Clinical, electrocardiographic and electrophysiological characteristics, and catheter ablation results of left upper septal premature ventricular complexes.

BACKGROUND: To investigate the clinical, electrocardiographic and electrophysiological characteristics, and results of catheter ablation of left upper septal (LUS) premature ventricular complexes (PVCs) arising from the proximal left fascicular system. METHODS: Thirty-one patients who had undergone radiofrequency catheter ablation (RFCA) for idiopathic PVCs were enrolled in the study. All PVCs presented with narrow QRS complexes (<110 ms) with precordial QRS morphology of incomplete right bundle branch block type or identical to the sinus rhythm (SR) QRS morphology. RFCA was applied to the LUS area where the earliest fascicular potential (FP) was recorded during mapping. RESULTS: The mean QRS duration during SR and PVCs were 92.3 ± 7.9 and 103.2 ± 7.3 ms, respectively. The mean fascicular potential-ventricular interval during PVC at the target site was 32.7 ± 2.7 ms. The mean His-ventricular (H-V) interval during SR and PVCs were 45.1 ± 2.7 and 21.3 ± 3.6 ms, respectively. Left anterior hemiblock/left posterior hemiblock and left bundle branch block (LBBB) were observed in 16 (53.3%) and 4 (12.9%) patients after RFCA, respectively. The His to FP interval in SR and H-V interval during PVC were found as significant markers for predicting the postablation LBBB. RFCA was acutely successful in 29 of 31 patients (93.5%) in the first procedure. Two patients had a recurrence of PVCs during follow-up and one of them underwent a second successful ablation. The overall success rate was 90.3% (28/31) in a mean follow-up duration of 24.3 ± 15.4 months. CONCLUSIONS: LUS-PVCs have distinctive electrocardiographic and electrophysiologic characteristics and can be managed successfully by focal RFCA with detailed FP mapping of the left upper septum with a mild risk of left bundle branch injury.

Impact of Anatomically Guided Ganglionated Plexus Ablation on Electrical Firing from Isolated Pulmonary Veins.

BACKGROUND: The mechanisms underlying atrial fibrillation (AF) initiation and pulmonary vein isolation (PVI) effectiveness remain unclear. Ganglionated plexus (GPs) have been implicated in AF initiation and maintenance. In this study, we evaluated the impact of GP ablation in patients with pulmonary vein (PV) firing after PVI. METHODS: Patients with drug-refractory paroxysmal AF undergoing radiofrequency catheter ablation therapy with PVI were screened. Among 840 cases over a 3.75-year period, 12 cases were identified with persistent PV firing (left = 4 and right = 8) after PVI was achieved and left atrial sinus rhythm restored. Adjacent GP ablation was performed anatomically and followed if necessary by additional PV ablation. RESULTS: In eight patients, PV firing was terminated during GP ablation outside of the circumferential ablation line. In one patient, additional PV ablation resulted in cessation of PV firing and in the remaining three patients, firing could not be terminated by GP ablation or additional PVI. CONCLUSION: GP ablation outside of wide antral circumferential line frequently results in the cessation of rapid firing from electrically isolated PVs. These observations suggest that interactions between left atrium and PV beyond electrical conduction warrant consideration in AF mechanisms.

The relationship between right ventricular lead position and paced QRS duration.

BACKGROUND: The relationship between the anatomical location of right ventricular pacing site and paced QRS duration is unclear. In this study, we aimed to investigate the relationship between right ventricular pacing site and paced QRS duration using cardiac angiography. METHODS: Fifty patients were implanted with pacemakers. The right ventricular lead position was determined from the findings of cardiac angiography and the paced QRS duration was measured. Cardiac angiography was used to display the right ventriculogram (RVG) and the left ventriculogram (LVG). The RVG view was divided into three areas and the LVG view was divided into four areas. RESULTS: The paced QRS duration value was significantly longer in the right ventricular apex area compared with the outflow and inflow areas (160 ± 15 ms vs 140 ± 15 ms, P = 0.02, and vs 133 ± 17 ms, P < 0.001, respectively), but those values were not statistically significantly different between the right ventricular outflow and the right ventricular inflow areas (140 ± 15 ms vs 133 ± 17 ms, P = 0.187). When assessed with LVG views, there were the statistically significant differences in the paced QRS duration values in all areas except the apex area. (LV mid-anterior: 147 ± 11 ms vs LV base: 127 ± 13 ms, P < 0.001, and vs LV mid-septum: 129 ± 12 ms, P = 0.001, respectively.) CONCLUSIONS: Cardiac angiography showed that there was a relationship between the anatomical right ventricular pacing site and paced QRS duration. Cardiac angiography can help determine the areas that produce shorter paced QRS duration.

