Relationship between echocardiographic parameters and exercise test duration in patients after myocardial infarction.
BACKGROUND
The interdependence between echocardiographic parameters of left ventricle function, severity of heart failure (HF) and exercise test duration has not been thoroughly examined.


METHODS
We compared echocardiographic data in patients after myocardial infarction divided according to NYHA class to mild (class I and II, group 1 = 24 subjects) and advanced HF group (III and IV, group 2 = 36) and assessed their correlation with exercise duration (ED) in a symptom-limited treadmill test. Then we tried to determine independent predictors of ED.


RESULTS
The group with advanced HF had lower left ventricle ejection fraction, shorter duration and deceleration times of both mitral inflow waves (Et and At, Edt and Adt) and higher E/A ratio (1.4 +/- 1.1 vs. 0.9 +/- 0.4; p < 0.05) with more frequent restriction and pseudonormalization pattern (56% vs. 12%). Also early wave propagation (21 +/- 7 vs. 29 +/- 11 cm/s; p < 0.001) and all tissue Doppler velocities were lower, but ratio of early wave peak velocity to early diastolic velocity of mitral annulus was higher (E/E' 10.5 +/- 5 vs. 6.1 +/- 1.3 for velocity ratio; p < 0.001) in subjects with more severe clinical symptoms. Significant negative correlation with ED was observed for difference between duration of pulmonary vein atrial reversal flow and atrial wave of mitral inflow (DeltaAt; r = -0.54) and for E/E' ratio (r = -0.48), the highest positive correlation for left ventricular ejection fraction and duration of mitral inflow atrial phase (EF; r = 0.48, At; r = 0.46). In multivariate stepwise regression analysis two independent predictors of ED were identified: age and DeltaAt (Art-At).


CONCLUSIONS
Diastolic parameters showing the strongest correlation with ED (DeltaAt and E/E') are connected with restrictive left ventricle physiology. The only independent predictors of exercise duration in patients after myocardial infarction were: age and DeltaAt.
Wierzbowska-Drabik
Karina
K
Department of Cardiology, Medical University of Łódź, Poland. wierzbowska@ptkardio.pl
Krzemińska-Pakuła
Maria
M
Plewka
Michał
M
Drozdz
Jarosław
J
Kurpesa
Małgorzata
M
Trzos
Ewa
E
Rechciński
Tomasz
T
Chrzanowski
Lukasz
L
Kasprzak
Jarosław D
JD
D000367:Age Factors; D000368:Aged; D016275:Atrial Function; D003971:Diastole; D015150:Echocardiography, Doppler; D018619:Echocardiography, Doppler, Pulsed; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000503:physiopathology; D009203:Myocardial Infarction / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology; D011237:Predictive Value of Tests; D011667:Pulmonary Veins / Q000000981:diagnostic imaging / Q000503:physiopathology; D012720:Severity of Illness Index; D013318:Stroke Volume; D013997:Time Factors; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D016277:Ventricular Function, Left