K. Shirley Smith

Aetiology of Complete Heart-block

That complete heart-block in the elderly is often due to coronary sclerosis has been, and still is, very widely assumed. The prevalence of coronary heart disease in the later decades of life, when such block commonly occurs, and the occasional appearance of complete heart-block in cardiac infarction have lent colour to this assumption. Moreover, the weighty affirmations of earlier authors have tended to discourage a critical attitude in this matter. The purpose of the present paper is to study the aetiology of complete heart-block and in particular to weigh the evidence upon which this disorder has been attributed to coronary disease. It is well first to review earlier relevant publications (Table I).

Episodic, Postural, and Linked Angina

7. It is most important to follow plasma calcium and phosphorus levels about twice weekly post-operatively. The calcium gives the best measure of the success of operation and of the subsequent recovery of remaining normal parathyroid tissue. The phosphorus level usually remains low for some time after and does not help much in management. A rise to abnormally high levels suggests temporary hypoparathyroidism (unless it can be adequately explained as due to worse renal function) and means that therapy may be required to correct hypocalcaemia even if there is no bone disease present. 8. Temporary post-operative correction of calcium and phosphorus levels with subsequent return to preoperative levels indicates that another parathyroid tumour has been left behind and is situated near the site of operation. No change in calcium and phosphorus levels means that a tumour remains far from the site of operation, or else that a misdiagnosis has been made. 9. Alkaline phosphatase levels should be followed every one or two weeks when they were raised preoperatively. A fall to normal means that the bone disease is nearly healed and there is no likelihood of a recurrence of tetany. If vitamin D is being given this can usually be stopped. In some cases many months may elapse before this occurs. 10. Rarely, signs resembling tetany persist for a short time post-operatively when plasma calcium levels are nearly normal. This may be due to Mg lack and will then respond to intravenous MgSO4. One should always bear Mg-lack in mind if a patients mental and neuromuscular symptoms do not immnediately respond to treatment of hypocalcaemia.

Aging of Arteries in Relation to Hypertension

With a new clinical test for the assessment of the elastic quality of the arterial reservoir, evidence has been obtained suggesting that essential hypertension can be separated into 2 distinct clinical types. In one group the elevation of pressure appears to be the consequence of physiologic aging of arteries and in the other hypertension is imposed upon a normal elastic arterial system. Patients in the elastic group were younger and had a more severe type of hypertension than those in the inelastic group.

Use of pressor agents in shock in myocardial infarction.

Twelve children with chronic asthma were given a trial course of cortisone and later a trial course of prednisolone, and the results are compared. The expiratory flow rate (E.F.R.40) was used to assess the cases and to measure the response to treatment. The general effects and relief of symptoms produced by the two drugs were similar, rather more children being rendered symptom-free by prednisolone than by cortisone, on a given dosage. Seven cases responded better to prednisolone, and two cases responded better to cortisone. The results show that 15 mg. of prednisolone and 75 mg. of cortisone produced a similar satisfactory effect, and on this dosage a peak response was generally observed after two to three weeks. When the dose was reduced, the response usually waned. The response to adrenaline is at first inhibited and later enhanced during either cortisone or prednisolone therapy.

A clinical method of studying the elasticity of large arteries.

Studies of the physical characteristics of large arteries (Roy, 1880; Bramwell, 1924; Hallock and Benson 1937) have shown that the aorta is more elastic in the young than in the elderly. As age advances the great vessels dilate while their distensibility diminishes and the range of pressure over which the wall is approximately elastic is reduced. These changes are the result of the tension in the arterial wall being thrown on to the collagen fibres as the elastic tissue deteriorates. Clinical studies of arterial elasticity have been made by Bramwell and Hill (1922). Their method was based upon the velocity of transmission of the pulse wave, which is determined by the physical properties of the vessel wall. The pulse wave velocity was found to increase with age (Bramwell et. al., 1923 b) and with the elevation of pressure across the wall of the artery (Bramwell et. al., 1923 a and c). This work contributed much to the understanding of the effect of age upon the arterial tree; it confirmed, in vivo, the arterial changes, described earlier, in excised strips of aorta, and showed that loss of elasticity was not confined to the aorta and its immediate branches, but spread to the smaller and more muscular vessels, for example, from the brachial to the radial arteries. The consequence of this is seen in the well-known increase of pulse pressure with age Unfortunately, the elasticity of the large arteries cannot be assessed by pulse pressure measurements alone since the latter are affected by other variables such as stroke volume, the force and duration of ventricular ejection, the peripheral resistance, and the volume of the great vessels. The test to be described attempts to establish clinically whether the vessels forming the main arterial reservoir are mainly elastic or whether the tension is being thrown on to the inelastic collagen. The differentiation depends upon changes in pulse pressure occurring in vessels when the level of diastolic pressure is reduced with little change in stroke volume. From the data obtained by Roy (1880), Hallock and Benson (1937), and Remington et al. (1948) it is possible to predict that in young, more or less elastic arteries little change in pulse pressure would occur as the blood pressure was reduced without changing stroke volume, whereas in elderly, inelastic arteries progressive diminution in pulse pressure would be seen as the diastolic pressure fell. This theoretical basis of the …

