The detailed study of the ECG as well as non-invasive study of ventricular electrical activation may enable clinicians to better identify patients with NICD who will respond to CRT.Ĭopyright © 2015. A dedicated prospective study is therefore warranted in order for this question to be properly answered. Guidelines recommending implantation of CRT in this group are solely based on analyses of subgroups with small sample size. Unfortunately, prospective studies are lacking. Results from CRT therapy are contradictory in this patient group, despite a seemingly neutral trend. Conduction pathways can be either healthy or affected. NICD is most often associated with cardiomyopathy: e.g. Less studied than RBBB or LBBB, its pathophysiology is both complex and varied yet still reflects intramyocardial conduction delay. However, a large proportion of heart failure patients present with a widened QRS that is neither a LBBB nor a right BBB: nonspecific intraventricular conduction delay (NICD).
CRT was initially developed to treat patients who had left bundle branch block (LBBB) and delayed activation of the lateral left ventricular wall. Dyssynchrony results in widening of the QRS complex on the electrocardiogram (ECG). It aims to correct the electrical dyssynchrony present in 30-50% of patients in this population. Cardiac resynchronization therapy (CRT) is an electrical treatment of heart failure with reduced ejection fraction and wide QRS.