Narrow QRS ectopy with concealed connections from a para-Hisian origin to the proximal left fascicles.

INTRODUCTION: Catheter ablation of ectopy originating from the vicinity of the His bundle can be challenging. METHODS AND RESULTS: We report a case of a 33-year-old man with narrow QRS ectopy with preferential conduction from a para-Hisian origin to the proximal left fascicles, which was successfully eliminated by radiofrequency ablation in the right coronary cusp, guided by ultrahigh-resolution mapping of the His bundle, bundle branch, and fascicular electrograms. CONCLUSION: Some narrow QRS ectopy may originate from the vicinity of the conduction system, instead of the "true" conduction system, and have concealed connections from its origin to the conduction system.

Insight from the microelectrodes in case of two different types of premature ventricular contractions originating from left ventricular summit.

Premature ventricular contraction (PVC) is usually eliminated in the earliest activation site based on the conventional electrode of ablation catheter. However, the large size electrode may contain far-field potential. The QDOT MICRO ablation catheter has three micro electrodes with 0.33 mm electrode length, in addition to the conventional electrode with 3.5 mm electrode length. The micro electrodes can reflect only near-field potential. A 78-year-old with symptomatic frequent PVCs underwent catheter ablation. PVC-1 showed good pace-mapping in distal great cardiac vein (GCV). The local bipolar electrograms in the conventional electrode of ablation catheter preceded the PVC-QRS onset by 32 ms in distal GCV and 13 ms in left coronary cusp (LCC), but those in the micro electrodes preceded only by 13 ms both in distal GCV and LCC. PVC-1 was eliminated by radiofrequency (RF) application, not in distal GCV, but in LCC. PVC-2 showed good pace-mapping in LCC. The local bipolar electrograms in both the conventional electrode and the micro electrodes of ablation catheter preceded the PVC-QRS onset by 32 ms in LCC. PVC-2 was eliminated by RF application in LCC. Comparing the local electrograms of micro electrodes and the conventional electrodes may be important for identifying depth of the origin of PVCs.

Selective proximal left anterior fascicle pacemapping for guiding narrow QRS premature ventricular complex ablation from the right coronary cusp.

A 38-year-old woman with a structurally normal heart was referred for catheter ablation due to symptomatic, monomorphic, high burden (12%) premature ventricular complexes (PVC) refractory to medical therapy. The PVC's ECG morphology suggested an origin in the proximal left anterior fascicle (LAF). During procedure PVCs were mechanically suppressed. Consequently, selection of the ablation target site was based on pace-mapping. This case illustrates how ablation from the right coronary cusp (RCC) for PVC arising from the proximal LAF could be accurately guided by pace-mapping. At this location, pacing can result in both a selective and a non-selective capture of the proximal LAF.

S-R index in V1/V3 serves as a novel criterion to discriminate idiopathic premature ventricular contractions originating from posteroseptal right ventricular outflow tract versus right coronary cusp.

AIM: The current study aimed to establish a novel electrocardiographic (ECG) criterion for discrimination of idiopathic premature ventricular contractions (PVCs) originating from posteroseptal right ventricular outflow tract (sRVOT-p) versus right coronary cusp (RCC). METHODS: A total of 76 patients with idiopathic PVCs who underwent mapping and successful ablation were retrospectively included. Among them, 37 patients had PVCs from sRVOT-p origin and 39 patients from RCC origin. The surface ECGs during PVCs were recorded. S-R different index in V1/V3 was calculated with the following formula of 0.134*V3R-0.133*V1S. RESULTS: ECG characteristics showed wider total QRS duration, smaller R-wave amplitude on lead V2-V5, and larger S-wave amplitude on lead V1-V3 in sRVOT-p origin than RCC origin. Lead V3 was the most common transitional lead in two groups. Receiver operating characteristic (ROC) curve analysis showed that S-wave amplitude on lead V1 exhibited the largest AUC of 0.772, followed by the AUC of R-wave amplitude on lead V3 of 0.771. Subsequently, 0.134*V3R-0.133*V1S index was obtained by multiplication, subtraction, sum, and division of these ECG measurements, which exhibited the largest AUC of 0.808. The optimal cut-off value was -0.26 for differentiating RCC from sRVOT-p origin, with the sensitivity of 78.4% and specificity of 77.8%. Moreover, 0.134*V3R-0.133*V1S index was superior to previous criteria in analysis of PVCs originating from sRVOT-p and RCC. CONCLUSIONS: 0.134*V3R-0.133*V1S is a novel ECG criterion to discriminate sRVOT-p from RCC origin in patients with idiopathic PVCs, which may provide guidance for approach of radiofrequency catheter ablation.

