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Myocardial dysfunction with increased ventricular compliance in volume overload hypertrophy
Author(s) -
De Stefano Laercio Martins,
Matsubara Luiz Shiguero,
Matsubara Beatriz Bojikian
Publication year - 2006
Publication title -
european journal of heart failure
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.149
H-Index - 133
eISSN - 1879-0844
pISSN - 1388-9842
DOI - 10.1016/j.ejheart.2006.02.005
Subject(s) - volume overload , medicine , cardiology , pressure overload , compliance (psychology) , muscle hypertrophy , diastole , left ventricular hypertrophy , hemodynamics , myocardial hypertrophy , heart failure , blood pressure , cardiac hypertrophy , social psychology , psychology
Abstract The aim this study was to evaluate systolic and diastolic function in volume overload induced myocardial hypertrophy in rats. Volume overload myocardial hypertrophy was induced in thirteen male Wistar rats by creating infrarenal arteriovenous fistula (AVF). The results were compared with a SHAM operated group ( n = 11). Eight weeks after surgery, tail‐cuff blood pressure was recorded, then rats were sacrificed for isolated heart studies using Langendorff's preparation. AVF rats presented increased left and right ventricular weights, compared to controls. The increased normalized ventricular volume (V0/LVW, 0.141 ± 0.035 mL/g vs. 0.267±0.071 mL/g, P <0.001) in the AVF group indicated chamber dilation. Myocardial hydroxyproline concentration remained unchanged. There was a significant decrease in +d P /d t (3318±352 mm Hg s −1 vs. 2769±399 mm Hg s −1 ; P =0,002), end‐systolic pressure‐volume relation (246±56 mm Hg mL −1 vs. 114±63 mm Hg mL −1 ; P <0,001), and −d P /d t (1746±240 mm Hg s −1 vs. 1361±217 mm Hg s −1 P <0.001) in the AVF group, which presented increased ventricular compliance (Δ V 25 : SHAM=0.172±0.05 mL vs. AVF=0.321±0.072 mL, P <0.001) with preserved myocardial passive stiffness (Strain 25 : SHAM=13.5±3.0% vs. AVF=12.3+1.9%, P >0.05). We conclude that volume‐overload induced hypertrophy causes myocardial systolic and diastolic dysfunction with increased ventricular compliance. These haemodynamic features help to explain the long‐term compensatory phase of chronic volume overload before transition to overt congestive heart failure.