気管支喘息に伴い咳嗽失神を認めた1例

A Case of Cough Syncope with Bronchial Asthma

　症例は48歳，男性，咳嗽発作の直後に失神発作を起こし，転倒することがあったため，11月16日精査加療目的に当院に入院となった．入院後も咳嗽直後に数秒間の失神発作を認めたが，失神発作時のホルター心電図所見ではアダムス-ストークス症候群を疑わせるような不整脈は認めず，脳波，頭部CT，脳動脈造影所見にも異常所見を認めなかった．咳嗽時の大動脈圧，右房圧，肺動脈圧，髄液圧を同時測定したところ，咳嗽時にそれぞれの圧が著明に上昇した後，咳嗽直後には大動脈圧が40mmHgまで急激に低下し，それに一致して軽いめまい感を訴えた．この時の一過性の脳循環不全が失神発作に関与している可能性が示唆された．気管支喘息に対する治療を行い，咳嗽が軽減すると，失神発作も消失した．

A 48-year-old male was admitted to our hospital with syncope following coughing. Holter ECG showed regular sinus rhythm remained during the synopal epi-sode. Electroencephalography, computerized X-ray tomography of the brain, and cerebral angiography revealed no abnormal findings. Abrupt increase in right atrial pressure, pulmonary artery pressure, arterial pressure and cerebral spinal pressure associated with coughing was followed by a significant decrease insystolic arterial pressure to less than 40 mmHg. This was accompanied with faintness. The above events lead to a diminished cardiac output resulting in an alteration of the cerebral blood flow, cerebral hypoxia and loss of consciousness. Treatment of the bronchial asthma decreased the frequency of coughing and thus prevented syncope.