P1495ECG parameters as predictors of response to cardiac resynchronization therapy

Abstract

Aim: Cardiac resynchronization has proven benefit as treatment modality in patients with heart failure. Unfortunately, the use of current selection criteria is associated with a failure to respond of approximately 30% cases. The aim of our study is to define more ECG criteria which can predict response to cardiac resynchronization.

Methods and results: A total of 82 patients were enrolled in our study, and were followed for a mean of 25.6 months. Mean QRS duration in our group was 174ms, and 75% were LBBB, no patients with RBBB, 25% with wide QRS but undetermined BB morphology. To define if the patient is responder we used scoring system defined as: increase in LVEF more than 10% (1 point), lowering of NYHA class (1 point), QRS narrowing (1 point), hospitalization for heart failure in the follow-up period (-1 point). As non –responders were defined all patient with a score 0 or -1 (8 patients), and responders were all patients with the score 1-3 (74 patients). In the responder group we found significantly wider QRS (p=0,04), higher R6/S6 ratio (p=0,02), higher (S1+R6)-(S6+R1) (p=0,02), and higher R amplitude in V6 (p<0,01). When we divided the group of patients according to BB morphology the significance in LBBB patients was kept in R6/S6 ratio (p=0,03), (S1+R6)-(S6+R1) (p=0,02) and R amplitude in V6 (p<0,01). In undetermined BB morphology – group of patients we found significantly higher R amplitude in V6 (p=0,01) and significantly higher S amplitude in V6 (p<0,01).

Conclusion: We conclude that we could engage more ECG criteria to predict response to cardiac resynchronization therapy, even in the LBBB patients, but also in patients with wide QRS and undetermined BB morphology.