%0 Journal Article
%T QRS pattern and improvement in right and left ventricular function after cardiac resynchronization therapy: a radionuclide study
%A Giulia Domenichini
%A Haran Burri
%A Cinzia Valzania
%A Gilberto Gavaruzzi
%A Francesco Fallani
%A Mauro Biffi
%A Henri Sunthorn
%A Igor Diemberger
%A Cristian Martignani
%A Huberdine Foulkes
%A Eric Fleury
%A Giuseppe Boriani
%J BMC Cardiovascular Disorders
%D 2012
%I BioMed Central
%R 10.1186/1471-2261-12-27
%X Consecutive patients (pts) undergoing CRT implantation underwent radionuclide angiography at baseline and at mid-term follow-up. The relationship between baseline QRS pattern and mechanical dyssynchrony using phase analysis was evaluated. Changes in left and right ventricular EF (LVEF and RVEF) were analyzed with regard to baseline QRS pattern.We enrolled 56 pts, 32 with left bundle branch block (LBBB), 4 with right bundle branch block (RBBB) and 20 with non-specific intraventricular conduction disturbance (IVCD). A total of 48 pts completed follow-up. LBBB pts had significantly greater improvement in LVEF compared to RBBB or non-specific IVCD pts (+9.6 ¡À 10.9% vs. +2.6 ¡À 7.6%, p = 0.003). Response (defined as ¡Ý 5% increase in LVEF) was observed in 68% of LBBB vs. 24% of non-specific IVCD pts (p = 0.006). None of the RBBB pts were responders. RVEF was significantly improved in LBBB (+5.0 ¡À 9.0%, p = 0.007), but not in non-specific IVCD and RBBB pts (+0.4 ¡À 5.8%, p = 0.76). At multivariate analysis, LBBB was the only predictor of LVEF response (OR, 7.45; 95% CI 1.80-30.94; p = 0.006), but not QRS duration or extent of mechanical dyssynchrony.Presence of a LBBB is a marker of a positive response to CRT in terms of biventricular improvement. Pts with non-LBBB pattern show significantly less benefit from CRT than those with LBBB.Cardiac resynchronization therapy (CRT) reduces morbidity and mortality in patients (pts) with congestive heart failure [1-5] improving clinical status [1-3] and favoring ventricular reverse remodeling [2,5-7]. However clinical and/or echocardiographic response is present in only 50-70% of CRT pts [3,8], suggesting that the link between standard criteria for CRT and expected response is often weak. Several parameters of electrical and mechanical dyssynchrony have been proposed to improve pt selection, even though QRS duration is currently the only recommended parameter [9,10]. In CRT pts a baseline left bundle branch block (LBBB) has been demons
%K Cardiac resynchronization therapy
%K Left ventricular ejection fraction
%K Right ventricular ejection fraction
%K Dyssynchrony
%K Nuclear angiography
%K QRS morphology
%U http://www.biomedcentral.com/1471-2261/12/27