抄録
In 27 anesthetized open-chest dogs, we measured blood velocities in the septal artery, which is predominantly intramyocardial, using a 20-MHz multichannel pulsed Doppler method. Blood velocity measurements were performed under conditions of normal, left main coronary stenosis with or without vasodilators (adenosine or nitroglycerin), increased cardiac contractility by isoproterenol (ISP) and pacing-induced tachycardia. The phasic pattern in the septal artery was characterized by a diastolic predominant pattern, and by a significant systolic retrograde flow which is called a “coronary slosh phenomenon”. A septal arterial blood velocity area was divided into three components : systolic retrograde velocity area (SR), systolic forward velocity area (SF) and diastolic forward velocity area (DF). Increasing severity of coronary stenosis caused a fall in total inflow by a decreased DF and by an increased SR flow. Vasodilators under coronary stenosis enhanced this phenomenon. ISP caused biphasic systolic retrograde flows, i.e., early and- mid to- late-retrograde flows, resulting in an augmentation of the slosh phenomenon. Pacing-induced tachycardia mainly decreased the DF with a reduction of diastolic time with a slight decrease in the SR. We conclude that the slosh phenomenon of the intramyocardial blood was augmented by coronary stenosis with and without vasodilators and enhancement of cardiac contractility, but not by pacing-induced tachycardia.
