Bipolar catheter ablation with dedicated radiofrequency system for highly refractory ventricular arrhythmia-Does the rate of success depend on arrhythmia origin?

INTRODUCTION: Despite rapid technological progress, some arrhythmias are still resistant to standard unipolar ablation. These include arrhythmias arising from the base of the heart, cardiac crux, or epicardium. Bipolar radiofrequency ablation (B-RFA) may be useful in some cases, however, data on the efficacy of this approach in various arrhythmia localizations are scarce. The aim of this study was to assess the efficacy of B-RFA in patients with ventricular arrhythmias originating from various locations, occurring refractory to standard unipolar ablation approaches. METHODS: An observational, single center study was conducted over a 30-month period. B-RFA were performed using dedicated radio frequency (RF) generator and electroanatomic mapping system. RESULTS: Twenty-four procedures, in 23 patients with a median (range) of 1 (1-2) previously failed unipolar ablation procedures, were included in the final analysis. There were 12 ablations of ventricular arrhythmias originating from interventricular septum with an acute success rate of 75%, and 12 from left ventricular (LV) summit with an acute success rate of 58%. The midterm success rate (median interquartile range follow-up of 205 days [188-338]) was 66% and 50%, respectively. CONCLUSIONS: B-RFA is a promising method of catheter ablation for refractory cardiac arrhythmias. A higher success rate was observed in ablation for difficult ventricular arrhythmias originating from interventricular septal region than LV summit.

Cardioneuroablation for reflex asystolic syncope: Mid-term safety, efficacy, and patient's acceptance.

BACKGROUND: Cardioneuroablation (CNA) is a promising therapy for reflex asystolic syncope; however, convincing data on the mid-term safety and efficacy of this procedure are lacking. OBJECTIVE: The purpose of this study was to assess the mid-term safety, efficacy, and patient acceptance of CNA. METHODS: This prospective observational single-center study included 115 consecutive patients (mean age 39 ± 13 years; 58% female) treated between 2016 and 2022 who completed at least 1-year follow-up. RESULTS: No significant procedure-related acute complications occurred. During median follow-up of 28 months (range 12-75), 95 (83%) remained free from syncope. Of the 20 patients (17%) with syncope recurrence, syncope burden decreased from a mean 17 (median 6.5) to 3.75 (median 2.5) episodes (P = .015). In 9 of 10 patients, pacing system removal was possible. Repeated CNA was needed in 3 patients (3%), whereas pacemaker implantation was performed in 5 (4%). The most frequent mid-term complication of CNA was sinus rhythm acceleration (from 60 ± 14 bpm to 90 ± 16 bpm; P <.0001), which was symptomatic in 31 patients (27%); 8 patients (7%) required chronic beta-blocker and/or ivabradine. Sinus node modification was necessary in 1 patient. Other complaints included dyspnea, chronic chest pain, and decreased exercise capacity, which were mild and reported by 16 patients (14%). Patient acceptance of CNA was very high: 96% stated that it was worth undergoing the procedure. CONCLUSIONS: Mid-term efficacy of CNA exceeds 80%, and acute complications are absent. The most frequent mid-term chronic complication is inappropriate sinus tachycardia, which in 7% required chronic treatment. The procedure is well accepted by patients.

Subclinical Dysfunction of Left Atrial Compliance after Cryoballoon versus Radiofrequency Ablation for Paroxysmal Atrial Fibrillation.

