Fabien Squara

Comparison between radiofrequency with contact force-sensing and second-generation cryoballoon for paroxysmal atrial fibrillation catheter ablation: a multicentre European evaluation

AIMS Whether pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (PAF) using contact force (CF)-guided radiofrequency (RF) or second-generation cryoballoon (CB) present similar efficacy and safety remains uncertain. METHODS AND RESULTS We performed a multicentre study comparing procedural safety and arrhythmia recurrence after standardized PVI catheter ablation for PAF using CF-guided RF ablation (Thermocool(®) SmartTouch™, Biosense Webster; or Tacticath™, St Jude Medical) (CF group) with second-generation CB ablation (Arctic Front Advance™, Medtronic) (CB group). Overall, 376 patients (mean age 59.8 ± 10.4 years, 280 males) were enrolled in 4 centres: 198 in CF group and 178 in CB group. Procedure was shorter for CB group than for CF group (109.6 ± 40 vs. 122.5 ± 40.7 min, P = 0.003), but fluoroscopy duration and X-ray exposure were not statistically different (P = 0.1 and P = 0.22, respectively). Overall complication rate was similar in both groups: 14 (7.1%) in the CF group vs. 13 (7.3%) in the CB group (P = 0.93). However, transient right phrenic nerve palsy occurred only in CB group (10 patients, 5.6%; P = 0.001 vs. CF group) and severe non-lethal complications (embolic event, tamponade, or oesophageal injury) occurred only in CF group (5 patients, 2.5%; P = 0.03 vs. CB group). No periprocedural death occurred in either group. Single-procedure freedom from any atrial arrhythmias at 18 months post-ablation was comparable in CF group and CB group (76 vs. 73.3%, respectively, log rank P = 0.63). CONCLUSION Pulmonary vein isolation using CF-guided RF and second-generation CB leads to comparable single-procedure arrhythmia-free survival at up to 18 months with similar overall complication rate.

Ventricular premature depolarization QRS duration as a new marker of risk for the development of ventricular premature depolarization-induced cardiomyopathy

BACKGROUND Frequent ventricular premature depolarizations (VPDs) can cause cardiomyopathy (CMP). The mechanisms underlying its development remain unclear, with VPD burden being only a weak predictor of risk. OBJECTIVE To determine whether VPD QRS duration at the time of initial presentation could predict risk for the subsequent development of CMP in patients with normal left ventricular ejection fraction (LVEF). METHODS From consecutive patients referred for ablation between January 1, 2006, and April 2, 2013, with ≥10% VPDs on 24-hour Holter monitoring, we identified 45 patients with normal LVEF and an electrocardiogram of the targeted VPD, who were then followed for at least 6 months (median 14 months; interquartile range [IQR] 8-32 months) before intervention. We excluded patients with structural or genetic heart disease. RESULTS Of the 45 patients, 28 (62%) maintained normal LVEF and 17(38%) developed VPD-induced CMP. VPD burden was similar (26.5% [IQR 19.3%-39.5%] vs 26.0% [IQR 16.4%-41.0%]; P = 0.4) between the 2 groups. Patients who developed VPD-induced CMP had significantly longer VPD QRS duration (159 ms vs 142 ms; P < .001) and a longer sinus QRS duration (97 ms vs 89 ms; P = .04). A VPD QRS duration of ≥153 ms best predicted development of VPD CMP (82% sensitivity and 75% specificity). Longer VPD QRS duration and a non-outflow tract site of VPD origin were independent risk factors for left ventricular dysfunction after multivariate analysis. CONCLUSION VPD QRS duration longer than 153 ms and a non-outflow tract site of origin might be useful predictors of the subsequent development of VPD-induced CMP.

Scar progression in patients with nonischemic cardiomyopathy and ventricular arrhythmias

BACKGROUND Disease progression in patients with nonischemic cardiomyopathy (NICM) is poorly understood. OBJECTIVE To assess left ventricular (LV) scar progression and dilatation by using endocardial electroanatomic mapping. METHODS We studied 13 patients with NICM and recurrent ventricular tachycardia. Two detailed sinus rhythm endocardial voltage maps (265 ± 122 points/map) were obtained after a mean of 32 months (range 9-77 months). The scar area, defined by low bipolar (BI; <1.5 mV) and unipolar (UNI; <8.3 mV) endocardial voltage, and the LV volume were measured and compared. A scar difference of >6% of the LV surface and an increase in LV volume of ≥20 mL were considered beyond measurement error. RESULTS Six (46%) patients had an increase in scar area beyond boundaries of prior ablation. Five patients had an increase in UNI and 1 patient had an increase in both BI and UNI areas. The increase in BI area represented 16% and the increase in UNI area represented 6.5%-46.2% of the LV surface. A significant decrease in LV ejection fraction was found only in patients with scar progression (from 39% ± 8% to 32% ± 8%; P = .003). LV dilation (LV volume increase ranging between 9% and 23%) was noted in 3 patients, all of whom had scar progression. CONCLUSIONS Progressive scarring with an increase in the area of UNI and less commonly BI electrogram abnormality is seen in 46% of the patients with NICM and ventricular tachycardia and is associated with LV dilatation and decrease in LV ejection fraction. The prominent UNI abnormality suggests predominantly midmyocardial or epicardial scarring.

