Lee T M, Su S F, Chen M F, Liau C S, Lee Y T
Department of Internal Medicine, National Taiwan University Hospital, Taipei.
Heart. 1996 Dec;76(6):490-4. doi: 10.1136/hrt.76.6.490.
To investigate the effects of transvalvar flow rate on aortic valve resistance and valve area after percutaneous transvenous balloon dilatation of the mitral valve in a homogeneous group of patients with rheumatic heart disease.
Retrospective analysis of 12 patients with combined aortic and mitral stenosis who had undergone balloon dilatation of the mitral valve over a period of 9 years.
Tertiary referral centre.
Twelve (8 women, 4 men; mean (SD) age 37 (9) of 227 consecutive patients with critical mitral stenosis undergoing transvenous balloon dilation of the mitral valve in the centre also had aortic stenosis, defined as a transaortic pressure gradient of more than 25 mm Hg measured at a catheterisation study before valvuloplasty.
Echocardiographic variables (mitral valve area measured by the pressure half-time method and planimetry, and the aortic valve area derived from the continuity equation) and haemodynamic measurements (cardiac output, left ventricular mean systolic pressure, aortic mean pressure, transaortic valve pressure gradient, mitral valve and aortic valve areas derived from the Gorlin formula, and aortic valve resistance) were assessed before and after transvenous balloon dilatation of the mitral valve. Follow up catheterisation to measure haemodynamic variables was performed one week after mitral valvuloplasty.
Mean transaortic flow rate increased 33% after mitral valvuloplasty (from 198 (68) to 254 (41) ml/s, P = 0.002). Aortic valve areas derived from the Gorlin formula were significantly increased from 0.57 (0.12) to 0.73 (0.14) cm2 (P = 0.006) after mitral valvuloplasty. However, aortic valve area and valve resistance derived from the continuity equation were independent of the increase in flow rate after mitral valvuloplasty (from 1.29 (0.35) to 1.30 (0.29) cm2 and from 317 (65) to 259 (75) dyn.s.cm-5, both P = NS).
The Gorlin-derived aortic valve area tends to be flow-dependent, and continuity equation-derived aortic valve area and catheterisation-derived valve resistance seem to be less flow-dependent. In patients with combined mitral and aortic stenosis, these flow-independent indices are important for decision-making.
在一组患有风湿性心脏病的同质患者中，研究经皮经静脉二尖瓣球囊扩张术后跨瓣血流速度对主动脉瓣阻力和瓣口面积的影响。
对12例患有主动脉瓣和二尖瓣联合狭窄且在9年期间接受二尖瓣球囊扩张术的患者进行回顾性分析。
三级转诊中心。
在该中心连续227例接受经静脉二尖瓣球囊扩张术的严重二尖瓣狭窄患者中，有12例（8名女性，4名男性；平均（标准差）年龄37（9）岁）同时患有主动脉瓣狭窄，定义为在瓣膜成形术前导管检查时测得的跨主动脉压力阶差超过25 mmHg。
在二尖瓣经静脉球囊扩张术前和术后评估超声心动图变量（通过压力减半时间法和平面测量法测量的二尖瓣瓣口面积，以及根据连续性方程得出的主动脉瓣瓣口面积）和血流动力学测量值（心输出量、左心室平均收缩压、主动脉平均压、跨主动脉瓣压力阶差、根据Gorlin公式得出的二尖瓣和主动脉瓣瓣口面积，以及主动脉瓣阻力）。二尖瓣成形术后1周进行随访导管检查以测量血流动力学变量。
二尖瓣成形术后平均跨主动脉血流速度增加了33%（从198（68）ml/s增至254（41）ml/s，P = 0.002）。二尖瓣成形术后，根据Gorlin公式得出的主动脉瓣瓣口面积从0.57（0.12）cm²显著增加至0.73（0.14）cm²（P = 0.006）。然而，根据连续性方程得出的主动脉瓣瓣口面积和瓣口阻力与二尖瓣成形术后血流速度的增加无关（分别从1.29（0.35）cm²增至1.30（0.29）cm²，以及从317（65）dyn.s.cm⁻⁵降至259（75）dyn.s.cm⁻⁵，P均无统计学意义）。
根据Gorlin公式得出的主动脉瓣瓣口面积倾向于依赖血流，而根据连续性方程得出的主动脉瓣瓣口面积和导管检查得出的瓣口阻力似乎对血流的依赖性较小。在患有二尖瓣和主动脉瓣联合狭窄的患者中，这些不依赖血流的指标对决策很重要。
