Chronic traumatic aneurysms of the thoracic aorta.

During the last 10 years (1975-1985), a total of 18 cases of posttraumatic aneurysm at the level of the thoracic isthmus were operated on. Six of the 18 were women (19-71 years of age) and 12 were men (17-61 years of age). The mean age at the time of injury was, respectively, 22 and 25.8 years and, at the time of operation, 34.5 and 35.5 years. The patients were all involved in a motor vehicle accident, except for 2 (1 falling, 1 crushing). Thirty-nine percent of the patients had no apparent thoracic injury and 89% had associated injuries (bony fractures, craniofacial, visceral and abdominal). Eight of the 18 were asymptomatic at the time of operation, the others had various symptoms (pain, fever, dyspnea, cough, hoarseness, murmur, or hemoptysis). Enlargement of the aortic button was present in every case. Seventeen patients were operated on electively from 4 months to 50 years after the injury. Circumferential rupture was total in 9 patients and partial (2/3 to 9/10) in the others. Complete repair was done by either prosthetic Dacron tube (3), Dacron patch (2), or direct suture (12). Protection by femoro-femoral bypass was used in 3 and simple aortic cross-clamp was used in 14. Mean time of aortic cross-clamp was 36.9 minutes (range, 16-80 min). Among these 17 patients, there was no hospital mortality and no late death. One patient had regressive paraplegia. One patient was submitted to an emergency operation for an intrapulmonary rupture of an infected aneurysm and died in the operating room before completion of the repair.(ABSTRACT TRUNCATED AT 250 WORDS)

[Auricular flutter after cardiothoracic surgery. Treatment by auricular stimulation using the esophageal approach]. / Flutter auriculaire après chirurgie cardio-thoracique. Traitement par stimulation auriculaire par voie oesophagienne.

Transoesophageal atrial pacing was used in 10 patients to interrupt post-operative atrial flutter after cardio-thoracic surgery. The method was successful in all cases. The arrhythmia was converted directly into sinus rhythm in 8 patients and into atrial fibrillation followed by spontaneous reversion to sinus rhythm in 2 patients. The results differed according to the underlying disease. Return to sinus rhythm was the rule in all patients who underwent coronary artery bypass grafting and pneumonectomy, whereas transient atrial fibrillation seemed to be more frequent (and should be considered a satisfactory result) in patients with heart valve surgery. Relapses of arrhythmias seemed to be more resistant to transoesophageal stimulation irrespective of the operation performed. The method is non-invasive, easy to carry out and safe in patients receiving digitalis. The risk of ventricular pacing is very low. The burning sensation and chest pain experienced during stimulation are well tolerated. Transoesophageal pacing is as effective as epicardial atrial stimulation and more effective in such patients than temporary transvenous atrial pacing.

The QT interval: a predictor of the plasma and myocardial concentrations of amiodarone.

A study was performed to assess whether plasma and myocardial concentrations of amiodarone correlated with changes on the surface electrocardiogram. Nine patients--seven with angina and two with paroxysmal ventricular tachycardia--were treated with oral amiodarone (200-400 mg daily) for at least nine months before undergoing cardiac surgery. QT intervals were measured from lead II of the surface electrocardiograms recorded before amiodarone treatment and immediately before surgery. Patients with prominent U waves after taking amiodarone were excluded from the study. Plasma and myocardial samples were collected at the beginning of the surgical procedure for estimating plasma and myocardial concentrations using the high performance liquid chromatographic technique. Amiodarone caused a significant lengthening of the QTc interval. There was a good correlation between plasma and myocardial concentrations, and both correlated well with the percentage increase in the QTc interval. Although there was a strong correlation between the dosage given (mg/kg/day) and both plasma and myocardial concentrations, the correlation with the percentage increase in the QTc interval was weaker but still highly significant. Despite previous reports to the contrary, the findings indicate that the plasma concentration of amiodarone does correlate well with the myocardial concentration. The degree of lengthening of the QTc interval may be used clinically to estimate the myocardial concentration of amiodarone.

