Left ventricular summit ablation through open sternotomy with hybrid utilization of standard electrophysiology catheters and maneuvers

Abstract

IntroductionCatheter-based radiofrequency ablation is the most common treatment option to prevent recurrent implantable cardioverter-defibrillator (ICD) therapies in patients with ventricular tachycardia (VT).1Cronin E.M. Bogun F.M. Maury P. et al.2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias.Heart Rhythm. 2020; 17: e2-e154Abstract Full Text Full Text PDF PubMed Scopus (105) Google Scholar However, in patients with nonischemic cardiomyopathy, the radiofrequency ablation is considered ineffective owing to nonuniformity in the distribution of scar.2Anter E. Hutchinson M.D. Deo R. et al.Surgical ablation of refractory ventricular tachycardia in patients with nonischemic cardiomyopathy.Circ Arrhythm Electrophysiol. 2011; 4: 494-500Crossref PubMed Scopus (54) Google Scholar An epicardial scar may require ablation via the coronary venous system or using the pericardial approach.3Al-Khatib S.M. Stevenson W.G. Ackerman M.J. et al.2017 AHA/ACC/HRS Guideline for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society.J Am Coll Cardiol. 2018; 72: e91-e220Crossref PubMed Scopus (456) Google Scholar In some patients with left ventricular summit VT, owing to proximity of proximal coronary vessels, inability to deliver adequate lesions within the anterior interventricular vein (even with impedance limiter turned off), and inaccessible pericardial space owing to adhesions, a surgical approach with epicardial mapping may have to be done. We present a patient with nonischemic dilated cardiomyopathy, recurrent VT, and ICD therapies, who after failure of percutaneous approaches underwent elective open sternotomy, mapping using a traditional electrophysiology catheter on a beating heart, and subsequent cryoablation. Open surgical epicardial entrainment mapping and cryoablation of summit VT has not been previously reported.Case reportA 63-year-old patient with a history of recurrent VT (Figure 1), nonischemic cardiomyopathy, and chronic systolic heart failure with recurrent ICD therapies was referred for ablation. Comorbidities included deep vein thrombosis, history of pulmonary embolism on anticoagulation, morbid obesity, sleep apnea, and anxiety from recurrent ICD therapies.She had failed medical therapy with amiodarone and mexiletine and had previously undergone 2 VT ablation procedures including endocardial and attempted epicardial approaches. The coronary sinus approach was not feasible owing to the completely occluded great cardiac vein and anterior interventricular vein.4Roberts-Thomson K.C. Steven D. Seiler J. et al.Coronary artery injury due to catheter ablation in adults: presentations and outcomes.Circulation. 2009; 120: 1465-1473Crossref PubMed Scopus (125) Google Scholar Percutaneous pericardial approach was not feasible owing to extensive pericardial adhesions.5Santangeli P. Marchlinski F.E. Zado E.S. et al.Percutaneous epicardial ablation of ventricular arrhythmias arising from the left ventricular summit: outcomes and electrocardiogram correlates of success.Circ Arrhythm Electrophysiol. 2015; 8: 337-343Crossref PubMed Scopus (104) Google Scholar Owing to recurrent VT, she was taken to the electrophysiology lab for another epicardial VT ablation via open sternotomy.Median sternotomy was performed by a cardiothoracic team. ICD was used to induce clinical VT with a ventricular burst at 340 ms. During induced VT (identical morphology to clinical VT), the patient was hemodynamically stable; epicardial activation and entrainment mapping were done to identify critical isthmus using a PentaRay catheter (Boston Scientific, Marlborough, MA; Figure 2A ). Entrainment mapping (Figure 3; stim-QRS/TCL = 30%, Stim-QRS = electrogram-QRS) was identified at the border between LV summit and anterolateral epicardial