Intravascular volume dependency of left ventricular mass calculation by two-dimensional guided M-mode echocardiography.
BACKGROUND
Increased left ventricular mass (LVM) is an independent risk factor for cardiovascular morbidity and mortality, and may be used for risk stratification. Two-dimensional echocardiography, the most commonly used technique for estimation of LVM, uses the third power of the left ventricular internal diameter (LVID) for the calculation.


OBJECTIVE
To determine whether a decrease in intravascular volume after dialysis may cause inaccurate estimation of LVM by echocardiography.


METHODS
Thirty-eight patients undergoing hemodialysis due to chronic renal failure constituted the study group (14 women [37%] and 24 men [63%], mean age +/- SD 38.7+/-10.9 years). LVID, and interventricular and posterior wall thicknesses were measured by two-dimensionally guided M-mode echocardiography. Stroke volume and cardiac output were calculated using left ventricular outflow tract diameter and the pulsed-wave Doppler time-velocity integral obtained from left ventricular outflow tract. LVM was calculated by using Devereux's formula, and was indexed for body surface area and height. All echocardiographic parameters were measured or calculated before and after dialysis (on the same day), and then compared.


RESULTS
There were no significant changes in wall thickness; however, LVID, LVM, the LVM/body surface index and the LVM/height index significantly decreased after dialysis (P<0.001 for each parameter). There was a significant correlation between the change in LVID and the change in LVM (P<0.001, r=0.59). Stroke volume and cardiac output also decreased significantly after hemodialysis (P<0.001 for each parameter).


CONCLUSIONS
Intravascular volume-dependent change in LVID causes inaccurate estimation of LVM, so volume status should be kept in mind, especially in serial assessment of LVM.
Kilickap
Mustafa
M
Cardiology Department, Ankara University School of Medicine, Ankara, Turkey. mkilickap@yahoo.com
Turhan
Sibel
S
Sayin
Tamer
T
Nergizoglu
Gokhan
G
Kutlay
Sim
S
Duman
Neval
N
Rahimov
Uzeyir
U
Kumbasar
Deniz
D
Akgun
Gunes
G
Erol
Cetin
C
D000328:Adult; D001827:Body Height; D001830:Body Surface Area; D001835:Body Weight; D002302:Cardiac Output; D004452:Echocardiography; D005260:Female; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D007676:Kidney Failure, Chronic / Q000628:therapy; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D006435:Renal Dialysis; D013318:Stroke Volume; D016896:Treatment Outcome