Ventricular ectopy from the non-coronary cusp: Pathophysiological and anatomical considerations.

Non-coronary cusp (NCC) is a rare site for ventricular arrhythmias because it does not come into direct contact with the ventricular myocardium. Instead, the NCC comes in contact with the membranous septum near the His region. We describe a case of a young man with a ventricular ectopy who was successfully ablated in the NCC. In our case the much greater prematurity in the NCC than in the His region suggests that the arrhythmic site of origin is not in the peri-His area but most likely a myocardial extension adjoining the aortic root.

Can the 12-lead ECG distinguish RVOT from aortic cusp PVCs in pediatric patients?

BACKGROUND: The ability to differentiate right ventricular outflow tract (RVOT) from coronary cusp (CC) site of origin (SOO) by 12-lead ECG in pediatric patients may impact efficacy and procedural time. The objective of this study was to predict RVOT versus CC SOO by ECG in pediatric patients. METHODS: Pediatric patients (<21 years) without structural heart disease with RVOT or CC premature ventricular contraction (PVC) ablations performed (2014-2018) were evaluated through multi-institution retrospective review. Demographics, ECG PVC parameters, ablation site, recurrence, and repeat procedures were collected. RESULTS: Thirty-seven patients were evaluated (mean age 14.6 years, weight 60.6 kg): 11 CC and 26 RVOT PVC SOO. CC PVCs were less likely to exhibit left bundle branch block (64% vs 100%, P = .005), had larger R-wave amplitude in V1 (0.27 vs 0.11 mV, P = .03), larger R/S ratio in V1 (0.37 vs 0.09, P = .003), and had precordial transition in V3 or earlier (73% vs 15%, P = .002). A composite score was created with the following variables: isodiphasic or positive QRS in V1, R/S ratio in V1 > 0.05, S wave in V1 < 0.9 mV, and precordial transition at or before V3. Composite score ≥ 2 was associated with a CC SOO (OR 42.0, P = .001, and AUC 0.86). CONCLUSIONS: 12-lead ECG of PVCs from the CC was associated with larger V1 R-wave amplitude, larger R/S ratio in V1, and precordial transition at or before V3. A composite score may help predict PVC/VT arising from the CC.

Right ventricular outflow tract obstruction caused by a right coronary cusp prolapse: An unusual finding.

Patients with large sub-pulmonic ventricular septal defect (VSD) present early as a results of their complications. Some present late, due to the restriction of VSD by the right coronary cusp (RCC) due to its prolapse. In this report, we present a rare case of sub-pulmonic VSD in a 33-year-old man who developed a sub-pulmonic stenosis due to the prolapse of the RCC into the right ventricular outflow tract.

A case of successful radiofrequency catheter ablation of ventricular tachycardia from the noncoronary cusp.

Idiopathic ventricular tachycardias (VTs) originating from the non-coronary cusp (NCC) are very rare. The previous reports suggested NCC-VTs were characterized by a narrower QRS duration and smaller III/II ratio than VTs originating from other coronary-cusps. We present a rare case of an NCC-VT with a local fragmented potential recorded at the NCC inconsistent with the known ECG characteristics of NCC-VTs.

Anomalous Origin of Right Coronary Artery from the Non-coronary Cusp Demonstrated by Echocardiography and CT Angiography.

