超音波パルス・ドプラー法を用いたDDD VVIペーシングモードにおける心拍出量の比較—スワンガンツカテーテル法との比較

Comparison of cardiac output between in DDD and in VVI by pulsed Doppler echocardiographic method:Correlation with Swan-Ganz catheter method

　超音波パルス・ドプラー（PD）法を用いて，心房・心室ペーシング時（DDD）と心室ペーシング時（VVI）で心拍数（P）を変化させ，分時心拍出量（CO）および一回拍出量（SV）の差について検討し，またスワンガンツカテーテル（SG）法にて，同様にCOを測定し比較した。

　〔対象〕洞不全症候群で体内式マルチプログラマブル心房・心室ペースメーカー植え込み患者：14例。

　〔方法〕断層心エコー・ドプラー装置を使用し，大動脈弁弁輪部ドプラー流速波形より平均流速を求め，COを算出した。

　〔結果・考案〕COは，各Pで心房収縮を有するDDDの方がVVIより高く，ともにPの上昇につれて増加し，120PPMになるとDDDでは心房収縮の関与が少なくなり減少した。PD法のCO測定は，SG法との間に有意差を認めず，簡易検査法として有用と思われた。

Difference of cardiac output and stroke volume between that in DDD and that in VVI was studied by pulsed Doppler echocardiography at different pacing rates.

Moreover, to evaluate the usefulness of the meth-od by pulsed Doppler echocardiography, cardiac out-put by the Swan-Ganz catheter method was measured and compared.

Fourteen patients age 37-83 years (mean 65 years) with sick sinus syndrome and implanted multipro-gramable dual chamber pacemakers were studied.

Cardiac output was measured as the product ofthe echocardiographically determined cross sectional area of the aortic anulus and the Doppler-determined mean velocity of left ventricular outflow over sys-tole.

Cardiac output was greater in DDD with atrial kick than in VVI at each pacing rate, and increased with elevation of the rate, but it was smaller at 120 PPM than at 110 PPM in DDD.

Stroke volume was greater in DDD than in VVI at each pacing rate, and maximum volume was at 60 PPM in both modes.

The data by pulsed Doppler echocardiography and by Swan-Ganz catheter method have high cor-relation.

Besides being related with pulse rate, these results may be related with sich things as myo-cardial contractility, preload and afterload. For ex-ample, the tension of autonomic nervous system, the changing of venous return volume, the disease of arteriosclerosis and old myocardial infarction, temperature, blood viscosity and so on.

We will continue the study considering these factors.