The Annals of thoracic surgery
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The cardiovascular effects of atrial, ventricular, and sequential pacing at PR intervals of 175, 150, 125, and 100 msec were studied immediately following cardiopulmonary bypass in patients with aortic stenosis, aortic insufficiency, or coronary artery disease. Atrial pacing increased the cardiac output and mean arterial blood pressure only in the patients with coronary artery disease. ⋯ Our results suggest that if augmentation of heart rate is required in the period immediately after bypass, atrial pacing should be used in preference to ventricular pacing. In the presence of second- or third-degree heart block when atrial stimulation is ineffective, sequential pacing with an individualized PR interval becomes the therapeutic choice.
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A technique for cardioplegic infusion and left heart venting during coronary artery bypass grafting.
A method for administering cardioplegia and venting the left heart that utilizes a single cannula in the aortic root and minimizes the risk of air entering the left heart is presented. This technique permits precise control of flow and pressure of the cardioplegic solution. Left heart decompression is accomplished by siphon drainage with controlled negative pressure. This method effectively vents the left heart while preventing aspiration of air around the cannula insertion site or retrograde through an opened coronary artery with a nonocclusive proximal lesion during the construction of the distal anastomoses.
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Double-lumen endobronchial tubes offer many advantages during thoracic operations. However, technical problems with tube placement and potentially life-threatening complications have discouraged widespread use of standard double-lumen tubes. Some of these problems may be reduced with a new polyvinyl chloride (PVC) double-lumen tube. ⋯ In 8 of 16 intubations with the Carlens tube and in 14 of 62 intubations with the Robertshaw tube, there were complications. In all, 22 of 78 intubations (28%) using conventional double-lumen tubes were complicated compared with 5 of 136 (4%) using the PVC tube. The technical problems and risks of endobronchial intubation were reduced significantly with the PVC double-lumen tube.