Certain coronary anomalies have been associated with sudden cardiac death. Anomalous origin of the right coronary artery (RCA) from the posterior non-coronary aortic cusp is exceedingly rare. Through multimodality imaging, we present a young female with an anomalous RCA arising from the non-coronary cusp. Given the unobstructed origin and benign course, no intervention was recommended.

Anomalous right coronary artery arising from left coronary cusp with coexisting valvular heart disease.

We report an unusual case, a 50 year old female with an abnormal right coronary artery originating from the left coronary cusp. The patient, who had a history of hypertension presented with chest pain and shortness of breath to the emergency department. She was diagnosed with ischaemic heart disease (IHD) and had hypertension as one of the coronary risk factor. Echocardiography revealed poor progression of R waves. She was scheduled for echocardiography thereafter which revealed severe aortic stenosis with aortic root dilatation. The patient was discharged due to absence of any complications or other anomalies. This case is unique because of the simultaneously presenting valvular pathology, along with the anomalous origin of the right coronary artery which was detected, as an incidental finding, during coronary angiography.

Radiofrequency catheter ablation at the non-coronary cusp for the treatment of para-hisian accessory pathways.

AIMS: Radiofrequency catheter ablation (RFCA) is well established as a definitive therapy of accessory pathways (APs). Successful RFCA of anteroseptal APs at the non-coronary cusp (NCC) have been reported in several case reports. We aimed to evaluate the prevalence, safety, efficacy, and long-term outcome of RFCA at the NCC for the treatment of para-hisian APs. METHODS AND RESULTS: Our study included 17 patients (58.8% female, mean age 46.9 ± 15.9 years) with para-hisian APs. We performed two different ablation approaches which targeted at either the right anterior septum (RAS) (n = 10) or the NCC (n = 7) as the initial target. We compared safety, efficacy, and long-term outcome between these two approaches. The para-hisian APs were successfully ablated in 15 patients and damaged in 1 patient, for the remaining patients, the ablation was abandoned for the suspicion of no atrioventricular conduction. Considering all ablation sites of the para-hisian APs, radiofrequency (RF) delivered at the NCC had a higher success rate (11/12 vs. 5/12, P < 0.05) and a lower complication rate (0/12 vs. 4/12, P < 0.05) compared with the RAS. During a mean follow-up period of 22.4 ± 15.0 months, all the patients were free of arrhythmias without any anti-arrhythmic drugs. CONCLUSION: Para-hisian APs can be safely and effectively ablated at the NCC. Compared with the ablation at the RAS, RF delivered at the NCC has a higher immediate success, lower complication rate, and good long-term outcome.

Collagenous fibroma of the right coronary cusp: a case report and literature review.

Collagenous fibroma (desmoplastic fibroblastoma) is a rare benign tumor. This type of tumor mostly occurs in the subcutaneous tissues or skeletal muscle, and to the best of our knowledge, there is no unique case report of it occurring in the cardiac valves. This is the first description of collagenous fibroma in a human heart.

Successful catheter ablation of a left anterior accessory pathway from the non-coronary cusp of the aortic valve.

Left anterior accessory pathways are considered to be rare findings. Catheter ablation of accessory pathways in this location remains a challenging target, and few reports about successful ablation of these accessory pathways are available. We describe our experience regarding a case of a manifest left anterior accessory pathway ablation using radiofrequency energy at the junction of the left coronary cusp with the non-coronary cusp.

Successful ablation of frequent atrial premature beats from non-coronary aortic cusp with remote magnetic navigation.

A 59-year-old female with structurally normal heart was admitted to our hospital for treatment of highly symptomatic, drug refractory atrial premature beats (APB). ECG revealed atrial parasystolic trigeminy. The arrhythmogenic focus was mapped and ablated using magnetic remote navigation and 3D electroanatomical mapping system. To our knowledge, this is the first report on successful ablation of frequent APBs in the non-coronary aortic cusp.

