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Biomedical subjects

R J Northcote

Publications and source records attributed to R J Northcote.

At least 37 records · Page 2Linked to original sources
PubMed1986

Influence of intrinsic sympathomimetic activity on respiratory function during chronic beta blockade: comparison of propranolol and pindolol.

The long term effect of beta blockers and the influence of intrinsic sympathomimetic activity on respiratory function were assessed in patients with chronic stable angina pectoris randomised to receive treatment with propranolol (n = 21) or pindolol (n = 19) for one year. Forced expiratory volume in one second (FEV1) had fallen by a mean of 240 ml after one year (p less than 0.001) in those treated with propranolol compared with 120 ml in those treated with pindolol (p less than 0.05). The difference between the groups was significant (p less than 0.01). Vital capacity fell significantly only in those treated with propranolol (p less than 0.05 at one year). In those in whom the basal ratio of FEV1 to forced vital capacity was low (less than 70%) propranolol, but not pindolol, caused a significant (p less than 0.05) fall in FEV1 throughout treatment. Long term administration of pindolol has a less adverse effect on respiratory function than propranolol, which results in a progressive deterioration in respiratory function over one year.

Forced Expiratory Volume↗
PubMed1986

Continuous 24-hour electrocardiography in thyrotoxicosis before and after treatment.

Ten thyrotoxic individuals, who otherwise had no evidence of cardiovascular disease, underwent continuous ambulatory 24-hour ECG monitoring, before and after antithyroid treatment. The mean age of the subjects was 41 +/- 14.4 years (mean +/- SD) with a range of 22 to 66 years. When subjects were thyrotoxic, the mean heart rate for the group was 104 +/- 10.8 bpm. This fell to 82 +/- 6.8 bpm when the subjects were rendered euthyroid (p less than 0.001). Circadian rhythm of heart rate response was maintained in the thyrotoxic state, although heart rate variability was significantly increased (p less than 0.001). The prevalence of ventricular premature contractions was not significantly different before and after treatment, although premature atrial contractions were more prevalent during the middle third of the day (p less than 0.01) when subjects were euthyroid. These findings support the view that normal adrenergic responsiveness persists in hyperthyroidism, and for most individuals treatment does not significantly alter the prevalence of ectopic activity.

Adult↗
PubMed1986

Sudden death and vigorous exercise--a study of 60 deaths associated with squash.

The circumstances surrounding 60 sudden deaths (59 men, one woman) associated with squash playing are described. The mean age (SD) of those who died was 46 (10.3) years (range 22-66 years). Necropsy reports were available in 51. The certified cause of death was coronary artery disease in 51 cases, valvar heart disease in four, cardiac arrhythmia in two cases, and hypertrophic cardiomyopathy in one case. There were only two deaths from non-cardiac causes. Forty five of those who died had reported prodromal symptoms, the most common of which was chest pain, and 22 were known to have had at least one medical condition related to the cardiovascular system during life, the most common of which was systemic hypertension (14 subjects). Those dying from coronary artery disease had a high frequency of risk factors. Some of these deaths might have been prevented by appropriate counselling of players after prospective medical screening, which would have detected most of the patients with overt cardiovascular disease and some of those with subclinical coronary artery disease.

Adult↗
PubMed1985

Delay in diagnosis of right atrial myxoma.

Clinical, echocardiographic, and nuclear angiographic findings in a 51-year-old woman who presented with a history of dyspnea are discussed. Initial echocardiography revealed no abnormality. However, a subsequent radionuclide angiogram revealed a filling defect on the right side of the heart. This represented a right atrial myxoma. Radionuclide angiography can provide a useful noninvasive tool in the diagnosis of intracardiac tumors when echocardiography has not been helpful.

Diagnosis, Differential↗
PubMed1985

Systolic murmurs in pregnancy: value of echocardiographic assessment.

A systolic murmur discovered in antenatal care is the most common reason for cardiological assessment during pregnancy. We have assessed the value of clinical and echocardiographic assessment in 50 consecutive patients who were referred to our cardiac clinic following the discovery of a cardiac murmur at an antenatal clinic. Most of the murmurs occurred at 10-12 weeks gestation; 46 subjects had cardiac murmurs confirmed at the cardiac clinic, of whom 16 gave a history suggestive of a previous cardiovascular disorder. Of the 16 patients, 13 had been found to have a murmur earlier in life which was thought to be of no clinical significance. Complications during pregnancy were infrequent. The most frequent murmur discovered was a soft midsystolic murmur heard with greatest intensity at the left sternal edge. The results of electrocardiography and echocardiography were not helpful in assisting with the diagnosis or substantially altering antenatal management in these patients. We do not feel that echocardiography has an important role in the assessment of systolic murmurs in pregnancy in the absence of other clinical or ECG abnormalities.

Adolescent↗
PubMed1985

Systolic time intervals in adolescents with insulin-dependent diabetes mellitus.

Systolic time intervals were used to evaluate left ventricular performance in 20 diabetic adolescents with a mean age of 15.2 +/- 2.2 years (range 9-17 years) and were compared with an age- and sex-matched control group. Pre-ejection period index (PEPI), left ventricular ejection time index (LVETI), total electromechanical systole index (QS2I) and the PEP to LVET ratio were calculated at rest and following sustained isometric handgrip (SIHG). None of the diabetics had demonstrable microangiopathy or autonomic neuropathy. There was no significant difference in resting or post-exercise heart rate, PEPI, LVETI or PEP/LVET ratio between the two groups. QS2I was significantly prolonged (p less than 0.05) at rest in the diabetics, but was not significantly different following SIHG. These results indicate that cardiac contractility is not detectably abnormal in young diabetics, compared to their adult counterparts who may develop impaired myocardial performance.

Adolescent↗
PubMed1985

Beta-adrenoceptor blockade and intrinsic sympathomimetic activity--relevance in the treatment of ischaemic heart disease.

Beta adrenoceptor blockade has become one of the major therapeutic interventions in the medical management of ischaemic heart disease over the last 15 years. A number of beta adrenoceptor blockers have been developed with differing pharmacological properties including cardioselectivity and intrinsic sympathomimetic activity (ISA). The relevance of this latter property has been in some doubt. A number of reports suggest that ISA confers haemodynamic benefits although there does not appear to be any clear therapeutic advantage. In addition it would appear that patients with severe or rest angina might benefit more from a pure beta antagonist rather than one with ISA when the beta blocker is used as monotherapy, but this situation rarely arises. This paper reviews and assesses the value of treatment of ischaemic heart disease with beta blockers possessing intrinsic sympathomimetic activity.

Adrenergic beta-Antagonists↗
PubMed1984

Sudden death in squash players.

A series of thirty sudden deaths (twenty-nine men, one woman) associated with squash playing is described. The subjects' mean age was 46.7 +/- SD 9.58 years (range 22-66). Necropsy results were available for twenty-seven subjects. Significant coronary heart disease (CHD) was found in twenty-three, valvular heart disease in three, and hypertrophic obstructive cardiomyopathy in one, and cardiac arrhythmia, in the absence of other pathology, was thought to have preceded death in two. One subject died from intracerebral haemorrhage. Twenty-two had reported prodromal symptoms, and of those with CHD, sixteen had had at least one identifiable CHD risk factor. Twelve subjects had been known by their family physician to have a medical disorder related to the cardiovascular system.

Adult↗