It has been suggested that cryoballoon (CB) ablation for paroxysmal atrial fibrillation (PAF) may lead to more extensive left atrial (LA) injury than radiofrequency (RF) ablation; however, results are conflicting. We sought to address this issue using modern echocardiographic techniques estimating the LA function after successful CB and RF ablation for PAF. A total of 90 patients (66% males, mean age 57 ± 10 years) successfully treated (no AF recurrences confirmed in serial 4-7 day ECG Holter monitoring) with RF (51%) or CB (49%) ablation for PAF were retrospectively studied. Echocardiography with speckle tracking (STE) was performed before and 12 months after the procedure. The peak longitudinal LA strain (LAS) and strain rate (LASR) during the reservoir (r), conduit (cd), and contraction (ct) phases were measured in sinus rhythm. Analysis of covariance was applied to compare changes in the echocardiographic parameters over time with the baseline measurements as covariance and the type of ablation as the factor. The parallelism of the slopes of the covariance was tested. The LA diameter decreased (38.3 ± 4.1 mm vs. 36.8 ± 3.6 mm, p < 0.001) in the whole study group at 12 months after ablation. The LASRr and LASRcd increased (1.1 ± 0.3 s-¹ vs. 1.3 ± 0.3 s-¹, p < 0.001 and 1.1 ± 0.3 s-¹ vs. 1.2 ± 0.3 s-¹, p < 0.001, respectively) whereas other LA strain parameters remained unchanged in the whole study group at 12 months after ablation. In the analysis of LA function at 12 months after the procedure regarding the mode of ablation, the worsening of parameters reflecting LA compliance was observed in patients with better pre-served baseline values in the CB ablation subgroup. For baseline LAScd >28%, the difference ΔCB - ΔRF was -7.6 (11.7; -3.4), p < 0.001, and for baseline LAScd >16%, ΔCB - ΔRF was -1.8 (-3.2; -0.4), p = 0.014. The traditional Doppler-derived parameter e' showed the same trend-for baseline e' ≥12 cm/s, ΔCB - ΔRF was -1.7 (-2.8; -0.6), p = 0.003. We conclude that worsening of parameters reflecting LA compliance was observed 12 months after CB ablation compared to RF ablation for PAF in patients who underwent a successful procedure and had better-preserved baseline LA function. This might suggest subclinical dysfunction of LA after the CB ablation procedure. The clinical significance of these findings warrants further investigations.

Is catheter-tissue contact force value important for ablation of ventricular arrhythmias originating from the left ventricular papillary muscles?

Background: Good catheter-tissue contact is mandatory to create effective ablation lesions. The minimal contact force value for ablation of arrhythmias originating from the left ventricle is 8.0-10.0 grams but is not known for arrhythmias arising from papillary muscles. Purpose: To analyze contact force values during successful ablation procedures of arrhythmias originating from the left ventricular papillary muscles. Methods: 24 consecutive patients (mean age 57.9 ± 11.9 years, 16 males) underwent ablation of premature ventricular complexes originating from left ventricular papillary muscles with the use of CARTO electro-anatomical system and intracardiac echocardiography. Results: Acute complete abolition of ventricular ectopy was obtained in 23 (96%) patients. The fluoroscopy time was 3.9 ± 3.5 min and procedure duration - 114.8 ± 37.9 min. The mean contact force during successful ablations was 3.0 ± 1.1 grams and 3.18 ± 1.8 grams for antero-lateral and postero-medial papillary muscle, respectively (NS). The mean contact force during a single unsuccessful ablation was 3.0 grams. At control Holter ECG, the mean Ectopy Burden was Reduced in the Antero-Lateral Papillary Muscle Group from 18.0% ± 7.9% to 2.6% ± 2.9% (p = 0.005415) and in the Postero-Medial Papillary Muscle Group - from 34.8% ± 13.7%-1.7% ± 1.3% (p = 0.012694). During Median 27 (IQR: 17-34) Months of Follow-up There one Recurrence of Arrhythmia. Conclusion: The values of contact force for successful ablation of ventricular ectopy originating from the left ventricular papillary muscles may be much lower than those for ablation of other foci which questions the role of contact force measurement when ablating these arrhythmias.

Cardioneuroablation for Reflex Syncope: Efficacy and Effects on Autonomic Cardiac Regulation-A Prospective Randomized Trial.

BACKGROUND: Treatment of cardioinhibitory vasovagal syncope (VVS) is difficult. Recently, cardioneuroablation (CNA) has emerged as a new therapeutic option. OBJECTIVES: This study sought to assess the effects of CNA on syncope recurrences in patients with VVS. METHODS: This study was a prospective, open, randomized, controlled, investigator-initiated trial comparing CNA versus optimal nonpharmacologic therapy in patients with cardioinhibitory VVS. Patients were included if they had documented symptomatic cardioinhibitory or mixed VVS and positive atropine test. CNA was performed using radiofrequency ablation of the ganglionated plexi from the left and right atria. Follow-up lasted 2 years. Primary endpoint was time to first syncope recurrence. Secondary endpoints included changes in sinus rhythm and heart rate variability measured in Holter electrocardiography at baseline and 3, 12, and 24 months after CNA, as well as changes in quality of life at baseline and after completion of follow-up. RESULTS: A total of 48 patients (17 male, mean age 38 ± 10 years, 24 in CNA group, 24 in control group) entered the study. The primary endpoint occurred in 2 patients (8%) from the CNA group versus 13 control patients (54%) (P = 0.0004). After CNA the mean sinus rhythm at 24-hour Holter electrocardiography was significantly faster and heart rate variability parameters significantly changed toward parasympathetic withdrawal compared with baseline values. Quality of life significantly improved in the CNA group (30 ± 10 points vs 10 ± 7 points; P = 0.0001), whereas it remained stable in control patients (31 ± 10 points vs 30 ± 10 points; P = 0.5501). CONCLUSIONS: This is the first randomized study documenting efficacy of CNA in patients with cardioinhibitory VVS. Larger studies are needed to confirm these findings. (Cardioneuroablation for Reflex Syncope [ROMAN]; NCT03903744).

Ultrasound-guided extracardiac vagal stimulation-New approach for visualization of the vagus nerve during cardioneuroablation.

BACKGROUND: Fluoroscopy-guided extracardiac vagal stimulation (ECVS) from the internal right and left jugular veins (RIJV and LIJV) is routinely used to document vagal response (sinus arrest and/or atrioventricular block) during cardioneuroablation. Ultrasound-guided ECVS allows direct visualization and selective stimulation of the vagus nerve (VN). OBJECTIVES: The objectives of this study were to assess the feasibility of ultrasound-guided ECVS and to compare it with fluoroscopy-guided ECVS. METHODS: The study group consisted of 48 patients (25 men [52%]; mean age 38 ± 15 years) in whom fluoroscopy-guided ECVS and ultrasound-guided ECVS were performed. For fluoroscopy-guided ECVS, a pacing electrode was introduced into the RIJV and into the LIJV up to the level of the jugular foramen under fluoroscopic guidance. For ultrasound-guided ECVS, the VN and electrode were visualized using ultrasonography. Partial vagal response was defined as induction of sinus arrest or atrioventricular block, whereas full vagal response was defined as induction of both. RESULTS: ECVS was performed in all patients from the RIJV and in 45 from the LIJV. Visualization of the VN using ultrasound was possible in 44 patients (92%). During ECVS from the RIJV, partial vagal response was obtained in 39 (81%) using fluoroscopy-guided ECVS vs 45 (94%) using ultrasound-guided ECVS (not significant) whereas full vagal response was obtained in 27 patients (56%) using fluoroscopy-guided ECVS vs 40 (83%) using ultrasound-guided ECVS (P = .0071). For ECVS from the LIJV, partial vagal response was achieved in 40 (89%) vs 44 (98%) patients (not significant) whereas full vagal response was achieved in 30 (67%) vs 40 (89%) patients (P = .021) (fluoroscopy-guided ECVS vs ultrasound-guided ECVS, respectively). CONCLUSION: Ultrasound-guided ECVS is feasible and full vagal response is achieved significantly more frequently than using fluoroscopy-guided ECVS.

Daily ECG transmission versus serial 6-day Holter ECG for the assessment of efficacy of ablation for atrial fibrillation - the AGNES-ECG study.