Coronary morphology and conduction system disturbance induced by therapeutic embolization of the coronary septal artery.

BACKGROUND: Percutaneous transluminal septal myocardial alcohol ablation (PTSMAA) is not a procedure without complications. It may produce heart arrhythmias, especially those due to disturbances of atrioventricular (AV) and interventricular (IV) electrical conduction. OBJECTIVE: The goal of this study was to evaluate the relationship between the anatomical patterns of the right coronary artery and the left anterior descending artery (LAD) and to relate them to the AV and IV bundle branch blocks provoked by PTSMAA. METHOD: Twenty patients with obstructive hypertrophic cardiomyopathy resistant to treatment with drugs successfully underwent PTSMAA. Electrocardiographic analyses were done before and after PTSMAA, and the results were compared with the abnormal septal anatomy. RESULTS: The effectiveness of PTSMAA was obtained in 18 (90%) of the 20 patients by ethanolization of the first great septal branch. In the other 2 patients (10%), 2 septal branches underwent alcoholization. First-grade temporary AV block (AVB) was observed in 6 patients (30%). Ten patients experienced severe bradycardia due to total AVB that required a temporary pacemaker, but 3 of the patients (15%) required a permanent pacemaker. Fourteen patients (70%) experienced permanent complete right branch block, and 2 developed incomplete left anterior block and incomplete left posterior block. Six patients presented with no electrical conduction disturbance at all. CONCLUSION: According to the results of the present investigation with the AV node artery derived from the right coronary artery in all cases, complete and permanent AV conduction system blockade occurred after PTSMAA in all types of anatomy regarding the observed LAD.

How valvular calcification can affect the outcomes of transcatheter aortic valve implantation.

Introduction In transcatheter aortic valve implantation (TAVI), assessment of aortic valve calcification is not as standardized as aortic annulus measurement. Aortic valve calcification is important for stable anchoring of the prosthesis to the aortic annulus. However, excessive aortic valve calcification is related to procedural complications. Areas covered This review covers the methods to assess aortic valve calcification and the implications of aortic valve calcium burden for TAVI outcomes. We performed a systematic review of the literature in Pubmed and secondary sources. Furthermore, future perspectives on how to integrate aortic valve calcification assessment in the management of patients with aortic stenosis is discussed. Expert opinion Thorough assessment of the aortic valve and aortic root components including aortic valve calcification is key in the planning of TAVI. Aortic valve calcification load, location and extension are important contributors to paravalvular regurgitation. Asymmetric calcification burden with greater calcification of the left-coronary cusp related to higher need of permanent pacemaker implantation. Patients with moderate and severe left ventricular outflow tract/subannular calcification are more susceptible to aortic annular rupture. Periprocedural dislodgement of calcium form cusps and commissures is one of the main reasons of coronary artery ostial occlusion during transcatheter aortic valve implantation. Abbreviations Ao, aorta; LA, left atrium; LAA, left atrial appendage; LV, left ventricle; LVOT, left ventricular outflow tract; THV, transcatheter heart valve.

A new approach for contrast-enhanced X-ray imaging of the left atrium and pulmonary veins for atrial fibrillation ablation: rotational angiography during adenosine-induced asystole.

AIMS: Atrial fibrillation ablation is a complex procedure that requires detailed anatomic information about left atrium (LA) and pulmonary veins (PVs). The goal of this study was to test rotational angiography of the LA during adenosine-induced asystole as an imaging tool in patients undergoing atrial fibrillation ablation. METHODS AND RESULTS: Seventy patients with paroxysmal or persistent atrial fibrillation undergoing PV isolation were included. After transseptal puncture, adenosine (30 mg) was given intravenously, and during atrioventricular block, contrast medium was directly injected in the LA; a rotational angiography was performed (right anterior oblique 55 degrees to left anterior oblique 55 degrees). Rotational angiography images were assessed qualitatively in all patients and quantitatively in 45 patients in comparison with computed tomography (CT) images. The majority of rotational angiography imaging data (94%) were deemed at least 'useful' in delineating the LA-PV anatomy. The so-called 'ridge' between left superior PV and left atrial appendage was delineated in 90% of the patients. All accessory PVs were independently identified by rotational angiography and CT. A blinded quantitative comparison of PV ostial diameters showed an excellent correlation between rotational angiography and CT measurements (r > 0.90 for all PVs). No serious adverse effects occurred in association with adenosine. CONCLUSION: Intra-procedural contrast-enhanced rotational angiography of the LA-PV during adenosine-induced asystole is feasible and provides anatomical information of high diagnostic value for atrial fibrillation ablation.

