Changes in left ventricular synchrony and systolic function in dilated cardiomyopathy patients with fragmented QRS complexes.
AIMS
Fragmented QRS (f-QRS) complexes are associated with adverse cardiovascular events in patients with coronary heart disease; however, the effects on patients with dilated cardiomyopathy (DCM) remain elusive. This study is to investigate the changes of left ventricular (LV) synchrony and systolic function in DCM patients with f-QRS complexes.


METHODS AND RESULTS
Twenty DCM patients with f-QRS complexes and 29 DCM patients without f-QRS (n-QRS) complexes were enrolled. The LV segmental longitudinal, radial and circumferential time to peak strain and general longitudinal systolic strain, radial strain, circumferential strain were measured, respectively, by speckle tracking imaging. The LV segmental standard deviations and maximal differences were also calculated. The LV dyssynchrony was defined as the time in peak anteroseptal wall to posterior wall strain >130 ms or longitudinal strain delay index >25%. The mean QRS durations in f-QRS and n-QRS groups were not different (P = ns). The incidence of LV dyssynchrony was 15/20 (75%) vs. 5/29 (17%) in two groups (P < 0.01). Two patients died of sudden death in f-QRS group during 2 years follow-up; however, no death in n-QRS group (P < 0.05). Patients in f-QRS group showed worsening LV dyssynchrony in f-QRS group after 2 years follow-up (P < 0.05). Overall, LV function was comparable at baseline (P = ns), but had significantly worsened only in the f-QRS group (P < 0.05).


CONCLUSION
The f-QRS complex is significantly associated with LV dyssynchrony in DCM patients and can be used as a reliable index to evaluate ventricular synchrony and predict the prognosis in DCM patients with narrow QRS complexes.
['Zhao|Ling|L|', 'Lu|Juan|J|', 'Cui|Zhi-Min|ZM|', 'Pavri|Behzad B|BB|', 'Dai|Min|M|', 'Qian|Da-Jun|DJ|', 'Shen|Wei-Gang|WG|', 'Guo|Tao|T|', 'Wang|Ru-Xing|RX|']
D000200:Action Potentials D001145:Arrhythmias, Cardiac D002311:Cardiomyopathy, Dilated D016022:Case-Control Studies D016757:Death, Sudden, Cardiac D018618:Echocardiography, Doppler, Color D004562:Electrocardiography D005260:Female D006329:Heart Conduction System D006801:Humans D008297:Male D008875:Middle Aged D011237:Predictive Value of Tests D011379:Prognosis D011446:Prospective Studies D012307:Risk Factors D013599:Systole D013997:Time Factors D018487:Ventricular Dysfunction, Left D016277:Ventricular Function, Left
Dilated cardiomyopathy Fragmented QRS complex Speckle tracking imaging Ventricular dyssynchrony