ECHOCARDIOGRAPHIC CHARACTERISATION OF RIGHT VENTRICULAR CONTRACTILITY-
FINDINGS IN HEALTH AND DISEASE. U.V
Premawardhana* and D.S.
Celermajer. Cardiology
Department, Royal Prince Alfred Hospital, Sydney, NSW. Right
ventricular (RV) dysfunction may occur in a variety of disease states, such as
inferior myocardial infarction or pulmonary hypertension. Despite this, RV
function is difficult to measure by any currently available technique, and
therefore normal contractility as well as changes with age and disease are only
poorly characterised. Tissue Doppler
Imaging (TDI) is a novel ultrasound modality for measuring regional myocardial
contractility. We therefore used TDI to assess regional RV function in health
and disease. We studied 23 healthy young controls (29+5 years), 11 older
controls (65+9 years), 10 subjects with dilated cardiomyopathy (DCM, 64+9
years) and 9 adults with pulmonary hypertension (PHT, 49+18 years). In
each case, peak myocardial velocity was measured by TDI (Vingmed System V) in
the RV free wall and septum, at the annulus, base, mid-portion and apex. In the young
controls, intra and inter-observer reproducibility were both high (r values
>0.85, p <0.001). Within-subject reproducibility was best for RV free
wall measurements, but poor at the apex. In both young
and old controls, there was a gradient of contraction velocity from annulus to
apex (annulus fastest, in the young subjects 10.3+2.0 cm/sec vs3.7+2.2
cm/sec at apex, p<0.001). RV annulus velocities were slower in the older
controls (8.9+1.4 cm/sec, p=0.02). Other RV velocities (of basal, mid
and apical segments and septal velocities) did not change significantly with
aging. Both RV and LV
myocardial velocities were significantly lower in the DCM subjects (for
example, RV annulus 6.8+2.7 cm/sec vs 8.9+1.4 in older controls,
p=0.02). There were no significant differences in the PHT group compared with
controls, in either RV or LV contractile parameters. Therefore, TDI
provides reproducible and quantifiable information about RV contractility. In
the normal RV, contractility is fastest at the base of the ventricle compared
to the apex. Contractile velocity may slow, however, with increasing age or in
the presence of myocardial disease.