Determination of cardiac and plasma drug levels during long-term amiodarone therapy.

A study of plasma and cardiac concentrations of amiodarone during the course of long-term oral therapy was made possible by the improvement of analytical high performance liquid chromatography of plasma and tissue extracts. The plasma level was found to increase linearly with the daily dose of the drug, above a threshold value of c. 1 . 9 mg kg-1 day-1. Similarly, the cardiac content increased linearly with the daily dose, with no threshold, showing that the drug is taken up and accumulated in the cardiac tissue, with no obvious difference between atrial and ventricular samples (P greater than 0 . 05). Both plasma and heart showed no saturation at high drug intake, a justification for increasing the oral intake in severe cases. The linear relationship between tissue and blood concentrations allows a prediction of the cardiac level from a simple and routine blood analysis.

Risks and benefits of aortocoronary bypass surgery in patients aged 65 years or more.

Between January 1970 and July 1978, 85 patients aged 65 years or more underwent aortocoronary bypass surgery at the Montreal Heart Institute. The mortality during the operation and the first 29 days thereafter was 12% overall, but was only 5% when the myocardium was protected by the use of cold cardioplegic solutions. Of the 75 patients who survived this period 7 (9%) had a perioperative transmural myocardial infarction. Nonfatal noncardiac complications were more common in these patients than in younger patients, but did not lead to permanent deficits. Three patients died after discharge from hospital, two of cardiac causes. Only one patient had a nonfatal myocardial infarction after discharge. The actuarial 5-year survival rate for all the patients was 80%. After a mean follow-up period of 30 months the condition of 94% of the patients was improved by at least one class of the New York Heart Association functional classification, and 68% were asymptomatic. It is concluded that aortocoronary bypass surgery can be performed in selected older patients with a relatively low in-hospital mortality and morbidity. Symptomatic improvement occurs in almost all such patients. Cardiac catheterization and aortocoronary bypass surgery should therefore be performed in selected older patients with severe angina that is refractory to optimum medical therapy.

[Recurrent angina after coronary surgery. Results of reoperations for myocardial revascularization]. / L'angor récidivant après chirurgie coronarienne. Résultats des réinterventions de revascularisation myocardique.

40 patients presented with invalidating angina after initial revascularisation surgery (44 operations). The relapse of angina was attributed to thrombosis or stenosis of the graft (33 p. 100), graft failure plus the presence of non-bypassed coronary lesions (progression of coronary artery disease or incomplete initial revascularisation) (52 p. 100) or to the presence alone of coronary lesions which had not been bypassed (15 p. 100). At reoperation 37 stenosed or thrombosed grafts were replaced or repaired and 36 new aortocoronary bypasses were implanted. The perioperative risk was comparable to that of the initial operation (4,5 p. 100 mortality, 13,6 p. 100 myocardial infarction). The long term clinical improvement (34 months) was however less satisfactory (30 p. 100 unimproved). Several factors may account for the relatively high failure rate: the incidence of incomplete revascularisation; perioperative myocardial infarction and, above all, rapid progression of the coronary artery disease. Reoperation for myocardial revascularisation should therefore be restricted to patients with severe angina despite medical therapy, in whom the angiographic appearances suggest that optimal revascularisation might be possible.

MB creatine kinase and the evaluation of myocardial injury following aortocoronary bypass operation.

Myocardial injury was studied in 104 patients undergoing coronary artery grafting without cold chemical cardioplegia using the quantity of the isoenzyme MB of the creatine kinase liberated as an indicator. This method of evaluation, which is said to permit comparison of different techniques of myocardial protection, allowed us to consider the relative importance of several factors believed to have an influence on intraoperative myocardial injury. Indices of significance were duration of symptoms before operation, presence of chronic arterial hypertension, and the type of antiangina treatment employed. Other operative factors included severity of the arterial lesions, number of anastomoses performed, and duration of extracorporeal circulation and of aortic cross-clamping.