心筋梗塞における左房径と心血行動態の関係—左房係数による左室拡張末期圧の推定

Relationship between left atrial diameter and cardiac function in myocardial infarction:assessment of left ventricular end-diastolic pressure by the left atrial index

　急性心筋梗塞（AMI）の治療で，急性期には観血的血行動態のモニターが有用であるが^1〜3），回復期には観血的な指標は得にくい。今回我々は左室機能を反映すると考えられる左房径を心エコー図にて測定し，左室拡張末期圧（left ventricular end-diastolic pressure, LVEDP）肺動脈楔入圧（pulmonary capillarywedge pressure, PCWP）および左室駆出分画（ejection fruction, EF）との関係を検討した。

To study the assessment of cardiac function in acute myocardial infarction (AMI), we measured left atrial diameter, left ventricular end-diastolic pressure (LVEDP), pulmonary capillary wedge pressure (PCWP), ejection fraction (EF) in 20 patients with acute myocardial infarction. Left atrial diameter wasmeasured using echocardiography and was expressed as left atrial index (LAI, mm/m₂) dividing by body surface area.

LAI in AMI was 21.3±2.7 mm/m₂ and significantly larger than LAI in normal subject (19.9±2.0 mm/m₂) (p<0.05), In AMI, LVEDP was 13.3±3.4 mmHg, PCWP was 9.0± 2.8 mmHg and EF was 52.3± 14.8%, Relationship (r value) between LAI and LVEDP (r = 0.70, p<0.001, y 0.87 x-5.4 x; LAI, y ; LVEDP) was greater than PCWP and LVEDP (r = 0.60, p <0.01).LVEDP calculated from LAI using this method was directly measured LVEDP directly measured-J:2.4 mmHg.In 9 patients, LAI was larger than 20.9 mm/m₂, in 8 patients of them LVEDP was higher than 13 mmHg.In 11 patients LAI was smaller than 20.9 mmHg, only in 2 of them LVEDP was lower than 13 mmHg.It concluded that sen-sitivity was 88.9%, specificity was 81.8%, accuracy was 85.0%.Relationship between LAI and PCWP (r = 0.30), LAI and EF (r=0.36) were not sig-nificant.We can measure LAI repeatedly in AMI non-invasively, and predict LVEDP.Thus, the mea-surement of LAI is useful in treatment of AMI.