title: Abnormal coronary flow profiles at rest and during rapid atrial pacing in patients with hypertrophic cardiomyopathy.
abstract: To examine the mechanism of myocardial ischemia in hypertrophic cardiomyopathy (HCM), coronary flow velocity was measured in the left anterior descending coronary artery (LAD) using a Doppler guide wire in 11 patients with HCM and in 8 normal controls. The average peak velocity (APV), percent increase of APV (%APV), and APV during systole (Vs) and diastole (Vd) were calculated at rest and during rapid atrial pacing. The APV in HCM reached a peak value at a heart rate of 90 beats/min, while in the controls the APV increased continuously until the heart rate reached 130 beats/min [%APV (130 beats/min); 103+/-30% in HCM vs 139+/-23% in controls, p<0.04]. During rapid atrial pacing, Vs in the controls increased, whereas Vs in HCM decreased further. During high-rate pacing, Vd in HCM reached a peak value at a heart rate of 90 beats/min, whereas in the controls, Vd increased continuously until the heart rate reached 130 beats/min. The acceleration rate of early diastolic flow was significantly lower in HCM than in the controls (1.85+/-0.66 vs 3.18+/-1.62 m/s2, p<0.03). This abnormal response might be due to an increase in the reverse systolic flow and a decrease in the diastolic flow, probably caused by a slow acceleration of early diastolic flow velocity in the LAD.
authors.affiliation: The Second Department of Internal Medicine, Yamaguchi University School of Medicine, Ube, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Kawamura
authors.forename: T
authors.initials: T
authors.lastname: Fujii
authors.forename: T
authors.initials: T
authors.lastname: Miura
authors.forename: T
authors.initials: T
authors.lastname: Kawabata
authors.forename: T
authors.initials: T
authors.lastname: Okamura
authors.forename: S
authors.initials: S
authors.lastname: Yoshitake
authors.forename: H
authors.initials: H
authors.lastname: Iida
authors.forename: T
authors.initials: T
authors.lastname: Hiro
authors.forename: M
authors.initials: M
authors.lastname: Kohno
authors.forename: M
authors.initials: M
authors.lastname: Matsuzaki
mesh_terms: D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity; D002312:Cardiomyopathy, Hypertrophic / Q000503:physiopathology*; D003326:Coronary Circulation; D005260:Female; D006325:Heart Atria / Q000503:physiopathology; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged