Electromagnetic interference of permanent pacemakers by mobile phones in Thailand.

The possible permanent pacemaker function interference by mobile telephones is concerned worldwide. Previous studies from the other countries with different mobile telephone systems and permanent pacemakers provided useful but indirect information. We in vitro studied the interaction between local mobile telephones and permanent pacemakers in Thailand. Seventeen mobile telephones from different systems and brands were tested in the laboratory with seven permanent pacemakers from different companies. We found no interference in the function of permanent pacemakers. The application of the information may be limited from the in vitro nature of the study. However this would be the useful reference for the future in vivo study.

Percutaneous balloon pulmonary valvuloplasty in children: experience at Siriraj Hospital.

Twenty-seven children with pulmonary valvar stenosis with pressure gradient (PG) > or = 40 mmHg underwent percutaneous balloon pulmonary valvuloplasty (PBPV) at Siriraj Hospital between February 1993 and August 1996. There were 13 males and 14 females, with an age range from 2 months to 14 years, and body weight from 4.7 to 42.1 kg. The majority (92.6%) were asymptomatic. Before the PBPV, the pulmonary valve annulus (PVA) measured by echocardiography was significantly greater than that measured by cardiac catheterization (15.2 +/- 3.7 vs 14.5 +/- 3.9 mm, P = 0.006). However, there was linear association (r = 0.972) between the two methods. The PG obtained by the two methods showed no significant difference (90.8 +/- 35.3 by echocardiography vs 97.3 +/- 47.2 mmHg by catheterization, P = 0.266). Immediately after PBPV, the right ventricular systolic pressure (113.7 +/- 41.1 pre vs 62.3 +/- 28.1 mmHg post) and the PG 103.4 +/- 43.4 pre vs 49.0 +/- 31.1 mmHg post) were significantly reduced (p < or = 0.0005). At 6-mo follow-up echocardiography, the PG was 28.6 +/- 17.6 mmHg and was significantly reduced (P = 0.0005). The PVA significantly increased at the 12 mo follow-up (15.2 +/- 3.6 pre vs 17.6 +/- 3.8 mm post, P = 0.001). Only minor complications were reported in the present study; bleeding (3.7%), transient bradycardia (7.4%) and pulmonary regurgitation not more than moderate severity (79%). The immediate and intermediate results of PBPV are excellent with a success rate of 85 per cent.

Immediate angioplasty results of total coronary artery occlusion in Thai population.

Attempted angioplasty of totally occluded vessels may be done. However, a lower success rate is expected compared to those with subtotal occlusion. The complication rate is comparable to that of partial occlusion in experienced hands.