Electroanatomic characteristics of the mitral isthmus associated with successful mitral isthmus ablation

AIMS The success of mitral isthmus (MI) ablation has been related to CT scan defined MI anatomy. We sought to correlate electroanatomical MI characteristics with MI ablation success in patients with perimitral flutter (PMF). METHODS AND RESULTS In 53 consecutive patients (46 males, 61 ± 10 years) with PMF, MI was ablated with endocardial ± coronary sinus (CS) linear radiofrequency (RF) ablation lesion. Acute (termination of PMF during ablation) and long-term procedural success were studied. Mitral isthmus characteristics (thickness--minimal endocardial to CS distance, length, maximal MI bipolar voltage), as well as MI ablation line length and width, RF duration, and delivered energy were analysed. In 43 of the 53 patients (81%), acute success was observed. This was more frequently achieved in patients with thinner MI (2.4 ± 3.1 vs. 7 ± 3.2 mm; P = 0.0009). Mitral isthmus thickness predicted ablation failure with a ROC area of 0.84. The best threshold to predict MI ablation failure was 8.3 mm with a sensitivity of 67% and a specificity of 97%. Left atrial size was of greater importance in failed cases (2D echo surface: 24.1 ± 2.5 vs. 32.5 ± 6.9 cm2, P = 0.005; electroanatomic volume: 124 ± 32 vs. 165 ± 23 mL, P = 0.02). None of the other electroanatomical characteristics were associated with outcome. After a mean follow-up of 28 ± 15 months, 21 patients (39%) had atrial fibrillation (AF) or atypical flutter (PMF recurrence in four). CONCLUSION Smaller MI thickness is associated with acute success in PMF ablation. Mitral isthmus electroanatomical characteristics might be used for decision-making on strategy during persistent AF ablation and for selecting the best location for interrupting PMF.

Self-taught axillary vein access without venography for pacemaker implantation: prospective randomized comparison with the cephalic vein access

Aim Axillary vein access for pacemaker implantation is uncommon in many centres because of the lack of training in this technique. We assessed whether the introduction of the axillary vein technique was safe and efficient as compared with cephalic vein access, in a centre where no operators had any previous experience in axillary vein puncture. Methods and results Patients undergoing pacemaker implantation were randomized to axillary or cephalic vein access. All three operators had no experience nor training in axillary vein puncture, and self-learned the technique by reading a published review. Axillary vein puncture was fluoroscopy-guided without contrast venography. Cephalic access was performed by dissection of delto-pectoral groove. Venous access success, venous access duration (from skin incision to guidewire or lead in superior vena cava), procedure duration, X-ray exposure, and peri-procedural (1 month) complications were recorded. results We randomized 74 consecutive patients to axillary (n = 37) or cephalic vein access (n = 37). Axillary vein was successfully accessed in 30/37 (81.1%) patients vs. 28/37 (75.7%) of cephalic veins (P = 0.57). Venous access time was shorter in axillary group than in cephalic group [5.7 (4.4-8.3) vs. 12.2 (10.5-14.8) min, P < 0.001], as well as procedure duration [34.8 (30.6-38.4) vs. 42.0 (39.1-46.6) min, P = 0.043]. X-ray exposure and peri-procedural overall complications were comparable in both groups. Axillary puncture was safe and faster than cephalic access even for the five first procedures performed by each operator. Conclusion Self-taught axillary vein puncture for pacemaker implantation seems immediately safe and faster than cephalic vein access, when performed by electrophysiologists trained to pacemaker implantation but not to axillary vein puncture.

Three-dimensional right-ventricular regional deformation and survival in pulmonary hypertension

Aims Survival in pulmonary hypertension (PH) relates to right ventricular (RV) function. However, the RV unique anatomy and structure limit 2D analysis and its regional 3D function has not been studied yet. The aim of this study was to assess the implications of global and regional 3D RV deformation on clinical condition and survival in adults with PH and healthy controls. Methods and results We collected a prospective longitudinal cohort of 104 consecutive PH patients and 34 healthy controls between September 2014 and December 2015. Acquired 3D transthoracic RV echocardiographic sequences were analysed by semi-automatic software (TomTec 4D RV-Function 2.0). Output meshes were post-processed to extract regional motion and deformation. Global and regional statistics provided deformation patterns for each subgroup of subjects. RV lateral and inferior regions showed the highest deformation. In PH patients, RV global and regional motion and deformation [both circumferential, longitudinal, and area strain (AS)] were affected in all segments (P < 0.001 against healthy controls). Deformation patterns gradually worsened with the clinical condition. Over 6.7 [5.8-7.2] months follow-up, 16 (15.4%) patients died from cardio-pulmonary causes. Right atrial pressure, global RV AS, tricuspid annular plane systolic excursion, 3D RV ejection fraction, and end-diastolic volume were independent predictors of survival. Global RV AS  > -18% was the most powerful RV function parameter, identifying patients with a 48%-increased risk of death (AUC 0.83 [0.74-0.90], P < 0.001). Conclusion Right ventricular strain patterns gradually worsen in PH patients and provide independent prognostic information in this population.

