Heart failure & cardiomyopathies
R-Rʹ interval in the left bundle branch block predicts long-term outcomes after cardiac resynchronization therapy by estimating greater mechanical dyssynchrony and viable myocardium
Main finding · Event-free survival after CRTResult — go to the resultHazard ratio 0.21Authors' conclusion
These findings suggest that RR' in complete LBBB was associated with mechanical dyssynchrony, extent of viable myocardium, and long-term outcomes following CRT.
Study context
- Population
- Cardiac resynchronization therapy (CRT) recipients with left bundle branch block (LBBB) (mid-QRS notching in V1, V2, V5, V6, I, aVL)34 men
- Participants
- 49 recipients
- Exposure
- Long RR' vs short RR' in LBBB before CRT
- Outcome
- All-cause death and HF hospitalization
Main finding
Event-free survival after CRT
Hazard ratio
0.21
P = 0.014
As reported in the abstract
Observational data: associations, not effects.
Further findings
| Outcome | RR' | QRSd |
|---|---|---|
| Prediction of volumetric response | ||
| AUC | 0.73 | 0.67 |
Mechanical dyssynchrony and viable myocardium
- Long RR' showed more frequent eyeball dyssynchrony and significantly greater radial (SL) and circumferential (AP and SL) dyssynchrony and %viable segment than short RR'
Original publication
R-Rʹ interval in the left bundle branch block predicts long-term outcomes after cardiac resynchronization therapy by estimating greater mechanical dyssynchrony and viable myocardium. Heart Rhythm. Published 26 December 2023. doi:10.
Summarised from the published abstract; every number is checked against it