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Biomedical subjects

S L Chan

Publications and source records attributed to S L Chan.

At least 145 records · Page 8Linked to original sources
PubMed1984

The treatment of urinary tuberculosis.

During the last 7 years we treated 92 patients with tuberculosis of the urinary tract. Patients with tuberculous infection were divided into 3 groups according to treatment: group 1--no surgical treatment (18 patients), group 2--ablative surgery (45 patients) and group 3--reconstructive surgery (29 patients). Antituberculous drugs, consisting of rifampin, pyrazinamide, isoniazid and ethambutol, were given according to the severity and extent of the infection process. The results of medical and surgical treatment were most gratifying. Surgical morbidity was low and there was no immediate mortality.

Adult↗
PubMed1984

Baroreflex sensitivity measured by the phenylephrine pressor test in patients with carotid sinus and sick sinus syndromes.

Baroreflex sensitivity was measured by the heart rate response to the transient rise in blood pressure induced by phenylephrine, in 11 patients with carotid sinus syndrome, 6 patients with sick sinus syndrome and nine age and blood pressure matched controls. Patients with carotid sinus syndrome were divided into those with a hypersensitive carotid sinus reflex manifest as sinus arrest (n = 9) and those with a reflex manifest as atrioventricular block (n = 2). The mean gain of the baroreflex sensitivity was significantly increased (p less than 0.001) in patients with carotid syndrome manifest as sinus arrest (12.7 +/- 5.1 ms . mmg-1) compared to that in patients with sick sinus syndrome (3.8 +/- 2.6 ms . mmHg-1) and controls (4.2 +/- 2.1 ms . mmHg-1). Patients with carotid sinus syndrome manifest as atrioventricular block did not have increased baroreflex sensitivity measured by their sinus node response (2.1 +/- 0.5 ms . mmHg-1). There was significant correlation (p less than 0.001) between the corrected carotid sinus inhibitory response to carotid sinus massage and the measurement of baroreflex sensitivity in the carotid sinus syndrome patients. Patients with carotid sinus syndrome manifest as reflex sinus arrest have an increased gain in baroreflex sensitivity for their age, which is not seen in patients with symptomatic sinoatrial disease. This study provides further evidence of a different mechanism of bradycardiac symptoms in patients with carotid sinus and sick sinus syndromes.

Aged↗
PubMed1984

The management of urinary tuberculosis--a logical approach.

The chemotherapy of urinary tuberculosis is controversial as far as choice of drug regimen and duration of treatment are concerned. We propose a course of treatment that is tailored to the pathological state of infection and the type of surgical procedure performed. One hundred and ten patients with tuberculous infection were divided into three groups. Group I comprised 27 patients in whom surgery was not necessary; Group II contained 48 patients where ablative surgery was carried out; Group III consisted of 35 patients who underwent reconstructive surgery. Anti-tuberculous drugs (rifampicin, pyrazinamide, isoniazid and ethambutol) were given according to this tailored regimen. Patient compliance and results of treatment were excellent.

Adult↗
PubMed1983

Sustained improvement in exercise tolerance following physiological cardiac pacing.

Fifty-three patients have received 'physiological' pacemakers, 37 with atrioventricular (AV) block having atrial synchronous units (VAT or VDD) implanted and the remaining 16 patients with both AV block and sick sinus syndrome having 'universal' (DDD) pacemakers. Effort tolerance was assessed by serial bicycle ergometry and in 16 patients direct comparisons between ventricular pacing and atrial synchronous pacing could be made acutely. Physiological pacemakers were found to increase maximum effort tolerance by 43% compared to pre-pacing values (P less than 0.01). The increase was sustained over a mean of 33 months post pacing. The atrial synchronous mode increased maximum effort tolerance by 34% acutely compared to ventricular inhibited pacing. Dual chambered 'physiological' pacemakers represent a significant therapeutic advance over standard ventricular inhibited pacemakers.

Adult↗
PubMed1983

Physiological benefits of atrial synchrony in paced patients.

