Intraventricular dyssynchrony in light chain amyloidosis: a new mechanism of systolic dysfunction assessed by 3-dimensional echocardiography.
BACKGROUND
Light chain amyloidosis (AL) is a rare but often fatal disease due to intractable heart failure. Amyloid deposition leads to diastolic dysfunction and often preserved ejection fraction. We hypothesize that AL is associated with regional systolic dyssynchrony. The aim is to compare left ventricular (LV) regional synchrony in AL subjects versus healthy controls using 16-segment dyssynchrony index measured from 3-dimension-al (3D) echocardiography.


METHODS
Cardiac 3D echocardiography full volumes were acquired in 10 biopsy-proven AL subjects (60 +/- 3 years, 5 females) and 10 healthy controls (52 +/- 1 years, 5 females). The LV was subdivided into 16 segments and the time from end-diastole to the minimal systolic volume for each of the 16 segments was expressed as a percent of the cycle length. The standard deviations of these times provided a 16-segment dyssynchrony index (16-SD%). 16-SD% was compared between healthy and AL subjects.


RESULTS
Left ventricular ejection fraction was comparable (control vs. AL: 62.4 +/- 0.6 vs. 58.6 +/- 2.8%, p = NS). 16-SD% was significantly higher in AL versus healthy subjects (5.93 +/- 4.4 vs. 1.67 +/- 0.87%, p = 0.003). 16-SD% correlated with left ventricular mass index (R 0.45, p = 0.04) but not to left ventricular ejection fraction.


CONCLUSIONS
Light chain amyloidosis is associated with left ventricular regional systolic dyssynchrony. Regional dyssynchrony may be an unrecognized mechanism of heart failure in AL subjects.
Migrino
Raymond Q
RQ
Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, USA. rmigrino@mcw.edu
Harmann
Leanne
L
Woods
Timothy
T
Bright
Megan
M
Truran
Seth
S
Hari
Parameswaran
P
D000686:Amyloidosis / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D009202:Cardiomyopathies / Q000000981:diagnostic imaging* / Q000503:physiopathology; D019560:Echocardiography, Three-Dimensional; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013318:Stroke Volume; D013599:Systole; D018487:Ventricular Dysfunction, Left / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology