Residual echocardiographic and computed tomography findings after thoracoscopic occlusion of the left atrial appendage using the AtriClip PRO device.

OBJECTIVES: Thoracoscopic occlusion of the left atrial appendage (LAA) has become a routine part of thoracoscopic ablation for the treatment of atrial fibrillation (AF). Evaluation of residual findings of the occluded LAA by echocardiography has yet to be described. METHODS: Patients with AF indicated for hybrid ablation (thoracoscopic procedure followed by catheter ablation) were enrolled in this study. LAA was occluded as a routine part of the thoracoscopic procedure. Follow-up transoesophageal echocardiography was performed at the end of the procedure, 2-5 days and 2-3 months after the procedure (before the endocardial stage). The residual pouches of the LAA were measured in the mitral valve view (30-110°) and in the perpendicular view. The depth of the residual pouch was measured from the ostial plane (connecting the Coumadin ridge and the circumflex artery) to the deepest part of the residuum. The volume of the residual pouch and the distance from the circumflex artery to the proximal and the distal ends of the AtriClip were measured using computed tomography. RESULTS: Forty patients were enrolled in this study. The success rate for the occlusion of the LAA, assessed on transoesophageal echocardiography 2-5 days after surgery, was 97.5%. Regarding the residual findings, no reperfused LAAs were found, and only residual stumps remained. The depth of the stump was 12.9 ± 5.9 mm, the area was 2.2 ± 1.1 cm2, and the volume was 3.6 ± 1.9 ml (all data are shown as mean ± standard deviation). CONCLUSIONS: The occlusion of the LAA using an AtriClip PRO device was a clinically safe procedure with high efficacy and was associated with the presence of a small residual pouch after occlusion. Clinical trial registration: NCT02832206.

Two-staged hybrid ablation of non-paroxysmal atrial fibrillation: clinical outcomes and functional improvements after 1 year.

OBJECTIVES: Hybrid ablation of atrial fibrillation (AF) is a promising treatment strategy; however, data regarding its efficacy and safety are still limited. METHODS: Patients with non-paroxysmal AF were enrolled. First, a thoracoscopic, epicardial isolation of pulmonary veins and the left atrial posterior wall ('box lesion') was performed; a novel unipolar/bipolar radiofrequency device was used. Moreover, in 12 patients enrolled thereafter, the left atrial appendage was occluded. Electrophysiological evaluation and catheter ablation were performed 2-3 months later, with the goal of verifying or completing (if needed) the box lesion and ablation of the ganglionated plexi and the cavotricuspid isthmus. Outcomes were assessed using 1-week and 24-h Holter monitoring, repeated echocardiography and laboratory measurements. RESULTS: Thirty-eight patients (13 persistent and 25 long-standing persistent AF) were enrolled with a mean AF duration of 33 ± 32.9 months. The procedure was successfully completed in 35 patients; 3 patients underwent only the surgical part because of a postoperative left atrial appendage thrombus (2 patients) and perioperative stroke (1 patient). After 6 months, 30 (86%) patients were arrhythmia-free, whereas 80% were also off antiarrhythmics. After 1 year, 28 (82%) patients were arrhythmia-free, 79% were off anti-arrhythmics and 47% were off anticoagulation treatment. Four (10.5%) serious postoperative complications occurred, including 1 stroke, 1 right phrenic nerve palsy and 2 pneumothoraxes with a need for drainage. Significant improvements were observed in echocardiographic, functional and serological parameters. CONCLUSIONS: Hybrid ablation is an effective treatment strategy for patients with persistent or long-standing persistent AF. Over 80% of patients were arrhythmia-free 1 year after the procedure. Sinus rhythm restoration was accompanied by improvements in functional, echocardiographic and serological markers.

Routine use of intracardiac echocardiography for atrial flutter ablation is associated with reduced fluoroscopy time, but not with a reduction of radiofrequency energy delivery time.

