ECHOCARDIOGRAPHY
A one lead electrocardiogram was recorded continuously during the TTE
and TEE (informed written consent was taken from all patients before
TEE). Two-dimensional and Doppler echocardiographic studies were
performed in the left lateral decubitus position in conventional views
(parasternal long, short-axis, and apical two and four-chamber view)
according to American Society of Echocardiography
guidelines.11 All patients were evaluated using
two-dimensional M-mode, pulsed- and continuous-wave Doppler
echocardiography. The mitral valve area (MVA) was calculated using
planimetry and pressure half-time methods. The maximum and mean
pressures gradients across the valve were measured by continuous-wave
Doppler from the apical four-chamber view. The left ventricular
end-diastolic and end-systolic diameters, interventricular septum and
posterior wall thickness, left ventricular ejection fraction and left
atrial diameter (LAD) were recorded from the parasternal long-axis view.
Modiļ¬ed parasternal short-axis view [as described by Herzog et al12 ] was used to visualize the left atrial
appendage.
Tissue Doppler imaging (TDI) :
This was performed in the apical four chamber view, with probe placed in
the lateral annulus. A Doppler velocity range of (-20 to 20) cm/sec was
selected. The three major velocities were recorded: one positive
systolic velocity (Sa-wave) and the two negative diastolic velocities
(E- and A-waves). The peak systolic and diastolic velocities were
measured at a sweep speed of 50 mm/sec.