The relation between local repolarization and T-wave morphology in heart failure patients

Area of Science:

• Cardiology
• Electrophysiology
• Cardiac Repolarization

Background:

• T-wave duration and morphology are key indicators of ventricular repolarization.
• The relationship between depolarization time (TD) and repolarization time (TR) conventionally explains T-wave concordance.
• Limited understanding exists regarding T-wave morphology and TD-TR relationships in heart failure patients.

Purpose of the Study:

• To investigate T-wave morphology and TD-TR relationships in heart failure patients with varying QRS complex characteristics.
• To elucidate the mechanisms behind discordant T-waves in patients with left bundle branch block (LBBB).

Main Methods:

• Acquired electro-anatomic maps of the left ventricle (LV), right ventricle (RV), and coronary sinus (CS).
• Studied patients with heart failure and narrow QRS (nQRS), LBBB, and non-LBBB wide QRS.
• Determined TD and TR from acquired electrograms.

Main Results:

• In nQRS and non-LBBB patients, TD-TR slopes indicated repolarization followed depolarization.
• In LBBB patients, earlier RV repolarization explained discordant T-waves, but LV TD-TR slopes showed no major spatial gradient.
• A significant transseptal repolarization gradient (~100ms) was observed.
• TD-TR relation slopes overlapped across groups despite differing T-wave morphologies.

Conclusions:

• Interventricular repolarization dispersion explains discordant T-waves in LBBB.
• T-wave morphology is influenced by factors beyond the TD-TR relationship alone.