Use of three-dimensional catheter guidance and trans-esophageal echocardiography to eliminate fluoroscopy in catheter ablation of left-sided accessory pathways.

BACKGROUND: Newer technologies such as three-dimensional mapping and echocardiography can decrease x-ray exposure during catheter ablation. Many right-sided tachycardias can now be ablated without fluoroscopy. Left-sided tachycardias, however, have not yet been ablated using a zero fluoroscopy approach. OBJECTIVE: This study sought to examine the utility of trans-esophageal echocardiography (TEE) in providing adequate imaging as an alternative to fluoroscopy for transseptal puncture. When combined with NavX guidance (St. Jude Medical, St. Paul, MN, USA), fluoroscopy may not be necessary. METHODS: Ten pediatric patients with supraventricular tachycardia (SVT) had accessory pathways mapped to the left side. Right atrial and coronary sinus geometries were created using NavX. Once a left-sided pathway was confirmed, a transseptal puncture was performed. A guide wire was placed in the SVC and confirmed by TEE. A transseptal sheath and dilator were advanced over the wire and positioned with TEE guidance so that the tip of the dilator was tenting the fossa ovalis. A transseptal needle was advanced across the fossa. Left atrial location of the needle tip was confirmed on TEE by saline contrast injection. The sheath and dilator were advanced over the needle with continuous pressure monitoring and TEE. Once the sheath was appropriately positioned, the ablation was completed using NavX guidance. RESULTS: All patients had acutely successful ablations and none required the use of fluoroscopy. Number of cryo lesions ranged from five to 19, with a mean of 9. Mean procedure time was 4.4 hours, with a range of 3.2 hours to 7.2 hours. There were no complications. One patient had recurrence. CONCLUSIONS: Three-dimensional mapping combined with TEE shows potential for eliminating fluoroscopy use during catheter ablation.

Efficacy of adjuvant anterior left atrial ablation during intracardiac echocardiography-guided pulmonary vein antrum isolation for atrial fibrillation.

BACKGROUND: Recent data have shown that the septum and anterior left atrial (LA) wall may contain "rotor" sites required for AF maintenance. However, whether adding ablation of such sites to standard ICE-guided PVAI improves outcome is not well known. OBJECTIVE: To determine if adjuvant anterior LA ablation during PVAI improves the cure rate of paroxysmal and permanent AF. METHODS: One hundred AF patients (60 paroxysmal, 40 persistent/permanent) undergoing first-time PVAI were enrolled over three months to receive adjuvant anterior LA ablation (Group I). These patients were compared with 100 randomly selected, matched first-time PVAI controls from the preceding three months who did not receive adjuvant ablation (Group II). All 200 patients underwent ICE-guided PVAI during which all four PV antra and SVC were isolated. In group I, a decapolar lasso catheter was used to map the septum and anterior LA wall during AF (induced or spontaneous) for continuous high-frequency, fractionated electrograms (CFAE). Sites where CFAE were identified were ablated until the local EGM was eliminated. A complete anterior line of block was not a requisite endpoint. Patients were followed up for 12 months. Recurrence was assessed post-PVAI by symptoms, clinic visits, and Holter at 3, 6, and 12 months. Patients also wore rhythm transmitters for the first 3 months. Recurrence was any AF/AFL >1 min occurring >2 months post-PVAI. RESULTS: Patients (age 56 +/- 11 years, 37% female, EF 53%+/- 11%) did not differ in baseline characteristics between group I and II by design. Group I patients had longer procedure time (188 +/- 45 min vs 162 +/- 37 min) and RF duration (57 +/- 12 min vs 44 +/- 20 min) than group II (P < 0.05 for both). Overall recurrence occurred in 15/100 (15%) in group I and 20/100 (20%) in group II (P = 0.054). Success rates did not differ for paroxysmal patients between group I and II (87% vs 85%, respectively). However, for persistent/permanent patients, group I had a higher success rate compared with group II (82% vs 72%, P = 0.047). CONCLUSIONS: Adjuvant anterior LA ablation does not appear to impact procedural outcome in patients with paroxysmal AF but may offer benefit to patients with persistent/permanent AF.

