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Biomedical subjects

G Louridas

Publications and source records attributed to G Louridas.

At least 37 records · Page 2Linked to original sources
PubMed1993

Use of half of the Palmaz-Schatz stent in a stent-related dissection.

The placement of a Palmaz-Schatz stent may be associated with the development of a dissection and this may increase the danger of coronary thrombosis. In this case report we describe the use of half of the Palmaz-Schatz stent to cover such a dissection. The use of the half stent, by reducing the amount of metal and stent overlapping, may reduce the incidence of thrombosis and restenosis.

Aortic Dissection↗
PubMed1992

The value of the ejection fraction as a predictor of postoperative cardiac mortality in patients undergoing peripheral vascular surgery.

Retrospective evaluation was undertaken in 131 patients who underwent peripheral vascular operations before which a multigated scan had been obtained. The patients were assigned to one of three groups according to their pre-operatively determined ejection fraction; 82 patients had an ejection fraction greater than 55%, in 38 patients the ejection fraction was between 36% and 54% and in 11 patients it was 35% or less. Two cardiac deaths occurred in each of the three groups. Although mortality in the three groups just failed to achieve statistical significance, metanalysis of published reports indicates that significant mortality exists for patients with an ejection fraction of less than 35% compared with those with an ejection fraction of over 55%. In this series, if the ejection fraction was used as the sole indicator, it was not an accurate predictor of peri-operative cardiac mortality. However, when used in conjunction with patient factors, such as cardiac history and status of the resting ECG, it did define a group of patients in whom there was a significant clinical risk of peri-operative cardiac mortality.

Adult↗
PubMed1991

Takayasu's arteritis in a pregnant woman. A case report.

Takayasu's arteritis in a pregnant white patient is described. This case highlights the fact that, irrespective of race, any patient who presents for the first time in pregnancy with pulseless hypertensive disease or other features suggestive of Takayasu's arteritis, should have their management in labour determined by the number of complications that are present. These are retinopathy, arterial aneurysms, hypertension and aortic regurgitation. These prognostic criteria will result in a classification of patients that will lead to appropriate management.

Adult↗
PubMed1991

Heparin-induced thrombocytopenia.

A series of 114 patients was prospectively investigated to determine the prevalence of heparin-induced thrombocytopenia. Of these patients only 7 (6.1%) were found to have the condition, and no cases of heparin-induced thrombocytopenia plus thrombosis were detected.

Adult↗
PubMed1990

The role of the aortic aneurysm diameter aortic diameter ratio in predicting the risk of rupture.

This study was performed to examine the ratio between the size of an infrarenal aortic aneurysm and the normal aorta proximal to it, in the hope of identifying a high-risk group of patients. All patients underwent a computed tomography scan of the abdomen, at which time the diameters of the largest aneurysm and of the normal proximal aorta were measured. The ratio was calculated by dividing the diameter of the normal aorta (in centimetres) into the diameter of the aneurysm. One hundred and thirty patients were assessed. One hundred asymptomatic patients had a mean ratio of 2.0. The 30 symptomatic patients were subdivided into 2 groups; 17 were symptomatic but had no evidence of rupture (mean ratio 2.7), and the remaining 13 had a contained rupture (mean ratio 3.4). There was a significant difference between the asymptomatic patients and the two symptomatic groups (P less than 0.001). The results suggest that the aneurysm/aorta ratio may be helpful in identifying the high-risk aneurysm. Patients with a ratio of 2.7 or greater are likely to become symptomatic, whereas those with a ratio of 3.4 or greater are at risk of rupture.

Aorta, Abdominal↗
PubMed1988

Management of tender abdominal aortic aneurysm.

Forty-eight patients with tender haemodynamically stable abdominal aortic aneurysms were evaluated. The aneurysms in 18 of these patients (37.5%) were found, at the time of surgery, not to have leaked. The mortality rate in patients with these tender non-leaking aneurysms undergoing emergency surgery was 16.6%. This high mortality rate can be improved by using computed tomography pre-operatively to prevent patients with non-leaking aneurysms from undergoing emergency surgery.

Aged↗
PubMed1984

Vascular access for haemodialysis--experience at Johannesburg Hospital.

Experience with angio-access in patients with chronic end-stage renal failure undergoing haemodialysis, including those with arteriovenous fistulas constructed within the past 3 years, is reviewed. In patients in group 1, 137 fistulas were constructed; the patency rate at 2 years was 66% and at 4 years 47%. Complications were due to thrombosis, aneurysm and poor operative technique. In group 2 fistulas were constructed from synthetic material in 33 patients; the patency rate at 2 years was 44% and at 4 years 36%. Complications were due to thrombosis and sepsis. No correlation was found between raised fibrinogen levels and fistula or graft failures. Dialysis needles of different gauges were compared; the 16-gauge Terumo needle was found to cause no hemolysis and was adequate for use in dialysis.

Adolescent↗
PubMed1984

Pulmonary hypertension and respiratory failure in the development of right ventricular hypertrophy in patients with chronic obstructive airway disease.

The high incidence of right ventricular hypertrophy in patients with chronic obstructive pulmonary disease is a well-known fact. In clinical medicine according to our present status of thinking, severe impairment of ventilatory function and pulmonary hypertension are the two essential prerequisites for right ventricular involvement. To investigate this accepted assumption we studied 51 patients with chronic obstructive pulmonary disease, while they were in a remission period. The patients were subjected to clinical examination, chest roentgenography, spirometry, blood gas examination, electrocardiography, vectorcardiography, echocardiography, and right heart catheterization. The majority of the patients with significantly compromised ventilatory function and abnormal blood gases had right ventricular hypertrophy with elevation of the pulmonary artery pressure. Two subgroups of patients could be distinguished: One included 15 patients (29.4% of all patients) with normal pulmonary artery pressure and evidence of right ventricular hypertrophy. In this subgroup are included 10 patients (19.6% of all patients) showing mild ventilatory impairment and mild hypoxaemia. The second subgroup consisted of 5 patients (9.8% of all patients) with elevated mean pulmonary artery pressure at rest and right ventricular hypertrophy showing relatively mild ventilatory impairment and moderate hypoxaemia. Two conclusions could be drawn: (1) the pulmonary artery pressure at rest could be normal despite the evidence of right ventricular hypertrophy, and (2) a mild ventilatory impairment does not exclude an elevated pulmonary artery pressure or the development of right ventricular hypertrophy in patients with chronic obstructive pulmonary disease.

Aged↗
PubMed1983

Superior vena-caval obstruction in urban blacks. A report of 82 cases.

Eighty-two patients with superior vena-caval obstruction (SVCO) were studied retrospectively. Carcinoma of the bronchus was responsible for the syndrome in 60 patients; of the remaining 22 patients, 7 had mediastinal lymphomas, 5 retrosternal goitres, 4 oesophageal cancer, 3 vascular aneurysms, 2 thymic tumours, and 1 granulomatous mediastinitis. Rigid bronchoscopy, scalene node biopsy or aspiration, cervical mediastinoscopy, anterior mediastinotomy, transthoracic needle biopsy and median sternotomy were the procedures used to make a definitive diagnosis. It is noteworthy that in 9 of the 82 patients malignant disease was not the cause of the SVCO. Seven of the remaining 73 patients had lymphoma causing compression of the superior vena cava. A significant proportion (19.5%) of urban Blacks with SVCO had causes other than hopeless bronchogenic carcinoma as the basis for their condition.

Adolescent↗
PubMed1983

Interactions among the critical factors affecting sinus node function: the quantitative effects of the duration and frequency of atrial pacing and of vagal and sympathetic stimulation upon overdrive suppression of the sinus node.

A multifactorial analysis was used in anesthetized dogs in order to characterize the effects of the duration of overdrive, the atrial pacing interval, and the frequencies of vagal and sympathetic stimulation on overdrive suppression of the sinus node. The sinus node recovery time (SNRT) and the summated effect (SE) over the first 20 cardiac cycles were measured with various combinations of the independent variables. We conclude that (1) both the rate and the duration of overdrive have significant effects on SNRT and SE; (2) vagal stimulation has greater effects on SNRT and SE than does the rate or duration of overdrive; (3) sympathetic stimulation had only a small effect on overdrive suppression; and (4) there were significant interactions between vagal stimulation and the duration of overdrive and between the duration and rate of overdrive, but not between sympathetic and vagal stimulation.

Animals↗
PubMed1983

Nifedipine in bronchial asthma.

In 11 patients with bronchial asthma and regular overnight falls in PEFR of greater than 15%, we demonstrated significant bronchodilation restricted only to large airways after the administration of a single dose of 10 mg of nifedipine. A statistically significant increase in PEFR, SGaw, and FEV1 was noticed at 1 and especially 2 hr after nifedipine administration. During 4 days of nifedipine treatment (10 mg t.i.d.), the overnight fall in mean PEFR was statistically significant (p less than 0.02) and less than the mean fall of PEFR during the 4 days of placebo treatment. Thus nifedipine does modify the basal bronchial tone of patients with asthma and diminishes the circadian swing of airway resistance.

Adult↗