Electrocardiogram features of premature ventricular contractions/ventricular tachycardia originating from the left ventricular outflow tract and the treatment outcome of radiofrequency catheter ablation

The value of QRS onset of the outflow tract PVC in V1 and V2 leads recorded in fourth, third, and second intercostal spaces to differentiate main origins of premature ventricular contraction—A prospective cohort study

Background

Electrocardiography (ECG) is now proposed as a simple and cost‐effective tool to determine the location of arrhythmias before ablation. We aimed to examine the value of the QRS onset of outflow tract PVC in V1 and V2 leads recorded in fourth, third, and second intercostal spaces to differentiate two main origins for premature ventricular contraction (PVC) including right ventricular outflow tract (RVOT) and left ventricular outflow tract (LVOT).

Methods

In this prospective cohort study, a total of 58 patients were studied, from whom a surface ECG was obtained using V1 and V2 leads in the fourth, third, and second intercostal spaces. ECG and Electrophysiology studie (EPS) data were then recorded and compared to determine the sensitivity and specificity of QRS onset in locating arrhythmias. The reciever operating characterictic (ROC) curve analysis was applied to test diagnostic performance.

Results

Based on the time of PVC initiation in each of the V1 and V2 leads in the fourth intercostal space, if PVC is recorded earlier in the V1 lead, its source in 95.8% of the patients is RVOT and if PVC preceded the V2 lead, 70.59% of the patients had PVC from LVOT. Comparing of QRS onset in V1 and V2 leadsrecorded from third% and and second intercostal spaces had considerable sensitivity and specificity to determine the origin of the outflow tract PVC (81.82 and 94.12%, respectively)

Conclusion

Simultaneous recording of outflow tract PVCs from second third and fourth intercostal spaces and comparing their onset can determine the left and right outflow tract PVCs with high sensitivity and specificity.

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.

Aortic cusp ablation for premature ventricular contractions and ventricular tachycardia in children: a 5-year single-center experience

PURPOSE

Aortic cusps might be the source of supraventricular or ventricular arrhythmias. For many years, aortic cusp ablation has been widely used to treat premature ventricular contractions (PVCs) and ventricular tachycardia (VT). However, the data on the outcomes of this procedure in children are limited. The study aimed to convey or describe our own aortic cusp ablation experiences in children and, thus, contribute to the literature.

METHODS

The focus was pediatric cases of ventricular arrhythmia in which the origin of the PVCs was ablated above the Valsalva. The sample comprised patients who underwent aortic cusp ablation between 2013 and 2018. The demographic characteristics, noninvasive test results, procedure details, and follow-up results for the patients were noted.

RESULTS

The 3D EnSite Precision cardiac mapping system and limited fluoroscopy were used. A total of 26 procedures were performed on 22 patients. The mean age was 14.4 ± 3.0 (9-19) years, and the mean weight was 57.3 ± 17.5 (27-99) kg. The mean follow-up period after the first presentation was 38.6 ± 22.9 (3-72) months. There were significant differences in the values of the transition index, V2S/V3R, IIR/IIIR, aVRS/aVLS ratio, and QRS polarity in I at various locations. The most common ablation site was the left coronary cusp (LCC). Radio frequency (RF) ablation, cryoablation, and irrigated RF ablation were found to be effective energy sources in 15, 4, and 3 patients, respectively. Patients who underwent ablation at the LCC-right coronary cusp (RCC) commissure were more likely to present with only VT and to experience worsening symptoms. Twelve patients had previously undergone ablation of the right ventricular outflow tract (RVOT). Ablation in the RVOT had been previously performed in all the patients who eventually underwent ablation at the RCC and the LCC-RCC commissure.

CONCLUSION

Aortic cusp ablation can be safely performed in children. The careful evaluation of previous noninvasive tests provides important data for determining the location. There might be significant differences in the signs and requirements on the basis of the locations during mapping and ablation.