Distinguishing ventricular arrhythmia originating from the right coronary cusp, peripulmonic valve area, and the right ventricular outflow tract: utility of lead I.

INTRODUCTION: Outflow tract ventricular arrhythmia (OTVA) can be complicated to target for ablation when originating from either the periaortic or pulmonary valve (PV) region. Both sites may present with a small R wave in lead V1. However, the utility of lead I in distinguishing these arrhythmia locations is unknown. METHODS AND RESULTS: Thirty-six consecutive patients (mean age 41 ± 14 years, 13 male) underwent catheter ablation for OTVA. OTVA origin was determined from intracardiac electrogram tracings and electroanatomic maps. Observers blinded to results measured QRS waveform amplitude and duration from standard 12-lead ECG tracings. Measurements with highest diagnostic performance were modeled into an algorithm. Sites of successful ablation were anterior right ventricular outflow tract (RVOT; n = 6), posterior RVOT (n = 4), PV (n = 18), and right coronary cusp (RCC; n = 8). Highest performing surface ECG discriminators were from lead I to V1 vectors: RCC, lead I R wave ≥ 1.5 mV, and V1 R wave ≥2.0 mV (sensitivity 87%, specificity 93%); PV, V1 R wave > 0 mV, and lead I R/(R+S) ≤ 0.75 (sensitivity 78%, specificity 72%); anterior RVOT, V1 R wave = 0 mV, and lead I R/(R+S) <0.4 (sensitivity 67%, specificity 97%); posterior RVOT, V1 R wave > 0 mV, and lead I R/(R+S) > 0.75 (sensitivity 75%, specificity 84%). Sequential algorithmic application of these criteria resulted in an overall accuracy of 72% in predicting site of OTVA origin. CONCLUSIONS: A relatively large R wave in lead I is seen with RCC origin but not PV origin. A sequential algorithm has limited but potentially significant value beyond assessment of lead I in approaching OTVA.

Idiopathic ventricular tachycardia cured by radiofrequency application from the distal great cardiac vein and the left coronary cusp.

A 79 year-old male without structural heart disease suffered from drug refractory ventricular tachycardia (VT). VTs and premature ventricular complexes (PVCs) with the same morphology occurred incessantly with a concordant R pattern in chest leads and a tall R in Lead II, III, and aVF. The origin was expected to be near the left epicardial ventricular outflow tract (LVOT), which was termed the left ventricular summit area. Pace-mapping from the LVOT and the left coronary cusp (LCC) did not match well with the QRS morphology of the PVC. A good match was obtained from the distal great cardiac vein (GCV), and radiofrequency (RF) delivery eliminated the PVC and VT. However, the PVC recurred four times upon cessation of RF delivery. By placing an ablation catheter at the LCC, we obtained pace-mapping showing two different types of QRS morphologies; one was an rS pattern in V1, and the other was an R pattern in V1 with a longer stimulus to QRS interval, which was a nearly perfect match to the PVC. RF application to the LCC permanently eliminated PVCs and VTs. Several VTs from the epicardial LVOT can be cured by RF application from both the distal GCV and the LCC.

Electroanatomic mapping-guided radiofrequency ablation of adenosine sensitive incessant focal atrial tachycardia originating from the non-coronary aortic cusp in a child.

Incessant focal atrial tachycardia may be encountered in the pediatric age group although it is rarely seen. Ablation using radiofrequency or cryothermal energy is the preferred method for drug-resistant cases. Recently, 3D electroanatomic mapping systems have been increasingly used for mapping and ablation. In this report, we presented, for the first time, a pediatric case with incessant focal atrial tachycardia originating from the non-coronary aortic sinus and ablated using 3D electroanatomic mapping system.

Acute occlusion of the left main coronary artery following impedance rise after high-frequency catheter ablation.

We present a case of catheter ablation of a premature ventricular complex complicated by left main injury. During ablation from the left coronary cusp, a sudden rise in impedance was followed by ST elevation on the ECG. Angioplasty and stenting were performed immediately; however, the stent subsequently developed repeated stenosis.