Right Ventricular Function Following Cardiac Resynchronization Therapy Navin Rajagopalan, MD, Matthew S. Suffoletto, MD, Masaki Tanabe, MD, Glen Miske, DO, Nini C. Thomas, MD, Marc A. Simon, MD, Raveen Bazaz, MD, John Gorcsan III, MD, and Angel López-Candales, MD* The effect of cardiac resynchronization therapy (CRT) on right ventricular (RV) function has not been well described. The purpose of this study was to use tissue Doppler imaging to assess changes in RV function after CRT. Thirty-five patients with heart failure (age 65  10 years; 26 men) who underwent color tissue Doppler imaging of the right ventricle both immediately before CRT and >3 months (mean 6  3) after were studied. Myocardial systolic velocity was measured at the tricuspid annulus and basal and midventricular segments of the right ventricle free wall and averaged to obtain a measure of global RV function (RV S m ). Left ventricular ejection fraction was also measured using biplane Simpson’s method before and after CRT. RV S m significantly improved after CRT (5.4  1.9 to 7.1  2.6 cm/s; p <0.001), as did left ventricular ejection fraction (26  6% to 34  10%; p <0.001). Twenty-one of 35 patients (60%) showed an increase in RV S m >1 cm/s, with an increase >2 cm/s in 13 of those patients (37%). Improvement was seen in both ischemic and nonischemic patients and was independent of improvement in left ventricular ejection fraction and baseline left ventricular dyssynchrony. In conclusion, CRT resulted in improved RV function measured as RV S m . CRT had beneficial effects on RV function independent of improvement in left ventricular ejection fraction. © 2007 Elsevier Inc. All rights reserved. (Am J Cardiol 2007;100:1434 –1436) Tissue Doppler imaging, in addition to being useful in the quantification of left ventricular dyssynchrony, was also shown to be a reliable and reproducible method of analyzing global and regional left and right ventricular (RV) func- tion. 1–3 Several studies reported the utility of tissue Doppler imaging not only in assessing RV function, but also in providing prognostic information. 4–6 However, this tech- nique has not been previously used to assess long-term RV response to cardiac resynchronization therapy (CRT). The aim of this study was to use tissue Doppler imaging to assess changes in RV function after CRT. Methods The study population consisted of 35 of 39 consecutive patients (mean age 65  10 years; 26 men) referred for CRT who underwent color tissue Doppler analysis of the right ventricle both 48 hours before and 3 months (mean 6  3) after CRT. Four patients (10%) were excluded because of inadequate visualization of the RV free wall on the baseline echocardiogram. All patients had baseline left ventricular systolic ejection fraction 35% and were in New York Heart Association functional class III or IV. Left ventricular dyssynchrony before CRT was assessed in all 35 patients. A cardiac resynchronization pacing system was implanted with a RV apical and left ventricular lead positioned in a posterior or lateral epicardial vein through the coronary sinus. The University of Pittsburgh Institutional Review Board approved the protocol, and all patients gave informed consent. Transthoracic echocardiography, including color tissue Doppler analysis, was performed in all patients at baseline and after CRT (GE-Vingmed Vivid 7 system; GE Vingmed Ultrasound, Horten, Norway). Left ventricular volume and ejection fraction were measured from the apical 4- and 2-chamber views using biplane Simpson’s rule according to American Society of Echocardiography standards. 7 Systolic pulmonary artery pressure was estimated by calculating the systolic pressure gradient between the right ventricle and right atrium with the maximum velocity of the tricuspid regurgitant jet using the modified Bernoulli equation, and then adding to this gradient estimated right atrial pressure based on the size of the inferior vena cava and its variation with respiration. 8 Color-coded tissue Doppler cine loops were captured as routinely performed in our echocardiography laboratory from 3 beats obtained in the apical 4-chamber view at depths of 14  2 cm with pulse repetition frequency set at 1 kHz, Nyquist velocity range  16 cm/s, and frame rates 99  9 Hz. The imaging angle was adjusted to obtain the best possible parallel alignment of the ultrasound beam with the right ventricle. Images were analyzed offline using the commercially available software EchoPAC PC, version 6.00 (GE Vingmed Ultrasound). Regions of interest (7  15 mm) were placed in the tricuspid annulus, as well as basal and midventricular segments of the RV free wall. The re- Cardiovascular Institute, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania. Manuscript received April 27, 2007; revised manuscript received and accepted June 10, 2007. *Corresponding author: Tel: 412-647-6570; fax: 412-647-0568. E-mail address: lopezcandalesa@upmc.edu (A. Lopez-Candales). 0002-9149/07/$ – see front matter © 2007 Elsevier Inc. All rights reserved. www.AJConline.org doi:10.1016/j.amjcard.2007.06.037