Peter Bačík, Gabriela Kaliská
Trials of cardiac resynchronization therapy (CRT) have consistently shown improvement in morbidity, quality of life,
and survival in patients with reduced left ventricular ejection fraction, advanced heart failure symptoms, and prolonged
QRS complex. This is the reason for a reflection in the guidelines for CRT. The recent ones have expanded the indications
for CRT to include less severe symptoms, and patients with non-LBBB with a QRS over 130 ms. Despite the majority
of patients who benefit from CRT, it is generally estimated that 30–35% of patients do not respond to CRT. Lack
of response to CRT may be attributed to the current selection criteria including only functional class, LVEF, QRS duration,
and QRS morphology. Traditionally favorable relationships of female sex with non-ischemic cardiomyopathy to
CRT response may relate to smaller LV volumes in these patients. In this analysis we try to identify the pre-implantation
predictors of favorable response, such as QRS duration>150 ms, non-ischemic cardiomyopathy, TAPSE >15 mm, sinus
rhythm, the absence of chronic bronchopulmonal obstructive disease, and the absence of renal disease.