大森 浩二, 森田 久樹, 水重 克文, 中島 茂, 深田 英利, 千田 彰一, 松尾 裕英

Koji OHMORI, Hisaki MORITA, Katsufumi MIZUSHIGE, Shigeru NAKAJIMA, Hidetoshi FUKUDA, Shoichi SENDA, Hirohide MATSUO

香川医科大学第二内科

Second Department of Internal Medicine, Kagawa Medical School

キーワード : Doppler echocardiography, Flow vector, Myocardial infarction, Diastolic behavior, Left ventricular wall motion

Twenty-five patients (pts) with old myocardial infarction (OMI) including 10 pts with antero-septal (AS), 8 pts with inferior and/or posterior (I-P), 7 pts with both AS and I-P OMI, and 20 healthy subjects (H) were studied to evaluate the influence of the left ventricular wall motion abnormalities on the transmitral inflow vectors. We recorded the vectors of the rapid inflow (R), and the inflow due to the atrial contraction (A) on the left ventricular long axis plane using the simultaneous two-beam 2-D Doppler echocardiography. We measured the angles between each vector and the direction toward the apex, the maximam absolute velocities (VR, VA), and deceleration half-time of R (DHT). The OMI pts were classified into "mild", "moderate", and "severe" groups according to the severity of the diastolic wall motion abnormality evaluated by left ventriculography.
R and A were directed toward the posterior wall (PW) in H by 4±15 (mean±SD) degrees and 2±21 degrees, respectively. R was directed toward PW in AS by 17±10 degrees, and toward the interventricular septum (IVS) in P-I by 9±16 degrees (pIn conclusion, the direction of the transmitral inflow was influenced by regional wall motion abnormality and deviated toward noninfarct region. This finding implies that a conventional single-beam technique gives a false reading in OMI when failing to account for inflow deviation. Through the assessment of absolute velocities, we can clearly ascertain a variety of inflow velocity patterns in OMI which depends on the severity of wall motion abnormality, that is, R showed a low-velocity and prolonged-duration pattern in moderate OMI, and a high-velocity and short-duration pattern in severe OMI.