PURPOSE: To compare daily ECG transmissions using trans-telephonic monitoring (TTM) with repeated 6-day Holter ECG in detecting atrial fibrillation (AF) episodes following ablation. METHODS: Each patient underwent two types of recordings: daily ECG TTM lasting 30 s and standard 6-day ambulatory ECG monitoring performed 3, 6, and 12 months after ablation. Number of patients with detected AF recurrences, time to first detected recurrence of AF, and AF burden were assessed. RESULTS: Fifty patients (9 females, mean age 57 ± 11 years) were included. The mean duration of the follow-up was 382 ± 38 days. A total of 17,573 (mean 351 ± 111 per patient) TTM recordings were performed and 99.95% of recordings were of quality sufficient to assess cardiac rhythm. Altogether, 14 (28%) patients had AF recurrence. Holter ECG detected AF recurrence in 7 (14%) patients whereas TTM - in 12 (24%) patients, p = 0.0416 (TTM only - 7 (14%), Holter ECG only - 2 (4%), and both methods - 5 (10%)). Time to the first AF recurrence tended to be shorter using TTM than Holter ECG (156 ± 91 vs 204 ± 121 days, p = 0.0819). There was no significant difference in AF burden assessed by TTM versus Holter ECG recordings 3.1 ± 0.14% vs 4.8 ± 0.2%, p = 0.21. CONCLUSIONS: Compared with Holter ECG, daily 30-s ECG recordings detected more patients with AF recurrences. Time to first detected AF episode tended to be shorter using TTM. Daily ECG recordings transmitted using smartphone may replace standard Holter ECG in detecting AF after ablation. TRIAL REGISTRATION: Clinical Trials Identifier: NCT03877913.

Cardioneuroablation changes the type of vasovagal response in patients with asystolic reflex syncope.

BACKGROUND: Cardioneuroablation (CNA) has been recently proposed as a new therapy in patients with asystolic vasovagal syncope (VVS) caused by parasympathetic overactivity. OBJECTIVE: To assess the impact of CNA on the type of VV response during tilt testing (TT). METHODS: The study group consisted of 20 patients (7 males, mean age 38 ± 9). All patients had a history of syncope due to asystole and confirmed asystolic VVS at baseline TT (TT1). CNA was performed in the right and left atrium. The second TT (TT2) and Holter ECG were performed three months later. All patients completed one-year follow up. RESULTS: At TT1, twenty patients had cardioinhibitory syncope and 1 had mixed VVS with asystole > 3 s. During one-year follow-up no spontaneous syncopal episodes were noted. At TT2, 6 patients had no syncope whereas the remaining 13 had syncope - twelve due to vasodepressor mechanism and only one due to asystole. Mean heart rate after CNA was significantly faster and heart rate variability parameter (SDNN) lower than before the procedure (82 ± 9 vs 69 ± 11 beats/min, p = 0.0003 and 74 ± 22 vs 143 ± 40 ms, p = 000001, respectively). These changes were similar in those who fainted during TT2 and those who did not (84 ± 10 vs 81 ± 5 beats/min, p = NS and 72 ± 24 vs 72 ± 19 ms, p = NS, respectively). CONCLUSIONS: CNA profoundly affects type of VV reaction causing normalization of the response to tilting or changing cardiodepression to vasodepression. Changes in heart rate and heart rate variability are consistent with attenuation of parasympathetic activity.

Cardioneuroablation - Induced shift in sinus node activation: A new parameter of vagal denervation?

Experimental studies demonstrated a shift in the leading pacemaker site based on parasympathetic or sympathetic dominance. Radiofrequency catheter ablation of ganglionated plexi (GP) might be used to overcome deleterious effects of enhanced parasympathetic tone. Herein, we present two patients who underwent GP ablation due to cardioinhibitory type reflex syncope and symptomatic bradycardia, respectively. In both cases complete vagal denervation was achieved and was associated with a cranial shift of sinus node activation area with corresponding changes in surface P wave morphology. This unique phenomenon needs to be confirmed in the larger prospective study.

