Belgi Aytül, Yalçinkaya Selim, Cetin Seyhan, Kabukçu Mehmet, Gölbaşi Ilhan, Sancaktar Oktay
Akdeniz University Department of Cardiology, Antalya, Turkey.
Acta Cardiol. 2003 Dec;58(6):539-45. doi: 10.2143/AC.58.6.2005319.
The mechanisms of the different haemodynamic and clinical responses to dobutamine infusion in mitral stenosis (MS) are not clearly established. The aim of this study was to evaluate the relation between left atrial (LA) function and haemodynamic response in patients with MS during dobutamine infusion.
Forty-two consecutive moderately symptomatic patients (33 women, 9 men; mean age 46+/-9, range from 26 to 66), New York Heart Association (NYHA) class II with MS (mean mitral valve area 1.7+/-0.1 cm2) were evaluated with dobutamine stress echocardiography. Haemodynamic measurements were obtained at rest and during peak dobutamine infusion. LA fractional shortening at rest was used as an index of global LA function. Group I consisting of patients with significantly elevated pulmonary artery pressure (> 60 mm Hg) and mean transmitral gradient (> 15 mm Hg) at peak dobutamine infusion were defined as haemodynamically serious MS. Group II consisted of the remaining 30 patients whose haemodynamic data were below these levels. While baseline haemodynamic parameters and mitral valve characteristics were not different between the two groups, LA fractional shortening was significantly lower (18.9+/-2.8 vs. 32.3+/-5.1%, p<0.0001) and left atrial dimension was significantly larger in group I (49.7+/-2.3 mm vs 43.6+/-5.3 mm, p<0.0001). Left atrial fractional shortening was negatively correlated with the increase in mean transmitral gradient (r:-0.58, p<0.01). When the patients were divided using a LA fractional shortening level of 25% as the cut-off point, we observed that the patients with low LA fractional shortening had a greater increase in mean transmitral gradient (7.3+/-3.1 mm Hg vs. 4.6+/-1.4 mm Hg), p = 0.005) and pulmonary artery pressure (22.4+/-3.5 mm Hg vs. 16.1+/-8.5 mm Hg, p = 0.001) compared to the patients with high LA fractional shortening. Based on these haemodynamic results, management was changed in 12 patients (28%): 5 underwent percutaneous mitral balloon commissurotomy and 7 received intensive medical treatment.
The present study demonstrates that haemodynamic response during dobutamine stress echocardiography correlates with LA fractional shortening in patients with MS. The evaluation of left atrial function at rest in patients with ambiguous symptoms and mild mitral stenosis may be useful in clinical decision making. Atrial dysfunction at rest may predict the haemodynamic response during stress echo in these patients.
二尖瓣狭窄（MS）患者对多巴酚丁胺输注产生不同血流动力学和临床反应的机制尚未明确确立。本研究的目的是评估MS患者在多巴酚丁胺输注期间左心房（LA）功能与血流动力学反应之间的关系。
对42例连续的中度症状患者（33例女性，9例男性；平均年龄46±9岁，范围26至66岁）进行了多巴酚丁胺负荷超声心动图评估，这些患者为纽约心脏协会（NYHA）II级的MS患者（平均二尖瓣面积1.7±0.1 cm²）。在静息状态和多巴酚丁胺输注峰值时进行血流动力学测量。静息时的左心房缩短分数用作整体左心房功能的指标。将在多巴酚丁胺输注峰值时肺动脉压显著升高（>60 mmHg）且平均二尖瓣跨瓣压差显著升高（>15 mmHg）的患者定义为血流动力学严重MS组（I组）。II组由其余30例血流动力学数据低于这些水平的患者组成。虽然两组之间的基线血流动力学参数和二尖瓣特征无差异，但I组的左心房缩短分数显著更低（18.9±2.8%对32.3±5.1%，p<0.0001），左心房内径显著更大（49.7±2.3 mm对43.6±5.3 mm，p<0.0001）。左心房缩短分数与平均二尖瓣跨瓣压差的增加呈负相关（r：-0.58，p<0.01）。当以左心房缩短分数25%作为分界点对患者进行分组时，我们观察到左心房缩短分数低的患者与左心房缩短分数高的患者相比，平均二尖瓣跨瓣压差增加更大（7.3±3.1 mmHg对4.6±1.4 mmHg，p = 0.005），肺动脉压增加更大（22.4±3.5 mmHg对16.1±8.5 mmHg，p = 0.001）。基于这些血流动力学结果，12例患者（28%）的治疗方案发生了改变：5例接受了经皮二尖瓣球囊交界切开术，7例接受了强化药物治疗。
本研究表明，MS患者在多巴酚丁胺负荷超声心动图检查期间的血流动力学反应与左心房缩短分数相关。对症状不明确且二尖瓣狭窄较轻的患者进行静息时左心房功能评估可能有助于临床决策。静息时的心房功能障碍可能预测这些患者在负荷超声心动图检查期间的血流动力学反应。
