Right ventricular diastolic dysfunction in patients with left ventricular hypertrophy: analysis of right ventricular myocardial relaxation using two-dimensional speckle tracking imaging.
BACKGROUND
Although several previous studies have suggested the presence of right ventricular (RV) diastolic dysfunction in patients with hypertrophic cardiomyopathy (HCM) and those with hypertensive left ventricular hypertrophy (HT-LVH), the mechanisms are still unclear. This study aimed to clarify the relationship between the RV global diastolic dysfunction in these patients and the regional myocardial diastolic function, including synchronicity of the interventricular septum and RV free wall.


METHODS
In 20 age-matched patients with HT-LVH, 20 patients with HCM and 22 control subjects without pulmonary hypertension, RV isovolumic relaxation time (IRTR) was measured using continuous-wave Doppler echocardiography. The early diastolic peak strain rate (E SR) and time from QRS to E SR (T-E SR) were measured in the apical, mid-ventricular and basal segments of the interventricular septum and RV free wall using two-dimensional speckle tracking imaging (2DST).


RESULTS
IRTR was more prolonged both in HT-LVH and in HCM than in the controls. The averaged septal E SR was reduced both in HT-LVH and in HCM (P < 0.0001, respectively), but the averaged RV free wall E SR was decreased only in HCM (P = 0.0007). E SR averaged for six septal and RV free wall segments was correlated with IRTR (r = -0.46, P = 0.0001). Neither intergroup difference nor correlation with IRTR was observed in a coefficient of variation of T-E SR for the six segments.


CONCLUSIONS
RV global diastolic function is impaired in patients with HT-LVH and HCM due to relaxation abnormalities, not an asynchrony, of the myocardium surrounding the RV cavity. The detection of RV free wall relaxation abnormality using 2DST may be useful to differentiate HCM from HT-LVH.
Division of Laboratory and Transfusion Medicine, Hokkaido University Hospital, Sapporo, Japan.
Sanae
S
Kaga
Faculty of Health Sciences, Hokkaido University Graduate School, Kita-12, Nishi-5, Kita-ku, Sapporo, 060-0812, Japan. mikami@cme.hokudai.ac.jp.
Taisei
T
Mikami
Faculty of Health Sciences, Hokkaido University Graduate School, Kita-12, Nishi-5, Kita-ku, Sapporo, 060-0812, Japan.
Hisao
H
Onozuka
Division of Laboratory and Transfusion Medicine, Hokkaido University Hospital, Sapporo, Japan.
Satomi
S
Omotehara
Faculty of Health Sciences, Hokkaido University Graduate School, Kita-12, Nishi-5, Kita-ku, Sapporo, 060-0812, Japan.
Ayumu
A
Abe
Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
Satoshi
S
Yamada
Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
Masako
M
Okada
Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
Hiroshi
H
Komatsu
Division of Laboratory and Transfusion Medicine, Hokkaido University Hospital, Sapporo, Japan.
Mamiko
M
Inoue
Division of Laboratory and Transfusion Medicine, Hokkaido University Hospital, Sapporo, Japan.
Shinobu
S
Yokoyama
Division of Laboratory and Transfusion Medicine, Hokkaido University Hospital, Sapporo, Japan.
Mutsumi
M
Nishida
Division of Laboratory and Transfusion Medicine, Hokkaido University Hospital, Sapporo, Japan.
Chikara
C
Shimizu
Division of Laboratory and Transfusion Medicine, Hokkaido University Hospital, Sapporo, Japan.
Kazuhiko
K
Matsuno
Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
Hiroyuki
H
Tsutsui
Hypertension; Hypertrophic cardiomyopathy; Left ventricular hypertrophy; Right ventricular diastolic function; Two-dimensional speckle tracking imaging