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After cardiac operations, careful management substantially reduces the risks of negative complications during or after the removal of temporary epicardial pacing wires. Herein, we report the case of a 58-year-old man who, 4 days after undergoing aortic root replacement, developed pericardial tamponade after the removal of temporary epicardial pacing wires. Consequent to the tamponade, a right-to-left shunt developed through a previously undiagnosed patent foramen ovale. The patient underwent emergency surgery to repair myocardium that had ruptured due to the removal of the wires, and he recovered uneventfully.
Temporary epicardial pacemakers are frequently implanted in cardiac surgical patients before chest closure, with acceptable safety rates. However, complications can occur during routine procedures and early and late after surgery, due not only to migration of the epicardial pacing wires but also to their insertion and removal.1
Herein, we report a rare case of pericardial tamponade and a right-to-left shunt through a previously undiscovered patent foramen ovale (PFO); the tamponade occurred after the removal of epicardial pacing wires.
In 2008, a 58-year-old man presented at our hospital with severe aortic regurgitation and aneurysmal dilation of the ascending aorta. Transthoracic echocardiography (TTE) revealed a bicuspid aortic valve with severe regurgitation and mild stenosis. The ascending aorta above the sinus of Valsalva was dilated to 6.1 cm. The patient underwent aortic root replacement with valve preservation (the David procedure). After an uneventful cardiac operation and before chest closure, 2 epicardial pacing wires were placed on the right ventricle (RV). The patient was transferred to the surgical intensive care unit and later to the ward; all the while, he was in sinus rhythm and had an acceptable hemodynamic status. On the 4th postoperative day, the pacing wires were removed. The patient immediately became cyanotic and fainted. Transesophageal echocardiography (TEE) revealed pericardial tamponade (Fig. 1) and a right-to-left shunt through a previously undiagnosed PFO (Fig. 2). The tamponade compressed the right atrium and the RV, severely restricting the passage of blood through the tricuspid valve. Continuous-wave Doppler echocardiography revealed increased right atrial pressure and a mean pressure gradient of about 12 mmHg between the right atrium and the RV that mimicked tricuspid stenosis. The patient was urgently taken to the operating room. The source of bleeding was determined to be a myocardial rupture caused by removal of the epicardial pacing wires. The myocardium was repaired, and the patient experienced an uneventful postoperative recovery. As of his last follow-up visit, he had experienced no further problems.
Epicardial pacing is regularly used to identify and control dysrhythmias after cardiac operations and to ensure patients' hemodynamic status.2 However, the implantation of temporary epicardial pacemakers during cardiac operations is not free from risk.3,4 Indeed, a complication rate of 0.09% has been reported.4 Removal of the temporary wires is believed to trigger ventricular dysrhythmias3; therefore, when removal entails considerable risk, the physician may opt to leave the pacing wires in place.5 However, Meier and colleagues1 reported a case of an epicardial pacing wire that migrated into a patient's RV and pulmonary artery 3 years after insertion, leading to ventricular tachycardia. The incidence rate of pericardial tamponade after epicardial pacing-wire removal has not been reported.
Documented complications of pacing-wire insertion and removal include cardiac arrest, tamponade, hemothorax, pneumothorax, vascular injury or rupture, hemoptysis, and infections during standard procedures.1 Right ventricular rupture and pericardial tamponade have also occurred upon the insertion of epicardial pacing wires.4 Akowuah and colleagues6 reported a case of subepicardial hematoma that compressed the RV as a result of bleeding that was caused by the insertion of pacing wires.
Our patient's case is noteworthy in that the pericardial tamponade and the increased right atrial pressure resulted in blood flow through the PFO. A 1984 study of autopsy cases revealed an incidence of 27.3% of patent PFO.7 Contrast echocardiography and the Valsalva maneuver are frequently used to identify PFO. In association with the Valsalva maneuver, TEE has been shown to have a higher sensitivity in detecting PFO than has TTE.8 Because we did not perform a Valsalva maneuver or a contrast study specific for the evaluation of PFO, we cannot rule out the presence of the PFO in our patient before surgery. Accordingly, it is possible that the bleeding and the increased right atrial pressure revealed an existing PFO.
Pericardial tamponade is a grave (albeit rare) complication that can occur during the removal of temporary epicardial pacing wires. Such cases require timely diagnosis and intervention to avert catastrophic consequences. In addition, complications might be prevented by the careful insertion and gentle removal of the temporary wires. After the wires are removed, the patient's discharge from the hospital is best delayed for several hours or overnight due to the risk of cardiac tamponade, and electrocardiography should be used to monitor the occurrence of dysrhythmias.
Address for reprints: Bahare Saidi, MD, Department of Cardiology Echocardiography, Day General Hospital, Tavanir St., Vali-ye-Asr Ave., 1434873111 Tehran, Iran