Automated detection of premature ventricular contraction in ECG signals using enhanced template matching algorithm

Nowadays, with the increasing number of people who suffer from cardiovascular diseases such as irregular heartbeats (arrhythmia), there is a vital need to pay more attention to healthcare conditions. Therefore, the production of smart biomedical garments becomes of great necessity. The first step of manufacturing such smart garments is to build an electrocardiogram (ECG) analysis system. In this paper, the premature ventricular contraction (PVC), which is a serious life-threatening cardiovascular condition, is recognised. In addition, an improved template matching technique is developed, implemented, and evaluated to identify the irregularity of PVC beats in the QRS complex and T wave. The improvement in this technique is that a PVC recogniser is established by analysing the maximum and minimum correlation coefficient values instead of the maximum values only. Moreover, a sufficient number of features are relied upon for the accurate detection of PVC beats. The template matching algorithm is evaluated on the MIT-BIH arrhythmia, St. Petersburg Institute of Cardiological Technics (INCART), QT, MIT-BIH Supraventricular Arrhythmia, and Fantasia databases. The results show a valuable accuracy enhancement when compared with those of other recent approaches.

Radiofrequency catheter ablation of ventricular arrhythmias arising from the region above pulmonary valve

BACKGROUND

Ventricular arrhythmias (VAs) arising from the origin above pulmonary valve lack comprehensive investigation. This study aimed to disclose the characteristics and radiofrequency catheter ablation (RFCA) outcomes for those VAs.

METHODS

One hundred six VAs arising from the region above pulmonary valve treated with RFCA were included in this study.

RESULTS

Seventy-five cases were identified in the pulmonary sinus cusps (PSCs, 32 in left sinus cusp (PLC), 15 in right (PRC), 28 in anterior (PAC)) and 31 cases were in the main stem of pulmonary artery (MSPA, 18 above PLC (LMSPA), 3 above PRC (RMSPA), 10 above PAC (AMSPA)). Compared with PSCs VAs, MSPA VAs exhibited a higher R wave amplitude in the inferior leads, a total inferior R amplitude > 5.1 mV predicting MSPA origins. LMSPA, RMSPA and AMSPA VAs resembled PLC, PRC and PAC VAs in electrocardiographic characteristics respectively. No electrophysiological differences were found between PSCs and MSPA VAs. The irrigated-up catheter and R0 Swartz long sheath were more utilized for ablation of PSCs VAs than for MSPA VAs. All these VAs were successfully eliminated by RFCA.

CONCLUSION

VAs arising from the origin above pulmonary valve were common. Based on certain electrocardiographic characteristics, they could be roughly located, which contributed to an effective RFCA.

Reversal of premature ventricular complexes induced cardiomyopathy. Influence of concomitant structural heart disease

BACKGROUND

We examined the effect of radiofrequency (RF) catheter ablation of premature ventricular complexes (PVCs) on left ventricle (LV) function recovery in patients with LV dysfunction, regardless the presence of structural heart disease (SHD).

METHODS

Seventy seven patients with impaired LV ejection fraction (EF) (37.1±9.4), suspected to have PVCs cardiomyopathy (PVC-CM) (>10% PVCs burden), referred for RF ablation were enrolled, and divided into 2 groups according to the presence of SHD. SHD was ruled out by echocardiography, coronary angiography or MRI. CARTO 3 mapping system was used employing activation mapping in the majority of cases. Initial success was defined as complete elimination or residual PVCs≤10 beats/30min. Long term success was defined as reduction in PVCs burden >80% on follow-up holter. Echocardiography was done after 6 months. Improvement of EF >5% was considered significant.

RESULTS

Forty two (55.8%) cases had SHD. PVCs burden was 28.4±9.8%. EF improved to 48.6±10.3. Initial success, overall success, post procedural PVCs burden and EF were comparable in both groups. EF improved in 47(75%) of successful cases with no significant differences between both groups. Post-MI Patients were the least category to improve. PVCs burden before and after ablation were the independent predictors of LVEF recovery by multivariate analysis. Cutoff values of >18%, <8% had 100% sensitivity and 85%, 87% specificity, respectively.

CONCLUSIONS

PVCs elimination by RF ablation results in significant improvement even restoration of LV function regardless of PVC origin, or the presence of concomitant SHD. PVCs burden before and after ablation are the main predictors of LVEF recovery.

Recurrence after successful catheter ablation for ventricular arrhythmia from the aortic root

OBJECTIVE

The mechanism underlying recurrence after successful ablation of ventricular arrhythmias (VAs) was unclear. Spectrum analysis can help to identify near-field activation. The purpose of this study was to quantify the changes of near-field activation in response to ablation at the VAs origin in the aortic root (AR-VAs) and to assess its relationship with late ablation outcome.