Right atrial angiography facilitates transseptal puncture for complex ablation in patients with unusual anatomy.

OBJECTIVE: The number of transseptal punctures performed worldwide has increased exponentially with the development of ablation therapies for atrial arrhythmias. Safe access into the left atrium in these procedures is often complicated by abnormal anatomy. We assessed the potential of right atrial angiography to facilitate transseptal puncture for atrial ablation. METHODS AND RESULTS: We examined all transseptal punctures performed for complex left atrial ablation in our centre over a 29-month period. In cases where conventional transseptal techniques failed, we performed orthogonal right atrial angiography to define cardiac anatomy and orientation. During the study period, 255 transseptal procedures were performed. Of these, 16 cases were complicated by distorted atrial anatomy, extreme cardiac rotation or unexpected location of the atria in relation to the diaphragm, preventing left atrial access using conventional fluoroscopy. The application of right atrial angiography facilitated successful transseptal puncture in all patients when use of conventional mapping catheters and fluoroscopy proved unhelpful. There were no complications relating to right atrial angiography. CONCLUSION: These cases highlight a number of difficulties encountered when performing transseptal punctures. Previously reported adjunctive techniques require specialised equipment, general anaesthesia or multiple catheters that may be unavailable or impede the procedure. Right atrial angiography is a simple and safe adjunct to conventional techniques to facilitate complex transseptal procedures.

Automated lesion annotation during pulmonary vein isolation: influence on acute isolation rates and lesion characteristics.

PURPOSE: Recovery of pulmonary vein (PV) conduction is a common mechanism of atrial fibrillation recurrence after PV isolation (PVI), underscoring the need for durable lesion formation. We aimed to evaluate the utility of an automated lesion annotation algorithm (ALAA) on acute isolation rates and resulting lesion characteristics. METHODS: Fifty patients underwent PVI using a contact force (CF) sensing catheter and ALAA. Single antral circles around ipsilateral PVs were performed with ALAA-1 settings including catheter stability (range of motion ≤2 mm, duration >10 s). Target CF was 10-20 g but not part of ALAA-1 settings. If PV conduction persisted after circle completion, force over time was added to automated settings (ALAA-2). Emerging gaps were subsequently ablated, followed by re-assessment for PVI. RESULTS: ALAA-1 isolated 70 % of the left and 78 % of the right PVs using 756.3 ± 212.3 s (left) and 737.1 ± 145.9 s (right) of energy delivery. ALAA-2 settings identified 29 gaps in previously unisolated PVs, closure significantly increased isolation rates to 88 % of the left and 96 % of the right PVs with additional 325.4 ± 354.1 s (left) and 266.8 ± 279.5 s (right) of energy delivery (p = 0.001). Lesion characteristics significantly differed between ALAA-1 (n = 3521 lesions) and ALAA-2 (n = 3037 lesions) settings, and between isolated and non-isolated PV segments, particularly with respect to CF. Interlesion distances with ALAA-2 were significantly longer in the left superior, left superior-anterior, and right superior-posterior segments when compared to ALAA-1. CONCLUSIONS: Settings of an ALAA affect lesion characteristics reveal areas of insufficient lesion formation and influence acute effectiveness of PVI. Combination of CF and stability shows superior performance over stability alone.

Comparison of single and double vein approaches for His bundle ablation and pacemaker placement for symptomatic rapid atrial fibrillation.

BACKGROUND: His Bundle ablation (HBA) with permanent pacemaker (PPM) implantation is an effective strategy for controlling heart rate in symptomatic patients with rapid atrial fibrillation (AF), resistant to pharmacologic therapy. The standard double vein (DV) approach involves mapping and HBA from a femoral approach to achieve complete heart block (CHB), while single chamber (SC), dual chamber (DC), or biventricular (BiV) PPM is then placed via a subclavian approach. METHODS: We compared 7 patients with drug-resistant rapid AF who underwent the standard DV approach to 8 patients who underwent a single vein (SV) approach, in which HBA and PPM implantation were performed through the subclavian vein. The two groups were compared for acute success in creating CHB, total procedure and fluoroscopy times and patient discomfort. Results are expressed as mean +/- standard error (SEM). RESULTS: The procedure times for the SV versus DV were 70.4 +/- 11.4 v 100.0 +/- 19.2 min, and the fluoroscopy times, 13.9 +/- 3.1 (SV) v 13.0 +/- 2.9 (DV). All patients were discharged in stable condition with CHB and SC, DC pacemaker or BiV/Implantable Cardioverter Defibrillator (ICD). CHB with symptomatic improvement was maintained in all patients over a mean follow-up period of 22.6 months (SV), and 9.6 months (DV). CONCLUSION: The SV approach for HBA combined with PPM implantation was at least as effective and may be more efficient than the classic DV approach, and should be considered as an alternative to DV technique to reduce procedural time and patient discomfort.