Ablation for paroxysmal atrial fibrillation-real-life results from a middle-volume electrophysiology laboratory.

INTRODUCTION: A significant improvement in safety and efficacy of ablation for paroxysmal atrial fibrillation (PAF) has been reported by experienced centers over recent years; however, data from real-life surveys and smaller electrophysiology (EP) laboratories have been less optimistic. AIM: To asses efficacy of ablation for PAF in a middle-volume EP center over last years. METHODS: Retrospective analysis of 1 year efficacy and safety of ablation for PAF in three cohorts of patients treated between 2011 and 2014 (period I), 2015-2017 (period II), and 2018-2019 (period III). RESULTS: Of 234 patients (mean age 57 ± 9 years, 165 males), 81 (35%) were treated in period I, 84 (36%) in period II, and 69 (29%) in period III. The overall efficacy of ablation during all analyzed periods was 67%. The overall efficacy of ablation increased over time-from 56% in period I to 68% in period II and 81% in period III. Significant improvement was achieved using radiofrequency ablation (RF) (53% in period I vs 82% in period III, and 55% in period II vs 82% in period III, p = 0.003 and 0.0012, respectively) whereas positive trend in the improvement of cryoballoon efficacy was NS. The rate of peri-procedural complications was 9% and it did not change significantly over time. CONCLUSIONS: This real-life observational study from a medium volume EP center shows that progress in PAF ablation, especially RF, reported by highly-skilled centers, can be reproduced in real life by less experienced operators.

Acceleration of sinus rhythm following ablation for atrial fibrillation: a simple parameter predicting ablation efficacy.

BACKGROUND: Pulmonary vein isolation (PVI) is a well­established treatment method in patients with paroxysmal atrial fibrillation (AF). However, the predictors of a successful outcome are less well known. It has been suggested that PVI­induced changes in autonomic control of sinus rate (SR) may correspond to ablation efficacy. AIMS: We aimed to assess whether PVI­induced changes in SR may help identify responders to PVI. METHODS: The study group consisted of 111 consecutive patients (mean [SD] age, 55 [10] years; 81 men) who underwent the first ablation of paroxysmal AF (radiofrequency [RF] ablation, 56 patients; cryoballoon [CB] ablation, 55 patients). The SR was calculated from a standard 12­lead electrocardiogram recorded a day before and 2 days after ablation. Patients were followed for 1 year on an outpatient basis and underwent serial 4- to 7­day Holter electrocardiogram recordings at 3, 6, and 12 months after ablation. RESULTS: Ablation was effective in 74 patients (67%). Univariate and multivariate analyses showed that younger age, faster SR, and a greater increase in SR (ΔSR) after ablation were significantly associated with successful outcome. The results were similar between patients who underwent RF and CB ablation. The sensitivity, specificity, negative predictive value, and positive predictive value of ΔSR higher than 15 bpm for the identification of responders were 53%, 73%, 80%, and 44%, respectively. CONCLUSIONS: Acceleration of SR following ablation for paroxysmal AF may serve as an additional simple clinical parameter that may improve the prediction of outcome after PVI.

Long-term follow-up and comparison of techniques in radiofrequency ablation of ventricular arrhythmias originating from the aortic cusps (AVATAR Registry).

