Left Ventricular Remodeling Results in Homogenization of Myocardial Work Distribution.
Adaptation, Physiological
Animals
Cardiac Pacing, Artificial
Disease Models, Animal
Energy Metabolism
Female
Fluorodeoxyglucose F18
/ administration & dosage
Glucose
/ metabolism
Hypertrophy, Left Ventricular
/ diagnostic imaging
Myocardium
/ metabolism
Positron-Emission Tomography
Radiopharmaceuticals
/ administration & dosage
Sheep, Domestic
Time Factors
Ventricular Dysfunction, Left
/ diagnostic imaging
Ventricular Function, Left
Ventricular Remodeling
cardiac resynchronization therapy
dyssynchrony
myocardial metabolism
myocardial work
remodeling
Journal
Circulation. Arrhythmia and electrophysiology
ISSN: 1941-3084
Titre abrégé: Circ Arrhythm Electrophysiol
Pays: United States
ID NLM: 101474365
Informations de publication
Date de publication:
05 2019
05 2019
Historique:
entrez:
27
4
2019
pubmed:
27
4
2019
medline:
28
1
2020
Statut:
ppublish
Résumé
The interaction between regional left ventricular (LV) myocardial work and metabolism in remodeled hearts has not yet been well established. Our aim was to investigate the effect of inhomogeneous LV work distribution on regional metabolism and remodeling in our animal model with reversible dyssynchrony due to pacing. In 12 sheep, 8 weeks of right atrial and right ventricular free wall (DDD) pacing lead to LV dilatation, a thinned septum, and thickened lateral wall. Left bundle branch block-like dyssynchrony caused by DDD pacing could be acutely reverted by right atrial pacing (AAI) only. Invasive hemodynamics and echocardiography were used to assess regional work by stress-strain loop area and compared with regional glucose metabolism measured by Glucose metabolism by positron emission tomography with anatomic correction on gated positron emission tomography reconstruction showed a different regional distribution than with clinical reconstructions and correlated best and significantly with regional myocardial work. At baseline, work was homogeneously distributed with normal conduction (AAI pacing), whereas during dyssynchrony (DDD pacing), the lateral wall was more loaded, and the septum was unloaded. After 8 weeks of remodeling under DDD pacing, however, an almost homogeneous work distribution was found with DDD pacing, whereas with AAI pacing, the thin septum showed exaggerated loading and the lateral walls a low load. Our experimental observations were confirmed in 5 patient responders to cardiac resynchronization therapy. Regional LV glucose metabolism closely correlates with regional work. Our data indicate that regionally different LV remodeling after exposure to inhomogeneous loading conditions, such as during LV dyssynchrony, is an adaptive process that helps to equilibrate work distribution. Correction of the inhomogeneous loading conditions, such as during cardiac resynchronization therapy, then triggers a reverse LV remodeling through the same mechanism.
Sections du résumé
BACKGROUND
The interaction between regional left ventricular (LV) myocardial work and metabolism in remodeled hearts has not yet been well established. Our aim was to investigate the effect of inhomogeneous LV work distribution on regional metabolism and remodeling in our animal model with reversible dyssynchrony due to pacing.
METHODS
In 12 sheep, 8 weeks of right atrial and right ventricular free wall (DDD) pacing lead to LV dilatation, a thinned septum, and thickened lateral wall. Left bundle branch block-like dyssynchrony caused by DDD pacing could be acutely reverted by right atrial pacing (AAI) only. Invasive hemodynamics and echocardiography were used to assess regional work by stress-strain loop area and compared with regional glucose metabolism measured by
RESULTS
Glucose metabolism by positron emission tomography with anatomic correction on gated positron emission tomography reconstruction showed a different regional distribution than with clinical reconstructions and correlated best and significantly with regional myocardial work. At baseline, work was homogeneously distributed with normal conduction (AAI pacing), whereas during dyssynchrony (DDD pacing), the lateral wall was more loaded, and the septum was unloaded. After 8 weeks of remodeling under DDD pacing, however, an almost homogeneous work distribution was found with DDD pacing, whereas with AAI pacing, the thin septum showed exaggerated loading and the lateral walls a low load. Our experimental observations were confirmed in 5 patient responders to cardiac resynchronization therapy.
CONCLUSIONS
Regional LV glucose metabolism closely correlates with regional work. Our data indicate that regionally different LV remodeling after exposure to inhomogeneous loading conditions, such as during LV dyssynchrony, is an adaptive process that helps to equilibrate work distribution. Correction of the inhomogeneous loading conditions, such as during cardiac resynchronization therapy, then triggers a reverse LV remodeling through the same mechanism.
Identifiants
pubmed: 31023060
doi: 10.1161/CIRCEP.118.007224
doi:
Substances chimiques
Radiopharmaceuticals
0
Fluorodeoxyglucose F18
0Z5B2CJX4D
Glucose
IY9XDZ35W2
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM