Development of mitral and tricuspid regurgitation in right ventricular apex versus right ventricular outflow tract pacing Sevil Hemayat & Akbar Shafiee & Saeed Oraii & Farideh Roshanali & Farshid Alaedini & Amirhossein Sami Aldoboni Received: 8 September 2013 /Accepted: 28 January 2014 /Published online: 14 March 2014 # Springer Science+Business Media New York 2014 Abstract Purpose This study aimed at comparing the development of tricuspid and mitral regurgitation between the right ventricular outflow tract (RVOT) and right ventricular apex (RVA) pacing. Methods We prospectively enrolled 164 patients for perma- nent pacemaker implantation due to sick sinus syndrome or atrioventricular block and randomly divided them into two equal groups to receive either RVOT or RVA pacing. Patients with heart failure or valvular disease were excluded. The post- procedural echocardiographic evaluations were performed 1 year after the pre-procedural echocardiography, and the results were compared with respect to the development of mitral and tricuspid regurgitation and probable changes in the ejection fraction (EF). Results Age, gender, pacing mode, and baseline cardiac rhythm did not significantly differ between the RVOTand RVA pacing groups. The incidence of mitral regurgitation was significantly higher in the RVA group (p =0.03), but the incidence of tricuspid regurgitation was similar in both groups. There was a trend toward less tricuspid regurgitation in the RVOT group; howev- er, it was not statistically significant. The mean EF was not significantly different between the study groups. Conclusion It seems that the incidence of mitral regurgitation in RVA pacing is significantly higher than that in RVOT pacing. The formation of tricuspid regurgitation needs to be discussed in the future. Clinical trial registration number IRCT201103146061N1 Keywords Pacemaker . Right ventricular outflow tract . Right ventricular apex . Mitral regurgitation . Tricuspid regurgitation Abbreviations AV Atrioventricular ECG Electrocardiography EF Ejection fraction LV Left ventricle MR Mitral regurgitation PPM Permanent pacemaker RV Right ventricle RVA Right ventricular apex RVOT Right ventricular outflow tract TR Tricuspid regurgitation TTE Transthoracic echocardiography 1 Introduction Cardiac pacing is currently the standard treatment for sick sinus syndrome and other conductive disorders [1, 2]. Due to the increasing number of people who received pacemakers in recent years, it is important to identify different aspects of pacing and reduce its potential complications [3]. Selecting a proper site for pacing has always been a challenge for cardiologists [4]. The S. Hemayat Faculty of Medicine, Islamic Azad University, Tehran, Iran A. Shafiee Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran S. Oraii (*) Tehran Arrhythmia Clinic, 30 Tavanir Street, Vali-Asr Ave, P. O. Box 15175-536 Tehran, Iran e-mail: Oraii@comcast.net F. Roshanali Department of Echocardiography, Day General Hospital, Tehran, Iran F. Alaedini Islamic Republic of Iran Academy of Medical Sciences, Tehran, Iran A. S. Aldoboni Department of Cardiology, Faculty of Medicine, Islamic Azad University, Tehran, Iran J Interv Card Electrophysiol (2014) 40:81–86 DOI 10.1007/s10840-014-9878-y