左右冠動脈血流速波形の差異について—ドプラガイドワイヤーによる検討

Phasic Coronary Flow Patterns in Human Left and Right Epicardial Coronary Arteries

　目的：冠動脈主要分枝の血流速波形の差異を検討する．方法：狭窄性病変のない右冠動脈（RCA）14例，左前下行枝（LAD）10例を対象とした．Cardiometrics社製のドプラガイドワイヤー（FloWire）を用いて，RCA,LADの近位部，遠位部の冠血流速波形を記録した．拡張期，収縮期の流速波形下の面積比（D／S）を算出，また6例で右室枝（RV），8例で前中隔枝（SB）の流速波形を記録した．結果：RCAのD／Sは，近位部2.36±0.21，遠位部3.26±0.20で，遠位部で有意に高値であった．D／Sは4PDで3.66±0.21,4AVで2.85±0.26と，心室中隔を灌流する4PDで有意に高値であった．RVのD／Sは1.80±0.36と低値であった．LADのD／Sは，近位部5.15±0.50，遠位部5.48±0.44で差がなく，RCAの左室灌流部分（4PD,4AV）に比べて拡張期優位の波形であった．SBのD／Sは7.96±1.34で，LADより高値の傾向であった．総括：ヒトの冠血流速波形はLADでRCAに比べ拡張期優位であった．この理由として，SBのD／Sが高いこと，RCAでRVのD／Sが低いこと，およびRCAの左室灌流部分のD／SがLADより低いことが関与している可能性がある．

The aim of this study was to clarify the difference of phasic flow patterns between left and right human epicardial coronary arteries using an intravascular Doppler guidewire (Cardiometrics Inc.). We measured coronary flow velocity in 24 angiographically normal epicardial arteries (14 right coronaries (RCA), 10 left anterior descending (LAD)). The flow velocity integral during systole (SPVI) and diastole (DPVI) were calcu-lated. We used DPVI/SPVI (D/S) as a parameter for phasic coronary blood flow pattern. The proximal RCA and rigit ventricular branch (RV) had low D/S of 2.36± 0.21 and 1.80±0.36, but distal RCA had higher D/S of 3.26±0.20 than the former. As for distal RCA, the post-erior descending artery (4PD: 8 arteries), having septal branches, had a higher D/S than the posterior left ventricular artery (4AV: 6 arteries) (D/S in 4PD 3.66± 0.21 vs. 4AV 2.85±0.26, p＜0.05). The proximal and distal LAD, having septal branches, also showed a significant diastolic predominance with D/S of 5.15± 0.50 and 5.48±0.44, respectively. Septal branches (SB) characteristically showed diastolic predominance with the highest D/S of 7.96±1.34. In comparison, the distal segments of RCA showed less diastolic predominance than the distal LAD. We conclude that the septal branch flow, having the most diastolic-predominance, RV flow with low D/S, and distal RCA flow, having lower D/S than distal LAD, affect the phasic flow pattern of each epicardial coronary artery.