Freedom from pulmonary vein stenosis after multiple applications of epicardial ablation energy.

OBJECTIVES: In patients undergoing cardiac surgical procedures, pulmonary vein isolation may be easily accomplished, and it is important to achieve bidirectional conduction block across created lesions. The primary aim of this study was to assess the risk of pulmonary vein stenosis (PVS) after multiple applications of epicardial bipolar radiofrequency energy. METHODS: Thirty-five consecutive patients who were referred for off-pump coronary revascularization with concomitant pulmonary vein isolation and left atrial appendage occlusion were prospectively included in the study. The ablation protocol provided 8 standard epicardial applications of bipolar energy with additional applications until the acute bidirectional conduction block was achieved. Three to 6 months after surgery, patients underwent computed tomography to assess PVS. RESULTS: In all patients, bidirectional conduction block was achieved across the created lesions. In 31 (89%) patients, conduction block was accomplished after the standard 8 energy applications on each side. In 4 (11%) patients, additional applications of energy were needed. All patients had computed tomography (128 total pulmonary veins) scans, which showed no evidence of PVS. CONCLUSIONS: Multiple applications of bipolar radiofrequency energy during off-pump epicardial pulmonary vein isolation did not lead to PVS. Creating bidirectional conduction block using multiple energy applications through created lesions is feasible in all patients using the ablation protocol described.

Intraoperative epicardial focal pulmonary venous electrocardiography in patients with atrial fibrillation.

OBJECTIVES: In patients referred to off-pump coronary artery bypass grafting, pulmonary vein isolation (PVI) may be used for those with persistent atrial fibrillation (AF), an alternative to the Maze procedure. However, the success rate of PVI in persistent AF is limited. The study assesses the prognostic value of focal epicardial electrocardiography of the pulmonary veins (PVs) for surgical ablation results. METHODS: We mapped 140 PV in 35 cases undergoing off-pump coronary artery bypass grafting. Data obtained using a sensing-pacing probe before ablation were analysed. The composite study end-point consisted of the need for electrical cardioversion for in-hospital recurrence of AF and the presence of AF at hospital discharge and after 6 months follow-up confirmed by 24-h Holter electrocardiographic monitoring. RESULTS: In patients with epicardial far-field (FF) signals recorded over at least 1 PV, the composite end-point occurred in 61% (14) vs 25% (3) of patients with no FF signal recorded over any PV (P = 0.04). The presence of FF signals in at least 1 PV significantly increased the risk of composite end-point occurrence (odds ratio 3; P = 0.04). The composite end-point occurred in 86% (6) of patients with FF signals recorded over all PVs and in 39% (11) in the remainder of the study population (P = 0.03). CONCLUSIONS: Intraoperative epicardial focal electrocardiography of PVs revealed more than 40% of PVs had only FF atrial signals. The presence of FF signals in PVs is related to a lower early effectiveness of PVI on ablating AF. Epicardial focal electrocardiography of PVs may be a clinically effective intraoperative tool in the decision-making process between less invasive PVI and the standard Maze procedure.

Left Atrial Ganglionated Plexi Detection is Related to Heart Rate and Early Recurrence of Atrial Fibrillation after Surgical Ablation.

INTRODUCTION:: Left atrial ganglionated plexi ablation is an adjuvant technique used to increase the success rate of surgical ablation of atrial fibrillation. Ganglionated plexi ablation requires previous detection. We aimed to assess determinants of successful ganglionated plexi detection and to correlate range of ganglionated plexi ablation with risk of early atrial fibrillation recurrence. METHODS:: The study involved 34 consecutive patients referred for surgical coronary revascularization with concomitant atrial fibrillation ablation. Ganglionated plexi detection was done by inducing vagal reflexes in the area of the pulmonary veins and left atrial fat pads. RESULTS:: Detection of GP was successful in 85% of the patients. There was no difference in preoperative characteristics nor in atrial fibrillation type between patients in whom ganglionated plexi detection was successful and others. The number of detected ganglionated plexi correlated significantly only with preoperative resting heart rate. Significant negative correlation was found in patients with preoperative heart rate>75 beat/min in terms of total number of detected ganglionated plexi (P=0.04). Average number of detected ganglionated plexi was significantly higher in patients with in-hospital atrial fibrillation recurrence requiring electrical cardioversion (3.8±3) in comparison to rest of the study population (2±1.3; P=0.02). In patients in whom 4 or more ganglionated plexi were detected, significantly increased risk of in-hospital atrial fibrillation recurrence was observed (OR 15; 95% CI 1.5-164; P=0.003). CONCLUSION:: Left atrial ganglionated plexi detection was unsuccessful in a considerable percentage of patients. Preoperative heart rate significantly influenced positive ganglionated plexi detection and number of ablated ganglia. Higher number of detected ganglionated plexi was related with early recurrence of atrial fibrillation.

Left atrial ganglionated plexi detection is related to heart rate and early recurrence of atrial fibrillation after surgical ablation

Abstract INTRODUCTION: Left atrial ganglionated plexi ablation is an adjuvant technique used to increase the success rate of surgical ablation of atrial fibrillation. Ganglionated plexi ablation requires previous detection. We aimed to assess determinants of successful ganglionated plexi detection and to correlate range of ganglionated plexi ablation with risk of early atrial fibrillation recurrence. METHODS: The study involved 34 consecutive patients referred for surgical coronary revascularization with concomitant atrial fibrillation ablation. Ganglionated plexi detection was done by inducing vagal reflexes in the area of the pulmonary veins and left atrial fat pads. RESULTS: Detection of GP was successful in 85% of the patients. There was no difference in preoperative characteristics nor in atrial fibrillation type between patients in whom ganglionated plexi detection was successful and others. The number of detected ganglionated plexi correlated significantly only with preoperative resting heart rate. Significant negative correlation was found in patients with preoperative heart rate>75 beat/min in terms of total number of detected ganglionated plexi (P=0.04). Average number of detected ganglionated plexi was significantly higher in patients with in-hospital atrial fibrillation recurrence requiring electrical cardioversion (3.8±3) in comparison to rest of the study population (2±1.3; P=0.02). In patients in whom 4 or more ganglionated plexi were detected, significantly increased risk of in-hospital atrial fibrillation recurrence was observed (OR 15; 95% CI 1.5-164; P=0.003). CONCLUSION: Left atrial ganglionated plexi detection was unsuccessful in a considerable percentage of patients. Preoperative heart rate significantly influenced positive ganglionated plexi detection and number of ablated ganglia. Higher number of detected ganglionated plexi was related with early recurrence of atrial fibrillation.

Right atrium positioning for exposure of right pulmonary veins during off-pump atrial fibrillation ablation.

OBJECTIVES: Concomitant surgical ablation of atrial fibrillation (AF) is recommended for patients undergoing off-pump coronary revascularization in the presence of this arrhythmia. Achievement of optimal visualization of pulmonary veins while maintaining stable haemodynamic conditions is crucial for proper completion of the ablation procedure. This study evaluates the safety and feasibility of right atrial positioning using a suction-based cardiac positioner as opposed to compressive manoeuvres for exposure during off-pump surgical ablation for AF. METHODS: Thirty-four consecutive patients underwent pulmonary vein isolation, ganglionated plexi ablation and left atrial appendage occlusion during off-pump coronary artery bypass grafting. Right atrial suction positioning was used to visualize right pulmonary veins. Safety and feasibility end points were analysed intraoperatively and in the early postoperative course. RESULTS: In all patients, right atrial positioning created optimal conditions to complete transverse and oblique sinus blunt dissection, correct placement of a bipolar ablation probe, detection and ablation of ganglionated plexi and conduction block assessment. In all patients, this entire right-sided ablation procedure was completed with a single exposure manoeuvre. Feasibility end points were achieved in all study patients. CONCLUSIONS: This report documents the safety and feasibility of right atrial exposure using a suction-based cardiac positioner to complete ablation for AF concomitant with off-pump coronary revascularization. This technique may be widely adopted to create stable haemodynamic conditions and optimal visualization of the right pulmonary veins.

Intraoperative Assessment of Left Atrial Diverticulum and Remnant Stump after Left Atrial Appendage Epicardial Occlusion.

OBJECTIVES: Epicardial left atrial appendage (LAA) closure with use of occluder is an emerging technique. Absence of remnant LAA stump is major criterion of successful obliteration. The aim of study was to assess early success rate of epicardial LAA closure. METHODS: Fifteen patients with persistent AF and coronary artery disease underwent off-pump coronary revascularization with concomitant ablation and LAA epicardial occlusion with use of two types of occluders. Before incision and after appendage closure, TEE was performed to assess the LAA anatomy, diameter of left atrial ridge, and remnant LAA stump after occlusion. RESULTS: In 80% (12) of patients, formation of a left atrial diverticulum was observed with the left atrial ridge forming the superior boundary. In 5 patients (33%), a minimal remnant LAA stump was found, none exceeding 1 cm (average length: 1.5 ± 2.3 mm). In all patients, blood flow in LAA cavity distal to the occluder was absent. There was no significant difference in LAA type, average left atrial diameter, LAA orifice, LAA length, left atrial ridge, or size of occluder used between patients with and without a remnant LAA stump. Occurrence of a remnant LAA stump correlated significantly with unfavorable anatomy (LAA orifice < 20 mm and LA ridge > 5 mm; r = 0.5774, P = 0.02). CONCLUSION: The early success of epicardial LAA occlusion is not dependent on LAA morphologic type or occluder used. A minimal remnant LAA stump not exceeding 1 cm in length without distal blood flow was observed in one-third of the cases.

Early operative comparison of two epicardial left atrial appendage occluding systems applied during off-pump coronary revascularisation in patients with persistent atrial fibrillation.

INTRODUCTION: Atrial fibrillation (AF) increases long-term mortality and stroke rate in patients having coronary artery bypass grafting (CABG). Because oral anticoagulation (OAC) is associated with both a significant incidence of discontinuation and well known complication rates, left atrial appendage occlusion might be beneficial for stroke prevention. This study presents the first clinical and practical comparison of two epicardial left appendage occluders (LAAO) accruing experience in application during off-pump coronary revascularisation in patients with persistent AF. MATERIAL AND METHODS: Fifteen consecutive patients with persistent AF were assigned to intraoperative LAA occlusion with either TigerPaw System II (n = 8) or AtriClip (n = 7) device during off-pump CABG and concomitant left atrial epicardial ablation. Both systems were analysed in terms of ease and safety of application along with intraoperative LAA occlusion success. RESULTS: Surgical risk was increased in the study population (mean EuroScore II: 3.2 ± 0.3%). In all patients in the AtriClip group successful off-pump LAA occlusion confirmed by intraoperative transoesophageal echocardiography was achieved. The TigerPaw application was quicker and easier, but in 2 patients it was unsuccessful. During the hospital stay there were no bleeding or thromboembolic events recorded. CONCLUSIONS: In a pilot cohort epicardial LAAO during off-pump CABG in patients with persistent AF was performed safely and successfully with an AtriClip device. The TigerPaw System requires technological improvement. It might be useful to adapt the use of the type of occluding device to the LAA morphologic type and target revascularisation vessels to avoid the additional use of a heart positioner or obviate coronary compression.