BACKGROUND: The ablation of cavotricuspid-isthmus (CTI) atrial flutter (AFL) dependent atrial flutter could be difficult in patients with complex anatomy of the CTI.The aim of the study was to assess whether the use of intracardiac echocardiography (ICE) was associated with less fluoroscopy time and faster ablations of cavotricuspid isthmus dependent atrial flutter (CTI-AFL). METHODS: Patients with an indication for an ablation of a CTI-AFL were enrolled. Patients in which ablation of a CTI-AFLas part of an atrial fibrillation ablation were not included. Randomization was done using the envelope method. Standard techniques (i.e., coronary sinus, 20-polar halo catheter, and an ablation catheter), and criteria of success (bidirectional block through the CTI) were used. In patients randomized to the ablation with ICE, a 10F AcuNav ICE probe (Siemens, Germany)was used. RESULTS: Seventy-nine patients were enrolled; 40 were randomized to ablation with ICE and 39 without ICE. The X-ray exposure was shorter (3.29±2.6 vs. 5.94±3.43 min, p<0.001) and total X-ray dose was reduced (3.30±1.98 vs. 6.68±5.25 Gy.cm2, p<0.001) in the ICE group. However, the total RF energy ablation time was not different between groups (ICE group: 604.56±380.46sec vs. 585.82±373.39 sec, p=0.8). The procedure duration was slightly longer in the ICE group (82.0±20.8 vs. 72.1±19.0 min, p=0.03). Procedural success was 100% (40/40) in the ICE group and 95% (37/39) in the control group. Two control patients required crossover to ICE at a prespecified point to achieve bidirectional block. There were two femoral hematomas in the ICE group and one in the control group. CONCLUSION: The use of ICE for atrial flutter ablation is associated with less fluoroscopy time and improved ability to achieve bidirectional block compared to traditional conventional flutter ablation methods. However, it is not asoociated with reduced ablation time or overall procedure duration.

Midterm outcomes of two-staged hybrid ablation of persistent and long-standing persistent atrial fibrillation using the versapolar epicardial surgical device and subsequent catheter ablation.

PURPOSE: Hybrid ablation of atrial fibrillation (AF) is a promising treatment strategy for patients with non-paroxysmal AF, although, data regarding mid-term outcomes are limited. METHODS: Patients with persistent or long-standing persistent AF were enrolled. Initially, a thoracoscopic, right-sided, epicardial ablation was performed, with a goal of creating a box lesion on the posterior wall of the left atrium; a novel versapolar radiofrequency (RF) catheter was used. In patients enrolled later, occlusion of the left atrial appendage was also performed. An endocardial procedure was performed 2-4 months later, with the goal of confirming/completing the box lesion and ablating the ganglionated plexi and cavotricuspid isthmus. Efficacy was assessed using multiple 24-h and 1-week Holter monitoring. Analysis was performed to search for variables associated with procedure's failure. RESULTS: Forty-one patients (14 persistent and 27 long-standing persistent AF) were enrolled with a mean AF duration of 33.5 ± 33.1 months. Mean follow-up was 507.2 ± 201.1 days (180-731). At the last follow-up visit, 27(65%) patients were arrhythmia-free, without anti-arrhythmics or need for re-ablation. Additional 4 patients (9.8%) were in sinus rhythm (SR) following re-ablation of postprocedural peri-mitral flutter and 4 (9.8%) were in SR on anti-arrhythmics. Longer periods of preoperative AF were independently associated with worse arrhythmia-free survival (p = 0.015). Serious postoperative complications occurred in 3 (7.3%) patients; only 1 (2.4%) patient had clinical consequences after 6 months. CONCLUSIONS: Hybrid ablation of non-paroxysmal AF using a novel, versapolar RF device yields promising mid-term results. Better arrhythmia-free survival rates were found in AF patients with shorter AF duration.

The absence of effect of ganglionated plexi ablation on heart rate variability parameters in patients after thoracoscopic ablation for atrial fibrillation.

