- Abbreviations: Max Left atrial maximum volume, Min Left atrial minimal volume, EF Ejection Fraction, SV Stroke Volume, R4AL right parasternal 4 chamber view measured with 2D Area/Length method, R4 2D monoplane Simpson method of discs, L2 left apical two chamber view, L4 left apical four chamber view, Biplane L2 and L4 combined to biplane volumetry, RTTPE Real Time Triplane Echocardiography, 4D-TomTecâ„¢ analysing software