Implantation of a cardiac pacemaker consists of two basic maneuvers: the placement of the pulse generator in a subcutaneous pocket and the insertion of a wire lead through a vein. This lead is threaded into the right ventricle of the heart under fluoroscopic control and positioned at the apex of the right ventricle in an appropriate manner using electronic measurements to determine the proper placement. Complications deriving from placement of the lead, such as perforation, are rare but can be life threatening. A perforation may cause blood to leak from the heart and accumulate in the pericardial sac surrounding the heart resulting in blood loss and causing pressure to alter the mechanical efficiency of the heart. This phenomenon is known as cardiac tamponade and can become a serious and potentially lethal condition. Patients who have a lead perforation of the heart may present with chest pain and shortness of breath (dyspnea). They may experience lightheadedness, syncope (fainting) and have hypotension (low blood pressure).
The diagnosis of lead perforation and pericardial effusion can be confirmed by echocardiogram and/or CT scan. When a pericardial effusion is diagnosed in a patient subsequent to pacemaker implantation, the presumptive diagnosis is lead perforation. If diagnosed in a timely fashion, the pericardial effusion can be treated relatively simply by either pericardiocentesis (needle aspiration of the fluid) or surgical drainage of the pericardium through a subxiphoid approach performed in the operating room under local anesthesia in which a small incision is made below the breast bone and the blood is drained from around the heart. A small catheter is left in the heart sac and removed in 24-48 hours.
It is important to remove the blood surrounding the heart because if left in place it may clot and become organized forming a fibrous scar-like peel around the heart which may constrict the heart motion. At that point, pericardiocentesis and the subxiphoid approach are inadequate, and the patient would require a sternotomy and pericardiectomy which is a more invasive and dangerous procedure.
The assumption of lead perforation is the presumptive cause of an effusion after pacemaker implantation. Failure to remove the pericardial fluid will allow progression of the fluid accumulation, subsequent fibrous organization of the fluid, and pericardial constriction.
Pacemaker lead perforation medical expert witness specialties include cardiac electrophysiology, cardiovascular surgery, and heart failure cardiology.