Entrainment mapping of dual-loop macroreentry in common atrial flutter: new insights into the atrial flutter circuit.

INTRODUCTION: The aim of this study was to determine using entrainment mapping whether the reentrant circuit of common type atrial flutter (AFL) is single loop or dual loop. METHODS AND RESULTS: In 12 consecutive patients with counterclockwise (CCW) AFL, entrainment mapping was performed with evaluation of atrial electrograms from the tricuspid annulus (TA) and the posterior right atrial (RA) area. We hypothesized that a dual-loop reentry could be surmised from "paradoxical delayed capture" of the proximal part of the circuit having a longer interval from the stimulus to the captured beat compared with the distal part of the circuit. In 6 of 12 patients with CCW AFL, during entrainment from the septal side of the posterior blocking line, the interval from the stimulus to the last captured beat was longer at the RA free wall than at the isthmus position. In these six patients with paradoxical delayed capture, flutter cycle length (FCL) was 227 +/- 12 ms and postpacing interval minus FCL was significantly shorter at the posterior blocking line than at the RA free wall (20 +/- 11 ms vs 48 +/- 33 ms, P < 0.05). In two of these patients, early breakthrough occurred at the lateral TA. A posterior block line was confirmed in all six patients in the sinus venosa area by intracardiac echocardiography. CONCLUSION: Half of the patients with common type AFL had a dual-loop macroreentrant circuit consisting of an anterior loop (circuit around the TA) and a posterior loop (circuit around the inferior vena cava and the posterior blocking line).

Phased-array intracardiac echocardiography for defining cavotricuspid isthmus anatomy during radiofrequency ablation of typical atrial flutter.

INTRODUCTION: Cavotricuspid isthmus (CTI) topography includes ridges, pouches, recesses, and trabeculations. These features may limit the success of radiofrequency ablation (RFA) of typical atrial flutter (AFL). The aim of this study was to assess the utility of phased-array intracardiac echocardiography (ICE) for imaging the CTI and monitoring RFA of AFL. METHODS AND RESULTS: Fifteen patients (mean age 64 +/- 9 years) underwent ICE assessment (imaging frequency 7.5-10 MHz) before and after RFA of AFL. The ICE catheter was positioned at the inferior vena cava-right atrial junction and the following parameters were measured: (1) CTI length from the tricuspid valve to the eustachian ridge; (2) extent of CTI pouching; and (3) thickness pre/post RFA of the anterior, mid, and posterior CTI. CTI length was 35 +/- 6 mm at end-ventricular systole but shorter (30 +/- 6 mm) and more pouched at end-ventricular diastole (P = 0.02). A pouch or recess was seen in 11 of 15 patients (mean depth 6 +/- 2 mm). The septal CTI was more pouched than the lateral CTI, but the latter had more prominent trabeculations. Trabeculations were seen in 10 of 15 patients, and at these locations the CTI was 4.6 +/- 1 mm thick. Anterior, mid, and posterior CTI thickness pre-RFA was 4.1 +/- 0.8, 3.3 +/- 0.5, and 2.7 +/- 0.9 mm, respectively (P < 0.001 by analysis of variance). ICE guided RFA away from unfavorable CTI features (recesses/thick trabeculations). RFA applications created discrete CTI lesions that coalesced, forming diffuse CTI swelling. Post-RFA thickness was as follows: anterior 4.8 +/- 0.8 mm (P = NS vs pre); mid 3.8 +/- 0.8 mm (P = 0.05 vs pre); and posterior 3.8 +/- 0.8 mm (P = 0.02 vs pre). CONCLUSION: Phased-array ICE permits novel real-time CTI imaging with excellent endocardial resolution and may facilitate RFA of AFL.