Electromechanical disease of the left atrium-interatrial block - Preliminary observations on left atrial function

Aims To compare the mechanical performance of left atria with electrical di sease (interatrial block) with normal atria. Methods Volumetric function was derived from orthogonal two-dimensional ech ocardiograms by a standard formula utilizing four- and two-chamber scan pla ces. Left ventricular Doppler A wave velocity was added for left atrial kin etic energy. Measured left atrial volumes included minimum volume, maximum volume, reservoir volume and volume at the P wave of the electrocardiogram. Derived Values included active emptying, passive emptying and total emptyi ng volumes, fractional emptying and active emptying fractions and left atri al kinetic energy. Conclusions Large differences in all values indicate an enlarged, weak left atrium in patients with interatrial block versus normal subjects. Investig ation must be extended to patients with left atria of equal size but withou t interatrial block. (C) 2000 The European Society of Cardiology.