Sequential versus simultaneous biventricular resynchronization for severe heart failure: evaluation by tissue Doppler...

Area of Science:

• Cardiology
• Biomedical Engineering

Background:

• Cardiac resynchronization therapy (CRT) with biventricular pacing improves heart failure outcomes.
• Simultaneous pacing is standard, but optimal timing remains debated.

Purpose of the Study:

• To evaluate sequential CRT using tissue tracking and 3D echocardiography.
• To determine the impact of individualized interventricular delay programming on cardiac performance.

Main Methods:

• Twenty patients with heart failure and bundle-branch block underwent CRT.
• Tissue tracking and 3D echocardiography assessed myocardial contraction before and after pacing.
• Multiple interventricular delays were tested to find optimal sequential programming.

Main Results:

• Sequential CRT significantly reduced delayed longitudinal contraction (DLC) and increased left ventricular ejection fraction (LVEF%).
• Optimal sequential CRT further improved DLC and LVEF% compared to simultaneous CRT.
• Three-month follow-up showed sustained improvements in LVEF% with sequential CRT.
• Sequential CRT increased diastolic filling time by 7%.

Conclusions:

• Sequential CRT offers significant advantages over simultaneous CRT for both systolic and diastolic performance.
• Tissue tracking is effective for optimizing interventricular delay in CRT.