INTRODUCTION: Radiofrequency ablation (RFA) of outflow tract ventricular arrhythmia (VA) that originates from the aortic cusps can be challenging. Data on long­ term efficacy and safety as well as optimal technique after aortic cusp ablation have not previously been reported. OBJECTIVES: This aim of the study was to determine the short- and long­ term outcomes after RFA of aortic cusp VA, and to evaluate aortic valve injuries according to echocardiographic screening. PATIENTS AND METHODS: This was a prospective multicenter registry (AVATAR, Aortic Cusp Ventricular Arrhythmias: Long Term Safety and Outcome from a Multicenter Prospective Ablation Registry) study. A total of 103 patients at a mean age of 56 years (34-64) from the "Electra" Registry (2005-2017) undergoing RFA of aortic cusps VA were enrolled. The following 3 ablation techniques were used: zero­fluoroscopy (ZF; electroanatomical mapping [EAM] without fluoroscopy), EAM with fluoroscopy, and conventional fluoroscopy­ based RFA. Data on clinical history, complications after RFA, echocardiography, and 24­ hour Holter monitoring were collected. The follow up was 12 months or longer. RESULTS: There were no major acute cardiac complications after RFA. In one case, a vascular access complication required surgery. The median (interquartile range [IQR]) procedure time was 75 minutes (IQR, 58-95), median follow­ up, 32 months (IQR, 12-70). Acute and long term procedural success rates were 93% and 86%, respectively. The long­ term RFA outcomes were observed in ZF technique (88%), EAM with fluoroscopy (86%), and conventional RFA (82%), without differences. During long­ term follow­up, no abnormalities were found within the aortic root. CONCLUSIONS: Ablation of VA within the aortic cusps is safe and effective in long­ term follow up. The ZF approach is feasible, although it requires greater expertise and more imaging modalities.

Risk of left atrial appendage thrombus in patients scheduled for ablation for atrial fibrillation: beyond the CHA2DS2VASc score.

INTRODUCTION: Atrial fibrillation (AF) increases the risk of thromboembolic events by promoting clot formation in the left atrial appendage (LAA). Transesophageal echocardiography (TEE) is routinely used to exclude the presence of an LAA thrombus before AF ablation. So far, it has not been established what is the optimal combination of noninvasive parameters for thromboembolic risk stratification in this setting and whether patients at very low risk require TEE. OBJECTIVES: The aim of the study was to assess predisposing factors for an LAA thrombus in patients scheduled for AF ablation and to identify those patients in whom preprocedural TEE is not necessary. PATIENTS AND METHODS: In consecutive 151 patients (107 men; mean age, 57 ±10 years) the type of AF and renal function were assessed in addition to the CHA2DS2VASc score to improve thromboembolic risk stratification. RESULTS: An LAA thrombus or dense echo contrast with a strong suspicion of a probable thrombus was detected in 15 patients (10%). Diabetes, age of 65 years or older, persistent AF, and estimated glomerular filtration rate (eGFR) of less than 60 ml/min/1.73 m2 were predictors of the LAA thrombus. A multivariate logistic regression analysis showed that only persistent AF and an eGFR of less than 60 ml/min/1.73 m2 were independent predictors of the LAA thrombus. The receiver operating characteristic curves showed that the greatest area under the curve (0.845) was achieved for the CHA2DS2VASc-AFR (CHA2DS2VASc plus the type of AF and renal function); the difference was not significant. A CHA2DS2VASc-AFR score of 2 or greater or a CHA2DS2VASc score of 1 or greater identified patients with the LAA thrombus with a sensitivity of 100% (and specificity of 54% and 36%, respectively). CONCLUSIONS: In patients scheduled for AF ablation, an LAA thrombus or dense echo contrast is a relatively common finding despite routine anticoagulant treatment. The addition of AF type and renal function to the CHA2DS2VASc score slightly improves thromboembolic risk stratification and may help identify patients who do not need preprocedural TEE.

Intracardiac echocardiography for immediate detection of intracardiac thrombus formation.

An 85-year-old man with persistent atrial flutter (AFL) with slow ventricular rate of 44/min, causing fatigue and presyncope, was referred for urgent treatment. In spite of thromboembolic risk scale value 4, he had not been treated with anticoagulants because of high risk of bleeding. The decision was made to perform urgent catheter ablation to interrupt and cure AFL. Intracardiac echocardiography probe was placed in the pulmonary artery and visualized left atrial appendage free from thrombus with its proper function. Heparin was administered and AFL stopped during energy application. Intracardiac echocardiography showed immediate thrombus formation in left atrial appendage owing to complete atrial standstill and no retrograde conduction during hemodynamically effective escape nodal rhythm. This case report shows that in patients with sinus node disease effective ablation of AFL with escape rhythm without retrograde conduction to the atria may result in complete 'electrically induced' atrial standstill and immediate thrombus formation.