METHODS AND RESULTS

Patients who underwent acutely successful ablation for AR-VAs were analysed. Ventricular electrograms acquired before and after ablation at VAs origin were subjected to spectrum analysis. The area under the curve of the high frequency component (HFC, 50-200 Hz) and the low frequency component (LFC, 0-50 Hz) was measured. The proportion of HFC to the frequency spectrum of 0-200 Hz was defined as the HFC ratio (HFCR). The reduction of HFC and HFCR in response to ablation was defined as HFC pre-post and HFCR pre-post, respectively. Documentation of VAs with the same morphology after an acute successful procedure was defined as recurrence. Fifty-six patients were analysed, and VAs recurred in 17 patients. HFCR pre-post, HFC pre-post, and HFC pre-ablation were significantly higher in patients without recurrence. And HFCR pre-post has the highest predictive value (area under the receiver-operating characteristic curve: 0.975). A HFCR pre-post of 1.0% differentiated two groups (sensitivity = 84.6%, specificity = 100%). Higher HFCR pre-post was correlated with shorter VAs termination time (correlation coefficient = -0.399, p = .009).

CONCLUSIONS

HFCR pre-post can quantify the near-field activation change during ablation. Incomplete destruction to the VAs foci could underlie recurrence after successful ablation.

Outflow tract ventricular premature beats ablation in the presence or absence of structural heart disease: Technical considerations and clinical outcomes

BACKGROUND

Premature ventricular beats (PVBs) are early depolarization of the myocardium originating in the ventricle. In case of very frequent PVBs, patients are severely symptomatic with impaired quality of life and are at risk of pre-syncope, syncope, heart failure, and sudden cardiac death particularly in the presence of structural heart disease. Ventricular outflow tracts are the most common sites of origin of idiopathic PVBs especially in patients without structural heart disease. We examined the role of radiofrequency catheter ablation in suppression of monomorphic PVBs of outflow tract origin in the presence or absence of structural heart disease, and its impact on improvement of left ventricular (LV) systolic function.

METHODS

Thirty-seven highly symptomatic patients with PVBs burden exceeding 10% were enrolled, provided that PVBs are monomorphic, originating in ventricular outflow tracts and regardless the presence or absence of structural heart disease. Patients were divided into 2 groups according to PVB site origin (RVOT vs. LVOT). 3D electro-anatomical mapping modalities were used in all patients employing activation mapping technique in the majority of cases. Acute success was considered when PVBs completely disappeared or when residual sporadic PVBs ≤ 1 beats/min or ≤10 beats/30 min after RF ablation. Patients were followed up for a mean period of 5.4 ± 1.2 months with long-term success defined as complete disappearance or marked reduction by more than 75% in the PVBs absolute number on 24 h holter monitoring.

RESULTS

Mean age of the study group was 39.9 ± 12.97 years, including 22 (59.4%) males. PVBs originated in RVOT in 17 cases and in LVOT in the remaining 20 cases. Prevalence of structural heart disease and consequently shortness of breath was higher in LVOT group. Initial ECG localization matched EP localization in the majority (94%) of cases. R wave duration index was the only significant independent predictor for RVOT origin with cut off value of <0.3 (P = 0.0057) upon multivariate analysis. Acute success was encountered in 32 (86%) patients with all cases of failure in the LVOT group. Recurrence occurred in 5 (15%) cases without significant difference between both groups. All cases of recurrence had residual PVBs at the end of the procedure. 18 cases out of the study group showed significant improvement of their EF (>5%) at the end of the follow-up period with no significant differences between both groups (p = 0.09). A linear correlation was observed between PVBs burden at follow up and magnitude of improvement of LV EF, particularly in patients with resting LV dysfunction and increased LV internal dimensions.

CONCLUSIONS

RF ablation is an effective and safe method for elimination of outflow tract PVBs irrespective of their origin and the presence or absence of structural heart disease. PVBs burden after ablation appears to be the main determinant for reversal of PVB induced myopathy particularly in those with increased LV internal dimensions.

Origins location of the outflow tract ventricular arrhythmias exhibiting qrS pattern or QS pattern with a notch on the descending limb in lead V1

Background

Ventricular outflow tract(VOT) ventricular arrhythmias(VAs) presenting qrS pattern or QS pattern with a notch on the descending limb in lead V1 were consistently thought of arising from the commissure between left and right coronary cusp (L-RCC) by previous studies. However, we found they could originate from other anatomic structures in VOT. This study aimed to investigate the exact origin of this kind VAs.

