Page 59 - The role of advanced echocardiography in patients with ischemic heart disease - Rachid Abou

A which indicates the maximum P-wave duration. Panel C shows one full cardiac cycle in lead
V1 obtained from a standard 12-lead ECG. Panel D shows a zoomed view of the box in section C
which indicates the minimal the P-wave duration. The onset and end of the P wave was defined
as the point of the first visible upward slope from the isoelectric line and the point of return to
isoelectric line. P wave dispersion is defined as the difference between P-maximum duration and
P-minimum duration. 3
Echocardiographic data were obtained with patients at rest in the left lateral decubitus position using commercially available ultrasound systems (Vivid 7 and E9; General Electric Vingmed, Horten, Norway). Data acquisition was performed with a 3.5-MHz or M5S transducer. Standard M-mode, 2-dimensional (2D), color, pulsed and continuous wave Doppler data were acquired and stored digitally for subsequent offline analysis (EchoPac BT13; GE Medical Systems, Horten, Norway). Left ventricular ejection fraction (LVEF) was calculated using the Simpson’s biplane method.10 LV mass was calculated according to Devereux et al, and indexed for body surface area.10 Diastolic function was measured in concordance with contemporary guidelines.13 Valvular morphology and function were assessed with 2D, color and pulsed and continuous wave Doppler echocardiography.51 Color-coded TDI data of the LA were obtained from the apical 4-chamber view to measure the PA-TDI duration, an echocardiographic parameter representing the total atrial conduction time (a marker of electromechanical delay – reflecting atrial fibrosis). To assess the PA-TDI duration, a fixed 9 × 9 pixel region of interest was placed on the LA lateral wall just above the mitral annulus to obtain the time velocity tracing of the LA wall. The time interval between the onset of the P-wave in lead II of the surface ECG and the peak A’-wave on TDI defined the PA-TDI (Figure 2).8
LA reservoir strain was evaluated using 2D speckle tracking on the apical 4-chamber view. The ECG was referenced to the onset of the QRS complex or the Q wave, and the region of interest was adjusted to the LA wall thickness. LA reservoir strain was measured as the peak longitudinal strain during ventricular systole (Figure 3).14
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