Oropharyngeal dysphagia and oculopharyngeal muscular dystrophy

Oculopharyngeal muscular dystrophy is an autosomal dominant transmitted condition seen mainly in French Canada. The largest number of publications on these patients concerns a Quebec family whose descendants have spread throughout the United States. Families of different ethnic origins have also been reported from around the world, although there is no evidence that the neuromuscular disease reported is the same, despite the similarity of the syndrome. When severe oropharyngeal dysphagia results, these patients can significantly benefit from a cricopharyngeal myotomy.     

Prediction of risk in noncardiac operations after cardiac operations

To determine the preoperative variables affecting the mortality rate and the development of severe complications in patients who have had myocardial revascularization or a valve replacement and who then undergo a noncardiac operation, we retrospectively studied data from 120 such patients over the 5 years from 1982 through 1986. Thirty-six percent of patients had a noncardiac operation during the first month after the cardiac operation. The mortality rate was 11%, and the morbidity rate was 56%. The statistical comparison of the predictive accuracy of postoperative complications of three simple, widely used classifications (American Society of Anesthesiologists physical status, New York Heart Association classification, Massachusetts General Hospital cardiac risk index) demonstrated the superiority of the simplified three-class cardiac risk index (Massachusetts General Hospital-cardiac risk index; predictive accuracy of 84%). In a multivariate discriminant analysis of 21 variables in this population, five variables (myocardial infarction in previous 6 months, S3 gallop or jugular vein distention, arrhythmia on last preoperative electrocardiogram, emergency operation, delay between cardiac and noncardiac operation) were identified as being the most predictive of a postoperative complication. When these variables were used in the function (DF3) obtained by linear discriminant analysis, the prediction accuracy of a postoperative complication reached 83%. Performance of the new models in a prospective validation population remained satisfactory (75% for Massachusetts General Hospital-cardiac risk index three-class index and 72% for DF3). Extensive statistical analysis of our data tested by a validation study provided simple predictive models based on clinical variables easily available even in emergency situations.     

Rapid sustained recovery after cardiac operations

After successful cardiac operations in the early 1980s the most common causes of prolonged hospitalizations were noncardiac disorders. We prevented or quickly corrected these noncardiac disorders after operations in succeeding patients and observed in the following 2 years that the shortest postoperative stays in the hospital were followed by the fewest rehospitalizations. In 240 consecutive patients the median length of hospital stay after operation was 4 days. The operations included coronary artery bypass procedures, aortic valve replacements, and mitral valve operations. Six patients (2.5%) were rehospitalized within 6 months after discharge and five patients (2.1%) were rehospitalized 6 to 24 months after discharge: Longer initial hospitalizations would not have prevented rehospitalizations. Forty of the 240 patients were discharged on the third postoperative day or earlier (one patient). None died or were rehospitalized in the following 2 years. Prevention or quick correction of noncardiac disorders allowed rapid recovery after heart operations, and rapid recovery indicated that health would be maintained.     

Chylopericardium after cardiac operations in children

BACKGROUND: Chylopericardium is a rare complication after operation for congenital heart disease. The incidence and clinical outcomes in a large cohort of surgical patients are unknown. METHODS: We retrospectively reviewed the clinical records spanning more than 12 years in a single institution of 16 children with chylopericardium after cardiac operation. RESULTS: We identified 16 patients with chylopericardium between 1985 and 1997. Chylopericardium was isolated in 7 patients. Twelve patients required pericardial drainage. Patients with isolated chylopericardium presented late and were treated initially as having postpericardiotomy syndrome. Three patients underwent thoracic duct ligation. There were two late deaths unrelated to the chylothorax. Associated diagnoses were internal jugular vein thrombosis and recurrent pulmonary vein obstruction (1 of 16 patients), an associated syndrome but not Turner or Noonan (10 of 16), superior cavopulmonary or total cavopulmonary anastomosis (7 of 16), atrioventricular septal defect repair (5 of 16), and repair of tetralogy of Fallot (2 of 16). CONCLUSIONS: Percutaneous drainage to relieve tamponade together with a low-fat or medium-chain triglyceride diet results in resolution in most cases of postoperative chylopericardium. If a pericardial effusion enlarges, fails to clear on aspirin therapy, or presents late after hospital discharge, diagnostic pericardial tap and a low-fat diet are indicated.     

