Global myocardial index (GMI) has been significantly related to left ventricular filling pressure. We hypothesized that GMI and echographic indicators of atrial dilatation were significantly different in pAF pts compared to normals.
Methods: 39 patients (pts) without structural heart disease, aged 52+/-10 years with pAF were compared to 36 control-matched pts aged 48+/-16 years. Following parameters were assessed: P-wave duration (Pd), GMI, left atrial dimensions (LAd=M-mode, parasternal, LAt and LAI are measurements of short and long-axis apical four chamber view), surface (LAs), volume (LAv), total ejection fraction (LA EF), right atrial dimension (RAd) and surface (RAs), total atrial surface (TAs=LAs+RAs). LAv was calculated using ellipse formula pi/6 (LAdxLAlxLAt).
Results: There was no difference between the 2 groups concerning Pd (p=0.1), LA EF (p=0.23), LAd (p=0.08) and LAt (p=0.06) while the rest of the parameters were significantly higher in pAF pts: GMI: 0.5+/-0.17 vs 0.36+/-0.06 (p=0.001); LAI: 5.4+/-0.5 vs 4.5+/-0.3 cm2 (p=0.001); LAs was founded increased in pAF pts (20.6+/-5.7 vs 16.3+/-2.1 cm2, p=0.001); TAs: 40.6+/-6.9 vs 30.6+/-5.1 cm2, p=0.0001; LAv: 51.6+/-10.4 vs 37.2+/-9.3 ml (p=0.0001).
Conclusions: Although apparently without structural heart disease, pAF pts presented evidence of increased filling pressions in left ventricle and indirect markers of atrial stretch. The role of increased intra-atrial pressure in pts pFA and predictive value of these parameters need to be evaluated in a larger number of patients.