[Changes in left ventricular function induced by isometric exercise in coronary disease].
The effects of isometric exercise on left ventricular function in 16 patients with chronic coronary heart disease were assessed by measuring left ventricular pressures and volumes under basal conditions and during a sustained effort of 2 minutes 30 seconds at 50% of the maximal effort. In 7 patients (Group I) with abnormal elevation of left ventricular end diastolic pressure (LVEDP) (over 4 mmHg) the end diastolic volume remained unchanged and the diastolic pressure-volume curve was displaced upwards. The ejection fraction fell together with the percentage filling during the first part of diastole with 50% filling occurring after 61% instead of 45% of diastole. The time constant T also increased showing abnormal relaxation. In 9 patients without abnormal elevation of LVEDP on exercise no changes in the other parameters studies were observed. Our results show that pathological elevation of LVEDP during isometric exercise is associated with a decreased ejection fraction and an abnormality of left ventricular relaxation with a reduced rate of filling during protodiastole and an upward displacement of the diastolic pressure-volume curve. The LVEDP alone is therefore an important index of the haemodynamic behaviour of the left ventricle during isometric exercise.
D003327:Coronary Disease / Q000503:physiopathology*; D003971:Diastole; D005260:Female; D006339:Heart Rate; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D007537:Isometric Contraction; D008297:Male; D008875:Middle Aged; D009126:Muscle Relaxation; D005082:Physical Exertion; D013997:Time Factors
Altérations de la fonction ventriculaire gauche induites par l'effort isométrique chez le coronarien.