Effects of Age‐Related Aortic Root Anatomic Changes on Left Ventricular Outflow Tract Pace‐Mapping Morphologies: A Cardiac Magnetic Resonance Imaging Validation Study

Outflow tract ventricular arrhythmias (OT VAs) are common and catheter ablation is an effective treatment option. We sought to investigate the relationship between age‐related anatomic aortic root changes and QRS morphology during left ventricular outflow tract (LVOT) pace‐mapping using cardiac magnetic resonance (CMR) imaging.

Electrical connection between ipsilateral pulmonary veins: Prevalence and implications for ablation and adenosine testing

BACKGROUND Anatomic studies have reported the presence of shared myocardial fibers between approximately half of ipsilateral pulmonary veins (IPVs). OBJECTIVE The purpose of this study was to assess the prevalence of electrical connection between IPVs and the impact of antral isolation with or without carina ablation on IPV connection. METHODS Thirty consecutive patients undergoing atrial fibrillation (AF) ablation (14 redo) were included. Wide antral pulmonary vein isolation (PVI) was performed with or without carina lesions. For each PV set, IPV electrical connection was assessed before and after PVI by pacing and recording from the ostium of both IPVs using a circular mapping catheter and the ablation catheter. Adenosine was given after PVI to assess for acute PV reconnection. RESULTS Before PVI without preceding AF ablation procedure, all the PVs had ipsilateral connection albeit frequently via the left atrium. After PVI, 65.6% of the IPVs were connected without carina ablation vs 17.7% if prior carina ablation (P = .001). Left vs right IPVs were connected in 57.1% and 72.2% of the cases without carina ablation, respectively, vs 30% and 0% of cases with carina ablation (P = .19 and P = .001). When transient PV reconnection was demonstrated during adenosine challenge, connected IPVs uniformly demonstrated simultaneous reconnection. CONCLUSION Electrical connection between IPVs is uniformly demonstrated before any ablation. Two-thirds of the IPVs are connected after antral PVI, and carina ablation decreases IPV connection. Connected IPVs consistently show the same response to adenosine challenge; therefore, a single catheter positioned in either of the IPVs with electrical connection is sufficient to confirm reconnection in both veins.

Two-year clinical outcome after a single cryoballoon ablation procedure: A comparison of first- and second-generation cryoballoons

BACKGROUND The ablation of paroxysmal atrial fibrillation (PAF) by cryoballoon has increased dramatically in recent years. However, there are few data comparing first- and second-generation cryoballoons. AIM To compare safety and mid-term (2-year) efficacy of first- and second-generation cryoballoons in PAF ablation, using cryoballoon size tailored to pulmonary vein anatomy. METHODS In this single-centre study, we included the last 50 consecutive PAF patients who underwent cryoballoon-based pulmonary vein isolation using the first-generation cryoballoon (CB-1) and the first 50 patients using the second-generation cryoballoon (CB-2). The choice of 23 or 28mm cryoballoon was driven by patient anatomy. After discharge, follow-up was with systematic outpatient visits at 3, 6, 9, 12 and 24 months, including 12-lead electrocardiogram, Holter monitoring and telephone interviews, plus additional electrocardiograms, as required, in case of symptoms. Arrhythmia recurrence was defined as a documented atrial tachycardia or fibrillation episode>30seconds after a 3-month blanking period. RESULTS At 24 months, freedom from arrhythmia after a single procedure was similar for both generations of cryoballoon (72.0% and 72.0% for CB-1 and CB-2, respectively; P=0.95). Mean procedure and fluoroscopy times were longer in the CB-1 group than in the CB-2 group: 139±37.8 vs 95.2±21.3minutes and 10.2±7.2 vs 5.1±2.4minutes, respectively (P<0.02 for both). Transient right phrenic nerve palsy occurred only in the CB-1 group (five patients, 9.8%). CONCLUSIONS CB-1 and CB-2 showed similar efficacy for PAF ablation, with similar arrhythmia recurrence 24 months after a single ablation procedure. However, our findings suggest that CB-2 may have more effective cooling capabilities, enabling shorter procedure and fluoroscopy times.

Loss of local capture of the pulmonary vein myocardium after antral isolation : prevalence and clinical significance.

Capture of the myocardial sleeves of the pulmonary veins (PV) during PV pacing is mandatory for assessing exit block after PV isolation (PVI). However, previous studies reported that a significant proportion of PVs failed to demonstrate local capture after PVI. We designed this study to evaluate the prevalence and the clinical significance of loss of PV capture after PVI.