Plehn J F, Arbuckle B E, Southworth J, Nugent W, Plume S, Marrin C A
Section of Cardiology, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA.
J Heart Valve Dis. 1996 May;5(3):328-36.
Preliminary reports have suggested hemodynamic disparities between single leaflet tilting disc prostheses. We tested the hypothesis that similarities in prosthetic design may not necessarily indicate hemodynamic equivalence.
In a retrospective analysis, we compared the functional characteristics of two single tilting disc (Omniscience and Medtronic Hall) prostheses implanted in the aortic position in 30 patients matched for valve size and left ventricular systolic function.
Echocardiographic and Doppler analysis blinded to patient and valve type indicated similar quantitative left ventricular ejection fractions (64% +/- 6% for both) and cardiac outputs (4.8 +/- 1.2 vs. 4.6 +/- 1.2 l/min, p = 0.65) in the Onmiscience and Medtronic Hall groups, respectively. Transprosthetic instantaneous peak gradients were greater for Omniscience than for Medtronic Hall valves (44 +/- 8 vs. 35 +/- 11 mmHg, p < or = 0.02), as were the mean values (24 +/- 6 vs. 18 +/- 6 mmHg, p = 0.01). Even when 21 and 23 mm prostheses were analyzed separately to allow for unequal sewing ring diameters in the smallest valve sizes (Omniscience = 19 mm, Medtronic Hall = 20 mm), higher gradients were noted in the Omniscience prostheses. Effective orifice areas were smaller in the Omniscience than Medtronic Hall prostheses whether data from all prostheses (0.92 +/- 0.11 cm2 vs. 1.09 +/- 0.18 cm2, p < or = 0.05), or only data from 21 and 23 mm valves (0.94 +/- 0.11 cm2 vs. 1.10 +/- 0.18 cm2, p < 0.05) were included. Similarly, the dimensionless obstructive index, a parameter independent of left ventricular flow and annular size, was reduced in the Omniscience valves, indicating greater obstruction, whether all valves (0.31 +/- 0.04 vs. 0.36 +/- 0.07, p < or = 0.01) or only 21 and 23 mm valves (0.31 +/- 0.04 vs. 0.36 +/- .04, p < 0.001) were analyzed.
Despite prosthetic design similarities, resting hemodynamic assessment indicates greater stenosis in Omniscience than Medtronic Hall valves when placed in the aortic position. The long term effects of these differences in terms of ventricular diastolic and systolic function and mass regression requires further evaluation.
初步报告提示单叶倾斜盘式人工心脏瓣膜存在血流动力学差异。我们检验了这样一个假设，即人工瓣膜设计上的相似性不一定意味着血流动力学等效。
在一项回顾性分析中，我们比较了30例主动脉瓣位置植入的两种单倾斜盘式（Omniscience和美敦力Hall）人工瓣膜的功能特性，这些患者在瓣膜尺寸和左心室收缩功能方面相匹配。
对患者和瓣膜类型不知情的超声心动图和多普勒分析表明，Omniscience组和Medtronic Hall组的左心室射血分数定量值相似（均为64%±6%），心输出量分别为（4.8±1.2对4.6±1.2升/分钟，p = 0.65）。Omniscience人工瓣膜的跨瓣瞬时峰值梯度高于Medtronic Hall瓣膜（44±8对35±11 mmHg，p≤0.02），平均值也是如此（24±6对18±6 mmHg，p = 0.01）。即使分别分析21毫米和23毫米的人工瓣膜，以考虑最小瓣膜尺寸（Omniscience = 19毫米，Medtronic Hall = 20毫米）时缝合环直径不相等的情况，Omniscience人工瓣膜的梯度仍更高。无论是纳入所有人工瓣膜的数据（0.92±0.11平方厘米对1.09±0.18平方厘米，p≤0.05），还是仅纳入21毫米和23毫米瓣膜的数据（0.94±0.11平方厘米对1.10±0.18平方厘米，p < 0.05），Omniscience人工瓣膜的有效瓣口面积均小于Medtronic Hall人工瓣膜。同样，无量纲阻塞指数是一个独立于左心室流量和瓣环大小的参数，在Omniscience人工瓣膜中降低，表明阻塞更大，无论是分析所有瓣膜（0.31±0.04对0.36±0.07，p≤0.01）还是仅分析21毫米和23毫米瓣膜（0.31±0.04对0.36±0.04，p < 0.001）。
尽管人工瓣膜设计相似，但静息血流动力学评估表明，置于主动脉瓣位置时，Omniscience人工瓣膜比Medtronic Hall人工瓣膜狭窄更严重。这些差异对心室舒张和收缩功能以及心肌质量消退的长期影响需要进一步评估。
