失神発作をくり返し，ペースメーカー治療を必要とした頸動脈洞症候群の1例

A case of carotid sinus syndrome with frequent syncopes, necessitated pacemaker implantation

　頸動脈洞症候群はめまい，失神発作等を主徴とする疾患で^1）高齢者の失神発作の原因として鑑別上重要なものの1つであるが，今回我々は失神発作を頻回におこし，ペースメーカー治療を必要とした本症候群の1例を経験した。本例ではVVIモードの永久ペースメーカーを植え込むことにより症状の軽快を見たが，最近の治療の動向を含め文献的考察を行い報告する。

A 74-year-old man was admitted to our hospital because of a history of syncopal episodes for the last 2 years. In view of the presence of sinus bradycar-dia and syncopal attacks, the patient was monitored by telemetry that showed a 4 second ventricular ar-rest during which time the patient complained of lightheadedness. Left carotid sinus massage (CSM) induced a 8 second ventricular arrest and he fell into the syncope.

The hyperactive carotid sinus reflex by CSM di-sappeared when 1 mg of atropine sulfate was admi-nistered intravenously. The results of electrophysio-logic studies suggested that intrinsic sinus nodal dys-function was not the major cause for asystole. These findings made convincingly the diagnosis of cardioin-hibitory type of carotid sinus syndrome. Subsequen-tly, because of his multiple episodes of syncope, a permanent demand pacemaker (VVI mode) was inserted, resulting in the relief of symptoms.