Effect of cardiac resynchronization therapy on regional left ventricular function: a speckle tracking strain analysis.
OBJECTIVE
The mechanisms associated with cardiac resynchronization therapy (CRT) benefits have been elucidated in part, however little is known about the effects of biventricular pacing (BVP) on regional myocardial contractility.


RESULTS
Twenty patients with conventional CRT criteria were studied before and after device implantation. Speckle tracking strain analysis was performed from standard bidimensional acquisitions during different pacing configurations. Longitudinal and transverse strains were measured for the six basal left ventricular (LV) segments. Acute CRT improved LV end-diastolic and end-systolic volumes without significantly modifying LV ejection fraction. Moreover, CRT produced significant changes in regional strain. When compared with spontaneous rhythm, simultaneous BVP caused a significant increase in longitudinal septal strain (-4.8 vs. -7.3%, P = 0.003) and a significant decrease in longitudinal lateral strain (-8.2 vs. -5.9%, P = 0.03). Simultaneous BVP also induced a significant decrease in transverse lateral strain from 17.9 to 10.9% (P = 0.004).


CONCLUSIONS
In this acute echocardiographic study, BVP decreased lateral wall deformation while improving septal wall contraction, thus potentially improving LV contractile pattern.
Serri
Karim
K
Hôpital du Sacré-Coeur, University of Montreal, 5400, Boulevard Gouin Ouest, Montreal, Canada. karimserri@umontreal.ca
Lafitte
Stéphane
S
Réant
Patricia
P
Amyot
Robert
R
Sauvé
Claude
C
Bordachar
Pierre
P
Roudaut
Raymond
R
D000368:Aged; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D015150:Echocardiography, Doppler / Q000379:methods; D025401:Echocardiography, Stress / Q000379:methods; D005260:Female; D005471:Fluoroscopy; D006333:Heart Failure / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D008365:Manometry / Q000379:methods; D009200:Myocardial Contraction / Q000502:physiology*; D009206:Myocardium / Q000378:metabolism; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000502:physiology*