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Biomedical subjects

S D Pringle

Publications and source records attributed to S D Pringle.

54 records · Page 3Linked to original sources
PubMed1990

Simultaneous measurement of left ventricular function and perfusion.

A new radiopharmaceutical, methylisobutyl isonitrile (MIBI), has been developed as a technetium-99m-labelled alternative to thallium 201 for myocardial imaging. By virtue of the high specific activity of 99mTc, some 600 MBq may be administered as a 0.3 ml bolus, permitting the acquisition of a first-pass nuclear angiogram at rest and at peak exercise. The agent was assessed in ten sequential patients referred for routine cardiac catheterisation, who also underwent an exercise electrocardiographic (ECG) test. Good quality nuclear angiograms, planar perfusion and tomographic perfusion images were obtained; the results correlated well with the catheterisation data. Of 30 myocardial segments for which wall motion was judged normal/abnormal from the nuclear angiogram, results concordant with contrast studies were obtained in 27 (90%). In the case of the 50 segments analysed from the perfusion images, concordant results were obtained in 43 (86%) from the planar studies and in 42 (84%) from the tomographic studies. All normal segments were classified correctly.

Adult↗
PubMed1990

Left ventricular hypertrophy and mortality in hypertension: an analysis of data from the Glasgow Blood Pressure Clinic.

Three thousand seven hundred and eighty-three patients with non-malignant hypertension attending the Glasgow Blood Pressure Clinic between 1968 and 1983 were followed prospectively for an average of 6.5 years. Left ventricular hypertrophy (LVH) was present at the outset in 34.5% of the men, and 12.8% had ST-T changes. The corresponding figures for women were 21.5% and 8.8%. The prevalence of LVH increased with the severity of hypertension and was higher for a given blood pressure level in men than in women. All-cause age-adjusted mortality, expressed as deaths per 1000 patient-years, was 27.6 for men with normal electrocardiographs, 43.2 for men with LVH only (P less than 0.001) and 56.9 for men with LVH and ST-T changes (P less than 0.001). Similar trends were seen in women. The excess risk associated with LVH, with or without ST-T changes, could not be explained by age, increased blood pressure at referral to the clinic, or smoking habit, when these factors were considered either separately or in combination (regression analysis). Thus, our study demonstrates that LVH, with or without ST-T changes is an independent risk factor for mortality in hypertensive patients.

Age Factors↗
PubMed1990

The safety of felodipine.

Hypertensive patients, particularly the elderly, may often suffer from other diseases. Therefore, antihypertensive compounds should not negatively affect such disorders. Felodipine is a calcium antagonist that has potentially beneficial effects in angina pectoris and congestive heart failure. Further, it does not adversely affect lung function in asthmatic patients or glucose tolerance in patients with diabetes. Preliminary investigations also indicate that felodipine has no negative influence on plasma lipid levels. Although felodipine seems to be safe in most patients, treatment with felodipine should at present be avoided in pregnant women, since digital anomalies have been observed in rabbit fetuses. The adverse effects seen during treatment with felodipine are usually mild and transient and generally related to the vasodilatory action of the drug, the most common being ankle edema, headache, flushing, dizziness, and palpitations. The only significant drug interactions with felodipine occur with inducers and inhibitors of the cytochrome P-450 system, which is responsible for the metabolism of felodipine.

Animals↗
PubMed1989

Comparison of enalapril and atenolol in mild to moderate hypertension.

PURPOSE: Short-term therapy with angiotensin converting enzyme (ACE) inhibitors for hypertension is effective and well tolerated, and compared with beta blockers, may cause fewer adverse reactions. Furthermore, enalapril has been observed to have a greater effect on systolic blood pressure than beta blockers. We therefore decided to compare the ACE inhibitor enalapril and the beta blocker atenolol as monotherapy in a double-blind study of patients with mild to moderate hypertension. PATIENTS AND METHODS: After a four-week placebo run-in period, 162 patients were allocated randomly to receive atenolol (50 to 100 mg daily) or enalapril (20 to 40 mg daily) for 12 weeks. To assess the influence of these drugs on quality of life, a series of psychologic tests was performed, and a subset of patients also underwent treadmill exercise and pulmonary function tests. RESULTS: In 147 patients who completed the study, enalapril reduced supine blood pressure by 19/12 mm Hg, compared with 9/7 mm Hg for atenolol (p less than 0.001/p less than 0.005). The modest blood pressure response to atenolol was not due to poor compliance. A target blood pressure of 140/90 mm Hg or less was achieved by 35 percent of enalapril-treated atenolol (p less than 0.01). The frequency and severity of adverse effects with the two drugs were similar, and few important differences emerged from the quality-of-life assessments. CONCLUSION: At the doses used, enalapril induced a greater short-term blood pressure response than atenolol; long-term studies of its safety and efficacy are required.

Adolescent↗
PubMed1989

Infective endocarditis caused by Streptococcus agalactiae.

We report a series of five cases of infective endocarditis caused by Streptococcus agalactiae (group B streptococcus) in Glasgow over a 30 month period. There were three males and two females mean age 48.6 years (range 28-63 years). Only one patient had previous valvular heart disease. The infections were characterised by an acute presentation and an aggressive course with major arterial emboli. Despite early diagnosis and appropriate intravenous antibiotics three patients died, one after valve replacement and two before surgery could be undertaken. The remaining two patients had successful valve surgery and have recovered. S. agalactiae endocarditis is an uncommon but important condition which carries a high mortality. The infection is difficult to control with antibiotics alone and therefore early surgery may be indicated.

Adult↗
PubMed1989

Pathophysiologic assessment of left ventricular hypertrophy and strain in asymptomatic patients with essential hypertension.

To investigate the significance of the electrocardiographic (ECG) pattern of left ventricular hypertrophy and strain, two groups of asymptomatic patients with essential hypertension were compared. The patients were similar in terms of age, smoking habit, serum cholesterol and blood pressure levels, but differed in the presence (Group I, n = 23) or absence (Group II, n = 23) of the ECG pattern of left ventricular hypertrophy and strain. Group I patients had significantly more episodes of exercise-induced ST segment depression (14 versus 4, p less than 0.05) and reversible thallium perfusion abnormalities (11 of 23 versus 3 of 23, p less than 0.05) despite similar exercise capacity and absence of chest pain. Nonsustained ventricular tachycardia was detected on 24 h ambulatory ECG monitoring in two patients in Group I, but no patient in Group II. Coronary arteriography performed in 20 Group I patients demonstrated significant coronary artery disease in 8 patients. This study has shown that there is a subgroup of hypertensive patients with ECG left ventricular hypertrophy and strain who have covert coronary artery disease. This can be detected by thallium perfusion scintigraphy, and may contribute to the increased risk known to be associated with this ECG abnormality.

Angiography↗
PubMed1988

The effect of a long-acting somatostatin analogue on portal and systemic haemodynamics in cirrhosis.

Current interest in the pharmacological manipulation of portal pressure centres on the long-acting somatostatin analogue SMS 201-995. Nine haemodynamically stable cirrhotic patients who had previously bled from oesophageal varices had wedged and free hepatic venous pressures and cardiac index measured, using a Swan-Ganz catheter, before and at 60, 120 and 180 min after beginning a 60-min infusion of 25 microgram/h of SMS 201-995. Seven clinically similar patients had the same measurements performed without SMS 201-995. In all patients cardiac index was found to decrease and systemic vascular resistance increase at 60 min, although heart rates and arterial blood pressures were unchanged. The group given SMS 201-995 was significantly different from the control group in sustaining a fall in wedged hepatic venous pressure and trans-hepatic venous gradient at 60 min. SMS 201-995 causes a fall in portal pressure without a significant systemic haemodynamic effect.

Adolescent↗
PubMed1988

Serum C reactive protein in infective endocarditis.

