Objective To investigate the clinical application of electron-beam CT(EBCT)in the diagnosis of congenital cardiovascular diverticula. Methotis Retrospective analysis of 9 patients with congenital cardiovascular diverticula confirmed by operation and pathology was done.Of them,enhanced continuous volume scan was performed on 8 patients and enhanced single slice scan was performed on one patient with an Imatron C-150 scanner.Results The group of 9 pailents included one patient with diverticulum of the left ventricle.3 patients with diverticulum of the atria and 5 patients with diverticulum of the aorta.EBCT scan and three dimensional reconstruction could demonstrate not only the origin,size,shape,Location and adjacent structure of diverticula,but also other important complicated abnormalities such as ventrieuloarterial connection disorder,cardiac sepud defect,aortic coarctation and even dissection.Conclusion EBCT is an ideal noninvasive technique in the diagnosis of congenital cardiovascular diverticula

Objective To compare landiolol and esmolol for treatment of intraoperative arrhythmia in dogs.Methods Experiment Ⅰ Eighty-eight KM mice (44 males, 44 females) , aged 4-6 weeks, were studied.The median lethal dose (LD50) and median effective dose (ED50) of landiolol and esmolol were determined using the sequential method.Treatment index (TI) was calculated.Experiment Ⅱ Eighteen dogs (9 males, 9 females), aged 8-12 months, weighing 7-10 kg, were equally and randomly divided into 3 groups: model group (group M) , landiolol group (group L) and esmolol group (group E).Intraoperative arrhythmia model was established by using gastrointestinal surgery combined with epinephrine.When sustained ventricular arrhythmias occurred, normal saline 0.5 ml/kg, landiolol 8.3 mg/kg and esmolol 10.0 mg/kg were given intravenously in C, L and E groups, respectively.The duration of arrhythmias was recorded.If bradycardia occurred (decrease in heart rate [HR] ≥ 25％ of the baseline value) , isoprenaline 0.05 mg/kg and atropine 0.03 mg/kg were injected intravenously.The occurrence of bradycardia after the initial administration of landiolol and esmolol, and the accumulated dose of landiolol and esmolol consumed when bradycardia occurred were recorded.Isoprenaline and atropine-induced improvement in bradycardia was recorded.Results Compared with esmolol, the LD50 and TI of landiolol were significantly increased (P＜0.01), and no significant change was found in ED50 of landiolol (P＞0.05).The duration of arrhythmias was significantly shorter in L and E groups than in group C, and in group L than in group E (P＜0.01).After the initial administration of landiolol and esmolol, the incidence of bradycardia was 0 and 100％, respectively, and the accumulated dose of landiolol and esmolol consumed when bradycardia occurred was (30± 13) mg/kg.Atropine could not effectively treat bradycardia, while isoprenaline could treat bradycardia.Compared with group L, the time for HR to rise and the duration for HR returning to the baseline value were significantly prolonged in group E (P＜0.05).Conclusion Compared with esmolol, landiolol provides faster improvement in intraoperative arrhythmia, weaker negative chronotropic effect, and higher safety;isoproterenol produces better efficacy in treating landiololinduced bradycardia in dogs.