[The influence of increase in heart rate on coronary flow dynamics in the patients with aortic stenosis].
To clarify the causative factors responsible for the development of effort angina in aortic stenosis, the influence of an increase in heart rate by atrial pacing and isoproterenol infusion on the phasic left coronary flow velocity waveforms were studied using a pulsed Doppler velocimeter during cardiac surgery. Coronary flow velocity waveforms in aortic stenosis was characterized by a slowly increased diastolic inflow and an elongation of the time from the onset of diastole to the diastolic peak velocity. An increase in heart rate by pacing brought about a marked decrease in diastolic coronary flow since the slowly increasing diastolic flow was cut with the onset of following systole. On the contrary, after an increase in heart rate by infusion of isoproterenol, diastolic increasing rate in the coronary flow waveform accelerated and diastolic peak velocity markedly increased. As the results, isoproterenol produced a significant increase in diastolic coronary inflow.
Fujiwara
T
T
Department of Thoracic Surgery, Kawasaki Medical School.
Masaki
H
H
Yamane
H
H
Yoshida
H
H
Fukuhiro
Y
Y
Tabuchi
A
A
Katsumura
T
T
D000368:Aged; D001024:Aortic Valve Stenosis / Q000503:physiopathology*; D001783:Blood Flow Velocity; D003326:Coronary Circulation; D003971:Diastole; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007545:Isoproterenol / Q000008:administration & dosage / Q000494:pharmacology; D008297:Male; D008875:Middle Aged
D007545:Isoproterenol