Coming Full Circle: A Story of Collaboration

The collaboration between electrophysiologists and cardiothoracic surgeons to treat cardiac arrhythmias in the operating room (OR) has existed since the late 1970s.^1,2 During my fellowship (2005-2007) at Medical College of Virginia/Virginia Commonwealth University, Dr. Kenneth Ellenbogen and Dr. Mark Wood encouraged me to enter into the OR to better visualize the gross cardiac anatomy and relevant epicardial structures that are not fully appreciated by imaging or mapping tools in the electrophysiology laboratory.

Since starting in private practice in 2007, I have sought to work with cardiac surgeons who were interested in a collaborative approach to treat complex arrhythmias, and who had knowledge and understanding of basic electrophysiology — overall, a relatively small group. Early on, I collaborated with Dr. James Morris in performing bilateral pulmonary vein isolation and left atrial appendage exclusion to treat atrial fibrillation via mini-thoracotomies.^3,4 My role was to assist in the identification of ganglionated plexi and ensure bidirectional block across the epicardial surgical ablative lines delivered with a bipolar RF clamp and pen (AtriCure) utilized for the procedure.

In the past year, I have been collaborating with Dr. Erik Beyer from Florida Medical Center in Ft. Lauderdale, Florida. At this hospital, we have access to a hybrid operative suite where we perform complex endocardial and epicardial ablation, fluoroscopy, intracardiac echocardiography, and 3D electroanatomical mapping. This suite has allowed us to advance our treatment of complex arrhythmias by leveraging the benefits of both specialties working side by side. The following are case reports highlighting the evolving nature of our collaborative approach.

Case #1: True Hybrid Epicardial and Endocardial Atrial Fibrillation Mapping and Ablation

The patient is a 68-year-old female with a past medical history of obesity, chronic lung disease, typical atrial flutter, left atrial tachycardia, and atrial fibrillation (AF). She underwent a typical atrial flutter ablation in May 2009, and a left atrial tachycardia and pulmonary vein isolation in September 2010. After this, she was diagnosed with significant left to right shunting secondary to a patent foramen ovale, and underwent an intra-atrial septal closure with the AMPLATZER Septal Occluder device (St. Jude Medical).

She had recurrence of AF and underwent cardioversion in November 2015. She then underwent right-sided typical and atypical atrial flutter ablation in April 2016. She felt much improved for a few weeks, and then experienced recurrence of palpitations and dyspnea after returning to AF. She was then referred for a surgical ablation.

The patient was brought to the hybrid room, and under cardiopulmonary bypass, the left chest was opened via a left thoracotomy by Dr. Beyer. Under general anesthesia with a single-lumen endotracheal tube, the left lung was deflated and the pericardium was opened.

Using a Livewire Duo-decapolar Catheter (St. Jude Medical), a 3D electroanatomical voltage map of the posterior LA epicardium was created using EnSite (St. Jude Medical). Next, ablation of the left pulmonary veins was performed by using an Isolator Synergy Clamp (AtriCure). The veins were tested after ablation and entrance block was confirmed with an Isolator Transpolar Pen (AtriCure), with an Optima Duo-decapolar Catheter (St. Jude Medical) wrapped around the outside of the vein and a Livewire Duo-decapolar Catheter using EnSite voltage mapping. Next, using a cryoICE cryoablation probe (AtriCure), multiple (3-minute) ablative lesions were delivered along the posterior wall. Then, access to the left pulmonary vein was obtained with a 12 French sheath. Via the sheath, an Optima Duo-decapolar Catheter (St. Jude Medical) was used to create a 3D EnSite map of the endocardial left atrium. A 28 mm cryoballoon (Medtronic) with a 20 mm Achieve catheter (Medtronic) was used to ablate the right pulmonary veins. The patient broke to normal sinus rhythm during ablation of the right superior pulmonary vein (RSPV) (Figure 2). Finally, the left atrial appendage was clipped using an AtriClip (AtriCure).

Case #2: Epicardial Ventricular Tachycardia Mapping and Ablation Under Direct Visualization

The patient is a 60-year-old male with a non-ischemic idiopathic cardiomyopathy who has undergone multiple endocardial ventricular tachycardia (VT) ablations for recurrent sustained monomorphic VT. The patient also has a history of persistent AF and has a single-chamber ICD in situ. Prior to presentation, the patient received over 60 appropriate shocks from the device. The patient has failed mexiletine and amiodarone in combination to suppress ventricular arrhythmias.

In evaluating the patient for repeat ablation, the 12-lead ECG in VT suggested an epicardial inferior basal left ventricular (LV) origin. However, on physical exam, it was noted that the patient had a mass in the area inferior to the xiphoid process. An ultrasound of this area revealed a crumpled mesh in this area; access to the epicardium from this location would not be possible. 

