Umeda Tomofumi
Department of Cardiovascular Surgery, Nihon University School of Medicine, Tokyo, Japan.
Ann Thorac Cardiovasc Surg. 2007 Jun;13(3):172-7.
The closure sound of the ATS bileaflet mechanical valve is said to be quieter than that of the other mechanical valves. However, the reasons for this are still unknown. In this study, we investigated the reasons for the quietness of the ATS valve closure sound.
The valve closure sound was evaluated in 70 patients and in another 70 patients in whom the SJM valve had been used for single valve replacement, based on frequency analysis of the closure sound, measurement of the opening angle of the valve, cardiac function, and patient interviews.
In the valve closure sound analysis, the mean peak frequency of the valve closure sound was 1.02 kHz for the ATS valve, and the mean pressure was 22.8+/-4.04 dB. The mean peak frequency of the closure sound of the SJM valve was1.02 kHz, with another intermittent peak at 3 to 9 kHz in the human audibility range. The mean sound pressure was 25.0+/-3.20 dB. The noise classification score was 2.07+/-1.95 points for the SJM valve, significantly higher as compared with that for the ATS valve which was 0.36+/-0.95 points. Multilateral examinations showed a significant difference in the mean opening angle between the ATS and the SJM valves: the angle was 76.6+/-4.67 degrees for the ATS valve and 82.3+/-2.05 degrees for the SJM valve.
In view of the lower sound pressure in the human audibility range and lower patient awareness of the valve closure sound, the ATS valve would appear to be a superior mechanical valve when compared to the SJM valve from the point of view of the quality of life of the patients. The significant difference in the opening angle in patients with the ATS valve between those who were aware of the valve closure sound and those who were not suggested a possible association between the opening angle and the patient awareness of the valve closure sound.
据说ATS双叶机械瓣膜的关闭声音比其他机械瓣膜的关闭声音更安静。然而，其原因尚不清楚。在本研究中，我们调查了ATS瓣膜关闭声音安静的原因。
基于关闭声音的频率分析、瓣膜开口角度测量、心功能以及患者访谈，对70例患者和另外70例曾使用SJM瓣膜进行单瓣膜置换的患者的瓣膜关闭声音进行了评估。
在瓣膜关闭声音分析中，ATS瓣膜关闭声音的平均峰值频率为1.02kHz，平均声压为22.8±4.04dB。SJM瓣膜关闭声音的平均峰值频率为1.02kHz，在人类可听范围内3至9kHz处还有一个间歇性峰值。平均声压为25.0±3.20dB。SJM瓣膜的噪声分类评分为2.07±1.95分，与ATS瓣膜的0.36±0.95分相比显著更高。多方面检查显示，ATS瓣膜和SJM瓣膜之间的平均开口角度存在显著差异：ATS瓣膜的角度为76.6±4.67度，SJM瓣膜的角度为82.3±2.05度。
鉴于在人类可听范围内声压较低以及患者对瓣膜关闭声音的感知较低，从患者生活质量的角度来看，与SJM瓣膜相比，ATS瓣膜似乎是一种更优质的机械瓣膜。意识到瓣膜关闭声音的ATS瓣膜患者与未意识到的患者之间开口角度存在显著差异，这表明开口角度与患者对瓣膜关闭声音的感知之间可能存在关联。
