身体活動によりペーシングレートが変わるVVIペースメーカーのsensor機能の評価

Clinical evaluation of the sensor for body activity responsive pacemaker

　徐脈性不整脈に対するペースメーカー治療はすでに確立されているが，現在最も多く使用されているVVIペースメーカーは，一定のペーシングレートでしか作動できず，身体活動に応じたペーシングレートを得る事はむずかしい。ペースメーカーの進歩につれ種々の様式のものが臨床に応用され，より生理的状態に近いペーシングが可能となりつつある。今回，我々は身体活動を感知するsensorが組み込まれた新しいVVIペースメーカーの使用を経験し，そのsensor機能を種々の運動下で評価したので報告する。

Clinical evaluation of the sensor for body activity pacemaker was done in 28-year-old normal man and 79-year-old female (to whom the pacemaker were externally attached on the chest surface) equipped with Holter monitors recorded both intrinsic ECG and pacemaker impulses. There were good correlation bet-ween intrinsic heart rate and pacemaker rate on the movement of upper and lower extremities. However, the sensor had oversensed to the movement of upper extremity attached with pacemaker. The pacemaker has also good sensitivity to ordinary activities in both young and old ones.

Two patients (age 53 and 83) with sick sinus synd-rome and atrial fibrillation with slow ventricular res-ponse underwent permanent implantation. They demon-strated physiological rate responses with daily activities and their general conditions were improved.

An activity responsive pacemaker may be useful in selected patients with atrial fibrillation with slow ventri-cular response and sick sinus syndrome.