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Biomedical subjects

G Jackson

Publications and source records attributed to G Jackson.

At least 343 records · Page 19Linked to original sources
PubMed1978

The inotropic effects of UK 14,275, a phosphodiesterase inhibitor, in man.

1. UK 14,275 (Pfizer) an inotropic agent with cardiac phosphodiesterase inhibitory activity, was administered to ten healthy male volunteers. 2. The inotropic activity was assessed by non-invasive measurement of systolic time intervals (STI). 3. The compound had significant inotropic activity in the doses administered, as judged by the shortening of pre-ejection period (PEP), without any significant chronotropic activity. 4. The inotropic effect was abolished when measurements were repeated following beta-adrenoceptor blockade with oral propranolol. 5. The inotropic activity was compared to that of intravenous isoprenaline.

Adult↗
PubMed1978

Haemodynamic effects of atenolol in patients with coronary artery disease.

The haemodynamic effects of atenolol, a new cardioselective beta-blocking agent, have been studied at rest in 8 patients with coronary artery disease. The drug was administered intravenously in cumulative doses of 0.03, 0.06, and 0.12 mg/kg body weight. A significant decrease in heart rate was associated with a fall in cardiac output. However, this cardiac output fall was not entiely rate dependent, since stroke volume fell significantly both during spontaneous sinus rhythm and when heart rate was maintained constant by atrial pacing. A dose related and significant reduction occurred in left ventricular dP/dt max without significant change in left ventricular filling pressure or mean aortic pressure. Total peripheral resistance at rest rose after atenolol. The haemodynamic findings more closely resemble those which follow intravenous propranolol than those after intravenous practolol in a similar group of patients. These actions of atenolol suggest that it may be a useful agent in the treatment of patients with angina pectoris.

Adult↗
PubMed1978

Diagnosis of coronary artery disease by estimation of coronary sinus lactate.

In an attempt to assess the value of coronary sinus lactate estimation before and during atrial pacing for the diagnosis of obstructive coronary artery disease, 70 patients with angina were investigated in this way and by selective coronary arteriography. Thirty-five had radiologically normal coronary arteries and 35 had coronary artery disease. When the change in coronary arteriovenous lactate difference was less than 0.09 mmol/l (0.8 mg/100 ml) between the control and the peak atrial pacing sample, the coronary arteries were normal except in one patient who had distal disease of a single vessel. When the change was greater than 0.22 mmol/l (2.0 mg/100 ml) coronary artery disease was always found, and when the change was greater than 0.39 mmol/l (3.5 mg/100 ml) there was always disease of two or three vessels. Unfortunately, the presence or absence of coronary artery disease could not be predicted when the change fell between 0.09 and 0.22 mmol/l (0.8 and 2.0 mg/100 ml). Estimation of coronary sinus lactate before and during atrial pacing can thus frequently distinguish patients with normal coronary arteries from those with coronary artery disease.

Adult↗
PubMed1978

Comparison of atenolol with propranolol in the treatment of angina pectoris with special reference to once daily administration of atenolol.

Fourteen patients with angina pectoris completed a double blind trial of atenolol 25 mg, 50 mg, and 100 mg twice daily and propranolol 80 mg thrice daily. In comparison with placebo, all active treatments significantly reduced anginal attacks, consumption of glyceryl trinitrate, resting and exercise heart rate, resting and exercise systolic blood pressure, and significantly prolonged exercise time. There was no significant difference between the effects of propranolol and atenolol. Nine patients completed a further trial comparing atenolol given once or twice daily. Both regimens were effective and there was no significant difference between the reductions in anginal attacks, glyceryl trinitrate consumption, systolic blood pressure, or heart rate. Twenty-four-hour ambulatory electrocardiograms showed that atenolol consistently reduced heart rate throughout the 24-hour period whether given once or twice daily. Atenolol is a potent antianginal agent which, in most patients, is likely to be effective once daily.

Adult↗
PubMed1978

Contrast media during coronary arteriography: electrocardiographic changes in the presence of normal coronary arteries.

In forty patients with normal coronary arteries, the electrocardiographic changes secondary to Urografin 76 and Hypaque 85 injection into both coronary arteries were monitored. Hypaque caused significantly greater prolongation of the PR interval (p less than 0.001), depression of the ST segment (p less than 0.05) and depth of T wave inversion (p less than 0.05). These effects were more noticeable during right coronary artery injection. Both contrast media slowed the heart rate equally during right and left coronary artery injection. In the absence of coronary arterial disease the ECG changes secondary to contrast media injection probably reflect a direct toxic effect. It is possible that premedication with atropine will reduce these effects. Urografin 76 appears the less toxic of the two media, although one case of ventricular fibrillation occurred with each.

Angiocardiography↗
PubMed1977

Intra-aortic balloon assistance in cardiogenic shock after myocardial infarction or cardiac surgery.

Sixty-eight patients were referred for consideration of intra-aortic balloon assistance, 55 of whom were accepted. Thirty-one patients were in cardiogenic shock after myocardial infarction and the remaining 24 were cardiac surgical patients. Twenty-three of the myocardial infarct group were established on IABA and all 24 of the cardiac surgical patients. Of the 23 patients with cardiogenic shock after myocardial infarction, 19 showed initial haemodynamic improvement on intra-aortic balloon assistance and 5 (22%) survived to leave hospital. Of the 24 cardiac surgical patients, 15 could not be withdrawn from total cardiopulmonary bypass. With intra-aortic balloon assistance, 11 (73%) could be withdrawn from cardiopulmonary bypass and 5 (33%) were hospital and long-term survivors. The remaining 9 surgical patients were in cardiogenic shock in the early postoperative phase, though 5 showed initial haemodynamic improvement there was only one hospital survivor in this group. Intra-aortic balloon assistance was, therefore, of most value in patients dependent on cardiopulmonary bypass. The survival in patients with cardiogenic shock after myocardial infarction was marginally improved.

Assisted Circulation↗
PubMed1976

Inappropriate antihypertensive therapy in the elderly.

Six symptomless patients aged 64-84 (mean 72) years received antihypertensive therapy from their family doctors. Pretreatment systolic pressures ranged from 160 to 220 mm Hg and disastolic pressures from 80 to 120 mm Hg. Within one week of starting therapy all six patients were admitted as emergencies with epidoses of unconsciousness. Admission systolic pressures ranged from 80 to 150 mm Hg and diastolic pressures from 50 to 90 mm Hg. Before admission each patient had experiences symptoms of postural hypotension and had become housebound. After antihypertensive therapy was stopped, one patient had a residual left homonymous hemianopia but the others recovered completely. A raised systolic and distolic pressure is common in the elderly; potent antihypertensive treatment may seriously impair the quality of life and is often unecessary.

Age Factors↗
PubMed1976

The isolation of reovirus-like agents (rota-viruses) from acute gastroenteritis of piglets.

Isolations of reovirus-like agents (rotaviruses) were made from nine of 23 outbreaks of piglet diarrhoea on different farms and from both weaned and unweaned piglets. The viruses were shown to be morphologically and anti-genically similar to the rotaviruses of children and calves. Gnotobiotig piglets given intranasal inoculations of five different isolates developed acute gastroenteritis, and the virus was re-isolated from the faeces or intestinal contents. The piglet virus was not adapted to replicate in cell culture. We conclude that the pig rotavirus is commonly associated with outbreaks of gastroenteritis and is probably an important aetiological factor in this disease.

Animals↗