Lawson Mcdonald

CORONARY HEART-ATTACKS IN EAST LONDON

All cases of cardiac infarction, acute coronary insufficiency and sudden death occurring in residents of the London Borough of Tower Hamlets below age 65 were registered over nearly three years, and survivors were followed up for one year. The attack-rate in men aged 45-64 years was 1 per 100 per annum but the recurrence-rate in survivors was 1 per 100 per month. Immigrants from Asia had more than the average, and those from the Carribean one tenth of the average attack-rate. Although it was unusual for general practitioners to manage cases at home by choice, nonetheless two-thirds of the deaths happened outside hospital and half of these were not witnessed. Half of those suffering coronary heart-attacks had a previous history of coronary disease and a sizable minority were already unfit for work. Approximately half of those attacked were alive at one year.

Plasma-catecholamines after cardiac infarction.

Abstract Plasma noradrenaline and adrenaline were measured in fifty men after cardiac infarction and in fifty controls. Noradrenaline levels were significantly higher in the cardiac patients compared with the controls, but adrenaline levels were similar in the two groups. The catecholamine levels were analysed for the patients in relation to the incidence of dysrhythmias. Compared with patients who had no complications, patients with atrial dysrhythmias or early ventricular dysrhythmias had higher noradrenaline concentrations in their plasma. There was no such difference for patients with late ventricular dysrhythmias, and adrenaline levels were unremarkable. The raised noradrenaline levels are not thought to be related to stress because six other patients undergoing the stressful procedure of cardiac catheterisation had low levels. High noradrenaline levels in three racing drivers shortly after a race suggest that the beta-adrenergic effect of noradrenaline does not lead to ventricular dysrhythmias in the presence of a healthy heart. It is concluded that there is an increased noradrenaline release after myocardial infarction and that this is related to the development of serious dysrhythmias.

Mitral regurgitation in coronary heart disease.

Mitral reguritation is a relatively common finding in coronary heart disease. In this series of 127 patients, selected with a view to coronary or left ventricular surgery on the basis of severity of symptoms, the incidence was 39 (31%). Mitral regurgitation is significantly more common in patients with a history or electrocardiographic evidence of previous myocardial infarction. Clinically it may present as a pan- or late systolic or even a mid-systolic, ejection type murmur at the apex or at the left sternal edge; but in 39 per cent of the patients with angiographic mitral regurgitation no murmur was present. Angiographically important mitral regurgitation (grades 2-4/4) was usually associated with a systolic murmur; this finding was independent of ejection fractions. Left ventricular enlargement clinically or radiographically is likely to accompany mitral regurgitation but left atrial enlargement (electrocardiographically or on chest x-ray) is a more reliable pointer to mitral regurgitation and pulmonary venous hypertension is even more strongly suggestive of its presence. The electrocardiographic signs of papillary muscle infarction were rare in this series (15%) and were not related to angiographic mitral regurgitation. There was no difference in the incidence of mitral regurgitation in association with anterior or inferior myocardial infarction or in distribution of coronary artery disease. There is, however, a higher incidence of mitral regurgitation in more severe coronary arterial disease (P less than 0-05). The incidence of mitral regurgitation is significantly higher with reduction in left ventricular ejection fraction (P less than 0-001), with rise in the left ventricular end-diastolic pressure (P less than 0-02), and with abnormal contraction patterns, but the severity of mitral regurgitation is not significantly related to these findings.

Association of prolapse of posterior cusp of mitral valve and atrial septal defect.

Eleven patients with fossa ovalis atrial septal defects and prolapse of the posterior cusp of the mitral valve are described. Six patients had clinical evidence of mitral regurgitation, and in 2 others the electrocardiogram was unusual for uncomplicated fossa ovalis atrial septal defects. The varied appearance of the prolapsed cusp was shown by left ventricular angiography. The principal significance of this association is in its differentiation from atrioventricular defects.

POST-OPERATIVE HÆMORRHAGE AND RELATED ABNORMALITIES OF BLOOD COAGULATION IN CYANOTIC CONGENITAL HEART DISEASE

An abnormal tendency to post-operative hmorrhage may occur in patients with severe cyanotic congenital heart disease (Blalock, 1948). In preliminary findings by Somerville and McDonald (1960) the thromboplastin generation test showed evidence of defective blood coagulation in these patients. Blood coagulation has been further investigated in patients with cyanotic and acyanotic congenital heart disease, and in patients with polycythlmia from other causes.

Sustained-release quinidine (Kinidin Durules) in maintaining sinus rhythm after electroversion of atrial dysrhythmias.

mean relapse time being 3-75 months after DC shock. A second electroversion preceded and followed by maintenance Kinidin was performed, and the mean electrical energy for conversion to sinus rhythm remained unchanged at 142joules. The dose of slow-release quinidine was controlled by frequent quinidine blood levels. A careful follow-up study was maintained for 26 months. Twelve patients have remained in sinus rhythm for a sirnificantly longer period while taking Kinidin, in whom the mean quinidine blood level was 2-I ug./ml., eight reverted in a shorter time despite the same mean quinidine blood levels, and in four the length of time of maintained sinus rhythm was unchanged. Complications to the quinidine preparation occurred in four (25%) and included unduegain in weight, skin sensitivity,gastrointestinal bleeding, and severe diarrhoea. The results of the trial when analysed statistically show a small benefit in the use of this preparation in maintaining sinus rhythm for an additional four months after electroversion, when the optimal dose controlled by frequent blood levels is administered, but thereafter there is little evidence that Kinidin Durules are beneficial long term. It is concluded that Kinidin Durules may be worth while in selected patients in whom the drug is well tolerated, particularly if relapse to atrial fibrillation or flutter has occurred within the first few months after electroversion and in whom sinus rhythm is haemodynamically important.

HOMOGRAFT REPLACEMENT OF THE AORTIC VALVE: Immediate Results and Follow-up

Abstract Homograft replacement of the aortic valve was performed on 146 patients between 1964 and December, 1966. An additional surgical procedure was necessary in 50 patients: mitral valvotomy in 25, repair or replacement of the mitral and tricuspid valves in 22, and closure of a ventricular septal defect in 3. Mortality during the initial hospital admission was 24%. 101 patients are alive one to four years after surgery. Postoperative aortic regurgitation developed in more than half the patients but was usually trivial. It was of haemo-dynamic importance in 18 patients, 7 of whom are controlled on medical treatment. There have been no cases of systemic embolism, haemolytic anaemia, or sudden death. Of the 109 patients discharged from hospital with aortic homograft valves the result is considered excellent in 35, good in 38, satisfactory in 11, and poor in 10. Prosthetic replacement of the graft has been successfully performed in 5 patients. There have been 10 deaths since discharge from hospital; aortic regurgitation and infective endocarditis were the principal causes of late deaths.

Idiopathic calcified myocardial mass

Patterson, D., Gibson, D., Gomes, R., McDonald, L., Olsen, E., Parker, J., and Ross, D. (1974).Thorax,29, 589-594. Idiopathic calcified myocardial mass. Myocardial calcification can be subdivided into three groups—metastatic, dystrophic or an extension inwards from the pericardium. This case in which the calcified myocardial mass was initially delineated by radiography and by echocardiography and subsequently removed does not fit into any subdivision and has been termed idiopathic.

SYSTEMIC HYPERTENSION AFTER HOMOGRAFT AORTIC VALVAR REPLACEMENT A CAUSE OF LATE HOMOGRAFT FAILURE

Abstract 116 patients undergoing successful aortic valvar replacement with an irradiated homograft valve have been followed up for periods of 6 months to 51/2 years. 39 of the patients (34%) have developed a diastolic pressure of greater than 90 mm. Hg, and in all but 1 of these the diastolic pressure exceeded 100 mm. Hg. In 4 patients hypertension was first noted in the immediate postoperative period, but the prevalence then rose until 53% were hypertensive 5 years after surgery. Neither preoperative hypertension nor impaired renal function were significantly associated with the development of postoperative hypertension. The frequency of hypertension in males (39%) was significantly greater than in females (15%), and patients with preoperative aortic regurgitation developed hypertension more frequently (50%) than those with dominant aortic stenosis (27%). The presence of hypertension was a major determinant of late failure of the irradiated homograft. Significant regurgitation has occurred in 14% of the patients and necessitated reoperation in 4·3%. In the patients with hypertension before starting hypotensive treatment the incidence of homograft failure was 40%, as compared to 8% in the normotensive group (P

LONG-TERM RESULTS OF PULMONARY AUTOGRAFT REPLACEMENT FOR AORTIC-VALVE DISEASE

Abstract 43 patients who had aortic-valve replacement by pulmonary autograft were assessed two and a half to five years after operation. 3 patients required re-operation and 1 of them, the only late death in the series, died awaiting surgery. By clinical criteria, 40 patients were well. 35 had postoperative haemodynamic and angiocardiographic assessment which showed that mild aortic regurgitation was common. 8 had important aortic regurgitation which dated from the early postoperative period and generally occurred in those patients with severe preoperative regurgitation. There was no late valve failure, haemolysis, thromboembolism, or systolic-outflow gradients or evidence of progressive aortic regurgitation or valve failure.