Maximum ventricular dyssynchrony predicts clinical improvement and reverse remodeling during cardiac resynchronization therapy.
BACKGROUND
Tissue synchronization imaging (TSI) and tissue tracking imaging (TTI) might facilitate the evaluation of ventricular dyssynchrony.


METHODS
In 22 patients, TSI and TTI were performed before and < 1 month after onset of cardiac resynchronization therapy (CRT). With TSI guidance, maximum left ventricular (LV) intraventricular conduction delay (IVCDmax) was the greatest difference in time-to-peak velocity between septum and lateral wall. IVCD between the basal septum and lateral wall (IVCDbase) was also measured. Using TTI, the mean peak myocardial displacement of the basal septal and lateral walls (PMDbase), and the temporal coefficient of variation of the PMD in six LV regions (CV-PMDLV) were measured. The patients were divided into responders (whose LV end-systolic volume decreased by >/= 15% during a 27 +/- 9 months follow-up) and nonresponders.


RESULTS
Before CRT, IVCDbase was similar in both groups, and remained unchanged within the 1st month of CRT in both groups. However, before CRT, IVCDmax was greater in responders than in nonresponders (P < 0.05), and decreased only in the responders during CRT (P < 0.05). No significant difference was observed in PMDbase or CV-PMDLV between the two groups, before or during CRT.


CONCLUSIONS
TSI was useful to measure IVCDmax. A greater IVCDmax before CRT that decreased shortly after onset of CRT may predict long-term clinical improvement in CRT recipients.
Tada
Hiroshi
H
Division of Cardiology, Gunma Prefectural Cardiovascular Center, Maebashi, Gunma, Japan. tada.h@cvc.pref.gunma.jp
Toide
Hiroyuki
H
Okaniwa
Hiroki
H
Higuchi
Rumi
R
Nakajima
Tsutomu
T
Utsugi
Rika
R
Hashimoto
Tohru
T
Miyaji
Kohei
K
Kaseno
Kenichi
K
Tadokoro
Kazuyoshi
K
Naito
Shigeto
S
Nogami
Akihiko
A
Oshima
Shigeru
S
Taniguchi
Koichi
K
D000368:Aged; D001281:Atrial Fibrillation / Q000209:etiology / Q000628:therapy; D002304:Cardiac Pacing, Artificial; D015150:Echocardiography, Doppler; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D011237:Predictive Value of Tests; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging*; D020257:Ventricular Remodeling