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Biomedical subjects

R M McCredie

Publications and source records attributed to R M McCredie.

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

Smoking: a major predictor of left ventricular function after occlusion of the left anterior descending coronary artery.

The major predictors of left ventricular function after coronary artery occlusion were assessed in 108 consecutive patients who had complete occlusion of the left anterior descending artery as the only important lesion demonstrated at angiography between June 1978 and June 1983. A scoring system was used to identify regional damage on left ventriculograms. Forty two patients were classified as having good left ventricular function and 66 as having varying degrees of impairment. Apart from a history of myocardial infarction, the only variables discriminating between those with good and those with impaired left ventricular function were the area of distribution of the artery beyond the occlusion and cigarette smoking. Hypertension, hypercholesterolaemia, family history of vascular disease, diabetes, obesity, duration of angina, age, and presence of identifiable collaterals were not discriminators. Smoking was itself significantly associated with a history of infarction; but after controlling for this, smoking exerted a significant additional effect on the amount of left ventricular damage. It is concluded that smoking is not only a risk factor for myocardial infarction in patients with single left anterior descending artery occlusion, but that it is also a major factor in determining the extent of associated left ventricular damage.

Adult↗
PubMed1985

The acute haemodynamic effects of oral nicardipine.

The haemodynamic effects of oral nicardipine at two different doses were assessed in fifteen patients at rest following diagnostic cardiac catheterisation. Six patients received four doses of 20 mg nicardipine hydrochloride orally every 8 h, and nine patients received four doses of 30 mg orally every 8 h. No side effects were encountered with either dose. At both dose levels, there was a significant fall in systemic vascular resistance, significant increases in heart rate and cardiac output, and no change in stroke volume index. No changes were seen in pulmonary vascular haemodynamics, and there were no significant changes in mean arterial pressure. Plasma levels of nicardipine reached a peak within 1 h. In parallel with the haemodynamic effects, the plasma concentrations achieved after the third and fourth doses were higher than after the first dose. These haemodynamic changes are consistent with a vasodilator effect, which produces a decrease in peripheral vascular resistance. It would appear that the 30 mg dose has a more potent vasodilator action than the 20 mg dose and, in the patients studied, this larger dose was not associated with any side effects.

Administration, Oral↗
PubMed1978

Radionuclide quantitation of left-to-right cardiac shunts in children.

In order to evaluate the clinical usefulness of radionuclide methods measuring the magnitude of left-to-right cardiac shunts, a comparison has been made of the results obtained using these procedures with those estimated by cardiac catheterization. Seventy children in whom the presence or absence of a shunt had been established, were studied. Two methods for radionuclide shunt quantitation, the pulmonary to systemic blood flow ratio (Qp/Qs) of Maltz and Treves and their modified C2/C1, were evaluated. The former was found to be superior and showed a high correlation of shunt size with the catheter results. With attention to the performance of the investigation and in the data analysis, good discrimination can be achieved between normal patients and those with shunts. Because of the atraumatic nature of the investigation, it is concluded that the procedure is of value in the diagnosis of a cardiac murmur, the assessment of postoperative patients and the follow-up of patients known to have a small shunt.

Adolescent↗