Low Concordance Between Left Atrium Diameter and Volume in Patients with Higher Risk of Atrial Fibrillation Baja Concordancia entre Diámetro y Volumen del Atrio Izquierdo en Pacientes con Mayor Riesgo de Fibrilación Atrial

SUMMARY Background: Increased left atrial (LA) is directly related to LV diastolic dysfunction (DD), and both are associated with atrial fibrillation (AF). Although the diameter (LAD) is used as a measure of LA, many evidences show that LA volume index (iLAV) is more accurate. Objective: To evaluate the correlation between LAD and iLAV in patients (pt) with DD. Material and Methods: Among 892 pt referred to the echocardiography laboratory of a tertiary clinic, from Jan/08 to June/09, 540 pt with clinical and echocardiographic data were selected and 21 were excluded for being 32 and LAD > 40; and disagreement if iLAV ≤ 32 and LAD > 40 or iLAV > 32 and LAD ≤ 40. Results: Of 501 pt, 33 (6.6%) presented E/e’ ratio ≥ 15 and 468 (93.4%) < 15. There was a good correlation between LAD and iLAV in both patients with E/e’ ≥ 15 (r = 0.57), and E/e’ < 15 (r = 0.62). The disagreement between LAD and iLAV was higher in p with E/e’ ≥ 15 (21.2% vs 9% - p <0.0001). Clinical and echocardiographic data were, respectively, for E/e’ ≥ 15 and E/e’ < 15: male 54.5% vs 45.5% (p = ns), age 73.2 ± 12.4 vs 50.1 ± 16.5 (p <0.0001), LAD (cm) 38.8 ± 6.3 vs 35.2 ± 5.2 (p <0.0001); iLAV (ml/m2) 35 ± 16.2 x 21.9 ± 7 (p <0.0001), EF (%) 60.7 ± 16.2 vs 70.7 ± 6.9 (p <0.0001), E/e’ 21 , 1 ± 8.1 vs 16.5 ± 2.4 (p <0.0001), HBP 81.8% vs. 50.2% (p <0.0001), DM 21.2% vs. 9.4% (p = 0.04); CHF 24.2% vs. 3.2% (p <0.0001), CAD 33.3% versus 9% (p <0.0001). Conclusion: Patients with elevated left ventricular filling pressures are older, have larger LA diameter and volume, worse EF and higher incidence of HBP, diabetes, CHF and CAD. There is less agreement between LAD and iLAV in these patients.