Objective To study the value and feasibility of temporary emergency bedside cardiac pacing. Method Two hundred patients with severe witnessed bradycardia were treated with temporary emergency cardiac pacing. We treated 130 patients with emergency bedside pacing and 70 patients with x-ray-guided pacing. Results Emergency bedside pacing was successful in 127 patients except three patients and no postoperative complications occurred. X-ray-guided pacing was successful in all 70 patients but three patients experienced complications: one deep venous thrombosis and two cardiac tamponades due to myocardial perforation. The pacing electrodes were more likely to be displaced in X-ray-guided pacing than in emergency bedside pacing (six cases versus three cases) . The door-to-operation time was 30-90 min for x-ray-guided cardiac pacing and 5-15 min for emergency bedside pacing. Needle-to-pacing times were similar for both procedures (3.5 ± 1.5 min for x-ray guided pacing versus 4± 2.5 min for bedside pacing). Conclusions Temporary emergency bedside cardiac pacing is a rapid, efficient and safe procedure for treating severe witnessed bradycardia. The technique is easily mastered and may prove lifesaving in an emergency.

OBJECTIVETo study the karyotype of four Ephedra plants in order to provide the cytologic evidence for the genetic diversity and identification genetic resources of Ephedra.

METHODThe roots of germinating seeds were used to study the karyotype of four Ephedra plants by staining and slide-preparing technique of mitotic chromosomes.

RESULTthe optimal root-sampling time was about 10: 20 - 10:40 am. Using 0.002 mol x L(-1) 8-Hydroxyquinoline to pretreating the intravital root tips, the optimal pretreatment time for E. Sinica, E. intermedina, E. equisetina and E. przewalskii was 4, 5, 4.5 and 3.5 h, respectively. E. przewalskii and E. equisetina were diploid, E. Sinica and E. intermedina were belonged quadruple. The karyotype formulae of the four species were 2n = 2x = 14 = 2M + 8m + 4sm, 2n = 2x = 14 = 10m + 4st, 2n = 4x = 28 = 20m (2SAT) +8st, and 2n = 4x = 28 = 20m (SAT) + 6st + 2sm, respectively.

CONCLUSIONAll the karyotypes of four Ephedra species were 2A type, which was the symmetric karyotype.

Chromosomes, Plant ; genetics ; Ephedra ; cytology ; genetics ; Karyotyping ; methods ; Mitosis