Ferro G, Saccà L, Piscione F, Spinelli L, Spadafora M, Duilio C, Chiariello M
Department of Medicine, 2nd Medical School, University of Naples, Italy.
Cardiology. 1988;75(2):90-9. doi: 10.1159/000174355.
The electromechanical events occurring during acute myocardial ischemia were assessed in 10 patients who developed spontaneous angina during cardiac catheterization. Aortic pressure and electrocardiogram were recorded, and heart rate and systolic and diastolic time intervals were measured under control conditions, at the onset of angina and during the relief of chest pain. In 5 patients spontaneous angina was accompanied by an increase in heart rate and systemic arterial pressure and by ST segment changes in anterior or anterolateral precordial leads. Diastolic time, expressed as percent of cardiac cycle, shortened from 48.8 +/- 3.6% at rest to 33.6 +/- 4.8% (p less than 0.01) at the onset of angina, as a consequence of a significant increase in both electromechanical systole and heart rate, and returned to control values within 10 min after sublingual nitroglycerin. In the remaining 5 patients, spontaneous angina was accompanied by a decrease in heart rate and systemic arterial pressure and by ST segment changes in the inferior or inferolateral leads. The diastolic time increased significantly (p less than 0.05) from 39.4 +/- 6.1% at rest to 47.8 +/- 9% at the onset of angina, as a consequence of a significant decrease in heart rate and a slight decrease in electromechanical systole. Since coronary perfusion takes place mainly during diastole, our results suggest that the reflex increase in adrenergic tone may worsen myocardial ischemia by affecting diastolic perfusion time. In contrast, the increase in vagal tone may contribute to spontaneous relief of angina by prolonging diastolic perfusion time.
对10例在心脏导管插入术期间发生自发性心绞痛的患者，评估了急性心肌缺血期间发生的机电事件。记录主动脉压力和心电图，并在对照条件下、心绞痛发作时及胸痛缓解时测量心率以及收缩期和舒张期时间间隔。5例患者的自发性心绞痛伴有心率和体动脉压升高，以及胸前导联前壁或前侧壁ST段改变。以心动周期百分比表示的舒张期时间，从静息时的48.8±3.6%缩短至心绞痛发作时的33.6±4.8%（p<0.01），这是由于机电收缩期和心率均显著增加所致，舌下含服硝酸甘油后10分钟内恢复至对照值。其余5例患者的自发性心绞痛伴有心率和体动脉压降低，以及下壁或下侧壁导联ST段改变。舒张期时间从静息时的39.4±6.1%显著增加（p<0.05）至心绞痛发作时的47.8±9%，这是由于心率显著降低以及机电收缩期略有降低所致。由于冠状动脉灌注主要发生在舒张期，我们的结果表明，肾上腺素能张力的反射性增加可能通过影响舒张期灌注时间而加重心肌缺血。相反，迷走神经张力增加可能通过延长舒张期灌注时间而有助于心绞痛的自发缓解。
