compatible with the thesis that the defibrillation threshold in calves depends on body weight. The extrapolation of this observa- tion to man is extremely controversial. In this issue, two original articles present data in man which are at some variance with the observation in calves. In view of the importance of the required energy levels for human defibrillation, we are including two editorials on this subject. We hope that these viewpoints will stimulate the design of more definitive studies in man to settle this crucial issue.

BACKGROUND: Percutaneous Coronary Intervention (PCI) of coronary bifurcation lesion is technically quite demanding. It has been associated with a lower procedural success, higher rates of complication and restenosis. Side-branch occlusion and plaque shifting or 'snow plow' effect are not uncommon. Stenting of the main vessel may cause 'stent jail' of the side-branch. Modern stent design may allow passage of a balloon or stent into the side-branch through the struts of the stent placed in the main vessel. A newly developed 316 stainless steel tubular stent, the Rtrade mark stent is uniquely designed to provide flexibility, radial strength on deployment and conformability. Its large cell size facilitates PCI of bifurcation lesion. AIM: To assess the feasibility of R(trade mark) stent in the treatment of symptomatic patients with bifurcation coronary lesions. The main objective was to assess the ease of deployment, side-branch access and overall success of the R(trade mark) stent in this group of patients without any major adverse events. METHODS: Between December 1998 and September 2000 the R(trade mark) stent was used as a main stent in 28 consecutive patients with coronary bifurcation lesions, 46% of which had unstable angina. The mean age was 59 +/- 10 and 89% were male. Adjunctive medical therapy included clopidrogel, aspirin and intraprocedure heparin. Abciximab (ReoPro) was given to 9 patients. RESULTS: Successful stent deployment was achieved in all patients. Thirty-four R Stents and 16 other stents were used. Two patients had post-procedure rise in cardiac enzymes. There were no major adverse events at 30 days. LAD/D1 with LAD/diagonal was the target lesion in the majority of patients. Stenting of the side-branch was done in 18 and balloon dilatation in 9 patients. At 3-23 months (mean 11.8) follow-up, repeat angiography was done in 18 patients with restenosis in 4, two of them had repeat PCI and one had coronary artery bypass graft (CABG). CONCLUSION: Coronary bifurcation lesions are not uncommon. Current advances in stent technology offer a safe and effective revascularisation strategy for such complex lesions. The R(trade mark) stent appears to be a suitable device that provides good wall coverage, radial strength, conformability and easy side-branch access.

Background: Thrombolytic therapy has frequently been withheld from patients with complete heart block following acute myocardial infarction because of significant hypotension and the risk of bleeding should temporary transvenous pacing be required. We assessed the course of patients with acute myocardial infarction complicated initially by complete heart block who received thrombolytic therapy.Methods: Patients had clinical and ECG evidence of acute myocardial infarction of less than 6 hours' duration , were in complete heart block when first assessed, and were suitable for thrombolytic therapy. Coronary angiography was performed during the hospital stay, and left ventricular function was assessed by radionuclide ventriculography during convalescence.Results: Twenty-one patients were treated: 20 had an inferior myocardial infarction and 17 patients were first seen outside the hospital. Initial systolic blood pressure in 13 of 21 (62%) was 90 mm Hg or less. Thrombolytic therapy commenced at 154 minutes (mean) after the onset of infarction and 12 patients received prehospital thrombolysis. All patients had received intravenous atropine, and in seven 1:1 atrioventricular conduction had occurred. Of the 12 who remained in complete heart block at the time of receiving the thrombolytic agent, 10 reverted to 1:1 atrioventricular conduction and one to chronic atrial fibrillation within 2 hours. Of the two in second-degree atrioventricular block, both reverted to 1:1 atrioventricular conduction within 7 hours. Only four patients required temporary transvenous pacing (in three for complete heart block). Coronary artery patency was 79% (15 of 19), and mean global left ventricular ejection fraction was 57% +/- 10%. No hemorrhagic complications occurred; only one patient with anterior myocardial infarction and cardiogenic shock died.Conclusions: Thrombolytic therapy administered to patients with myocardial infarction complicated by complete heart block is safe and frequently results in resumption of normal atrioventricular conduction, thus reducing the need for pacing and improving prognosis.