C reactive protein (CRP) was measured serially in 29 patients with infective endocarditis. Twenty one patients were initially treated with antimicrobial drugs. In 13, serial measurement of CRP concentrations showed a progressive return to normal (less than 10 mg/l), which correlated with a satisfactory recovery. Of the remainder (eight patients), five had persistently high concentrations of CRP, indicating a failure to respond to antimicrobial treatment alone. Two of these five patients died and three underwent valve replacement. Of 11 patients treated with antibiotics and valve replacement, CRP concentrations returned to normal in nine. Two patients had infective complications and the CRP concentration did not return to normal. A transient rise in CRP concentration during an otherwise uneventful fall to normal was a sign of allergic reaction in two and of intercurrent infection in three more patients. Serial measurements of CRP concentrations in patients with infective endocarditis may be useful to monitor treatment and also to detect other infections and complications.

Adolescent↗
PubMed1988

Regression of electrocardiographic left ventricular hypertrophy following treatment of primary hyperaldosteronism.

The electrocardiograms (ECGs) of a series of 34 patients with primary hyperaldosteronism (PHA), 17 treated surgically (group I) nine treated medically (group II) and eight treated with/by both surgery and drug therapy (group III) were analysed to determine whether the treatment of PHA resulted in an improvement in the ECG changes of left ventricular hypertrophy (LVH) and also whether there was a difference in this improvement between medically and surgically treated patients. There was a significant reduction of blood pressure in the group as a whole (186/111 to 141/95 mmHg, P less than 0.001) and within each of the treatment groups (group I 183/108 to 137/98 mmHg, group II 188/112 to 147/93 mmHg, group III 193/115 to 144/92 mmHg). This reduction within each group was of a similar magnitude. There were reductions in both precordial voltages (SV1 + RV5) from 3.68 mV to 2.79 mV (P less than 0.01) and in the number of patients with ECG LVH from 15 to 8 (P less than 0.05). Again the reductions were of similar magnitude in each of the groups: group I 3.78 to 2.77 mV, group II 3.78 to 2.84 mV, group III 3.39 to 2.77 mV. Thus the improvement in blood pressure achieved by the treatment of PHA is accompanied by a reduction in precordial voltages and the number of patients with ECG-LVH. This improvement is independent of the type of treatment used.

Adult↗
PubMed1987

Left ventricular hypertrophy and myocardial ischemia in systemic hypertension.

Considerable attention has properly been focused in recent years on electrocardiographic abnormalities in patients with essential hypertension. It has been well established that both voltage evidence of left ventricular (LV) hypertrophy and LV hypertrophy and strain are ominous risk factors. A better understanding of the strain pattern in patients with LV hypertrophy has arisen from experimental animal studies showing how an increase in cardiac mass can lead to myocardial ischemia and from clinical studies showing that the patient with LV hypertrophy and strain is at risk from myocardial ischemia as a consequence of both associated coronary artery disease and increased LV mass. All the clinical syndromes associated with myocardial ischemia are increased in patients with LV hypertrophy and therefore earlier recognition of both cardiac involvement and myocardial ischemia is likely to improve survival in this particularly high-risk group of patients.

Animals↗
PubMed1982

The problem of psilocybin mushroom abuse.

1 We have reviewed the clinical features and management of 44 consecutive patients presenting to hospital over a 5 week period during an outbreak of ingestion of psilocybin containing mushrooms. 2 Patients presented to hospital usually because of dysphoric effects an average of 3.8 h after ingesting mushrooms. 3 Mydriasis was present in 40 patients but fewer than half showed other sympathomimetic features--tachycardia, hypertension or hyperreflexia. 4 Twenty-three patients experienced nausea and vomiting. 5 Distortions of perception chiefly visual were frequent as were paraesthesiae and feelings of depersonalization. 6 The effects of the mushrooms were short-lived and had worn off within 12 h in all but one patient. 7 Inducing emesis did not appear to hasten recovery from the effects of the mushrooms.

Adolescent↗