Temporary external DDD pacing after cardiac operations

Temporary atrial and ventricular pacing in the DVI, VVI, and AOO modes using atrioventricular sequential DVI devices is routinely used in cardiac operations. This study evaluated a new temporary external DDD pacemaker (Medtronic 5345 External Pulse Generator) capable of ten pacing modes. Thirty-nine devices have been applied to 38 adult patients (27 male, 11 female) after a variety of open heart procedures. Group 1 had atrial pacing wires placed 1.5 to 2.0 cm apart superiorly on the right atrium, group 2 had atrial wires placed 1.0 to 1.5 cm apart on the right atrial free wall, and group 3 had atrial wires placed on the right atrial free wall 0.8 cm apart, using a Silastic ring for fixation. Ventricular wires were placed on the free wall (group 1) or the diaphragmatic surface (groups 2 and 3) of the right ventricle. Postoperative atrial and ventricular sensing and pacing thresholds were obtained on return to the intensive care unit; analysis of variance demonstrated a significantly greater atrial sensing threshold in group 3. Four patients in group 1 permanently lost atrial sensing, 1 patient in group 2 intermittently lost atrial sensing at 24 hours with return at 36 hours postoperatively, and 1 patient in group 1 lost ventricular sensing capability. All other patients had adequate atrial and ventricular sensing capability documented until elective pacemaker removal (mean, 166 hours; range, 17 to 667.5 hours). Nineteen patients required some form of temporary pacing postoperatively; 11 patients demonstrated hemodynamic benefit from a pacing mode that is not available on the currently used DVI devices, and 7 of these required true DDD pacing capability. Six patients benefited from atrial pacing with adequate atrial sensing and simultaneous ventricular backup. Burst pacing with the device was used successfully to treat postoperative atrial flutter in 2 patients. We conclude that temporary external DDD pacing is feasible and effective in postoperative cardiac surgical patients. Atrial sensing is possible in most patients but electrode positioning is important for adequate thresholds. In some patients, hemodynamic as well as electrophysiologic improvement can be demonstrated with universal DDD pacing capability as compared with standard DVI pacing.     

Prophylactic tranexamic acid decreases bleeding after cardiac operations

Thirty-eight patients undergoing a cardiac operation randomly received either tranexamic acid, a potent inhibitor of plasminogen, or placebo in an effort to determine whether prophylactic antifibrinolytic therapy reduces chest tube drainage. Twelve-hour blood loss was 750 +/- 314 (standard deviation) ml in the placebo group and 496 +/- 228 ml in the drug group (p = 0.0057). Fibrin split products were present more frequently in patients in the placebo group (17 of 20 compared with four of 18 in the drug group; p = 0.0002). Tranexamic acid markedly decreased plasminogen availability (112 +/- 104 units in the placebo group versus 36 +/- 18 units in the drug group, p = 0.0058). Plasma fibrinogen concentrations were similar in the placebo and drug groups. Patients in the placebo group received more fresh-frozen plasma and more mediastinal shed blood than those in the drug group. No coagulation-related complication occurred in the group receiving tranexamic acid. We conclude that prophylactic tranexamic acid can be administered safely to inhibit fibrinolysis during cardiac operations, decrease postoperative bleeding, and possibly decrease the frequency of blood product transfusion.     

Respiratory gas exchange before and after cardiac operations

The changes in oxygen consumption and carbon dioxide production were measured both before and for 6 hours after a variety of cardiac operations. Core and peripheral temperatures were measured simultaneously. Oxygen consumption was initially similar to preoperative values but rose over the next 2.5 hours by an average of 31% above basal. Carbon dioxide production was initially higher than preoperative values, then declined briefly, and finally showed an average increase above basal of 29%. Core temperature rose from an initially slightly depressed level to a maximal level 4 hours postoperatively at an average rate of 0.4 degrees C/hr. It was not possible to separate cause and effect between the temperature and oxygen consumption increases, but more effective postoperative temperature control might limit metabolic demands at a critical time postoperatively.     

Unexpected, sustained ventricular tachyarrhythmia after cardiac operations

Unexpected, sustained ventricular tachyarrhythmia after cardiac operations is differentiated from sustained ventricular tachycardia and ventricular fibrillation from known antecedent causes, such as recent or perioperative myocardial infarction, low cardiac output, preoperative ventricular arrhythmia, sympathomimetic drugs, drug toxicity, and metabolic abnormalities. Sixteen of 2364 patients (0.68%) who underwent heart operations met strict exclusion criteria for unexpected sustained ventricular tachyarrhythmia that occurred 1 hour to 12 days after operation. Recurrent ventricular tachyarrhythmias occurred in 12 patients; three died (21%), despite resuscitation from the initial episode. All patients had significant preoperative left ventricular dysfunction and 14 had ejection fractions below 30%. Fifteen of the 16 patients had monomorphic ventricular tachycardia at the initial episode. Empirically prescribed therapy was not effective in suppressing ventricular tachyarrhythmias inducible by programmed stimulation during postevent electrophysiologic studies in 10 of the 13 survivors. Inducibility was eventually prevented by drugs in nine patients, three patients received automatic implantable cardiac defibrillators, and one patient underwent successful catheter ablation of ventricular tachycardia. No patient died of recurrent ventricular tachyarrhythmias during the follow-up of 8 to 55 (mean 29) months after hospital discharge.