Left ventricular torsion in paced patients.
BACKGROUND
In healthy people the left ventricle presents a counter-clockwise apical rotation and a clockwise basal rotation ending in late systole. In early systole (during isovolumic contraction) there is a fast and inverse rotation (counter-clockwise at the base and clockwise at the apex). This opposite rotation between apex and base produces the systolic torsion of the left ventricle. The effect of permanent conventional pacing on this torsion is little known.


OBJECTIVE
The aim of this study was to assess, by speckle tracking echocardiography, left ventricular rotation and torsion in patients conventionally paced at the apex of the right ventricle.


METHODS
Left ventricular apical and basal rotation and the consequent torsion were evaluated by means of speckle tracking echocardiography, in 13 paced patients, without ischemic or valvular disease, and in 17 healthy participants. Left ventricular dyssynchrony was evaluated by means of temporal uniformity of strain.


RESULTS
In the paced group there was a significant reduction in early-systolic clockwise torsion (-0.4 degrees +/- 1.2 vs. -1.5 degrees +/- 1.6; P = 0.04), and in late-systolic counter-clockwise torsion (15.1 degrees +/- 4.3 vs. 19.1 degrees +/- 5.5; P = 0.03). Circumferential temporal uniformity of strain averaged significantly lower in paced patients.


CONCLUSIONS
Conventional pacing from the apex of the right ventricle alters both the torsional mechanic and the synchrony of the left ventricle.
Devecchi
Paolo
P
Divisione Clinicizzata di Cardiologia, Azienda Ospedaliera Universitaria 'Maggiore della Carità', Novara, Italy. devecchipa@tin.it
Bolzani
Virginia
V
Sarasso
Gianni
G
Piccinino
Cristina
C
Marti
Giuliano
G
Occhetta
Eraldo
E
Bortnik
Miriam
M
Francalacci
Gabriella
G
Magnani
Andrea
A
Marino
Paolo
P
D000368:Aged; D000369:Aged, 80 and over; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects*; D016022:Case-Control Studies; D004452:Echocardiography; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D012399:Rotation; D054159:Torsion, Mechanical; D016277:Ventricular Function, Left