Laser-assisted extraction of pacemaker and defibrillator leads: the role of the cardiac surgeon.

BACKGROUND: The development of laser-assisted extraction techniques for chronically implanted pacemaker and defibrillator leads has reduced the need for open surgical removal. Reports of the mortality from laser-assisted extraction range from 1.9% to 3.4%. The purpose of this study was to determine the rate of major cardiovascular injury and emphasize the need for cardiothoracic surgical participation in this procedure. METHODS: A retrospective cohort study was performed of 112 consecutive laser-assisted lead extractions at a single university medical center during a 6-year period. Patient and lead characteristics were analyzed as well as indications, outcomes, and major complications. RESULTS: Successful lead extraction was accomplished in 103 (92%) of the 112 patients. Elective sternotomy after failure of laser-assisted lead removal was successfully performed in 4 patients. Emergent surgical intervention was required in 4 patients for caval perforation (n = 2), subclavian vein injury (n = 1), or right atrial injury (n = 1). Three of the 4 patients requiring emergent intervention died, for an overall series mortality of 2.6%. In July of 2006, a policy of cardiothoracic surgeon presence during the laser-assisted extraction was instituted. Since that time, there has been one emergent sternotomy and one elective sternotomy for lead removal with no procedure-related deaths. CONCLUSIONS: Despite recent advances in laser technology for the removal of pacemaker and defibrillator leads, the potential for major cardiovascular injury and death remains. Involvement of the cardiothoracic surgeon in both the preoperative decision-making process as well as the laser-assisted lead extraction is critical to prevent or emergently treat any major complications.

Unusual cause of superior vena cava syndrome diagnosed with transesophageal echocardiography.

PURPOSE: An unusual case of superior vena cava (SVC) syndrome caused by an infected right atrial-SVC junction thrombus may be diagnosed using transesophageal echocardiography. CLINICAL FEATURES: A 59-yr-old male with end-stage renal disease requiring hemodialysis presented with fungemia and later developed facial and bilateral upper extremity edema. Transesophageal echocardiography revealed subtotal occlusion of the SVC at its junction with the right atrium. The mass was surgically removed with cardiopulmonary bypass support. Pathological examination of the mass confirmed the presence of a large fungal colony of Candida species mixed in the thrombus. The patient's signs and symptoms of SVC obstruction resolved, and he was discharged from the hospital four weeks later in stable condition. CONCLUSION: Although usually caused by extrinsic tumour compression, SVC syndrome can result from intravascular caval obstruction. This etiology should also be considered in the differential diagnosis, particularly in patients with intravascular devices. Transesophageal echocardiography is a valuable diagnostic tool in these cases.

Selective activation of human atrial Galpha12 and Galpha13 by Galphaq-coupled angiotensin and endothelin receptors.

Galphaq-coupled receptors such as alpha1-adrenergic, angiotensin, and endothelin receptors, play key roles in cardiac physiology. These receptors have also been shown to couple to G proteins of the G12 family, including Galpha12 and Galpha13. In this report, we determined whether these G proteins interact with endothelin, angiotensin, and alpha1-adrenergic receptors in the human heart. We find that these receptors activate cardiac Galpha12 and Galpha13 differentially; endothelin receptors activate only Galpha12 (to 218 +/- 22% of unstimulated levels), angiotensin receptors activate only Galpha13 (to 236 +/- 49% of unstimulated levels), and alpha1-adrenergic receptors activate neither Galpha12 (123 +/- 18% of unstimulated levels) nor Galpha13 (113 +/- 12% of unstimulated levels). Consistent with these data, translocation of guanine nucleotide exchange factor p115RhoGEF, which responds to Galpha13, occurs only after stimulation of angiotensin receptors (shifting from 73 +/- 12% to 41 +/- 10% cytosolic). These differences in the activation of Galpha12 and Galpha13 by Galphaq-coupled receptors may underlie reported differences in the functions of these receptors.

Nonsurgical management of left main coronary artery aneurysms: report of 2 cases and review of the literature.

Aneurysms of the left main coronary artery are exceedingly rare clinical entities, encountered incidentally in approximately 0.1% of patients who undergo routine angiography. Thrombosis within the aneurysm can lead to distal embolization and myocardial infarction. These lesions can extend into adjacent coronary branches and can occur in the presence or absence of obstructive coronary disease. Depending on the severity of coexistent coronary stenoses, patients with left main coronary artery aneurysms can be effectively managed either operatively or medically. We report the cases of 2 patients who were treated medically for large left main coronary aneurysms and concomitant right coronary artery ectasia.