Relation of mechanical dyssynchrony with underlying cardiac structure and performance in chronic systolic heart failure: implications on clinical response to cardiac resynchronization.
OBJECTIVE
The aim of this study is to describe the relationship between ventricular mechanical dyssynchrony (VMD) and echocardiographic indices of cardiac remodelling.


RESULTS
We evaluated 219 ambulatory patients with chronic systolic heart failure [left ventricular ejection fraction (LVEF) <or= 35%, New York Heart Association functional classes II-IV] who underwent echocardiographic evaluation. The presence of dyssynchrony was defined by Bader criteria (intra-VMD > 40 ms and/or inter-VMD > 38 ms). In our study cohort, 59% of patients had evidence of dyssynchrony (including 44% with intra-VMD and 38% with inter-VMD, and 20% with both). Inter-VMD correlated with QRS width (r = 0.48, P < 0.0001) better than intra-VMD (r = 0.24, P < 0.001). Higher inter-VMD was associated with less restrictive filling patterns (rank sums P = 0.012) and larger left ventricular end-diastolic dimension (LVEDD, rank sums P = 0.020), but intra-VMD values were similar across diastolic stages and LVEDD tertiles.


CONCLUSIONS
In chronic systolic heart failure, evidence of mechanical dyssynchrony is prevalent but the underlying cardiac structure and performance may influence the degree of inter-VMD more so than intra-VMD. Our data suggest that the extent of inter-VMD is directly related to the degree of dilatation of the heart but inversely to diastolic dysfunction.
Tang
Wai Hong Wilson
WH
Department of Cardiovascular Medicine, Section of Heart Failure and Cardiac Transplantation Medicine, Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
Mullens
Wilfried
W
Borowski
Allen G
AG
Tong
Wilson
W
Shrestha
Kevin
K
Troughton
Richard W
RW
Martin
Maureen G
MG
Kassimatis
Kathleen
K
Agler
Debbie
D
Jasper
Sue
S
Grimm
Richard A
RA
Starling
Randall C
RC
Klein
Allan L
AL
D002908:Chronic Disease; D004452:Echocardiography / Q000706:statistics & numerical data*; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging* / Q000453:epidemiology* / Q000517:prevention & control; D006801:Humans; D008297:Male; D008875:Middle Aged; D009820:Ohio / Q000453:epidemiology; D015995:Prevalence; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000453:epidemiology* / Q000517:prevention & control