van den Brink R B, Verheul H A, Visser C A, Koelemay M J, Dunning A J
Department of Cardiology, Academic Medical Center, Amsterdam, The Netherlands.
Am J Cardiol. 1992 Feb 1;69(4):367-72. doi: 10.1016/0002-9149(92)90235-q.
Doppler echocardiographic evaluation of the prosthetic valve function is usually performed at rest, although this situation is not representative for patients' daily activities. Therefore, a symptom-limited Master 2-step test was performed in 61 asymptomatic patients with normal left ventricular function. No adequate Doppler signals were obtained in 5 of 61 patients (8%) within 60 second after termination of exercise. In patients with aortic valve prostheses (n = 24), heart rate increased from 74 +/- 10 to 105 +/- 18 beats/min, the maximal instantaneous gradient from 44 (range 22 to 90) to 68 (range 28 to 165) mm Hg (r = 0.89) and the mean gradient from 24 (range 12 to 50) to 39 (range 18 to 100) mm Hg (r = 0.90). In 6 of 11 patients with a maximal flow velocity ratio between the left ventricular outflow tract and the aortic valve prosthesis less than or equal to 0.25, the mean gradient increased to a value greater than or equal to 50 mm Hg after exercise, whereas in patients with a ratio of greater than or equal to 0.25, this never occurred. In patients with mitral valve prostheses (n = 39), heart rate increased from 80 +/- 12 to 116 +/- 14 beats/min and mean gradient from 6 (range 3 to 10) to 14 (range 6 to 25) mm Hg (r = 0.59). The correlation of the mean diastolic pressure gradient after exercise with pressure half-time was 0.66. Systolic pulmonary artery pressure at rest and after exercise could be determined in 22 of 39 patients (56%) and increased from 34 (range 20 to 70) to 57 (range 35 to 110) mm Hg. It is concluded that the response to exercise can, to a large extent, be inferred from Doppler parameters at rest, particularly in patients with aortic valve prostheses. The clinical implication of the high gradients found in some asymptomatic patients in the present study should be elucidated by follow-up studies.
人工瓣膜功能的多普勒超声心动图评估通常在静息状态下进行，尽管这种情况并不能代表患者的日常活动。因此，对61例左心室功能正常的无症状患者进行了症状限制性二级梯运动试验。61例患者中有5例（8%）在运动终止后60秒内未获得足够的多普勒信号。在主动脉瓣人工瓣膜置换患者（n = 24）中，心率从74±10次/分钟增加到105±18次/分钟，最大瞬时压差从44（范围22至90）毫米汞柱增加到68（范围28至165）毫米汞柱（r = 0.89），平均压差从24（范围12至50）毫米汞柱增加到39（范围18至100）毫米汞柱（r = 0.90）。在11例左心室流出道与主动脉瓣人工瓣膜的最大流速比值小于或等于0.25的患者中，有6例在运动后平均压差增加到大于或等于50毫米汞柱，而在比值大于或等于0.25的患者中，这种情况从未发生。在二尖瓣人工瓣膜置换患者（n = 39）中，心率从80±12次/分钟增加到116±14次/分钟，平均压差从6（范围3至10）毫米汞柱增加到14（范围6至25）毫米汞柱（r = 0.59）。运动后平均舒张压梯度与压力减半时间的相关性为0.66。39例患者中有22例（56%）可测定静息和运动后的收缩期肺动脉压，其从34（范围20至70）毫米汞柱增加到57（范围35至110）毫米汞柱。结论是，运动反应在很大程度上可从静息时的多普勒参数推断出来，尤其是在主动脉瓣人工瓣膜置换患者中。本研究中一些无症状患者发现的高压差的临床意义应通过随访研究予以阐明。
