DisopyramideとLidocaineの心機能に及ぼす影響について—Multigated RI angiographyによる比較検討

Cornparative Effects of Disopyramide and Lidocaine on Negative Inotropic Action:Evaluation by Multigated RI Angiography

　Disopyramide phosphateは新しい抗不整脈剤で化学構造はQuinidineと異っているが薬理学上は膜安定作用を有し，Quinidine様作用を示す。Disopyramideは心室性^1〜3），ならびに上室性不整脈^4〜6）に抗不整脈効果を有しているが，他の抗不整脈剤同様心筋に対するnegativeinotropic作用を有している^7〜10）。しかし，Disopyramide　phosphateのnegative intropic作用を左室容積変化の面より検討した報告はみない。著者らはペースメーカー植込み患者を対象とし，脈拍数をペーシングで制御下にmultigated RI angiography法^11）を用いDisopyramide　のnegative inotropic効果を左室容積変化の面よりLidocaineを対象抗不整脈剤として比較検討した。

Comparative effects of disopyramide and lido-caine on negative inotropic action were studied in 14 patients with pacemaker implantation. The subjects was divided in two groups, 7 patients with disopyramide group and 7 patients with lidocaine group. All had no clinical and hemo-dynamic signs of congestive heart failure. The cardiac output was measured using the dye densito-meter technique. The EDV, ESV, SV and EF were measured using multigated RI angiographic technique. Ohio-Nuclear scinticamera (Model Σ410S) and DEC, GAMMA-11 bata analysingsystem were used for this purpose. The data was analysed when the RI counts were reached to 2,000,000 counts after accumulation of 500 to 1500 cardiac beats. The test was started after adminis-tration of 10 to 15 mCi of ⁹⁹mTcalbumin. Measure-ments were taken before and at 3 minutes after the administration of an intravenous bolus of 1mg/kg of disopyramide phosphate or lidocaine over a 2 minute period. The cardiac output de-creased from 3.02 to 0.58 l/min to 2.81±0.32l/min in disopuramide group and from 3.76±0.54l/min to 3.5±0.56l/min in lidocaine group, respectively. However, no significant difference was observed between both group. The EDV did not change significantly in both group, while the ESV in-creased from 1204±524 to 1457±434 counts diso-pyramide group and from 1054±434 to 1080± 334 counts in lidocaine group, respectively. The increase in ESV was significantly higher in diso-pyramide group than in lidocaine group. The EF decreased from 0.51 to 0.09 to 0.41±0.06 in disopuramide group, and from 0.58±0.1 to 0.55±0.08 in lidocaine group, repectively. The decrease in EF was significantly higher in disopyramide group than in lidocaine group, repectively. The decrease in EF was significantly higher in diso-pyramide group than in lidocaine group (p< 0.05). Thus, the study demonstrated that the negative inotropic action of disopyramide was greater than that of lidocaine.