Over a five-year period, hemodynamic exercise capacity studies and a randomized controlled trial have been performed in a total of 50 patients. DVI vs. VVI pacing showed an increase in stroke work index (P less than 0.005) and a fall in left ventricular filling pressure (P less than 0.05) in 17 patients. VDD/DDD pacing vs. VVI showed an exercise capacity benefit in 44 patients (P less than 0.01) including 8 patients with sinus node disease and a lower peak heart rate (P less than 0.02). Maintenance of benefit was also shown of VDD/DDD pacing in the longer term (13 months) vs. acute (P - NS). The controlled trial VDD/DDD vs. VVI showed benefit in shortness of breath (P less than 0.01) and general well being (P less than 0.01). It is concluded that atrial synchronous ventricular pacing (VDD/DDD) is the mode of choice in suitable patients.

Bradycardia↗
PubMed1983

The role of rate hysteresis pacing in the hypersensitive carotid sinus syndrome.

The ability of rate hysteresis programming with the escape interval longer than the automatic interval to reduce the hypotensive response to carotid sinus massage at the onset of ventricular pacing was studied in six patients paced for carotid sinus syndrome. Rate hysteresis significantly reduced this hypotensive response and abolished spontaneous symptoms in two patients and symptoms reproduced by carotid sinus massage in four patients.

Adult↗
PubMed1983

Randomised controlled trial of physiological and ventricular pacing.

Thirteen patients have completed a randomised double blind cross over study to compare the effects of chronic ventricular and atrial synchronous pacing on exercise capacity and symptoms. Maximal symptom limited exercise was significantly increased after one month of atrial synchronous pacing compared with ventricular pacing. Symptomatic assessment (by diary card and monthly symptom scores) of "shortness of breath", "palpitation", and "general well-being" was significantly improved during the physiological pacing mode. Atrial synchronous pacing has been shown to be superior to ventricular pacing.

Adult↗
PubMed1982

Carotid sinus syncope treated by pacing. Analysis of persistent symptoms and role of atrioventricular sequential pacing.

Seventy patients have been paced for carotid sinus syndrome over four years. Twelve patients had persistent symptoms despite adequate ventricular pacing. Patients with persistent symptoms were found to have a significant vasodepressor response, a significant hypotensive response to ventricular pacing (pacemaker effect), and a severe hypotensive response to carotid sinus massage with introduction of ventricular pacing, which reproduced symptoms in all patients. A group of 14 asymptomatic paced carotid sinus patients was found to have a significantly lower vasodepressor response, pacemaker effect, and combined vasodepressor response plus pacemaker effect than the group with persistent symptoms. Atrioventricular sequential pacing was shown to eliminate the hypotensive effect of ventricular pacing and is considered to be the treatment of choice for patients with carotid sinus syndrome who have both cardioinhibitory and significant vasodepressor responses.

Aged↗
PubMed1981

Pulmonary dysfunction associated with cardiopulmonary bypass: a comparison of bubble and membrane oxygenators.

Intrapulmonary shunting and white cell sequestration in the lungs were compared prospectively in patients who underwent coronary artery grafting using either bubble or membrane oxygenators. Bubble oxygenators caused more sequestration of white cells, but this was not reflected in any detectable increase in pulmonary shunting. Postoperative blood loss was less in those patients who had been on membrane oxygenators. We conclude that there is little advantage in using the membrane oxygenator for uncomplicated short-term perfusions.

Cardiopulmonary Bypass↗
PubMed1980

Cecocystoplasty in the surgical management of the small contracted bladder.

Preliminary results have been reviewed for 17 patients with a small contracted bladder from chronic inflammatory disease who underwent cecocystoplasties. Except for 1 patient who was lost to followup results were considered excellent in 11, good in 2 and a failure in 3. The amount of diseased bladder resected and the configuration of the cecal segment used did not seem to bear any relationship to the surgical outcome. The importance of a concurrent Y-V plasty is emphasized. No case of significant electrolyte imbalance has been encountered. Results can be gratifying in selected patients after detailed voiding pattern documentation and thorough urological study ahve been completed.

Adolescent↗
PubMed1979

Idiopathic retroperitoneal fibrosis in children.

A case of idiopathic retroperitoneal fibrosis in an 11-year-old boy is presented. A review of 7 previous case reports revealed that there was no characteristic presentation in this disease process and that the diagnosis usually is suspected on an excretory urogram. The treatment is primarily surgical but corticosteroids may be helpful in selective cases.

Child↗