Biomedical subjects
Publications and source records attributed to J Deanfield.
A patient with hypertrophic cardiomyopathy, syncope, and frequent ventricular tachycardia was monitored during a syncopal episode. An unrecordable blood pressure and the loss of a left ventricular outflow tract murmur without evidence of arrhythmia suggested a primary haemodynamic mechanism such as reduction in left ventricular volume.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The natural history of electrocardiographic left ventricular hypertrophy was assessed in relation to clinical features, treatment with propranolol and prognosis in 100 patients with hypertrophic cardiomyopathy who were followed 5--20 years (mean 8 years). Seventy-one patients received propranolol, 120--800 mg/day (mean 240 mg). At diagnosis, the voltage measurement from SV1 + RV5 was 37 +/- 20 mm, the R wave in aVL was 12 +/- 6 mm and the mean frontal plane voltage was 15 +/- 10 mm. After 5 years, these values were increased to 43 +/- 22 mm (p less than 0.0002), 14 +/- 6 mm (p less than 0.003) and 17 +/- 10 mm (p less than 0.01), respectively. Neither a left ventricular outflow tract gradient nor propranolol treatment influenced these voltage changes. Twenty patients had an increase of more than 10 mm in SV1 + RV5, which was associated with exertional chest pain (p less than 0.006) and death (p less than 0.02). Four patients had a decrease of more than 10 mm in SV1 + RV5. Two of these received high-dose propranolol, one 720 mg/day for 12 years and another 800 mg/day for 12 years. No other patient received more than 480 mg of propranolol daily. In hypertrophic cardiomyopathy there is electrocardiographic evidence of progressive hypertrophy, which is associated with poor prognosis and is not influenced by treatment with propranolol in moderate dosage. Regression of hypertrophy is rare and may be related to long-term treatment with high-dose propranolol.
Infective pericarditis is rare; the characteristic presenting illness in 3 children, each aged under one year, is recorded. Early diagnosis is important since surgical drainage of the pericardium is often necessary in addition to antibiotic therapy. The clinical features may suggest pericarditis, but diagnosis is readily and reliably confirmed by echocardiography.
A patient with complete atrioventricular block was fitted with a temporary endocardial pacing wire via a right subclavian percutaneous approach. The result was initially satisfactory, but within a few days radiography for left-sided chest pain showed pneumopericardium. A permanent epicardial pacing system was therefore substituted and she remained well for three months. She was then admitted for syncope: the pacemaker was failing to capture, and radiography showed pericardial and pleural effusion. A new permanent endocardial pacing system using a wedged electrode was inserted and she made an uncomplicated recovery. Pneumopericardium complicating endocardial pacing has apparently not been reported before. Presumably the electrode had penetrated both the right ventricle and the pericardium into the adjacent lung.
Retrospective analysis of the clinical course of 254 patients with hypertrophic cardiomyopathy, followed up for 1 to 23 years (mean 6), disclosed that 58 had died, 32 of them suddenly. The 196 survivors were compared with the 32 patients who died suddenly and with the 38 who died suddenly or with heart failure. The combination of young age (14 years or less), syncope at diagnosis, severe dyspnea at last follow-up and a family history of hypertrophic cardiomyopathy and sudden death best predicted sudden death (false negative rate 30 percent, false positive rate 27 percent). A "malignant" family history was associated with poor prognosis, particularly in the younger patients; a family history of hypertrophic cardiomyopathy without sudden death was more frequent in the survivors (12 percent) than in the dead (5 percent). Patients who had a diagnosis in childhood were usually asymptomatic, had an unfavorable family history and a 5.9 percent annual mortality rate. In those aged 15 to 45 years at diagnosis, there was a 2.5 percent annual mortality rate and syncope was the only prognostic feature. Among those diagnosed between age 45 and 60 years, dyspnea and exertional chest pain were more common in the patients who died, and the annual mortality rate was 2.6 percent. Poor prognosis was better predicted by the history at the time of diagnosis and by changes in symptoms during follow-up than by an electrocardiographic or hemodynamic measurement.
Although it is a common congenital cardiac lesion, secundum atrial septal defect (ASD) rarely presents in infancy. Its natural history in the first two decades of life is generally benign. Reports of symptomatic ASD in early childhood stress the place of conservative management, and recommend that the operation should be deferred until school age. Few accounts of the indications for surgery in infancy exist. We present our experience of 6 patients who failed to respond adequately to conservative treatment and required operation for intractable heart failure due to isolated secundum ASD in the first year of life. As their presentation and physical signs were not typical of ASD seen in later childhood, they presented problems both of diagnosis and management.
