[Relationship between the force of left atrial ejection to left ventricular function in arterial hypertension].

UNLABELLED

The left atrial ejection force (LAEF), defined as that force exerted by the left atrium (LA) to accelerate the blood into the left ventricle during atrial systole, is well accepted for the evaluation of LA systolic function. The aim of this study is to determine whether LAEF is a precursor of the impairement of LV systolic function in patients with arterial hypertension (HTN). For that purpose we studied LAEF in 36 patients with HTN (av. age 58 +/- 8 years) with LV hypertrophy (Lvmi > 134 g/m2 for men and > 110 g/m2 for women). LV systolic function estimated by the fractional shortening (FSh) was 35 +/- 4% (28 to 44); 32 normal subjects (NS) were also analyzed. All subjects were submitted to echo and doppler examinations.

METHODS

LAEF was obtained by the formula: 1/3 x MVA x (A-vel)2, where MVA is mitral valve area measured by 2D echo while A-vel. is the late diastolic (atrial) mitral velocity.

RESULTS

1. LAEF increased significantly with age in NS (r = 0.78) p < 0.05). Age corrected LEAF was calculated as % LEAF = (actual LAEF/normal LAEF x 100. 2. Compared to NS. % LAEF was lower in HTN (78 + 25%). 3. There was a significant inverse correlation between LAEF and LV wall thickness (r = -0.46) (p < 0.05). 4. % LAEF was 66 +/- 31% in patients with FSh < 33% and 79 +/- 25% in those with FSh > 33% (p < 0.05). 5. In HTN with the duration > 15 years, % LAEF was lower than in patients with < 15 years (62 +/- 25 vs 76 +/- 24) (p < 0.05).

CONCLUSIONS

1. LAEF is decreased in more advance stages of HTN. 2. This impairment is related to LV hypertrophy and to the duration of the disease. 3. LAEF is a sensitive precursor for LV systolic deterioration in patients with hypertension.