Dr. Beyer and I decided to access the LV via a left thoracotomy. From this angle, under general anesthesia with a double-lumen endotracheal tube, the left lung was deflated and the pericardium was opened. The procedure was performed on a beating heart.

Using a Livewire Duo-decapolar Catheter (St. Jude Medical), a 3D electroanatomical voltage map of the LV epicardium was created using EnSite (St. Jude Medical). The map revealed an area of heterogeneous voltage between healthy tissue and dense scar. Visually, this area appeared to have been the site of previous endocardial ablation or scar. 

Using a cryoICE cryoablation probe (AtriCure), multiple (2-minute) ablative lesions were delivered along the scar border to connect to the dense scar. Ablation on the posterior descending artery was avoided, as it could be easily visualized and identified. 

After the ablative lesions were delivered, a Multifunctional Isolator Transpolar Pen (AtriCure) was used to delineate the scar border, and additional (30-second) ablative lesions were delivered with the pen. A post-voltage map, created using a Livewire Duo-decapolar Catheter (St. Jude Medical), confirmed contiguous epicardial ablation (Figure 3).

Case #3: Epicardial VT Mapping and Ablation Under Direct Visualization

The patient is a 65-year-old male with a post-infarct cardiomyopathy who has undergone prior endocardial ventricular tachycardia ablation for recurrent sustained monomorphic VT. The patient also has a dual-chamber ICD in situ. In the weeks prior to presentation, the patient received over 40 appropriate shocks from the device. The patient has failed mexiletine and amiodarone in combination to suppress arrhythmia.

In evaluating the patient for repeat ablation, the 12-lead ECG in VT suggested an epicardial lateral LV origin. Therefore, Dr. Beyer and I decided to access the LV from a left thoracotomy. 

Using a Livewire Duo-decapolar Catheter (St. Jude Medical), a 3D electroanatomical voltage map of the LV epicardium was created using EnSite (St. Jude Medical). The map revealed an area of heterogeneous voltage between healthy tissue and dense scar. This area was predicted by the 12-lead ECG in VT (Figure 4).

Using a cryoICE cryoablation probe (AtriCure), multiple (2-minute) ablative lesions were delivered along the scar border to connect to the dense scar. A post-voltage map, created using a Livewire Duo-decapolar Catheter (St. Jude Medical), confirmed contiguous epicardial ablation.

Discussion

Multidisciplinary medical-surgical physician teams have revolutionized many fields including endocrinology, oncology, and gastroenterology/hepatology. Recently, the treatment of various cardiovascular disease processes have markedly been improved upon with the employment of a collaborative approach. The most noted of late has been the proliferation of transcatheter aortic valve replacement teams. Whereas electrophysiologists and surgeons worked together closely in the late 1970s, these fields took divergent paths in subsequent years, with each specialty working in their own silo, especially in respect to the treatment of atrial fibrillation. Surgeons and electrophysiologists each developed a distinct understanding of the pathophysiology of atrial fibrillation, and therefore, of the way to best approach it. Part of this difference of opinion relates to different patient populations being addressed — those with concomitant valvular heart disease versus those with non-valvular atrial fibrillation. Having had the opportunity to learn from, work with, and educate cardiac surgeons since my entry into electrophysiology, I earnestly believe that the true hybrid approach, where the electrophysiologist and surgeon work side by side, will allow for improved understanding and treatment of complex arrhythmias. Persistent atrial fibrillation, epicardial ventricular tachycardia, and inappropriate sinus tachycardia seem to be reasonable opportunities for a collaborative approach. I look forward to continued collaboration in the years to come.

Disclosure: Dr. Kenigsberg has no conflicts of interest to report regarding the content herein. Outside the submitted work, he does report he serves as a speaker and consultant for AtriCure, as a proctor for St. Jude Medical and Medtronic.  

References

1. Guiraudon G, Fontaine G. Frank R, Escande G, Etievent P, Cabrol C. Encircling endocardial ventriculotomy: a new surgical treatment for life-threatening ventricular tachycardias resistant to medical treatment following myocardial infarction. Ann Thorac Surg. 1978;26:438-444. 
2. Josephson ME, Harken AH. Horowitz LN. Endocardial excision: a new surgical technique for the treatment of recurrent ventricular tachycardia. Circulation. 1979;601:430-439. 
3. Wolf RK, Schneeberger EW, Osterday R, et al. Video-assisted bilateral pulmonary vein isolation and left atrial appendage exclusion for atrial fibrillation. J Thorac Cardiovasc Surg. 2005;130(3):797-802. Erratum in: J Thorac Cardiovasc Surg. 2006 Apr;131(4):772.
4. Cox JL, Ad N, Palazzo T, et al. Current status of the maze procedure for the treatment of atrial fibrillation. Semin Thorac Cardiovasc Surg. 2000;12:15-19.