Since their introduction in 1980, implantable cardioverter defibrillators (ICD) have played a significant role in the management of malignant ventricular arrhythmias. The early ICD systems utilized epicardial patches and extra-cardiac wires that were often placed at the time of cardiac bypass surgeries using an anterior thoracotomy or median sternotomy approach. Epicardial patches and lead systems have given way to transvenous devices that can be implanted by surgeons or cardiologists without the need for major surgery. A rare but important complication of epicardial defibrillator patches is the potential for erosion into adjacent lung structures resulting in catastrophic outcomes.
A 59 year old male with non-ischemic dilated cardiomyopathy had four ICDs implanted over a period of nine years for sustained ventricular tachycardia. His first ICD unit utilized the epicardial patch/lead system and was implanted 15 years ago after he experienced an episode of sudden cardiac death. Over the next several years, he had three additional units implanted secondary to malfunction of various defibrillator components. His most recent ICD consisted of endocardial leads that were placed transvenously. The patient presented with complaints of hemoptysis, dyspnea, and left side pleuritic chest pain. His chest x-ray revealed opacities in the left upper lobe (LUL) and left lower lobe (LLL). A CT of the thorax demonstrated a soft tissue density in the lingula with partial atelectasis of the LLL. Bronchoscopy revealed the presence of an endobronchial lesion involving the lingular bronchus as well as the superior segment bronchus in the LLL. Biopsies were negative for malignancy. Due to his long history of tobacco smoking and concern for lung cancer, the patient was referred to cardiothoracic surgery for thoracotomy and possible lobectomy. A repeat bronchoscopy prior to the planned surgery revealed the presence of an ICD patch eroding into the lingular bronchus and lead wire eroding into the superior segment bronchus in the LLL. Due to extensive fibrosis involving adjacent structures, the patient was deemed not to be a candidate for surgical removal of the patch and wire. A repeat CT of the thorax one year later revealed further erosion of patch and wire into the previously involved bronchi. Following this, the patient required admission for massive hemoptysis. Despite bronchial artery embolization and control of bleeding, he ultimately died of pneumonia and sepsis.
Complications associated with ICDs utilizing epicardial patches and leads include early and delayed infection, constrictive pericarditis, malfunction of various defibrillator components, and erosion of ICD components into adjacent structures including the heart, lung, and vascular structures. Pulmonary complications associated with epicardial defibrillator hardware can occur early in the post-operative period and include pleural effusion, atelectasis, pneumothorax, and pneumonia (most commonly left-sided). These events are usually nonfatal. Late pulmonary complications result from distortion, migration, and erosion of epicardial defibrillators into adjacent lung structures. Reported complications include persistent atelectasis, progressive fibrosis of adjacent lung tissue, recurrent pneumonias, hemoptysis, hemothorax, bronchopleural and bronchopericardial fistulas, empyema, and chronic pleural effusions. Proposed mechanisms for patch distortion and migration include peri-patch infection, inflammation, and breakdown of the securing sutures.
Erosions of epicardial defibrillator hardware into adjacent pulmonary structures are rare and unpredictable events with potentially fatal outcomes. This complication should be considered in the differential diagnoses of recurrent hemoptysis, cough, and non-resolving pulmonary infections in patients with ICDs.
Nguyen-Steve Vu, None.