Impact of radiofrequency catheter ablation on echocardiographic and cardiopulmonary performance in patients with ventricular extrasystolic beats and suspected arrhythmia-induced cardiomyopathy.

Integrated backscatter intravascular ultrasound (IB-IVUS) is a useful method for analyzing coronary plaque tissue. We evaluated whether tissue composition determined using IB-IVUS is associated with the progression of stenosis in coronary angiography. Sixty-three nontarget coronary lesions in 63 patients with stable angina were evaluated using conventional IVUS and IB-IVUS. IB-IVUS images were analyzed at 1-mm intervals for a length of 10 mm. After calculating the relative areas of the tissue components using the IB-IVUS system, fibrous volume (FV) and lipid volume (LV) were calculated through integration of the slices, after which percentages of per-plaque volume (%FV/PV, %LV/PV) and per-vessel volume (%FV/VV, %LV/VV) were calculated. Progression of coronary stenosis was interpreted from the increase in percent diameter stenosis (%DS) from baseline to the follow-up period (6­9 months) using quantitative coronary angiography. %DS was 24.1 ± 12.8 % at baseline and 23.2 ± 13.7 % at follow-up. Using IB-IVUS, LV was 31.7 ± 10.5 mm3, and %LV/PV and %LV/VV were 45.6 ± 10.3 % and 20.2 ± 6.0 %, respectively. FV, %FV/PV, and %FV/VV were 35.5 ± 12.1 mm3, 52.1 ± 9.5 %, and 23.4 ± 7.1 %, respectively. The change in %DS was −0.88 ± 7.25 % and correlated closely with %LV/VV (r = 0.27, P = 0.03) on simple regression. Multivariate regression after adjustment for potentially confounding risk factors showed %LV/VV to be correlated independently with changes in %DS (r = 0.42, P = 0.02). Logistic regression analysis after adjusting for confounding coronary risk factors showed LV (odds ratio 1.08; 95 % confidence interval 1.01­1.16; P = 0.03) and %LV/VV (odds ratio 1.13; 95 % confidence interval 1.01­1.28; P = 0.03) to be independent predictors of the progression of angiographic coronary stenosis. Our findings suggest that angiographic luminal narrowing of the coronary artery is likely associated with tissue characteristics. IB-IVUS may provide information about the natural progression of luminal narrowing in coronary stenosis.

Antazoline for rapid termination of atrial fibrillation during ablation of accessory pathways.

BACKGROUND AND AIM: To assess safety and efficacy of antazoline for termination of atrial fibrillation (AF) occurring during ablation of accessory pathways (AP). METHODS: We analyzed electrophysiological mechanism of antazoline (changes in A-A interval) and the percentage of pre-excited QRS complexes before and after antazoline administration. The total dose administered and the time from the start of injection to sinus rhythm restoration were also measured. RESULTS: Out of consecutive 290 patients with Wolff-Parkinson-White syndrome undergoing radiofrequency (RF) ablation, 12 (4.1%) (4 females, mean age 36 ± 20 years) developed sustained AF which did not stop spontaneously within 10 min, and antazoline in 100 mg repeated boluses was administered. In all 12 patients the drug restored sinus rhythm after a mean of 425 ± 365 s (range 43-1245 s) using a mean cumulative dose of 176 ± 114 mg (range 25-400 mg). The drug slightly prolonged R-R intervals during AF (from 383 ± 106 to 410 ± 70 ms) and reduced the percentage of fully pre-excited QRS complexes (from 35% to 26%). Intracardiac recordings showed gradual increase in A-A intervals, as well as regularization and decreasing fractionation of atrial activity following drug injection (mean A-A interval of 162 ± 30 ms at baseline vs. 226 ± 26 ms shortly before sinus rhythm restoration, p < 0.001). AP was not completely blocked in any patient which enabled continuation of ablation. CONCLUSIONS: Antazoline safely and rapidly converts AF into sinus rhythm during ablation of AP. The drug does not block AP completely, enabling continuation of ablation. The drug converting AF into more organized atrial activity (atrial flutter/tachycardia) before sinus rhythm resumption.

