Results:
Our study enrolled 30 patients (18 females and 12 males) with mean age (62.600 ±5.028) and 30 controls (16 females and 14 males) with mean age (59.633 ± 6.672). we didn’t observe any significant difference regarding age and sex between the patients and controls (P value > 0.05). table 1
By comparing conventional echocardiographic parameters between the studied groups; LVEDD and LVESD didn’t show any significant difference between the controls and the patients during AS-VP mode (group I) (P value > 0.05) table 2 .
When we measured the LV ejection fraction by M- Mode, we didn’t observe any statistical difference between the controls and the patients during AS-VP mode (group I) (P value > 0.05). on the contrary; we found that LV ejection fraction measured by biplane 2D Simpson’s technique was significantly lower in patients during AS-VP mode (group I) than the controls (P value < 0.05) table 2.
By 2-D speckle tracking echocardiography; the patients during AS-VP mode (group I) had statistically significant lower global LV longitudinal systolic strain (LV LSS) when compared to the control (P Value < 0.001) table 3 .
As regard regional LV longitudinal systolic strain; most LV segments had significantly lower LSS in the patients during AS-VP mode (group I) when compared to the controls. Moreover, the apical segments had the lowest values (P value < 0.001) table 4 .
Programming the pacemakers from AS-VP mode (group I) to AP-VP mode at rate of 100 b/min in (group II) showed a significant decrease in both global and regional LV LSS. Moreover, the programming to asynchronous ventricular pacing (VVI mode) at rate of 100 b/min in group III demonstrated a further reduction of both global and regional LV LSS when compared to both groups (P value <0.05) table 5 ,6 & figure 4,5.