本藤 達也¹, 片山 恵子¹, 川本 敏雄¹, 岡本 光師², 唐川 真二³, 松浦 秀夫³, 梶山 梧郎³

Tatsuya HONDO¹, Keiko KATAYAMA¹, Toshio KAWAMOTO¹, Mitsunori OKAMOTO², Sinji KARAKAWA³, Hideo MATSUURA³, Goro KAJIYAMA³

¹三菱三原病院内科, ²県立広島病院第1内科, ³広島大学第1内科

¹Department of Internal Medicine, Mitsubishi Mihara Hospital, ²The First Department of Internal Medicine, Hiroshima Prefectural Hospital, ³The First Department of Internal Medicine, Hiroshima University School of Medicine

キーワード : Pseudonormalized left ventricular inflow pattern, Left atrial function, Afterload echocardiography, Apexcardiogram

Left atrial contribution decreases “paradoxically” in some patients with severe left ventricular dysfunction (pseudonormalized left ventricular inflow pattern). Although it is thought that the decreased left atrial contribution may be caused by atrial failure or atrial afterload mismatch, the mechanism has been remained unclear. The relationship between “a wave ratio” of apexcardiogram and mean velocity of left atrial dimensional shortening (mean Vd) was evaluated in 9 normal subjects (group N), 6 patients with pseudonormalized inflow pattern (group P), and the other 28 patients with heart diseases (group D). The peak velocity during the atrial contraction phase in group P was significantly lower than those in group N (p-1, group D; 1.0±0.4 sec^-1, group P; 0.5±0.1 sec^-1). However, left atrial contractility in group P was not attenuated as assessed by mean Vd-“a wave ratio” relationship. This suggests that atrial afterload mismatch may be one of the major determinants of decreased atrial contribution in group P.