Ishikawa K, Hayashi T, Kohashi Y, Otani S, Kanamasa K, Yamakado T, Tashi M, Osato S, Katori R
Jpn Circ J. 1984 Mar;48(3):225-32. doi: 10.1253/jcj.48.225.
Left ventricular size is one of the major determinants of myocardial oxygen consumption, therefore if oxygen inhalation reduces myocardial oxygen demand, such might be beneficial in the treatment of acute myocardial infarction. Routine diagnostic biplane left coronary cineangiograms were obtained during air or oxygen breathing in 11 patients with old myocardial infarction or angina pectoris. Coordinates of the points on the left coronary artery were measured and throughout one cardiac cycle frame by frame. The spatial distance (segment length: L) between any two of these points was calculated. Segment length at R wave on the electrocardiogram (LECG R) and minimum value (Lmin) for each segment were calculated. Arterial pO2 was elevated by oxygen breathing from 91 +/- 4 (+/- SE) to 427 +/- 18 mmHg. Left ventricular segment length was significantly reduced by oxygen breathing: LECG R being reduced following oxygen breathing from 62.3 +/- 3.0 to 60.6 +/- 3.0 mm (a decrease of 3.3 +/- 0.8%) and Lmin also being reduced from 55.9 +/- 2.8 to 54.4 +/- 2.8 mm (a decrease of 3.1 +/- 1.0%). These figures indicate that left ventricular size was reduced. Reduction in left ventricular size through oxygen inhalation, by reducing myocardial oxygen demand, should therefore be beneficial in coronary artery disease.
左心室大小是心肌耗氧量的主要决定因素之一，因此，如果吸氧能降低心肌需氧量，那么这可能对急性心肌梗死的治疗有益。对11例陈旧性心肌梗死或心绞痛患者在呼吸空气或氧气时进行了常规诊断性双平面左冠状动脉电影血管造影。测量左冠状动脉上各点的坐标，并在整个心动周期逐帧测量。计算这些点中任意两点之间的空间距离（节段长度：L）。计算心电图R波处的节段长度（LECG R）和每个节段的最小值（Lmin）。吸氧使动脉血氧分压从91±4（±SE）mmHg升高至427±18 mmHg。吸氧使左心室节段长度显著缩短：吸氧后LECG R从62.3±3.0 mm降至60.6±3.0 mm（降低3.3±0.8%），Lmin也从55.9±2.8 mm降至54.4±2.8 mm（降低3.1±1.0%）。这些数据表明左心室大小减小。因此，通过吸氧减小左心室大小，降低心肌需氧量，对冠状动脉疾病应该是有益的。
