The relation between local repolarization and T-wave morphology in heart failure patients.
BACKGROUND
Both duration and morphology of the T-wave are regarded important parameters describing repolarization of the ventricles. Conventionally, T-wave concordance is explained by an inverse relation between the time of depolarization (TD) and repolarization (TR). Little is known about T-wave morphology and TD-TR relations in patients with heart failure.


METHODS
Electro-anatomic maps were obtained in the left (LV) and right ventricle (RV) and in the coronary sinus (CS) in patients with heart failure with narrow (nQRS, n=8) and wide QRS complex with (LBBB, n=15) and without left bundle branch block (non-LBBB, n=7). TD and TR were determined from the thus acquired electrograms.


RESULTS
In nQRS and non-LBBB patients, TD-TR relations had a slope between 0 and +1, indicating that repolarization followed the sequence of depolarization. In LBBB patients, repolarization occurred significantly earlier in the RV than in the LV, fitting with the idea that the discordant T-waves in LBBB are secondary to the abnormal depolarization sequence. However, the slopes of the TD-TR relations in the LV and CS were not significantly different from zero, indicating no major spatial gradient in LV repolarization, despite a considerable gradient in depolarization. Remarkable was also the large (~100ms) transseptal gradient in repolarization. Values of the slopes of the TD-TR relation overlapped between the three patient groups, despite a difference in T-wave morphology between LBBB (all discordant) and nQRS patients (all flat/biphasic).


CONCLUSIONS
Discordant T-waves in LBBB patients are explained by interventricular dispersion in repolarization. T-wave morphology is determined by more factors than the TD-TR relation alone.
Center for Computational Medicine in Cardiology, USI, Lugano, Switzerland.
Francesco
F
Maffessanti
Maastricht University, Maastricht, The Netherlands.
Joris
J
Wanten
Center for Computational Medicine in Cardiology, USI, Lugano, Switzerland; INRIA Bordeaux Sud-Ouest & LIRYC - Institute of Cardiac Rhythmology, Bordeaux, France.
Mark
M
Potse
Cardiocentro Ticino, Lugano, Switzerland.
Francois
F
Regoli
Cardiocentro Ticino, Lugano, Switzerland.
Maria Luce
ML
Caputo
Cardiocentro Ticino, Lugano, Switzerland.
Giulio
G
Conte
Cardiocentro Ticino, Lugano, Switzerland.
Daniel
D
Sürder
Cardiocentro Ticino, Lugano, Switzerland; Otto von Guericke Universität, Magdeburg, Germany.
Annekatrin
A
Illner
Center for Computational Medicine in Cardiology, USI, Lugano, Switzerland.
Rolf
R
Krause
Cardiocentro Ticino, Lugano, Switzerland.
Tiziano
T
Moccetti
Center for Computational Medicine in Cardiology, USI, Lugano, Switzerland; Cardiocentro Ticino, Lugano, Switzerland.
Angelo
A
Auricchio
Maastricht University, Maastricht, The Netherlands. Electronic address: frits.prinzen@maastrichtuniversity.nl.
Frits W
FW
Prinzen
D000368:Aged; D000369:Aged, 80 and over; D004562:Electrocardiography / Q000379:methods; D005260:Female; D006329:Heart Conduction System / Q000502:physiology*; D006333:Heart Failure / Q000175:diagnosis* / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013318:Stroke Volume / Q000502:physiology*
Electro-anatomic mapping; Heart failure; Left bundle branch block; Repolarization; T-wave