佐倉 英一郎^{1, 3}, 岡本 光師², 横手 祐司¹, 土岡 由紀子¹, 松浦 秀夫¹, 梶山 梧朗¹, 坪倉 篤雄²

Eiichiro SAKURA^{1, 3}, Mitsunori OKAMOTO², Yuji YOKOTE¹, Yukiko TSUCHIOKA¹, Hideo MATSUURA¹, Goro KAJIYAMA¹, Tokuo TSUBOKURA²

¹広島大学医学部第一内科, ²広島大学医学部臨床検査医学, ³広島記念病院内科

¹The First Department of Internal Medicine, Hiroshima University School of Medicine, ²The Department of Clinical Laboratory, Hiroshima University School of Medicine, ³The Department of Internal Medicine, Hiroshima Memorial Hospital

キーワード : Pulsed Doppler echocardiography, Contractility, Afterload reduction, Dibutyryl cyclic AMP, Dilated cardiomyopathy

In 12 patients with dilated cardiomyopathy (DCM) and 10 patients with chest pain syndrome (controls) left ventricular ejection flow dynamics were studied by ultrasonic pulsed Doppler echocardiography before and after infusion of dibutyryl cyclic AMP (DBcAMP) at an infusion rate of 0.025-0.1 mg/kg/min. Pre-ejection period (PEP), acceleration time (AT), ejection time (ET) and peak velocity were determined from the left ventricular ejection flow velocity pattern. After DBcAMP infusion both DCM patients and the controls showed a significant increase in heart rate and mean velocity of circumferential fiber shortening (mean Vcf) and a significant reduction in mean blood pressure. PEP/ET and AT/ET were significantly larger in DCM patients than in the controls. Peak velocity was not significantly different between the patients and the controls. After DBcAMP, PEP/ET and AT/ET decreased significantly from 0.56±0.17, 0.35±0.07 to 0.45±0.12, 0.32±0.04 in DCM patients and from 0.30±0.05, 0.28±0.04 to 0.25±0.03, 0.26±0.04 in the controls, respectively. Peak velocity increased significantly from 79.5±14.4 cm/sec to 96.1±11.0 cm/sec in DCM patients and from 85.1±7.0 cm/sec to 100.5±13.1 cm/sec in the controls. A good negative correlation was noted between mean Vcf and PEP/ET or AT/ET (r=-0.76, -0.63). However, there was a poor correlation between mean Vcf and peak velocity (r=0.39). These results suggest that left ventricular systolic performance is reflected in the left ventricular pre-ejection period and acceleration period rather than in the peak velocity of ejection flow, so that ultrasonic pulsed Doppler echocardiography may provide a useful method for evaluating ejection flow dynamics.