Magnesium infusion dramatically decreases the incidence of atrial fibrillation after coronary artery bypass grafting.

BACKGROUND: Atrial fibrillation (AF) is one of the most common complications of cardiac surgery. Magnesium, like several other pharmacologic agents, has been used in the prophylaxis of postoperative AF with varying degrees of success. However, the dose and the timing of magnesium prophylaxis need to be clarified. The purpose of this study was to assess the effect of intermittent magnesium infusion on postoperative AF. METHODS: A total of 200 consecutive patients who had elective, isolated, first-time coronary artery bypass grafting were prospectively randomized to two groups. Patients in the magnesium group (n = 100) received 6 mmol MgSO4 infusion in 100 mL 0.9% NaCl solution (25 mL/h) the day before surgery, just after cardiopulmonary bypass, and once daily for 4 days after surgery. Patients in the control group (n = 100) received only 100 mL 0.9% NaCl solution (25 mL/h) at the same time points. RESULTS: Postoperative AF occurred in 2 (2%) patients in the magnesium group and in 21 (21%) patients in the control group (p < 0.001). Atrial fibrillation started, on average, 49.4 +/- 16.8 hours postoperatively. The postoperative length of hospital stay was not significantly different in patients with AF (7.4 +/- 8.0 days) compared with patients without AF (5.4 +/- 1.1 days; p = 0.236). CONCLUSIONS: The use of magnesium in the preoperative and early postoperative periods is highly effective in reducing the incidence of AF after coronary artery bypass grafting.

Absent right superior vena cava with hypoplastic proximal inferior vena cava.

We describe the precise preoperative diagnosis of a very rare anomaly that comprises absence of the right superior vena cava, persistence of the left superior vena cava, and proximal hypoplasia of the inferior vena cava draining into the left superior vena cava via the hemiazygos vein associated with a large atrial septal defect and tricuspid regurgitation.

Critical-illness polyneuropathy complicating cardiac operation.

Critical-illness polyneuropathy is a complication of septic syndrome. However, this complication has been largely unrecognized in cardiac surgery units. Difficulty in weaning from the ventilator is an important early manifestation. Electromyography should be routinely performed to establish the diagnosis. Here we report a case of polyneuropathy complicating surgical repair of acute aortic dissection.

Intermittent aortic cross-clamping and cold crystalloid cardioplegia for low-risk coronary patients.

BACKGROUND: Blood cardioplegic strategies have been shown to increase myocardial oxygen uptake, replenish depleted energy stores, and improve myocardial function and survival in the high-risk subset of patients. However, the superiority of these techniques over intermittent aortic cross-clamping and crystalloid cardioplegia in low-risk patients is still controversial. METHODS: This study consisted of two parts. In the first part, we assessed the results of a recent cohort of 399 consecutive low-risk patients undergoing their first coronary artery bypass grafting between 1993 and 1995 using cold crystalloid cardioplegia (n = 128) and intermittent aortic cross-clamping (n = 271). In the second part of the study, 40 consecutive low-risk patients undergoing elective first time coronary artery bypass grafting were randomly divided into two equal groups. One group received cold crystalloid cardioplegia and the other group had myocardial management with intermittent aortic cross-clamping. The two groups were compared with respect to hemodynamic, biochemical and ultrastructural changes. RESULTS: The overall mortality rate, the perioperative myocardial in the need for intraaortic balloon pumps, and the need for inotropic agents were 0.25%, 1.5%, 1%, and 5.8%, respectively. No significant differences were observed between the groups with respect to these clinically defined end points. CONCLUSIONS: Both intermittent aortic cross-clamping and cold crystalloid cardioplegia techniques may be used safely in low-risk patients undergoing first-time coronary artery bypass grafting.

Aortoventriculoplasty in a patient with complex left ventricular outflow tract obstruction, mitral valve stenosis and aneurysm of the ascending aorta.

We describe a new method of aortoventriculoplasty in a patient with calcified mitral stenosis, aortic valvular stenosis, severe left ventricular outflow tract obstruction, and aneurysm of the ascending aorta. This complex pathology was successfully treated with replacement of both the valves and a tubular dacron graft. The proximal end of the dacron tube was tailored as a patch for the repair of the ventricular septum and the aortic root, and the distal end was anastomosed to the distal ascending aorta. The patient had an uneventful recovery and postoperative echocardiography showed no significant residual gradient on the left ventricular outflow tract.