Diastolic flow velocity pattern of the left anterior descending coronary artery in hypertrophied heart, with special reference to the difference between hypertrophic cardiomyopathy and hypertensive left ventricular hypertrophy.
BACKGROUND
This study aimed to clarify the characteristics of diastolic flow velocity pattern of the left anterior descending coronary artery (LAD) in patients with left ventricular hypertrophy (LVH), and the difference in diastolic LAD flow velocity pattern between hypertensive LVH and hypertrophic cardiomyopathy (HCM).


METHODS
The flow velocity pattern was recorded at the mid-portion of the LAD by high-frequency transthoracic Doppler echocardiography in 22 patients with HCM, 10 hypertensive patients with LVH [LVH(+)HT], and 9 hypertensive patients without LVH [LVH(-)HT]. The diastolic flow pattern was analyzed. Standard two-dimensional echocardiogram and apexcardiogram (ACG) were also recorded.


RESULTS
The interventricular septal thickness (IVST) and the sum of the IVST and LV posterior wall thickness (PWT) (IVST + PWT) were greater in HCM than in HT (p < 0.01) patients. Early diastolic upstroke time (D-UT) of the LAD flow velocity wave was longest in HCM, and was longer in LVH(+)HT than in LVH(-)HT (p < 0.01) patients. Direct correlation was found between D-UT and IVST, IVST + PWT in patients with LVH(+)HT and LVH(-)HT (r = 0.80, 0.79, respectively; p < 0.01), but no correlation was found between these parameters in HCM. Late-diastolic step (LDS) formation of the LAD flow velocity wave was observed in 68% of HCM, 20% of LVH(+)HT, but none of the LVH(-)HT patients. The A wave ratio of ACG was higher in patients with LDS than in those without (p < 0.01). The LDS occurred coincidently with the A wave of ACG.


CONCLUSIONS
The diastolic LAD flow velocity pattern in hypertrophied heart is characterized by slow acceleration and LDS formation, reflecting impaired relaxation and increased stiffness of the LV, respectively. These abnormalities correlate with the degree of hypertrophy in hypertensive heart, but do not correlate with that in HCM.
Department of Cardiology and Clinical Research, National Hospital Organization Zentsuji Hospital, 2-1-1 Senyu-cho, Zentsuji, Kagawa, 765-8507, Japan. nfukuda@zentuuji.hosp.go.jp.
Nobuo
N
Fukuda
Department of Cardiology and Clinical Research, National Hospital Organization Zentsuji Hospital, 2-1-1 Senyu-cho, Zentsuji, Kagawa, 765-8507, Japan.
Yamato
Y
Fukuda
Department of Cardiology and Clinical Research, National Hospital Organization Zentsuji Hospital, 2-1-1 Senyu-cho, Zentsuji, Kagawa, 765-8507, Japan.
Satofumi
S
Morishita
Department of Cardiology and Clinical Research, National Hospital Organization Zentsuji Hospital, 2-1-1 Senyu-cho, Zentsuji, Kagawa, 765-8507, Japan.
Koichi
K
Sakabe
Department of Cardiology and Clinical Research, National Hospital Organization Zentsuji Hospital, 2-1-1 Senyu-cho, Zentsuji, Kagawa, 765-8507, Japan.
Hisanori
H
Shinohara
Department of Cardiology and Clinical Research, National Hospital Organization Zentsuji Hospital, 2-1-1 Senyu-cho, Zentsuji, Kagawa, 765-8507, Japan.
Yoshiyuki
Y
Tamura
Coronary flow velocity pattern; Hypertensive heart; Hypertrophic cardiomyopathy; Left anterior descending coronary artery