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Biomedical subjects

M Monaghan

Publications and source records attributed to M Monaghan.

30 records · Page 2Linked to original sources
PubMed1987

Inoperable aortic stenosis in the elderly: benefit from percutaneous transluminal valvuloplasty.

Eight patients with severe symptomatic calcific aortic stenosis were considered to be unsuitable for valve replacement. Four were admitted with pulmonary oedema and three in cardiogenic shock and one had angina at rest. With the use of echocardiographic and radiographic guidance percutaneous transluminal aortic valvuloplasty was carried out. Aortic gradients were reduced by an average of 40%. All four patients who presented with cardiac failure improved immediately and remained well six months later. The patient with angina was symptom free at nine months. Two of the three patients who presented in cardiogenic shock improved immediately and were well nine and three months later. The other patient died four hours after the procedure. Doppler echocardiographic studies showed a slight initial increase in aortic incompetence, but this did not worsen and valvar gradients remained improved three and six months later. Percutaneous valvuloplasty of the aortic valve is an effective therapeutic option in patients with severe calcific aortic stenosis who are unfit for surgery. Its role as an alternative to surgery has not been considered and should be investigated in a controlled clinical trial.

Aged↗
PubMed1987

Silastic catheter separation due to subcutaneous suture.

The development of large-bore, double-lumen Silastic catheters for introduction into the superior vena cava has made it possible for patients with renal failure to receive immediate dialysis while awaiting maturation of an arteriovenous fistula. Although infections and thrombotic complications have been well documented, separation of Silastic cannulas has seldom been described and is poorly explained. The authors report two such cases. In one the catheter was clearly sheared off due to snaring by a subcutaneous suture. In the second case, awareness of the possibility of such a complication allowed the authors to explore the catheter at the level of the venotomy. By dividing the suture under direct vision, they were able to remove the snared catheter before it became transected.

Adult↗
PubMed1985

Right atrial embolus. Echocardiographic features.

Although the value of echocardiography in detecting left heart thrombus is well recognised, right atrial thromboembolism has rarely been identified in life. In two patients with pulmonary embolism of varying severity cross sectional echocardiography identified a thrombus moving freely within the right atrium and clearly showed its string-like or even tubular structure. An embolectomy, based on the echocardiographic diagnosis, was undertaken successfully in one patient. The value of routine echocardiography in patients with suspected pulmonary embolism is yet to be confirmed.

Aged↗
PubMed1985

Milrinone in heart failure. Acute effects on left ventricular systolic function and myocardial metabolism.

Milrinone, a new bipyridine compound related to amrinone, is a potent non-adrenergic inotrope in experimental preparations and also shows vasodilator activity. In the present study the haemodynamic and metabolic effects of milrinone were evaluated in 12 patients with congestive heart failure. Milrinone 5 mg given orally produced a sharp reduction in left ventricular end diastolic pressure without significantly affecting stroke volume. The improvement in left ventricular function was due to a combination of vasodilation and positive inotropism. Thus small reductions in blood pressure and systemic vascular resistance were associated with increments in the isovolumic indices of left ventricular function. The relation between left ventricular end systolic pressure and dimension was displaced leftwards and downwards. Only reductions in left ventricular cavity dimension were statistically significant, however. Though myocardial oxygen consumption did not change significantly, it tended to increase whereas lactate consumption tended to decrease. This trend towards oxygen imbalance suggests the need for caution in the use of milrinone in patients with severe coronary artery disease.

Adult↗
PubMed1981

Burying by rats in response to aversive and nonaversive stimuli.

Previous investigations have shown that rats bury a variety of conditioned and unconditioned aversive stimuli. Such burying has been considered as a species-typical defensive reaction. In the present studies, rats buried spouts filled with Tabasco sauce, or condensed milk to which a taste aversion was conditioned, but did not bury water-filled spouts or spouts filled with a palatable novel food (apple juice) to which a taste aversion was not conditioned. However, in other experiments rats consistently and repeatedly buried Purina Rat Chow, Purina Rat Chow coated with quinine, and glass marbles. This indicates that a variety of stimuli, not all aversive or novel, evoke burying by rats. Whereas the behavior may reasonably be considered as a species-typical defensive behavior in some situations, the wide range of conditions that occasion burying suggests that the behavior has no single biological function.

Journal Article↗
PubMed1980

The use of human observers in psychopharmacological research.

During 1974-1978, over 40% of the nonhuman drug studies that appeared in Psychopharmacology, Pharmacology Biochemistry and Behavior, and Journal of Pharmacology and Experimental Therapeutics involved human observers; far fewer studies published in Journal of the Experimental Analysis of Behavior did so. In all of these journals, measures of interobserver agreement seldom were provided. The great majority of studies also failed to utilize one or more "blind" observers, unaware of experimental conditions. These findings are of interest in light of reports that observational data are affected by a wide range of factors and often provide an inaccurate index of behavior. The believability of observational data seemingly is enhanced by careful descriptions of recording procedures coupled with the use of two or more blind observers whose concordance in rating behavior has been determined. These procedures characteristically are followed in some behavioral sciences, such as applied behavior analysis, but not to the same degree in psychopharmacology.

Animals↗
PubMed1979

Regression of left ventricular hypertrophy during treatment with antihypertensive agents.

1 Echocardiography showed 14 of 24 patients with essential hypertension to have hypertrophy of their left ventricular walls. In eight of these 14 patients the left ventricular configuration initially fulfilled the criteria for asymmetric septal hypertrophy (ASH) and six were symmetrically hypertrophied, the remaining ten being normal. 2 Following 12 weeks' treatment of hypertension with the object of reducing the supine BP to 150/90 mmHg or below, there was a reduction of wall thickness so that only two of the eight continued to show ASH. 3 The six patients with symmetrical left ventricular hypertrophy also showed a significant reduction in the thickness of the septum and the posterior wall. Those with normal echocardiograms did not change. 4 This reduction of wall thickness produced by antihypertensive therapy may represent regression of left ventricular hypertrophy.

Adrenergic beta-Antagonists↗
PubMed1978

Some aspects of the cardiovascular pharmacology of UK 14,275 in patients with coronary artery disease.

1. A phosphodiesterase inhibitor, UK 14,275 (Pfizer) was administered intravenously to six patients with suspected coronary artery disease under-going diagnostic cardiac catheterisation to assess its inotropic activity. 2. Intracardiac haemodynamic measurements included pulmonary and systemic arterial pressure. Left ventricular end diastolic pressure and left ventricular dP/dtmax were also measured, in addition to cardiac output using the indocyanine green dye technique. 3. UK 14,275 resulted in a significant increase in LV dP/dtmax and cardiac output. 4. No chronotropic action was observed using this agent. 5. This agent may have potential therapeutic value in the management of cardiovascular failure associated with low cardiac output.

Aged↗