Related Experiment Videos
Electromechanical coupling, uncoupling, and ventricular function in patients with bundle branch block: a
Miguel Quintana1, Samir Saha, Morteza Rohani
1Department of Clinical Physiology and Cardiology, Huddinge University Hospital, Sweden. miguel.quintana@labmed.ki.se
Echocardiography (Mount Kisco, N.Y.)
|November 18, 2004
Summary
Left bundle branch block (LBBB) causes impaired left ventricular (LV) function due to delayed electromechanical coupling. Tissue-Doppler echocardiography (TDE) can assess these cardiac function changes.
Area of Science:
- Cardiology
- Cardiac Electrophysiology
- Echocardiography
Background:
- Left bundle branch block (LBBB) is linked to reduced left ventricular (LV) function, increased morbidity, and mortality.
- Mechanisms underlying LBBB's impact on cardiac function remain unclear.
Purpose of the Study:
- To investigate the impact of LBBB on LV function and coordination.
- To explore the utility of Tissue-Doppler echocardiography (TDE) in assessing cardiac function in LBBB.
Main Methods:
- Studied subjects with isolated LBBB, right bundle branch block (RBBB), and controls using 2D and TDE.
- Assessed inter- and intraventricular coordination via TDE velocity profiles.
- Evaluated LV function using 2D echocardiography, TDE-derived peak systolic velocities, and AV plane displacement.
Main Results:
- LBBB subjects exhibited longer electromechanical delays and isovolumic relaxation times.
- Compared to RBBB and controls, LBBB patients had shorter ejection times, lower peak systolic velocities, and reduced AV plane displacement.
- LBBB was associated with larger LV end-systolic volumes, lower LV ejection fraction, and increased atrial contribution to AV plane displacement.
Conclusions:
- Delayed electromechanical coupling in LBBB causes intra- and interventricular asynchrony, leading to depressed LV function.
- TDE can effectively assess electromechanical coupling and its effects on cardiac function in patients with bundle branch block (BBB).