Intracardiac echocardiography for detection of thrombus in the left atrial appendage: comparison with transesophageal echocardiography in patients undergoing ablation for atrial fibrillation: the Action-Ice I Study.

BACKGROUND: Transesophageal echocardiography (TEE) is the gold standard for the exclusion of thrombi in the left atrial appendage (LAA) before ablation for atrial fibrillation. Intracardiac echocardiography (ICE) is used to assist atrial fibrillation ablation; however, it can also be used for LAA imaging. The aim of our study was to determine whether ICE could replace TEE and to identify the optimal ICE placement for LAA visualization. METHODS AND RESULTS: Seventy-six consecutive patients (56 men; mean age, 55±9.6 years) scheduled for atrial fibrillation ablation underwent TEE before the procedure and LAA assessment by ICE. An 8F AcuNav probe was introduced into right atrium, pulmonary artery, and coronary sinus. LAA structure was analyzed by the echocardiographer and electrophysiologist who were blinded to the results of TEE. ICE probe was positioned in the right atrium in all patients, in the pulmonary artery in 64 of 74 (86%) patients, and in the coronary sinus in 49 of 74 (66%) patients. The LAA was properly visualized in 56 of 64 (87.5%) patients from the pulmonary artery versus 13 of 49 (26%) patients from the coronary sinus (P<0.001). From the right atrium, the whole LAA cavity could not be seen in any patient. In those patients in whom LAA was visualized properly by ICE, a perfect agreement between ICE and TEE was obtained (both techniques detected LAA thrombus in 2 patients and excluded LAA thrombus in the remaining patients). CONCLUSIONS: ICE can be used safely and effectively for the evaluation of LAA in patients undergoing atrial fibrillation ablation. ICE imaging from pulmonary artery is accurate for LAA visualization. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01371279.

Ablation of atrioventricular nodal reentrant tachycardia: predictors of long-term success.

BACKGROUND: Atrioventricular nodal reentrant tachycardia (AVNRT) is the commonest regular supraventricular tachyarrhythmia. Ablation in the area of slow pathway (SP) has been successfully implemented in everyday clinical electrophysiological practice for more than 20 years. Although the procedure is generally regarded as effective and safe, data on long-term effects and predictors of success or failure are incomplete. AIM: To identify predictors of successful AVNRT ablation. METHODS: The study group consisted of 359 patients (105 males, mean age 51.1 ± 16.7 years) who underwent AVNRT radiofrequency ablation using typical combined electrophysiological and anatomical approach. RESULTS: Acute success was achieved in 342 (95%) patients, including 187 (52%) with SP ablation and 155 (43%) with SP modification. Patients with SP modification were younger, had shorter AVNRT cycle length, less often had typical echo, and had more frequent isoproterenol usage after ablation. Long-term follow-up data was available for 308 patients (86% of the total study group). During the mean follow-up of 52.9 ± 27.3 months (median 48, range 12-130 months), 22 patients experienced AVNRT recurrences (long-term efficacy 93%). These patients had less often complete SP abolition than SP modification (27% vs. 56%, p < 0.001) and typical jump (vs. no jump or multiple jumps) at baseline (74% vs. 89%, p < 0.06) than patients without recurrences. Multivariate Cox regression analysis showed that typical jump was associated with a favourable outcome (HR 5.8, 95% CI 0.44-3.1, p = 0.0089). There were no significant differences in the use of 2 or > 2 electrode approaches between patients with or without AVNRT recurrences. CONCLUSIONS: Typical jump and complete SP elimination are associated with a better outcome. A 2-electrode approach is as effective as > 2 electrode approach. The electrophysiological profile of patients in whom complete SP elimination was achieved may differ from that of patients in whom only SP modification was possible.