Romano Minna Moreira Dias, Pazin-Filho Antônio, Crescêncio Júlio César, Schmidt André, Almeida-Filho Oswaldo César, Gallo-Júnior Lourenço, Marin-Neto José Antonio, Maciel Benedito Carlos
Division of Cardiology, Department of Internal Medicine, University Hospital, Medical School of Ribeirão Preto, University of São Paulo, Brazil.
Echocardiography. 2008 Jan;25(1):40-6. doi: 10.1111/j.1540-8175.2007.00562.x.
Although the influence of respiration on ventricular filling, as evaluated by Doppler technique, and the evaluation of diastolic velocities of mitral valve annulus (MVA), as measured by Doppler tissue imaging (DTI), can provide valuable information for the study of left ventricular (LV) diastolic function, the concomitant effects of aging, tidal volume (TV), and respiratory rate (RR) on these velocities have not been quantitatively investigated.
We evaluated 12 normal male volunteers (Group I) aged 20-26 years (mean: 22.8) and 8 normal subjects aged 41 to 54 years old (mean: 45.9) (Group II). Using DTI we measured peak early (E(a)) and late (A(a)) velocities of longitudinal axis expansion at lateral and medial MVA. Doppler mitral and tricuspid flow velocities were measured: peak early (E) and late (A) inflow velocity, early (E(i)) and late (A(i)) flow integral, and deceleration time of peak early mitral flow velocity (DT). Respiratory cycles were simultaneously recorded at RR of 9, 12, 15, and 18 cycles/min and TV of 600 and 900 mL during respiration (RESP).
(1) E, A, and A(i) in MV had negligible change during respiration, but E(i) was significantly reduced during inspiration; (2) DT reduced slightly with inspiration, but the change was significant only with TV of 900 mL; (3) an important increase of E in right ventricular flow was observed during inspiration; (4) variations of RR and TV did not significantly influence right and left ventricular inflow in normal subjects, in the conditions of this investigation; (5) a significant increase of E(a) at medial MVA was documented during inspiration only in young subjects; (6) a significant decrease of A(a) at medial MVA was observed during inspiration in both groups of volunteers; (7) RR and TV did not influence MVA velocities in young and adult subjects; (8) a consistent reduction in E(a) and a significant increase in A(a) were observed with increasing age; (9) these changes were more conspicuous and consistent than those documented in ventricular filling when young and middle-age men are compared, suggesting that the DTI is more sensitive to detect changes in diastolic function; and (10) in addition, these data suggest that, for evaluation of diastolic function, in clinical context, it is not necessary to control rigorously RR or TV.
尽管通过多普勒技术评估呼吸对心室充盈的影响以及通过多普勒组织成像（DTI）测量二尖瓣环（MVA）舒张期速度可为研究左心室（LV）舒张功能提供有价值的信息，但衰老、潮气量（TV）和呼吸频率（RR）对这些速度的协同影响尚未得到定量研究。
我们评估了12名年龄在20 - 26岁（平均：22.8岁）的正常男性志愿者（I组）和8名年龄在41至54岁（平均：45.9岁）的正常受试者（II组）。使用DTI，我们测量了外侧和内侧MVA纵向轴扩张的早期（E(a)）和晚期（A(a)）峰值速度。测量了二尖瓣和三尖瓣的多普勒血流速度：早期（E）和晚期（A）流入速度、早期（E(i)）和晚期（A(i)）血流积分以及二尖瓣早期峰值血流速度的减速时间（DT）。在呼吸过程中，同时记录了RR为9、12、15和18次/分钟以及TV为600和900 mL时的呼吸周期（RESP）。
（1）MV中的E、A和A(i)在呼吸过程中变化可忽略不计，但E(i)在吸气时显著降低；（2）DT在吸气时略有降低，但仅在TV为900 mL时变化显著；（3）在吸气时观察到右心室血流中的E有重要增加；（4）在本研究条件下，RR和TV的变化对正常受试者的右心室和左心室流入无显著影响；（5）仅在年轻受试者中，吸气时内侧MVA处的E(a)有显著增加；（6）两组志愿者在吸气时均观察到内侧MVA处的A(a)显著降低；（7）RR和TV对年轻和成年受试者的MVA速度无影响；（8）随着年龄增长，观察到E(a)持续降低且A(a)显著增加；（9）与比较年轻和中年男性心室充盈时记录的变化相比，这些变化更明显且一致，表明DTI对检测舒张功能变化更敏感；（10）此外，这些数据表明，在临床环境中，为评估舒张功能，无需严格控制RR或TV。