BACKGROUND: Hybrid ablation [thoracoscopic ablation (TA) of atrial fibrillation (AF) followed by catheter ablation (CA)] is an increasingly common method of the treatment for patients with AF. The aim of this study was to assess the response to ganglionated plexi (GP) ablation in patients with a previous TA (i.e., to assess whether TA had resulted in damage to the GP. Heart rate variability (HRV) was used as a marker of the autonomic response. METHODS: Twenty AF patients underwent pulmonary vein isolation (PVI) plus GP ablation (GP group) and 18 AF patients underwent CA including GP ablation as a part of hybrid ablation (i.e., all patients had undergone a previous TA; Hybrid group). In each group, a 5 min electrocardiogram (ECG) obtained before and after the CA were analyzed. Time and frequency domain parameters were evaluated. RESULTS: Vagal responses (VR) during CA were observed in 12 (60%) patients in the GP group; however, in the Hybrid group, VR was not observed in any of the patients during CA. The change in normalized power in the low frequency (LF) component and the ratio between the LF and high frequency (LF/HF ratio) components of the HRV spectra, before and after ablation, were statistically significant in the GP group (3.3±2.6 before vs. 1.8±1.9 after ablation) but unchanged, before or after CA, in the Hybrid group. CONCLUSIONS: GP ablation in patients subsequent to TA has a little influence on HRV parameters, which could be explained by GP damage during the preceding TA.

Electrophysiological findings after surgical thoracoscopic atrial fibrillation ablation.

BACKGROUND: Hybrid ablation (a combination of thoracoscopic epicardial ablation and catheter ablation) has become a new technique for atrial fibrillation treatment. OBJECTIVE: The goal of this study was to evaluate the success and electrophysiological follow-up after using the COBRA Fusion device to deliver a circumferential lesion set anterior to the pulmonary veins in an attempt to isolate the posterior left atrium (box isolation). METHODS: Surgical ablation was carried out via a thoracoscopic approach using the COBRA Fusion radiofrequency catheter. An electrophysiology study was done 2-3 months later to verify box isolation (and to complete it, if needed) and to perform right-sided isthmus ablation. Fat thickness along the presumed box lesion line was measured using preprocedural computed tomography. RESULTS: Thirty patients (mean age 60.0 ± 11.6 years; 22 men; 8 with long-standing persistent AF and 22 with persistent atrial fibrillation) were enrolled. The duration of the EP study was 216.3 ± 64.2 minutes. Box isolation, based on the EP study, was complete in 12 patients (40%) and incomplete in 18 patients (60%). Successful box isolation was achieved with catheter ablation in 16 of 18 patients (89%). A total of 39 gaps in these 16 patients were identified. Typical gap locations were the anterior-superior part of the superior pulmonary veins and the roofline. Fat thickness along the roofline was substantially higher than that along the inferior line (4.58 ± 1.61 mm vs 2.37 ± 0.76 mm; P < .001). CONCLUSION: There is a relatively low rate of complete isolation using the COBRA catheter ablation system. The superior line and anterior parts of superior pulmonary veins have most conduction gaps.

Double-gap-in-roof reentrant tachycardia following surgical thoracoscopic atrial fibrillation ablation.

A case of macro-reentrant tachycardia associated with a box lesion after thoracoscopis left atrial surgical atrial fibrillation (AF) ablation yet to be described. The goal was to clarify the mechanisms and electrophysiological characteristics of this type of tachycardia. A patient was admitted for an EP study following surgical thoracoscopic AF ablation (box lexion formation by right-sided Cobra thoracoscopic ablation). Thoracoscopic ablation was done as the first step of the hybrid ablation approach to the persistent AF; the second step was the EP study. At the EP study, he presented with incessant regular tachycardia (cycle length of 226 ms). An EP study with conventional, 3D activation and entrainment mapping was done to assess the tachycardia mechanism. Two conduction gaps in the superior line (roofline) between the superior pulmonary veins were discovered. The tachycardia was successfully treated with a radiofrequency application near the gap close to the left superior pulmonary vein; however, following tachycardia termination, pulmonary vein isolation was absent. A second radiofrequency application, close to the roof of the right superior pulmonary, vein closed the gap in the box and led to the isolation of all 4 pulmonary veins. No atrial tachycardia recurred during the 6-month follow-up. Conduction gaps in box lesion created by thoracospcopic ablation can present as a novel type of man-made tachycardia after surgical ablation of atrial fibrillation. Activation and entrainment mapping is necessary for an accurate diagnosis.