Methods

Forty-nine patients of VOT premature ventricular contrations/ventricular tachycardia(PVCs/VT) with lead V1 presenting qrS pattern or QS pattern with a notch on the descending limb undergoing successful radiofrequency catheter ablation(RFCA) in our center were analyzed.

Results

12-lead electrocardiogram(ECG) of these PVCs/VT were summarized. Among these PVCs/VT, 37 cases exhibited qrS morphology in lead V1, 12 cases presented QS pattern with a notch on the descending limb in the same lead. Based on the successful ablation sites, these PVCs/VT were divided into 2 groups: (1)Right ventricular outflow tract(RVOT) group (26 cases), and (2) Left ventricular outflow tract (LVOT) group(23 cases, 4 cases originating from the left coronary cusp(LCC), 2 from the right coronary cusp(RCC), 16 from the L-RCC, 1 from the area inferior to LCC(ILCC)). The ECG characteristics of each PVCs/VT were analyzed. Among these PVCs/VT, applying the precordial transitional zone index(TZ index) < 0 to predict LVOT origin was demonstrated with sensitivity of 95.65%, specificity of 96.15%, positive predicting value(PPV) of 95.65% and negative predicting value(NPV) of 96.15%. In LVOT group, further applying the r, R, m,or Rs morphology in lead I to predict L-RCC and RCC origin was demonstrated with sensitivity of 94.44%, specificity of 60.00%, PPV of 89.47% and NPV of 75.00%.

Conclusions

Ventricular outflow tract PVCs/VT with lead V1 presenting qrS pattern or QS pattern with a notch on descending limb not only arising from L-RCC, but also RVOT, LCC, RCC and ILCC. Combining TZ index and QRS morphology in lead I to predict origin site of these kind VAs is a convenient, simple and reliable method and facilitates the RFCA procedure.

Ablation of ventricular arrhythmia originating from the aortic sinus of Valsalva in an adolescent with anomalous origin of the right coronary artery

A 16-year-old patient underwent successful ablation of ventricular arrhythmia originating from the aortic sinus of Valsalva following surgical unroofing of an anomalous right coronary artery. This case illustrates the complexity of decision making in the management of patients with anomalous coronary arteries and the importance of keeping an open mind when determining ventricular arrhythmia aetiology and origin.

Differentiating the origin of outflow tract ventricular arrhythmia using a simple, novel approach

BACKGROUND

Numerous electrocardiographic (ECG) criteria have been proposed to identify localization of outflow tract ventricular arrhythmias (OT-VAs); however, in some cases, it is difficult to accurately localize the origin of OT-VA using the surface ECG.

OBJECTIVE

The purpose of this study was to assess a simple criterion for localization of OT-VAs during electrophysiology study.

METHODS

We measured the interval from the onset of the earliest QRS complex of premature ventricular contractions (PVCs) to the distal right ventricular apical signal (the QRS-RVA interval) in 66 patients (31 men aged 53.3 ± 14.0 years; right ventricular outflow tract [RVOT] origin in 37) referred for ablation of symptomatic outflow tract PVCs. We prospectively validated this criterion in 39 patients (22 men aged 52 ± 15 years; RVOT origin in 19).

RESULTS

Compared with patients with RVOT PVCs, the QRS-RVA interval was significantly longer in patients with left ventricular outflow tract (LVOT) PVCs (70 ± 14 vs 33.4±10 ms, P < .001). Receiver operating characteristic analysis showed that a QRS-RVA interval ≥49 ms had sensitivity, specificity, and positive and negative predictive values of 100%, 94.6%, 93.5%, and 100%, respectively, for prediction of an LVOT origin. The same analysis in the validation cohort showed sensitivity, specificity, and positive and negative predictive values of 94.7%, 95%, 95%, and 94.7%, respectively. When these data were combined, a QRS-RVA interval ≥49 ms had sensitivity, specificity, and positive and negative predictive values of 98%, 94.6%, 94.1%, and 98.1%, respectively, for prediction of an LVOT origin.

CONCLUSION

A QRS-RVA interval ≥49 ms suggests an LVOT origin. The QRS-RVA interval is a simple and accurate criterion for differentiating the origin of outflow tract arrhythmia during electrophysiology study; however, the accuracy of this criterion in identifying OT-VA from the right coronary cusp is limited.