Outcome of Patient with Refractory Nonischemic Dilated Cardiomyopathy Treated with the First Biventricular Pacemaker in Cambodia

Acute improvement in left ventricular function and mitral insufficiency has been reported using a biventricular pacemaker. In this article, we report on Cambodia’s first biventricular pacemaker implantation. Case Report The patient was a 45-year-old Cambodian male with one month of progressive dyspnea on exertion. He presented to Centre de Cardiologie de Phnom Penh in New York Heart Association Class IV congestive heart failure and cardiac cachexia on February 13, 2008. Initial physical examination revealed a blood pressure of 97/63, heart rate of 80 bpm, and elevated jugular venous pressure. Cardiac examination revealed a regular sinus rhythm, enlarged and laterally displaced cardiac point of maximal impulse, S4, S1, S2, and S3 gallop. A mitral systolic murmur with intensity of 4/6 was noted. Pulmonary examination revealed bilateral pulmonary rales. He also had hepatomegaly and 4+ peripheral edema. Initial electrocardiogram showed sinus rhythm, first-degree AV block, left branch block and left ventricular hypertrophy. Chest X-ray confirmed cardiomegaly and bilateral pulmonary edema. Echocardiography was performed demonstrating enlarged left ventricular dimensions (LVD = 83 mm, LA = 43 mm), severe left ventricular dysfunction with an estimated ejection fraction of less than 10% with left ventricular dysynchrony, and severe mitral regurgitation with elevation of pulmonary pressure at 50 mmHg. The patient was placed on furosemide 80 mg IV, carvediolol 6.25 mg, and dobutamine infusion. After several days of medical therapy, he continued to have NYHA Class IV heart failure. He also developed atrial fibrillation with a ventricular rate of 80-90 bpm. Due to his refractory congestive heart failure status, a biventricular pacemaker was recommended. However, a current generation biventricular device was not available at that time. A dual-chamber pacemaker and standard pacing leads, a “Y” adapter, and a coronary sinus lead were available. We decided to proceed and “Y” adapt the leads into a dual-chamber pacemaker on February 22, 2008. Procedure The patient was prepped and draped in a sterile manner in the cardiac catheterization laboratory. Prior to the procedure, echocardiography was repeated, confirming his severe left ventricular dysfunction. Lidocaine (1%) was used for local anesthesia. Access was achieved using the Seldinger technique, and three 8 French (Fr) SafeSheaths® (Pressure Products, Inc., San Pedro, California) were inserted into the left subclavian vein under fluoroscopy. Using curved and straight stylets, a Medtronic 5076 lead (Medtronic, Inc., Minneapolis, Minnesota) was placed in the right ventricular apex. St. Jude Medical’s 1488 lead (St. Jude Medical, St. Paul, Minnesota) was placed in the right atrium using the same method. We then exchanged out the third short SafeSheath for an 8 Fr multi-purpose catheter (Biosense Webster, Inc., a Johnson & Johnson company, Diamond Bar, California); this was the only long sheath available to us. In the LAO 30 view, the catheter was manipulated into the coronary sinus ostium, first by advancing it into the right ventricle, then retracting it while applying counterclockwise torque as the sheath was slowly withdrawn from the right ventricle (Figure 1). An injection was made to confirm the location, but due to the sharp angle of the sheath, the vein developed spasm distal to the sheath, and we could not visualize the branches. We passed a Hi-Torque Balance Middleweight guidewire (Abbott Vascular, Abbott Park, Illinois), searched for a branch vessel, then passed the guidewire down into it. An image was taken as a road map and the guidewire was removed. The only left ventricular lead available was the first-generation Biotronik Corox LV-H 75 lead (Biotronik, Berlin, Germany), a stylet-driven unipolar lead. It was placed into the sheath and advanced into the coronary sinus to the approximate location of the lateral branch. There was difficulty torquing the lead blindly into the branch vessel. We readvanced the BMW wire into the branch to guide us. The Corox lead was then torqued, and followed the guidewire alongside it into the lateral coronary sinus branch vessel (Figure 2). Unipolar pacing and sensing numbers were excellent, and there was no diaphragmatic stimulation. The multi-purpose sheath was not a peel-away sheath and no cutting tools were available. We used Mayo scissors and the scalpel to meticulously cut the sheath without damaging the lead. Since only dual-chamber pacemakers were available to us, we needed to “Y” adapt the two ventricular leads into the Identity 5380 dual-chamber pacemaker generator (St. Jude Medical) (Figure 3). The atrial lead was connected to the atrial port, and the “Y” adapter was placed in the ventricular port. The “Y” adapter was then used to connect the right ventricular lead and left ventricular lead. Again, thresholds and sensing numbers were excellent, and there was no diaphragmatic pacing noted. Over the next several days the patient improved. Repeat echocardiography on day 3 noted improvement in the ejection fraction to greater than 30% and significant reduction of the mitral insufficiency. He was discharged home one week after the procedure, as is the standard of care in Cambodia. Discussion This case report describes the first biventricular pacemaker implanted in Cambodia for refractory congestive heart failure and mitral insufficiency. Although a biventricular pacemaker was not available, we were able to “Y” adapt the leads into a conventional dual-chamber pacemaker. With improvements in devices, delivery systems, and left ventricular leads, implantation of a biventricular system has a high success rate. However, we were faced with improvising in that we were only able to use the equipment available to us, reminding us of the early days of biventricular device implantation. Post-operative echocardiography confirmed improvement in his left ventricular function. Acute improvement in left ventricular function as well as reduction in mitral insufficiency have been well described. The mechanism of mitral insufficiency is thought to be due to papillary muscle dysynchrony.1-3 Due to limitations of the echocardiography system, we were not able to do advanced measurements such as tissue Doppler index. However, improvements in his wall motion were noted by echocardiography, and reduction of mitral insufficiency was noted. The patient’s hemodynamics also improved. After several weeks of improvement in his heart failure status, the patient was able to return to work. Cardiac EP in Cambodia Cambodia is a country of approximately 13 million people. Phnom Penh is the capital of the country and the largest city. Approximately 2 million citizens live in the Phnom Penh area. Centre de Cardiologie de Phnom Penh is the only cardiac hospital in the country. It has a state-of-the-art cardiac catheterization laboratory with a modern cine fluoroscopy system. In most instances, primary angioplasty is performed for acute myocardial infarctions. Approximately 80 single- and dual-chamber pacemakers are implanted annually at the center. This is the first biventricular device implanted in Cambodia. Due to technical and financial reasons as well and limited follow-up capabilities, implantable cardioverter-defibrillators have not yet been implanted. Electrophysiology mapping equipment is also not available, and radiofrequency ablation therapy for arrhythmia treatment has not been performed. In a country with limited resources, complex device therapy is not yet an option. Hopefully in the future this will change. Acknowledgements. Authors William Choe, MD and Jeffery Terrell traveled to Cambodia with the Christian Medical Ministry to Cambodia/Jeramiah’s Hope, a medical missionary group from Denver, Colorado. The authors would like to acknowledge on behalf of the Cambodian people the gracious donations made by St. Jude Medical, Medtronic, and Biotronik, who all made this procedure possible.