title: The tissue velocity imaging and strain rate imaging in the assessment of interatrial electromechanical conduction in patients with sick sinus syndrome before and after pacemaker implantation.
abstract: Tissue velocity imaging (TVI) and strain rate imaging (SRI) were recently introduced to quantify myocardial mechanical activity in patients receiving cardiac resynchronization therapy. To clear whether atrial-demand-based (AAI) (R) atrial pacing can fully simulate the electromechanical conduction of physiological state and to clarify which one is more appropriate for the assessment of electromechanical activity of the heart between TVI and SRI, 30 normal subjects and 31 patients with sick sinus syndrome (SSS) before and after AAI(R) pacemaker implantation (PI) were investigated in this study. The results showed that the time intervals (ms), P-SRa assessed by SRI (not P-Va assessed by TVI) prolonged step by step from the lateral wall of the right atrium (RA), the interatrial septum (IAS) and the left atrium (LA) in normal subjects(5.01±0.62, 17.05±3.54 and 45.09±12.26, p<0.01). P-Va and P-SRa did not differ at the RA, IAS and LA in patients with SSS before PI (p>0.05), and they were significant longer than those of normal subjects (p<0.01). However, they shortened to normal levels in patients with SSS after PI and P-SRa showed again the trend of gradually prolonging from the RA, IAS to LA. At the same time, the peak velocities and the peak strain rates during atrial contraction also returned to normal values from lower levels. These data suggested that AAI(R) atrial pacing can successfully reverse the abnormal interatrial electromechanical conduction in patients with SSS, and SRI is more appropriate for the assessment of the electromechanical activity of atrial wall than TVI.
authors: Department of Ultrasound, The Fourth Affiliated Hospital of Nantong University, Yancheng, Jiangsu Province, PR China.
authors: Xiaozhi
authors: X
authors: Zheng
authors: Ping
authors: P
authors: Ji
authors: Hongwei
authors: H
authors: Mao
authors: Jianqun
authors: J
authors: Hu
references: JACC Cardiovasc Imaging. 2009 Dec;2(12):1350-6
references: 20083067
references: J Am Coll Cardiol. 2002 Aug 21;40(4):723-30
references: 12204503
references: Eur J Echocardiogr. 2003 Jun;4(2):92-100
references: 12749870
references: Europace. 2008 Feb;10(2):127-33
references: 18192700
references: Ultrasound Med Biol. 2001 Aug;27(8):1087-97
references: 11527595
references: Eur J Echocardiogr. 2000 Sep;1(3):154-70
references: 11916589
references: Eur J Echocardiogr. 2008 Jan;9(1):12-7
references: 17241819
references: J Am Coll Cardiol. 2004 Jan 21;43(2):248-56
references: 14736445
references: Eur J Echocardiogr. 2006 Jun;7(3):199-208
references: 16054869
references: Heart Vessels. 2010 Sep;25(5):410-6
references: 20676964
references: J Am Soc Echocardiogr. 2010 Feb;23(2):172-80
references: 20152699
references: Int J Cardiol. 2009 May 29;134(3):336-41
references: 18804876
references: Herzschrittmacherther Elektrophysiol. 2010 Sep;21(3):196-9
references: 20730439
references: Am J Med Sci. 2010 Feb;339(2):145-7
references: 20087168