Elgendi Mohamed, Bobhate Prashant, Jain Shreepal, Rutledge Jennifer, Coe James Y, Zemp Roger, Schuurmans Dale, Adatia Ian
Department of Computing Science, University of Alberta, Edmonton, Alberta, Canada.
Department of Pediatrics, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada.
Pulm Circ. 2014 Dec;4(4):685-95. doi: 10.1086/678513.
We studied digital stethoscope recordings in children undergoing simultaneous catheterization of the pulmonary artery (PA) to determine whether time-domain analysis of heart sound intensity would aid in the diagnosis of PA hypertension (PAH). Heart sounds were recorded and stored in .wav mono audio format. We performed recordings for 20 seconds with sampling frequencies of 4,000 Hz at the second left intercostal space and the cardiac apex. We used programs written in the MATLAB 2010b environment to analyze signals. We annotated events representing the first (S1) and second (S2) heart sounds and the aortic (A2) and pulmonary (P2) components of S2. We calculated the intensity (I) of the extracted event area (x) as [Formula: see text], where n is the total number of heart sound samples in the extracted event and k is A2, P2, S1, or S2. We defined PAH as mean PA pressure (mPAp) of at least 25 mmHg with PA wedge pressure of less than 15 mmHg. We studied 22 subjects (median age: 6 years [range: 0.25-19 years], 13 female), 11 with PAH (median mPAp: 55 mmHg [range: 25-97 mmHg]) and 11 without PAH (median mPAp: 15 mmHg [range: 8-24 mmHg]). The P2∶A2 (P = .0001) and P2∶S2 (P = .0001) intensity ratios were significantly different between subjects with and those without PAH. There was a linear correlation (r > 0.7) between the P2∶S2 and P2∶A2 intensity ratios and mPAp. We found that the P2∶A2 and P2∶S2 intensity ratios discriminated between children with and those without PAH. These findings may be useful for developing an acoustic device to diagnose PAH.
我们研究了在接受肺动脉（PA）同步导管插入术的儿童中数字听诊器的记录，以确定心音强度的时域分析是否有助于诊断肺动脉高压（PAH）。心音以.wav单声道音频格式记录并存储。我们在左第二肋间和心尖处以4000Hz的采样频率进行了20秒的记录。我们使用在MATLAB 2010b环境中编写的程序来分析信号。我们标注了代表第一心音（S1）和第二心音（S2）以及S2的主动脉瓣成分（A2）和肺动脉瓣成分（P2）的事件。我们将提取的事件区域（x）的强度（I）计算为[公式：见正文]，其中n是提取事件中心音样本的总数，k为A2、P2、S1或S2。我们将PAH定义为平均肺动脉压（mPAp）至少为25mmHg且肺动脉楔压小于15mmHg。我们研究了22名受试者（中位年龄：6岁[范围：0.25 - 19岁]，13名女性），其中11名患有PAH（中位mPAp：55mmHg[范围：25 - 97mmHg]），11名无PAH（中位mPAp：15mmHg[范围：8 - 24mmHg]）。患有PAH和未患PAH的受试者之间，P2∶A2（P = 0.0001）和P2∶S2（P = 0.0001）强度比值存在显著差异。P2∶S2和P2∶A2强度比值与mPAp之间存在线性相关性（r > 0.7）。我们发现P2∶A2和P2∶S2强度比值可区分患有和未患PAH的儿童。这些发现可能有助于开发一种用于诊断PAH的声学设备。
