Bukachi F, Waldenström A, Mörner S, Lindqvist P, Henein M Y, Kazzam E
Department of Medical Physiology, College of Health Sciences, Nairobi, Kenya.
Eur J Echocardiogr. 2008 Jul;9(4):522-9. doi: 10.1093/ejechocard/jen124. Epub 2008 Mar 14.
Peak left ventricular (LV) relaxation normally precedes peak filling (E), which supports the hypothesis that LV suction contributes to early-diastolic filling. The significance of similar temporal discordance in late diastole has previously not been studied. We describe the time relationships between mitral annular motion and LV filling in early and late diastole and examine the effect of normal ageing on these time intervals.
A total of 128 healthy subjects aged 25-88 years were studied. Transmitral and pulmonary venous flow reversals (Ar) were recorded by Doppler echocardiography. Mitral annular diastolic displacement-early (E(m)) and late (A(m))-were recorded by Doppler tissue imaging. With reference to electrocardiographic R and P-waves, the following measurements were made: R to peak E-wave (R-E) and E(m) (R-E(m)); onset P to peak A-wave (P-pA), A(m) (P-pA(m)), and Ar (P-pAr). The differences between [(R-E) and (R-E(m))] for early-diastolic temporal discordance (EDTD) and [(P-A) and (P-A(m))] for late-diastolic temporal discordance (LDTD) were calculated. Isovolumic relaxation time (IVRT) was also measured. Early-diastolic temporal discordance was approximately 26 ms in all age groups. Late-diastolic temporal discordance, however, was inversely related to age (r = -0.35, P < 0.001) and IVRT (r = -0.34, P < 0.001) and therefore decreased in the elderly vs. young (13 +/- 10 vs. 23 +/- 10 ms; P < 0.001). In multivariate analysis, age failed to predict LDTD in the presence of IVRT. A, A(m), and Ar were simultaneous at onset, and peak A(m) coincided with peak Ar in all age groups (r = 0.97, P < 0.001). No significant differences were noted in the RR intervals.
Sequential prolongation of IVRT with ageing reduces LDTD, thus converging the peaks of A(m), A, and Ar (atrial mechanical alignment)-a potential novel method to identify subjects at increased dependency on atrial contraction for late-diastolic filling.
正常情况下左心室（LV）舒张峰值先于充盈峰值（E），这支持了左心室抽吸有助于舒张早期充盈的假说。舒张晚期类似的时间不一致的意义此前尚未得到研究。我们描述了舒张早期和晚期二尖瓣环运动与左心室充盈之间的时间关系，并研究了正常衰老对这些时间间隔的影响。
共研究了128名年龄在25 - 88岁的健康受试者。通过多普勒超声心动图记录二尖瓣和肺静脉血流逆转（Ar）。通过多普勒组织成像记录二尖瓣环舒张早期位移（E(m)）和晚期位移（A(m)）。参照心电图R波和P波，进行以下测量：R波至E波峰值（R - E）和E(m)（R - E(m)）；P波起始至A波峰值（P - pA）、A(m)（P - pA(m)）和Ar（P - pAr）。计算舒张早期时间不一致（EDTD）的[(R - E)与(R - E(m))]之差以及舒张晚期时间不一致（LDTD）的[(P - A)与(P - A(m))]之差。还测量了等容舒张时间（IVRT）。所有年龄组的舒张早期时间不一致约为26毫秒。然而，舒张晚期时间不一致与年龄呈负相关（r = -0.35，P < 0.001）以及与IVRT呈负相关（r = -0.34，P < 0.001），因此老年人与年轻人相比有所减少（13±10与23±10毫秒；P < 0.001）。在多变量分析中，在存在IVRT的情况下年龄无法预测LDTD。在所有年龄组中，A、A(m)和Ar在起始时同步，且A(m)峰值与Ar峰值重合（r = 0.97，P < 0.001）。RR间期无显著差异。
随着年龄增长IVRT的顺序延长会减少LDTD，从而使A(m)、A和Ar的峰值汇聚（心房机械对齐）——这是一种潜在的新方法，用于识别舒张晚期充盈对心房收缩依赖增加的受试者。
