Electrocardiographic outcome of resynchronization therapy

Area of Science:

• Cardiology
• Biomedical Engineering
• Electrophysiology

Background:

• Cardiac resynchronization therapy (CRT) is effective for heart failure but candidate selection relies on limited ECG data.
• Quantifying mechanical dyssynchrony and optimizing CRT requires advanced methods beyond standard 12-lead ECG.
• Body surface potential mapping (BSPM) offers a more detailed view of ventricular activation patterns.

Purpose of the Study:

• To investigate the impact of different pacing modes on body surface potential maps (BSPM).
• To assess changes in QRS duration, activation times (ATmax, ATmin), and QT dispersion (QTd) with various pacing strategies.
• To evaluate the effectiveness of left ventricular pacing (LVP) and biventricular pacing (BVP) compared to right ventricular pacing (RVP) in CRT patients.

Main Methods:

• Studied 12 CRT recipients with heart failure and 12 healthy controls.
• Utilized a 123-electrode Biosemi system for BSPM acquisition.
• Measured QRS duration, ATmax, ATmin, and QTd during spontaneous rhythm, RVP, LVP, and ECHO-optimized BVP.

Main Results:

• Patients with dyssynchrony showed significantly prolonged QRS, ATmax, ATmin, and QTd compared to controls.
• LVP and BVP significantly improved all measured parameters (QRS, ATmax, ATmin, QTd) compared to baseline.
• RVP only improved ATmax, while LVP and BVP normalized activation times, indicating superior efficacy.

Conclusions:

• LVP and BVP demonstrate significant benefits in improving cardiac electrical and mechanical synchrony.
• BSPM analysis reveals that LVP and BVP can normalize ventricular activation patterns in CRT patients.
• These findings support the use of advanced pacing strategies like LVP and BVP for optimizing CRT outcomes.