Annotations

Patent ductus in infancy

Many children present with symptoms of cardiac failure in the first year of life, and a proportion of these will be found to be suffering from patent ductus arteriosus. It is important to distinguish this group, since prompt operation can be both lifesaving and curative. These children frequently present with feeding difficulties, failure to thrive, or as breathless babies, and it is not until a careful examination of the chest is undertaken that the presence of a cardiac murmur focuses attention on the heart as a possible cause of the symptoms.

Evidence of some degree of congestive failure, such as increase in venous pressure, hepatomegaly, or obvious dyspnea at rest, is very frequently present. When such signs are found, intensive medical therapy should be initiated without delay, and operation should be deferred until the cardiac failure has been adequately controlled with appro- priate medical therapy. Not infrequently an in- fection of the respiratory tract initiates cardiac decompensation, and, when there is any suggestion that this is so, appropriate antibiotic therapy should be commenced without delay. In general, these children show a prompt and gratifying re- sponse to treatment, and one can then proceed to operate, but it is most unwise to undertake operation in these cases before controlling any degree of cardiac failure which may be present.

In this age group the auscultatory findings are rarely typical, and the presence of a fully developed continuous murmur is unusual. Reliance must be placed on the peripheral signs. The presence of palmar pulsation and of a wide-amplitude peripheral pulse is always very suggestive of the presence of a patent ductus arteriosus. The electrocardiogram will usually show evidence of left ventricular strain, unless pulmonary hypertension or some other complication is also present, and radiography will demonstrate marked cardiomegaly with obvious evidence of a substantial left-to-right shunt. In general, no additional investigations should be carried out in these cases, since the children are usually seriously ill and to undertake such procedures as angiocardiography or cardiac catheterization may well militate against survival.

We have always adopted the attitude that if a patent ductus cannot be reasonably excluded on clinical examination, these children should be sub- mitted to exploratory thoracotomy. In practice, reliance on the peripheral signs and a careful appraisal of the clinical signs that are present will usually result in a correct diagnosis by an experienced cardiologist.

Douglas Cohen, MS., F.R.A.C.S. Adolph Baser Institute of Cardiology

Royal Alexandra Hospital for Children Sydney, Australia

Erythrocytosis and ischemic myocardial disease

It is generally recognized that both venous and arterial occlusions occur frequently in polycythemia Vera. Coronary artery thrombosis has been reported in from 61 to 25 per cent2 of patients with this disease, and treatment with radioactive phosphorus is said to decrease the incidence of coronary throm- bosis.* This would suggest that the association of coronary thrombosis and polycythemia is not mere coincidence. The patients reported in the literature usually have well-established erythremia. Yet there are patients in whom moderate erythrocytosis exists in association with coronary artery disease, and in whom the erythrocytosis is usually ignored.

In this group of patients it is difficult to know what influence the erythrocytosis has on the production or the course of myocardial ischemia. The increased viscosity of the blood would be expected to place a stress on the heart and result in some impairment to coronary flow. Possibly in part because of the increased viscosity of the blood, many of these patients have mild arterial hypertension.

Examination of the clinical records of such in- dividuals suggests that the erythrocytosis has an adverse effect on coronary blood flow. \ie have recently evaluated 12 patients with coronary artery disease and packed red cell volumes ranging between

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