晕厥病因和诊断策略-陈庆华.ppt

Example of marked bradycardia recorded during a spontaneous vasovagal syncope. The asystolic periods may be impressive in their duration but do not in themselves constitute an indication for cardiac pacing. From the files of DG Benditt, MD. University of Minnesota Cardiac Arrhythmia Center Vasovagal syncope is most effectively diagnosed if the detailed medical history is ‘classic’. However, this is not often the case, and supporting evidence is needed. Such supportive evidence may include: Patient history, physical examination, including ECG and blood pressure Patient experiences syncope during tilt table testing. Test completion without syncope is a negative result. The following is one tilt table protocol: At least a 2 hour fast Measure ECG, at least 3 leads, and continuous supine and upright blood pressure at time of symptoms. Patient remains supine on the table for 15-30 minutes. Tilt to 70 degrees for 20 minutes. Lower to horizontal and administer isoproterenol at 1-5 μg/min until heart rate increases 25%. Re-tilt for 10 minutes Brignole M, Alboni P, Benditt D, et al. Guidelines on management (diagnosis and treatment) of syncope—Update 2004. Europace. 2004;6:467-537. Benditt D, Ferfuson D, Grubb B, et al. Tilt table testing for assessing syncope. ACC expert consensus document. J Am Coll Cardiol. 1996;28:263-275. Optimal management strategies for VVS are a source of debate. Long-term prevention measures include: Patient education, reassurance, and instruction. Control of fluids, salt, and diet may help reduce incidence. Support hose may limit blood pooling in the legs and feet. Drug therapy should be used as a second line option. Midodrine and beta-adrenergic blockers are the agents most thoroughly studied to date Pacing may benefit some patients. Subsequent slides will examine the utility of pacing in very symptomatic VVS patients. When the patient has a relatively long prodrome, evasive action may prevent injury if not syncope. This might include phys