Ventricular-arterial uncoupling in heart failure with preserved ejection fraction after myocardial infarction in dogs - invasive versus echocardiographic evaluation.
BACKGROUND
Heart failure with preserved left ventricular ejection fraction and abnormal diastolic function is commonly observed after recovery from an acute myocardial infarction. The aim of this study was to investigate the physiopathology of heart failure with preserved ejection fraction in a model of healed myocardial infarction in dogs.


METHODS
Echocardiography, levels of neurohormones and conductance catheter measurements of left ventricular pressure-volume relationships were obtained in 17 beagle dogs 2 months after a coronary artery ligation, and in 6 controls.


RESULTS
Healed myocardial infarction was associated with preserved echocardiographic left ventricular ejection fraction (0.57 +/- 0.01, mean +/- SEM) and altered Doppler mitral indices of diastolic function. NT-proBNP was increased, aldosterone was decreased, and norepinephrine was unchanged. Invasive measurements showed a markedly decreased end-systolic elastance (2.1 +/- 0.2 vs 6.1 +/- 0.8, mmHg/ml, p < 0.001) and end-systolic elastance to effective arterial elastance ratio (0.6 +/- 0.1 vs 1.4 +/- 0.2, p < 0.001), with altered active relaxation (dP/dtmin -1992 +/- 71 vs -2821 +/- 305, mmHg/s, p < 0.01) but preserved left ventricular capacitance (70 +/- 6 vs 61 +/- 3, ml at 20 mmHg, p = NS) and stiffness constant. Among echocardiographic variables, the wall motion score index was the most reliable indicator of cardiac contractility while E', E/A and E'/A' were correlated to dP/dtmin.


CONCLUSIONS
In the canine model of healed myocardial infarction induced by coronary ligation, heart failure is essentially characterized by an altered contractility with left ventricular-arterial uncoupling despite vascular compensation rather than by abnormal diastolic function.
Mathieu
Myrielle
M
Department of Physiology and Pathophysiology, ULB, Brussels, Belgium. myrielle.mathieu@ulb.ac.be
El Oumeiri
Bachar
B
Touihri
Karim
K
Hadad
Ielham
I
Mahmoudabady
Maryam
M
Thoma
Philippe
P
Metens
Thierry
T
Bartunek
Jozef
J
Heyndrickx
Guy R
GR
Brimioulle
Serge
S
Naeije
Robert
R
Mc Entee
Kathleen
K
D000818:Animals; D001026:Coronary Artery Bypass; D003971:Diastole; D004285:Dogs; D004452:Echocardiography; D056966:Excitation Contraction Coupling; D006333:Heart Failure / Q000000981:diagnostic imaging* / Q000209:etiology / Q000601:surgery*; D006334:Heart Function Tests; D006439:Hemodynamics; D006801:Humans; D023421:Models, Animal; D009200:Myocardial Contraction; D009203:Myocardial Infarction / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery*; D013318:Stroke Volume