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Biomedical subjects

W S Smith

Publications and source records attributed to W S Smith.

At least 73 records · Page 4Linked to original sources
PubMed1978

[Clinical studies of the antiarrhythmic efficacy of disopyramide phosphate (Norpace) (author's transl)].

The antiarrhythmic action of Norpace was investigated in three clinical studies. 1. A single blind placebo controlled study in 10 centers confirmed the antiarrhythmic action of Norpace in 120 patients with ventricular or supraventricular cardiac arrhythmias. It was shown by means of continuous ECG recordings that Norpace produced a statistically significant reduction in the frequency of both ventricular and supraventricular extrasystoles. Paroxysmal ventricular tachycardia was prevented in 70% of the patients. 2. In a double blind comparative study of Norpace and quinidine sulphate a similar antiarrhythmic action against ventricular and supraventricular extrasystoles was shown in both patient groups. In contrast, the tolerance of Norpace was markedly superior to quinidne sulphate. 3. An acute study of the action of Norpace was also conducted. Therapeutic plasma levels were attained within 2 1/2 hours following an initial single dose and within 60 to 120 minutes when this dose was doubled. Orally administered disopyramide phosphate has therefore proved effective in both the short and longer term treatment of various types of supraventricular and ventricular arrhythmias. Its antiarrhythmic properties are very similar to those of quinidine sulphate. The dosage of disopyramide phosphate should be sufficiently high and must be individualized. The dosage generally lies between 400 and 800 mg daily and should be given in 4 divided doses at intervals of 6 hours. To achieve rapid therapeutic effects an initial dose of 2 x 150 mg is recommended. This method of administration will produce effective therapeutic plasma levels within 1 to 2 hours. Due to possible negative inotropic effects it is necessary to digitalize patients with congestive heart failure and caution should be exercised in poorly compensated patients. Observed side effects were mainly of the anticholinergic type.

Administration, Oral↗
PubMed1976

A system for rapid analysis of long-term recordings of heart rate and other physiological parameters.

Using miniature cassette tape recorders, measurement of ECG and other physiological measures is possible in industrial or working situations. The development of a semi-automatic high speed processing system for analysis of the tape recorded data is described. This system decodes the signals on the tape, converts ECG to heart rate and presents a listing of the heart rate variation over the recording period, which may be up to 24 hours. A punched paper tape copy of the listing is used for input into a mainframe computer for subsequent analysis. The recorders and processing system have been used extensively for three years on a study of industrial work stress, and have proved reliable, accurate, and of sufficient sensitivity for in-depth analysis. They allow considerable data to be collected, permitting the thorough statistical analysis necessary for the interpretation of complex physiological responses.

Computers↗
PubMed1975

First-degree atrioventricular block: a cause of false malfunction of a mitral disc-valve prosthesis. Case report.

Malfunction of a prosthetic mitral disc valve was clinically suspected on the basis of absent valve closing sound and an early opening click in a patient with first-degree atrioventricular (A-V) block. Premature closure and opening of the prosthetic valve was demonstrated by echocardiography. All abnormal auscultatory, phonocardiographic, and echocardiographic findings disappeared promptly upon spontaneous restoration of normal A-V conduction. The possible hemodynamic mechanism is discussed, and attention is drawn to this conduction abnormality as a cause of erroneous diagnosis of prosthetic mitral valve malfunction.

Adult↗
PubMed1975

Segmental resection for chondrosarcoma.

Specific anatomical and pathological criteria for resectability of so-called central chondrosarcoma of the extremities were set forth and a method of treatment based on autoclaving the segment and surrounding it with massive amounts of fresh autogenous cancellous bone was used in eight patients. Follow-up ranged from 3.2 to 13.5 years. The advantages of the method are: ease of procurement of bone graft, absence of storage and measurement problems, and lack of need for rigid immobilization. No secondary procedures were required because of fracture, resorption, or infection.

Adult↗