Division of Pulmonary Medicine and Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung, 40201, Taiwan, ROC.
School of Medicine, Chung Shan Medical University, Taichung, 40201, Taiwan, ROC.
Sci Rep. 2017 Sep 7;7(1):10929. doi: 10.1038/s41598-017-11189-x.
In COPD, pulmonary hyperinflation causes decreased stroke volume thereby decreased oxygen pulse (OP). While OP flattening is related to myocardial ischemia in cardiac patients, OP patterns have seldom been explored in COPD. The aims of the study were to investigate OP-curve patterns and associated factors in COPD. Seventy-five patients with stable COPD were enrolled. The demographics, cardiac size, physiological measurements and stress EKG were compared among OP-curve pattern groups. An algorithm to identify OP-curve patterns was developed in 28 patients. In the remaining 45 patients after excluding two with poor effort, this algorithm revealed 20 (44%) flattening, 16 (36%) increasing, and nine (20%) decreasing patterns. The flattening-type group had lower body mass, cardiac size, and diffusing capacity, and larger lung volumes (p = 0.05-<0.0001) compared to the increasing-type group. During exercise, the flattening-type group had a lower operable OP and more hyperventilation and dyspnea (p = 0.02-<0.01). None had ST-T changes. Most differences were related to body mass and mildly to inspiratory fraction. The decreasing-type group performed higher effort than the increasing-type group (p < 0.05). In conclusion, OP flattening was common and was associated with reduced body mass and pulmonary hyperinflation rather than with myocardial ischemia. The decreasing-type may be caused by motivation to exercise.
在 COPD 中，肺过度充气导致每搏量减少，从而导致氧脉冲（OP）降低。虽然 OP 变平与心脏患者的心肌缺血有关，但 OP 模式在 COPD 中很少被探讨。本研究的目的是探讨 COPD 中 OP 曲线模式及其相关因素。共纳入 75 例稳定期 COPD 患者。比较了 OP 曲线模式组之间的人口统计学、心脏大小、生理测量和应激心电图。在 28 例患者中开发了一种识别 OP 曲线模式的算法。在排除了 2 例用力不足的患者后，在剩余的 45 例患者中，该算法显示出 20 例（44%）变平、16 例（36%）递增和 9 例（20%）递减模式。与递增型组相比，变平型组的体重、心脏大小和弥散能力较低，肺容积较大（p = 0.05-<0.0001）。在运动过程中，变平型组的可操作性 OP 较低，过度通气和呼吸困难更多（p = 0.02-<0.01）。没有 ST-T 变化。大多数差异与体重和轻度吸气分数有关。与递增型组相比，递减型组的运动强度更高（p < 0.05）。总之，OP 变平很常见，与体重减轻和肺过度充气有关，而与心肌缺血无关。递减型可能是由于运动的动机所致。
