Vol. 91, Issue 1, 435-440, July 2001
Impaired distensibility of the left ventricle after stiffening
of the right ventricle
Masanori
Shirakabe,
Seiji
Yamaguchi,
Yoshiaki
Tamada,
Gajendra
Baniya,
Akio
Fukui,
Hiroshi
Miyawaki, and
Hitonobu
Tomoike
First Department of Internal Medicine, Yamagata University
School of Medicine, Yamagata 990-9585, Japan
Acute and chronic alterations of right
ventricular (RV) wall properties can change left ventricular (LV)
performance. We investigated whether and how stiffening of the RV free
wall alters LV diastolic distensibility. We used cross-circulated
isolated hearts, in which the LV and RV were independently
controllable. Stiffness of the RV free wall was altered by
intramuscular injections of glutaraldehyde into the RV free wall after
right coronary artery ligation. We measured circumferential and
longitudinal regional lengths in the septum and LV free wall. During
data acquisition, RV volume was held constant. After the RV free wall
was stiffened by glutaraldehyde, the LV diastolic pressure-volume
relation shifted upward and became steeper. Importantly, stiffening of
the RV free wall increased the diastolic regional area in the septum
and LV free wall under constant LV volume. The augmented regional
dimensions may result in enhanced regional tension under constant LV
volume and may be related to the observed increase in LV diastolic
intracavitary pressure. The impaired LV diastolic distensibility by
stiffening of the RV free wall may be at least partly explained by
myocardial stretch, probably due to LV deformation.
ventricular interdependence; ventricular geometry; left ventricular
stiffness; diastolic function; length-tension relation
