Background: Echocardiography is important in assessing left ventricular mechanical dyssynchrony (LVMD) and left
ventricular (LV) function after implant of a permanent pacemaker. Global longitudinal strain (GLS) and Left ventricular dyssynchrony assessment enable clinicians to detect early signs of LV dysfunction after cardiac pacing. This study assessed LV mechanical asynchrony and LV function in different pacing modes after permanent cardiac pacing by using tissue Doppler imaging (TDI) and speckle tracking echocardiography (STE).
Patients and Methods: Seventy female (42) and male (28) patients were enrolled in this prospective observational case study (mean age 60.99 ± 13.77 years) at Mansoura Specialized Medical Hospital over a period of 1 year from April 2018 to April 2019. All the patients were assessed by thorough history taking, clinical examination, conventional Echocardiography, TDI and two-dimensional (2D) STE.
Results: Regarding parameters assessed by STE, there was a significant decrease in global longitudinal strain GLS (P = 0.034*) while there was a significant increase in time to peak strain standard deviation (TP-SD) by STE (P < 0.001*). Also, there was significant decrease in GLS (P < 0.001*) and significant increase in TP-SD by STE (P = 0.001*) in dual chamber pacemaker (DDD) group. Similarly, there was a significant decrease in GLS (P < 0.001*) and a significant increase in TP-SD by STE (P < 0.001*) in ventricular demanding pacing (VVI) group.
Conclusion: The results show that GLS by 2D STE can help in detection of subclinical left ventricular dysfunction (LVD) after permanent pacemaker implantation before appearance of clinical symptoms. In addition, cardiac pacing can still lead to LVMD irrespective of the degree of the pacing mode. However, this may need upgrading later on to cardiac resynchronization therapy (CRT)