Digitised left ventricular echocardiograms were studied in nine children with congenital mitral stenosis to assess the severity of inflow obstruction. In six children the two prime indices of mitral stenosis were abnormal, with a prolonged time from minimum dimension to 20 per cent dimension change and a reduced peak dimension change during diastole. In three, however, these values did not suggest inflow obstruction, depsite significant gradients at cardiac catheterisation. Two-dimensional echocardiography was performed in 10 children with congenital mitral stenosis to determine the mitral annular size and the morphology of the valve and subvalvular apparatus. The annular size and number of papillary muscles could be assessed along with the detection of combined mitral abnormalities. Two-dimensional studies can reliably delineate the type of mitral abnormality, and should be performed in all cases with congenital heart disease having a high incidence of associated left ventricular inflow obstruction. Digitised M-mode left ventricular echocardiography is in general unreliable in assessing congenital obstruction, though it may be of some value in individual cases.
The effects of smoking on the treatment of angina has been studied in 10 patients. Each patient underwent 4 randomized 1-week treatments consisting of on and off smoking, and on and off propranolol (360 mg/day). At the end of each treatment a maximal exercise test was performed using 16 praecordial leads. Smoking was associated with a significantly higher heart rate, blood pressure, area and severity of ST-segment depression. This was not abolished by propranolol. Thus, smoking aggravates the simple haemodynamic variables used to assess myocardial oxygen requirements and the electrocardiographic signs of ischaemia; this is true even after treatment with propranolol.
This study examines the effects of increasing doses of nifedipine on exercise-induced ST-segment depression in patients with severe typical stable angina pectoris. 10 patients underwent four 1-week treatment periods in a single-blind clinical trial. These were nifedipine 0, 30, 60, and 90 mg in divided doses daily. At the end of each week a maximum exercise test was performed using 16 precordial electrocardiographic leads and the ST-segment changes measured immediately after exercise. In 4 patients nifedipine produced no effects on these electrocardiographic parameters; 4 patients improved and 2 deteriorated. Thus, a dose of nifedipine, effective in 1 patient, can have opposite effects in another.
In a prospective study of abnormalities of plasma sodium concentration carried out over one year 20 patients were identified who had a concentration exceeding 154 mmol(mEq)/1. Of these, eight patients had diabetes mellitus, eight had primary intracranial disorder, and four had become dehydrated. Five of the eight diabetics presented with hyperosmolar, non-ketotic precoma, and in all eight hypernatraemia developed despite treatment with hypotonic (0.45%) saline. There was a good correlation (r = -0.93) between the rates of change of plasma sodium and blood glucose concentrations, and thus a rise in plasma sodium concentration appeared to be a consequence of the treatment. In the early phase of treatment urinary sodium loss was extremely low despite a brisk diuresis, the infused sodium then predisposing the patients to hypernatraemia. All of the eight patients with intracranial disorders showed evidence of abnormal production of the antidiuretic hormone, six having frank diabetes insipidus. Severe hypernatraemia in this group was associated with a high mortality, fluid balance being difficult to maintain. Two of the four patients who had become dehydrated had had a recent gastrointestinal haemorrhage. In these patients infusion of 0.9% saline contributed to the hypernatraemia since urinary sodium loss was low. Severe hypernatraemia in adults is uncommon, but in established cases plasma and urinary biochemical indices should be measured frequently. Monitoring of the central venous pressure is usually necessary, and patients are best managed in an intensive care unit.
The effects of transient regional ischemia on monovalent cation uptake and extraction by the myocardium were studied in seven open chest dogs. Following a 10-20% stenosis of the left anterior descending coronary artery to prevent reactive hyperemia, the regional myocardial uptake of the monovalent cation 82Rb (ml/min/g X extraction) was measured before, during, and at 10, 30, and 60-80 min after a 10 min total occlusion of the left anterior descending coronary artery using positron emission tomography. Regional myocardial blood flow was also measured at the same time interval using radiolabeled carbonized microspheres. The regional myocardial extraction of 82Rb was calculated as uptake/flow. In normally perfused myocardial regions there was an inverse relationship between 82Rb extraction and blood flow [extraction = -0.56 (In flow) + 0.46, r = 0.93] over a range of flow from 0.3 to 4 ml/min/g. During the prolonged recovery of 82Rb uptake in the transiently ischemic region, flow had returned to normal levels but 82Rb extraction at a given value of flow was significantly decreased at the 30 and 60-80 min times after release of the occlusion compared with normally perfused regions. Thus, prolonged abnormalities in the 82Rb uptake and extraction occur in myocardium recovering from transient ischemia.