title: Radial left ventricular dyssynchrony by speckle tracking in apical versus non apical right ventricular pacing- evidence of dyssynchrony on medium term follow up.
abstract: BACKGROUND
  To study effects of various sites of right ventricular pacing lead implantation on left ventricular function by 2-dimensional (2D) speckle tracking for radial strain and LV dyssynchrony.
  
  
  METHODS
  This was retrospective prospective study. Fifteen patients each with right ventricular (RV) apical (RV apex and apical septum) and non-apical (mid septal and low right ventricular outflow tract [RVOT]) were programmed to obtain 100% ventricular pacing for evaluation by echo. Location and orientation of lead tip was noted and archived by fluoroscopy. Electrocardiography (ECG) was archived and 2D echo radial dyssynchrony was calculated.
  
  
  RESULTS
  The baseline data was similar between two groups. Intraventricular dyssynchrony was significantly more in apical location as compared to non-apical location (radial dyssynchrony: 108.2 ± 50.2 vs. 50.5 ± 24, P < 0.001; septal to posterior wall delay [SLWD] 63.5 ± 27.5 vs. 34 ± 10.7, P < 0.001, SPWD 112.5 ± 58.1 vs. 62.7 ± 12.1, P = 0.003). The left ventricular ejection fraction was decreased more in apical location than non apical location. Interventricular dyssynchrony was more in apical group but was not statistically significant. The QRS duration, QTc and lead thresholds were higher in apical group but not statistically significant.
  
  
  CONCLUSIONS
  Pacing in non apical location (RV mid septum or low RVOT) is associated with less dyssynchrony by specific measures like 2D radial strain and correlates with better ventricular function in long term.
authors.affiliation: Department of Cardiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum 695 011, Kerala, India.
authors.forename: Dinesh
authors.initials: D
authors.lastname: Choudhary
authors.affiliation: Department of Cardiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum 695 011, Kerala, India.
authors.forename: Amit Kumar
authors.initials: AK
authors.lastname: Chaurasia
authors.affiliation: Department of Cardiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum 695 011, Kerala, India.
authors.forename: S Mahesh
authors.initials: SM
authors.lastname: Kumar
authors.affiliation: Department of Cardiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum 695 011, Kerala, India.
authors.forename: Ajeet
authors.initials: A
authors.lastname: Arulkumar
authors.affiliation: Department of Cardiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum 695 011, Kerala, India.
authors.forename: Anees
authors.initials: A
authors.lastname: Thajudeen
authors.affiliation: Department of Cardiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum 695 011, Kerala, India.
authors.forename: Narayanan
authors.initials: N
authors.lastname: Namboodiri
authors.affiliation: Department of Cardiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum 695 011, Kerala, India.
authors.forename: G
authors.initials: G
authors.lastname: Sanjay
authors.affiliation: Department of Cardiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum 695 011, Kerala, India.
authors.forename: S P
authors.initials: SP
authors.lastname: Abhilash
authors.affiliation: Department of Cardiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum 695 011, Kerala, India.
authors.forename: V K
authors.initials: VK
authors.lastname: Ajitkumar
authors.affiliation: Department of Cardiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum 695 011, Kerala, India.
authors.forename: Tharakan
authors.initials: T
authors.lastname: Ja
keywords: Artificial Cardiac Pacing; Left Ventricle; Ventricular Function