Systolic time intervals and its relation to intraventricular dyssynchrony of the left ventricle in patients with dilated cardiomyopathy

Aim
To assess the value of systolic time intervals [as simple echocardiographic parameters of left ventricle (LV) systolic performance] and its relation to intraventricular dyssynchrony (by speckle tracking) of the LV in patients with dilated cardiomyopathy.


Patients and methods
All the studied individuals were subjected to ECG and transthoracic echocardiography to measure LV dimensions and systolic function by conventional and speckle-tracking echo. Left ventricular pre-ejection time (LVPET), left ventricular ejection time (LVET), and the ratio of LVPET to LVET were also measured (LVPET/LVET). Two-dimensional strain to measure time to peak negative strain value of the LV segments was averaged to calculate TPS-SD.


Results
The enrolled population were 153 cases, divided into 123 patients and 30 normal individuals. There was a significant lower LV global longitudinal strain % in the patient group. Moreover, insignificant shorter LVET was seen in the patients. LVET had an inversely significant correlation with QRS duration and dyssynchrony index. The LVPET and PET/LVET ratio had a significant linear correlation with QRS duration and dyssynchrony index measured by two-dimensional strain (r=0.4, P<0.01).


Conclusion
Systolic time interval can be easily and accurately measured in patients with DCM and may be considered as an indicator for presence of LV intraventricular dyssynchrony.