Urea, the Forgotten Diuretic

disbanded, and all those residents who were not ill were sent home. Close contact was kept with them, and in no case did they or any of their home contacts develop illness. The ward in which Case 8 was working before contracting encephalomyelitis was closed from June 8 to 18 for the admission of all except urgent cases. There was no spread to patients, although the probationers in training were visiting various hospitals in the group. All the patients admitted to the sick bay of the Royal Free Hospital, Grays Inn Road, were transferred to the infectious disease hospital of the group at Lawn Road as soon as the outbreak was diagnosed as acute infective encephalomyelitis, and succeeding cases were admitted directly to Lawn Road. Every attempt was made to correlate this epidemic with the previous outbreaks in the various hospitals of the group, but no success was achieved. Such pathological examinations as were carried out showed the same negative results as in previous epidemics. Some idea of the difficulties which arise during an outbreak of this description are typified by the fact that at the time of this small epidemic eight people working in or associated with the Royal Free Hospital were admitted or transferred to Lawn Road as suspected cases of acute infective encephalomyelitis which were not confirmed as such, the final diagnoses being as shown in the accompanying Table.

The changing electrocardiogram in Wilson block.

The significance of the Wilson variety of right bundle-branch block was investigated on the basis of serial electrocardiographic changes seen in almost half of the series. Wilson block may originate from both anteroseptal and posterior infarction; in the former it may form a solitary relic without prognostic significance; in the latter it denotes extensive septal involvement. It may modify the injury pattern of anterior infarction and may abolish the signs of posterior infarction; cardiac infarction may approximate it to the classic form of right bundle-branch block. Except in two patients, less than 4 per cent of the series, it was related to pathologic causes; it should therefore be regarded as a sign of organic heart disease.

Electrocardiographic assessment of posterior cardiac infarction

Abstract In a consecutive series of one hundred patients with posterior cardiac infarction assessed according to severity of the attack, 22 per cent were slight, 21 per cent moderate, and 57 per cent severe. This was in contrast to anterior cardiac infarction where this incidence was 42.2 per cent, 22.6 per cent, and 35.2 per cent, respectively. Greater gravity in posterior infarction can be explained by the frequency of arrhythmias and by the tendency of some slight posterior infarctions to become severe, a development exceptional in slight anterior infarction. In slight posterior cardiac infarction, the following electrocardiographic patterns were shown: absent pathologic Q waves in more than one-half the cases; R-T and T changes of the subacute type, for example, bowed R-T with isoelectric take-off and deep inversion of T; and electrocardiographic restoration in about one-fourth of the cases. The severe cases, in contrast, exhibited pathologic Q waves in almost every instance; an acute pattern, for example, high R-T take-off and monophasic T wave in the great majority, and arrhthmias were found in more than one-third of the cases. In the moderate group, the incidence of these signs was transitional, except that no arrhythmias were observed. There was no mortality in the slight and moderate group during the first two months. The mortality in the severe group of treated and untreated cases was 33 per cent. The diagnostic difficulties in slight posterior cardiac infarction were solved by effort test, Leads III R and aV FR . Recent bipolar leads advised for posterior infarction proved disappointing. No diagnostic problems have arisen in the moderate and severe cases. The absence of secondary T-wave changes in anterior chest leads proved an important point in the diagnosis of posteroanterior cardiac infarction. In five patients, slight cardiac infarction was followed by increasingly severe angina; two of these developed severe posterior cardiac infarction within a fort-night and one of them died. Early anticoagulant treatment appeared to delay the severe attack by months in one patient, while in the other two it seemed to prevent it. All the five showed electrocardiographic signs suggesting posterior subendocardial infarction, consisting in sagging or flat R-T depression in Leads II, III, and aV F . Effort test caused temporary extension of ischemia and transformed these dubious records into unequivocal ones. This result was considered an important indication for prompt anticoagulant treatment.

RADIOKYMOGRAPHY IN PATENT DUCTUS ARTERIOSUS

The introduction of radiokymography dates from the pioneer work of Gott and Rosenthal (1912). The modern multiple slit kymograph was developed subsequently by Stumpf and his coworkers (1934), while later studies were made by Faber and Kjaergaard (1936) and Bordet and Fischgold (1937). In an earlier paper one of us (Wood, 1939) described the kymographic patterns that comprise the borders of the normal cardiac silhouette. In the present study, X-ray kymography has been applied to the diagnosis of patent ductus arteriosus. The development during the past decade of the surgical treatment of the condition has greatly increased the importance of a diagnosis that may be difficult. In some cases the characteristic continuous murmur is not present and according to statistics quoted by Brown (1939) the pathognomonic murmur is absent in more than half of the cases. On the other hand Taussig (1947) claims that the diagnosis is based on the finding of a continuous murmur over the pulmonary area and that unless such a murmur is present the diagnosis cannot be made with certainty. It is when a murmur confined to systole is heard at the pulmonary area that diagnostic difficulties are likely to arise. Differentiation from pulmonary stenosis may not be easy and the possibility that patency of the ductus may be associated with other anomalies has to be remembered. It is an essential part of the diagnosis to exclude associated defects since when these exist ligature of a ductus may abolish an important compensatory mechanism. As exploratory operations are obviously undesirable, no effort must be spared to determine the correct diagnosis. We consider that the radiokymographic appearances which we now present should help to place the diagnosis of patent ductus arteriosus on a secure basis. METHOD OF INVESTIGATION AND RADIOGRAPHIC TECHNIQUE