospective, international multicentre study of consecutive patients referred for PVC ablation in 10 hospital centres from January 2017 to December 2021. Based on the mapping approach, two cohorts were identified: the 'Multipolar group', where a dedicated high-density mapping catheter was employed, and the 'PbP group', where mapping was performed with the ablation catheter. Procedural endpoints, safety, and acute (procedural) and midterm efficacies were assessed. Of the 698 patients included in this study, 592 received activation mapping [46% males, median age of 55 (41-65) years]-248 patients in the Multipolar group and 344 patients in the PbP group. A higher number of activation points [432 (217-843) vs. 95 (42-185), P < 0.001], reduced mapping time (40 ± 38 vs. 61 ± 50 min, P < 0.001), and shorter procedure time (124 ± 60 vs. 143 ± 63 min, P < 0.001) were reported in the Multipolar group. Both groups had high acute success rates (84.7% with Multipolar mapping vs. 81.3% with PbP mapping, P = 0.63), as well as midterm efficacy (83.4% vs. 77.4%, P = 0.08), with no significant differences in the risk of adverse events (6.0% vs. 3.5%, P = 0.24). However, for left-sided PVC ablation specifically, there was a higher midterm efficacy in the Multipolar group (80.7% vs. 69.5%, P = 0.04), with multipolar mapping being an independent predictor of success [adjusted OR = 2.231 (95% CI, 1.476-5.108), P = 0.02]. The acute and midterm efficacies of PVC ablation are high with both multipolar and PbP mapping, although the former allows for quicker procedures and may potentially improve the outcomes of left-sided PVC ablation.

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. 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). 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. 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.

Objective The purpose of this study was to investigate the value of notched unipolar electrogram (N-uniEGM) in guiding radiofrequency ablation of premature ventricular contractions (PVC) originating from the ventricular outflow tract (VOT) . Methods In 190 consecutive patients with idiopathic frequent VOT-PVC, mapping and radiofrequency ablation were performed using the Carto3 system in Heart center of Beijing Chaoyang Hospital from May 2011 to December 2017. The average PVC-burden before the procedure was 20.4%±11.2%. The characteristic of unipolar electrogram at successful target was analyzed. N-uniEGM was defined as unipolar electrogram with a QS morphology and one or more notches in the downstroke deflection. Patients were divided into two groups, N-uniEGM positive group and negative group. The success rate, the valid ablation time and the total ablation time were compared between two groups. The sensitivity and the specificity of N-uniEGM in predicting successful ablation were also evaluated. Results N-uniEGM was recorded in 124/190 (65.3%) patients, including 97 right ventricular outflow tract (RVOT) PVC, 22 aortic cusps PVC and 5 subaortic valve PVC. In the majority of patients, the sites presenting with N-uniEGM also showed ideal activation mapping and pace mapping. The average area of the sites presenting with N-uniEGM was merely (0.8±0.4) cm2. The number of notches in N-uniEGM in RVOT, aortic cusps, and subaortic value were (1.2±0.5) , (1.4±0.8) and (1.7±0.6) , respectively. The success rate of PVC ablation in patients presenting with N-uniEGM was 98.4% (122/124) . The valid ablation time was significantly shorter in patients with N-uniEGM than in those without it[ (7.6±3.8) s vs. (15.8±8.8) s, P<0.05]. The difference was also observed in the total ablation time[ (178±36) s vs. (260±114) s, P<0.05]. The sensitivity and the specificity of N-uniEGM in predicting successful ablation of VOT-PVC was 72.6% and 91.7%, respectively. Conclusions N-uniEGM is a highly specific and moderate sensitive predictor of successful radiofrequency ablation for patients with VOT-PVC. Key words: Ventricular premature complexes; Heart ventricules; Catheter ablation; Unipolar mapping

Mapping of premature ventricular contractions (PVCs) originating from the right ventricular outflow tract (RVOT) sometimes is not easy because of an unstable incidence and multiple foci of the PVCs. The aim of this study was to evaluate the effectiveness of electroanatomic mapping in catheter ablation of those PVCs. One hundred patients with 134 RVOT origin PVCs were randomly allotted to undergo either conventional (group I; 50 patients with 65 PVCs) or electroanatomic mapping (group II; 50 patients with 69 PVCs). In group II, electroanatomic mapping of the RVOT was performed using auto-freeze maps in patients with frequent PVCs, and pace mapping was performed marking the pacing sites on the remap which was made by extracting the anatomic frame out of the baseline map during sinus rhythm in patients with infrequent PVCs. Successful ablation was achieved in 44 (88%) group I patients and 48 (96%) group II patients (p = 0.14). The fluoroscopy and procedure times and those per PVC morphology were all significantly shorter in group II than group I overall (p < 0.0001 for all comparisons), and in each patient group with infrequent PVCs, frequent PVCs or unstable PVCs (p < 0.05-0.0001). The number of RF applications and that per PVC was significantly smaller in group II than group I (5.3 +/- 1.8 vs 6.2 +/- 2.4, and 4.4 +/- 1.2 vs 5.2 +/- 2.1; p < 0.05). The use of electroanatomic mapping may reduce the fluoroscopy and procedure times in the ablation of RVOT PVCs, but there is no evidence that it improves the overall efficacy of the procedure.

Spatial displacement on three-dimensional maps caused by rhythm differences in premature ventricular contraction ablation

Impact of age on catheter ablation of premature ventricular contractions

Impact of pacing output and cycle length on QRS morphology in ablation of premature ventricular contractions (PACE-MAP-trial)

Impact of pacing output and cycle length on qrs morphology in ablation of premature ventricular contractions (PACE-MAP-Trial)

A 57-year-old man undergoing mitral valvoplasty underwent catheter ablation of symptomatic premature ventricular contractions (PVCs) with a right bundle branch block and right inferior axis QRS morphology. Left ventriculography revealed a normal left ventricular function and visualized the anatomical relationships between the left ventricular outflow tract and the mitral annuloplasty ring. Electroanatomic mapping during the PVCs revealed a centrifugal activation pattern arising from the mitral annulus, and the PVCs were likely to be idiopathic. Successful radiofrequency ablation was achieved at the site close to the antero-paraseptal end of the mitral annuloplasty ring, which was located adjacent to the fibrous trigone.

Cardiac memory is recognized as altered T-waves when the sinus rhythm resumes after an abnormal myocardial activation period that recovers slowly over several weeks. The T-wave changes after ablation of frequent premature ventricular contractions (PVCs) as cardiac memory was not known. This study identified whether cardiac memory exists after successful ablation of PVCs from the right ventricular outflow tract (RVOT). We investigated 45 patients who underwent successful ablation of PVCs from RVOT and 10 patients who underwent unsuccessful ablation. We analyzed the amplitude of the T-wave, QT intervals, and QRST time-integral values of a 12-lead electrocardiogram before ablation and 1 day, 3 days, and 1 month after ablation. In the successful ablation group, the amplitude of the T-wave and QRST time-integral values of lead II, III, aVR, aVL, and aVF significantly changed after ablation and gradually normalized within 1 month. In addition, if the number of pre-ablation PVCs was small, then the corresponding impact was also small. However, the greater the number of pre-ablation PVCs, the more prominent the changes. Significant changes were not observed in the unsuccessful ablation group. When ablation of PVCs from RVOT was successful, primary T-wave changes because of cardiac memory and the gradual normalization of the amplitude of the T-wave were observed. No significant T-wave changes were detected after unsuccessful ablation.

To investigate the learning curve for atrial fibrillation (AF), supraventricular tachycardia (SVT), and premature ventricular contraction (PVC) radiofrequency ablation (RFA) using zero fluoroscopy. This is a retrospective, single-center study of 167 patients undergoing ablation between 2016 and 2019. Minimal fluoroscopy approach was initiated after the first 20 cases of PVI and SVT RFA. Procedures were divided consecutively into increments of 10 cases to determine operator learning curve. A total of 64 (38%) had SVT ablations, 26 (16%) had PVC ablations, and 77 (46%) had AF and underwent PVI. For SVT RFA, fluoroscopy time improved from 4.1 ± 3.5min during the first 10 cases to 0.8 ± 1.2min after 50 cases (p = 0.0001). Sixty-two out of 64 (97%) of cases were successful. In PVC RFA, fluoroscopy time was 7.7 ± 5.5min for the first 5, 2.3 ± 3.4min after 15, and 0min after 20 cases (p = 0.0008). Twenty-four out of 26 (92%) of cases were acutely successful with recurrence in 2/26 (8%) of patients over 9 ± 9months. In PVI, fluoroscopy time was 9.9 ± 3.3min over the first 20 cases, 2.6 ± 2.3min after 40 cases, and 0.1min after 50 cases (p < 0.0001). PVI procedure time was 170 ± 34min after 60 cases from 235 ± 41min initially (p 0.001). Six out of 77 (8%) had AF recurrence at 12months. Zero fluoroscopy ablation for AF, SVT, and PVC can be safely achieved without increasing procedure time. The steepest learning curve occurs over the first 20, 15, and 40 cases for SVT, PVC, and PVI ablation respectively.