Correlation between diastolic function and maximal exercise capacity on exercise test.
BACKGROUND
Increased pulmonary capillary pressure (PCP) is one of the mechanisms of exercise intolerance. Assessment of the diastolic function by echocardiography (ECHO) enables estimation of PCP.


OBJECTIVE
To identify variables that determine the exercise capacity in patients undergoing routine exercise test (ET), conventional ECHO, and tissue Doppler imaging (TD).


METHODS
A total of 640 patients undergoing ET, ECHO, and TD were retrospectively studied. Patients with ejection fraction < 55% were excluded. Mitral annulus velocities by conventional Doppler imaging were obtained in early diastole (E) and late diastole (A), and TD of the mitral annulus measured early diastole (e') and late diastole (a') velocities. E/e'> 10 was considered an estimate of increased PCP. Maximal exercise capacity was analyzed by the number of metabolic equivalents (MET). The patients were divided into two groups for analysis: MET<7 (n=48) and MET>7 (n=572). Morise score showed a population at low risk (60%) for coronary artery disease (CAD).


RESULTS
The number of patients with E/e' > 10 was significantly higher in the MET < 7 group in relation to the MET > 7 group (41.7% vs 9.4%, p=0.001), and so was the presence of any degree of diastolic dysfunction (76.6% vs 34.1% p=0.001). Using logistic regression analysis, age, female gender and A velocity (late diastole) were the independent variables related to a low exercise capacity (MET < 7).


CONCLUSIONS
Diastolic dysfunction as determined by ECHO, female gender, and age are associated with a lower exercise capacity in a population at low risk for CAD.
Instituto de Cardiologia do Distrito Federal, Brasília, DF, Brazil. mariaestefaniaotto@gmail.com
Maria Estefânia Bosco
ME
Otto
Márcio Mendes
MM
Pereira
Adenalva Lima de Souza
AL
Beck
Maurício
M
Milani
D000367:Age Factors; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging; D003971:Diastole / Q000502:physiology*; D004812:Epidemiologic Methods; D005080:Exercise Test / Q000379:methods*; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D055686:Metabolic Equivalent / Q000502:physiology*; D008875:Middle Aged; D011669:Pulmonary Wedge Pressure / Q000502:physiology; D012016:Reference Values; D012737:Sex Factors; D013318:Stroke Volume / Q000502:physiology; D014463:Ultrasonography; D016277:Ventricular Function, Left / Q000502:physiology*