Epicardial ventricular arrhythmia ablation: a clinical consensus statement of the European Heart Rhythm Association of the European Society of Cardiology and the Heart Rhythm Society, the Asian Pacific Heart Rhythm Society, the Latin American Heart Rhythm Society, and the Canadian Heart Rhythm Society

Figures

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  Figure 1. Anatomy of the human pericardium (anterior view)—fibrous pericardium (A) and serous pericardium with epicardium (B). Image adapted with permission from the Image Courtesy of the UCLA Cardiac Arrhythmia Center, Amara-Yad Project Collection.

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  Figure 2. Pericardial reflections and hilar orifices around the great cardiac vessels (posterior view). Image adapted with permission from the Image Courtesy of the UCLA Cardiac Arrhythmia Center, Amara-Yad Project Collection.

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  Figure 3. Upper panel: Anterior and posterosuperior view of the pericardium showing the superior or arterial hilum (red string) and the posterior or venous hilum (blue string), with the distribution of the main pericardial sinuses and recesses. Lower panel: Coronal and paramedian section of the thorax depicting the anatomical relations of the pericardium within the thorax. Left lower panel: 1. clavicle; 2. left brachiocephalic vein; 3. upper lobe of the right lung; 4. aortic arch; 5. superior vena cava; 6. right atrium; 7. coronary sinus; 8. liver; 9. second rib; 10. upper lobe of left lung; 11. pulmonary trunk; 12. ascending aorta and left coronary artery; 13. aortic valve; 14. pericardium; 15. left ventricle; 16. the lower lobe of the left lung; 17. diaphragm; 18. colon. Right lower panel: 1. aortic arch; 2. left atrium; 3. oesophagus; 4. right atrium; 5. liver. Image adapted with permission from the UCLA Cardiac Arrhythmia Centre, Amara-Yad Project Collection, and Wolters Kluwer.

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  Figure 4. Basics for ventricular arrhythmia-ECG morphological criteria in patients with non-ischaemic cardiomyopathy. Depolarization and ECG morphology in posterior and inferior monomorphic ventricular arrhythmias in patients with non-ischaemic cardiomyopathies with endocardial (A) and epicardial (B) exit sites. Adapted with permission from Vallès et al.27

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  Figure 5. Four-step algorithm based on inferior Q-waves in inferior and lead I, pseudodelta, and maximum deflection index to identify left ventricular epicardial ventricular tachycardia (VT) in patients with non-ischaemic cardiomyopathy based on VT-QRS morphology. This algorithm applies to ‘basal-superior/posterior’ VTs in non-ischaemic cardiomyopathy. Adapted with permission from Vallès et al.27

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  Figure 6. Major arteries located near the epicardial puncture site. Please note the vicinity of the left superior epigastric, left musculophrenic, and left internal thoracic (mammary) arteries to the puncture site. Image adapted with permission from the Image Courtesy of the UCLA Cardiac Arrhythmia Center, Amara-Yad Project Collection.

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  Figure 7. Left: Anatomic location of Larrey's space. Right: anterior (A, shallow < 45) vs. posterior (B, steep > 45) approach for subxiphoid puncture using Tuohy Needle. Be aware that using the posterior approach results in diaphragmatic puncture, potentially leading to intra-abdominal injuries. Image adapted with permission from the Image Courtesy of the UCLA Cardiac Arrhythmia Center, Amara-Yad Project Collection.

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  Figure 8. (A) Inferior subxiphoid puncture in right anterior oblique projection. (B) Anterior subxiphoid puncture in left lateral projection. Blue arrows show the entrance of the needle into the epicardial space. The green arrow indicates CO2 insufflation (upper arrow - B).

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  Figure 9. Virtual and fluoroscopic visualization of epicardial guidewire pathways is presented. The left panel: virtual guidewire trajectories through the anterior (red, the line without arrow) and inferior (yellow, the line with arrow) approaches on a 3D cardiac reconstruction. The arrowheads mark the location of the guidewire. The right panel: use of a long guidewire inside the pericardium (arrow heads) to demonstrate the crossing of multiple chambers encircling the heart. Image adapted with permission from the Image Courtesy of the UCLA Cardiac Arrhythmia Center, Amara-Yad Project Collection.

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  Figure 10. Surgical access for epicardial ablation. The surgical window approach for epicardial access involves creating a small subxiphoid incision to reach the pericardial space. (A and B) A limited incision is made just beneath the xiphoid process, and the subcutaneous tissues are dissected to reveal the pericardium. A small incision in the pericardium is performed under direct visualization to prevent injury to adjacent structures. (C and D) A flexible sheath is then advanced into the pericardial space, facilitating the insertion of mapping and ablation catheters. (E and F) 3D late potential mapping and 3D mapping integrated with fluoroscopy images.

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  Figure 11. Planning and ablation of epicardial ventricular tachycardia (VT) in a patient with cardiac sarcoidosis. (A) ECG: The initial step in procedural planning involves the ECG, showing the presence of a large pseudodelta wave, and the QRS axis-based algorithm indicates an inferoseptal and basal exit of the VT.87 The suspected segment of origin is highlighted in purple. (B) Cardiac imaging: Cardiac magnetic resonance imaging (CMR) confirms the presence of an inferoseptal scar. CMR Segmentation reveals a channel with an inferoseptal extension, potentially involved in the clinical VT. The CMR is integrated with a computed tomography scan to confirm the channel's anatomical location within the patient's specific anatomy. (C) Ablation procedure: Despite its clear epicardial origin, the VT was terminated after the first application, as the middle cardiac vein coincided with the VT isthmus trajectory. The lower panel illustrates the reconstruction of the coronary venous system and its integration with the electroanatomical map.

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  Figure 12. Epicardial puncture is not necessary in all patients with an epicardial substrate. Top panel: A patient with an early stage arrhythmogenic right ventricular cardiomyopathy (ARVC) is shown. The bipolar voltage map of the right ventricular endocardium (left) shows a small low-voltage area on the subtricuspid region. Unipolar voltage map of the right ventricular endocardium showing a significant area of low unipolar voltage (middle). Significant epicardial scar is observed in regions opposite those with low unipolar voltage. A large arrhythmogenic epicardial substrate area with late potential channels is shown (right). The ventricular arrhythmia (VA) was successfully ablated from the epicardium. Lower panel: A patient at a late stage of ARVC is shown. The bipolar voltage map of the right ventricle shows already a big area of low voltage on the endocardial surface (left). An extensive area of low unipolar voltage is observed (middle). The unipolar endocardial voltage map indicates the presence of epicardial involvement. The bipolar epicardial map shows a very large epicardial scar area. Bipolar vs. unipolar low-voltage area (LVA) ratios and epicardial arrhythmogenic substrate area…