The Journal of thoracic and cardiovascular surgery
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J. Thorac. Cardiovasc. Surg. · Feb 1994
Comparative StudyEffects of cardioplegic arrest on left ventricular systolic and diastolic function of the intact neonatal heart.
The effects of cardiopulmonary bypass and cardioplegic arrest on left ventricular systolic and diastolic function were studied in 20 intact neonatal lambs instrumented with ultrasonic dimension transducers and micromanometers for collection of left ventricular pressure-dimension data. Group I lambs underwent 2 hours of hypothermic cardiopulmonary bypass (25 degrees C) alone; group II lambs underwent 2 hours of hypothermic cardiopulmonary bypass (25 degrees C) with 1 hour of multidose, cold, crystalloid cardioplegic arrest (St. Thomas' Hospital No. 2 solution). ⋯ Second, preload behaved as though fixed, resulting in a loss of impedance matching (afterload mismatch). Although contractility as assessed by the end-systolic pressure-dimension relationship was significantly increased (because of increased levels of circulating catecholamines), global systolic performance as quantified by the stroke work/end-diastolic length relationship remained unchanged, reflecting the afterload sensitivity of the latter parameter in the face of fixed preload. We conclude that cardiopulmonary bypass in the intact neonate results in a loss of compliance and impedance matching rather than a loss of contractility; however, the addition of 1 hour of cold, crystalloid cardioplegic arrest results in no dysfunction beyond that attributable to cardiopulmonary bypass alone.
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J. Thorac. Cardiovasc. Surg. · Feb 1994
Comparative StudyOutcome of mitral valve repair in patients with preoperative atrial fibrillation. Should the maze procedure be combined with mitral valvuloplasty?
To examine late outcome of mitral valve repair in patients with preoperative atrial fibrillation, we reviewed the cases of 323 consecutive patients who underwent mitral valvuloplasty for mitral regurgitation from 1980 to 1991; average age of 215 men and 108 women was 64 years (range 14 to 88 years), and 224 patients (70%) were in New York Heart Association class III or IV before operation. The main indications for operation were severe mitral regurgitation (76%), coronary artery disease with associated mitral regurgitation (15%), and aortic valve disease (6%). At the time of mitral valve repair, coronary artery bypass grafting was done in 35% of patients, aortic valve replacement was done in 7%, and multiple other procedures were done in 10%. ⋯ Prevalence of late thromboembolic events was similar in patients with preoperative sinus rhythm compared with that in those with atrial fibrillation. These data suggest that mitral valve repair should be done before or soon after the onset of atrial fibrillation to maximize the chance of postoperative sinus rhythm and avoid long-term anticoagulation with warfarin. However, the early and late results of mitral valve repair in patients with chronic atrial fibrillation are good, and concomitant operation for supraventricular arrhythmia must have negligible morbidity and no adverse effect on operative mortality.
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J. Thorac. Cardiovasc. Surg. · Feb 1994
Clinically relevant diaphragmatic dysfunction after cardiac operations.
Phrenic nerve injury and diaphragmatic dysfunction can be induced by cardiac operation. The clinical consequences are not well-established. We evaluated 13 consecutive patients over a 2-year period with unexplained and prolonged difficulties in weaning from mechanical ventilation. ⋯ Estimating the prevalence of clinically relevant diaphragmatic dysfunction, we found it to be 0.5% when no topical cooling was used and 2.1% when iced slush with no insulation pad was added for myocardial protection (p < 0.005). The most striking finding was that the clinical course of the 13 patients was marked by severe intercurrent events, including cardiorespiratory arrest after early tracheal extubation in 5 patients, nosocomial pneumonia in 11, prolonged mechanical ventilation in all (58 +/- 41 days), and a fatal outcome in 3. We conclude that prolonged postoperative diaphragmatic dysfunction may cause severe life-threatening complications after cardiac operation and can be limited to some extent by avoiding the use of iced slush topical cooling of the heart.
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J. Thorac. Cardiovasc. Surg. · Feb 1994
Temporary and permanent restoration of airway continuity with the tracheal T-tube.
The advantages of the tracheal T-tube compared with a regular tracheostomy tube are a physiologic direction of air flow, preservation of laryngeal phonation, and superior patient acceptance. Between 1968 and 1991, 140 patients aged 7 months to 95 years underwent placement of T-, TY- (n = 7), or a modified extended T-tube (n = 4). Primary diagnosis was postintubation stenosis in 86 patients, burn injury in 13 patients, malignant airway tumors in 12 patients, and various disorders in 29 patients. ⋯ Long-term intubation in 112 patients exceeded 1 year in 49 patients and 5 years in 12 patients. Only 5 patients required tube removal for obstructive problems more than 2 months after placement. The tracheal T-tube restores airway patency reliably with excellent long-term results and represents the preferred management of chronic airway obstruction not amenable to surgical reconstruction.
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J. Thorac. Cardiovasc. Surg. · Feb 1994
Randomized Controlled Trial Clinical TrialAprotinin significantly decreases bleeding and transfusion requirements in patients receiving aspirin and undergoing cardiac operations.
Patients with heart disease are frequently maintained on a regimen of aspirin because of its ability to decrease thrombotic complications and reduce the prevalence of unstable angina and myocardial infarction. Aspirin-induced platelet acetylation also increases bleeding caused by impairment of platelet function during cardiac surgery. ⋯ High-dose aprotinin significantly reduces blood loss and red blood cell transfusions in patients receiving aspirin who undergo cardiac operations.