Biomedical subjects
Publications and source records attributed to Simon James.
American university students owned more than twice as many credit cards as British university students. However, scores on a credit card attitude scale predicted the number of cards owned by respondents in both countries.
A 6-item measure of computer anxiety was devised and showed good reliability and validity in both American and English samples so it could be useful in survey research when a brief measure of computer anxiety is needed.
Left atrial pacing is feasible via the coronary sinus. However, long-term characteristics of coronary sinus pacing parameters are largely undefined as yet. This study assessed the feasibility and long-term pacing parameters of coronary sinus pacing. Twenty four patients (13 men, 11 women) with a history of paroxysmal AF refractory to drug therapy underwent biatrial pacemaker implantation. Leads were sited in the high right atrium or right atrial appendage and in either proximal (PCS) or distal coronary sinus (DCS). Pacemaker parameters were measured at implant, 24 hours postimplant, 1 month, 3 months, and at 3 monthly intervals over a period of 2 years. Threshold, impedance, and energy requirements (E = Threshold2/impedance x pulse width) were measured. There was one lead displacement from the PCS within 24 hours postimplant. There were no other acute or chronic complications. The energy values at implant and at 2 years were 0.49 +/- 0.47 and 2.18 +/- 1.69 mJ for the PCS leads and 0.94 +/- 1.47 and 1.27 +/- 0.75 mJ for the DCS leads. P values were >0.05 at all points and suggested no significant difference between the two sites over the long-term. Chronic coronary sinus pacing is a safe and feasible technique. There was no significant difference in energy parameters for leads positioned in the proximal or distal coronary sites. The trends seen at both sites for chronic changes in pacing characteristics are analogous to those described for endocardial leads at other sites.
A brief 6-item scale to measure anxiety about computers, developed using American students, showed good internal consistency, reliability and construct validity for British students (77 men, 65 women).
British university students (n = 142) obtained a higher mean external locus of control score than did American university students (n = 185) overall and, in particular, on items related to politicians and government.
A preterm infant born to a woman with chronic lead poisoning was found to have the highest blood lead level recorded for a surviving neonate. Parenteral calcium disodium edetate, but not oral succimer, was effective in reducing the infant's lead burden in the neonatal period. An exposure assessment revealed the mother's long-term ingestion of lead-contaminated herbal tablets as the source.
OBJECTIVES: The purpose of this study was twofold: to assess whether biatrial pacing is superior to single-site pacing and capable of reducing the frequency of episodes of paroxysmal atrial fibrillation (PAF); and to compare pacing of the proximal coronary sinus (PCS) with the distal coronary sinus (DCS) and the effects of sequential or simultaneous biatrial pacing. BACKGROUND: Interatrial conduction abnormalities have a role in the initiation of PAF. Biatrial pacing alters the site and timing of atrial depolarization and may benefit those with drug-resistant PAF. METHODS: Nineteen patients with PAF who were intolerant of or refractory to medication were studied. All received right atrial (RA) and coronary sinus (CS) leads (either PCS or DCS). For three months the pacemaker was set in sensing mode only. Subsequently each patient completed three-month periods in random order in the following modes: RA pacing, CS pacing, biatrial pacing using inter-atrial delays of 15 and 70 ms. RESULTS: Sixteen patients received a benefit from one or more pacing modes. The greatest reduction in PAF episodes was seen during biatrial pacing, especially with leads sited at the high right atrium (HRA) and distal CS (p = 0.0048). There was no difference for sequential or simultaneous pacing. Three patients derived no benefit. CONCLUSIONS: In selected patients, biatrial pacing causes a significant decrease in atrial fibrillation episodes. Optimal lead sites were at the HRA and DCS. Simultaneous pacing conferred no benefit over sequential pacing.