title: Effects of Age-Related Aortic Root Anatomic Changes on Left Ventricular Outflow Tract Pace-Mapping Morphologies: A Cardiac Magnetic Resonance Imaging Validation Study.
abstract: BACKGROUND
  Outflow tract ventricular arrhythmias (OT VAs) are common and catheter ablation is an effective treatment option. We sought to investigate the relationship between age-related anatomic aortic root changes and QRS morphology during left ventricular outflow tract (LVOT) pace-mapping using cardiac magnetic resonance (CMR) imaging.
  
  
  RESULTS
  Fifty-one patients undergoing CMR imaging were divided into 3 groups based on age (<40, 40-60, >60 years). We measured the angle of the aortic root, the aorta to ventricular septal angle, the distance between the right coronary cusp (RCC) and left coronary cusp (LCC), and the distance between the ascending and descending aorta. Additionally, we evaluated the QRS morphologies obtained during pace-mapping from the LVOT. In older patients, LCC was more superior to the RCC (P < 0.01). Age was positively correlated with the aortic root angle (r2= 0.481, P < 0.01) as well as the distances between the ascending and descending aorta at a level below the arch (r2= 0.569, P < 0.01). In older patients, LVOT pace-mapping (performed in 16 patients) demonstrated higher maximal R-wave amplitude, and was greater when pacing from the LCC versus the RCC in lead III (1.8 ± 0.7 vs. 1.0 ± 0.5 mV, P = 0.02).
  
  
  CONCLUSIONS
  The anatomy of the aortic root changes with age, and age-related aortic root changes may affect the QRS morphology during pace-mapping. Understanding the potential anatomic changes that accompany aging is important to maximize the efficacy of catheter ablation of OT VAs.
authors.affiliation: Electrophysiology Section, Cardiovascular Division, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Shingo
authors.initials: S
authors.lastname: Maeda
authors.affiliation: Electrophysiology Section, Cardiovascular Division, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: William W
authors.initials: WW
authors.lastname: Chik
authors.affiliation: Electrophysiology Section, Cardiovascular Division, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Yuchi
authors.initials: Y
authors.lastname: Han
authors.affiliation: Electrophysiology Section, Cardiovascular Division, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Jackson J
authors.initials: JJ
authors.lastname: Liang
authors.affiliation: Electrophysiology Section, Cardiovascular Division, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Fabien
authors.initials: F
authors.lastname: Squara
authors.affiliation: Electrophysiology Section, Cardiovascular Division, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Arkles
authors.affiliation: Electrophysiology Section, Cardiovascular Division, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Mouhannad M
authors.initials: MM
authors.lastname: Sadek
authors.affiliation: Electrophysiology Section, Cardiovascular Division, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Pasquale
authors.initials: P
authors.lastname: Santangeli
authors.affiliation: Electrophysiology Section, Cardiovascular Division, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: David S
authors.initials: DS
authors.lastname: Frankel
authors.affiliation: Electrophysiology Section, Cardiovascular Division, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Erica S
authors.initials: ES
authors.lastname: Zado
authors.affiliation: Department of Surgery, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Takebayashi
authors.affiliation: Electrophysiology Section, Cardiovascular Division, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Dixit
authors.affiliation: Electrophysiology Section, Cardiovascular Division, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: David J
authors.initials: DJ
authors.lastname: Callans
authors.affiliation: Electrophysiology Section, Cardiovascular Division, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Francis E
authors.initials: FE
authors.lastname: Marchlinski
authors.affiliation: Electrophysiology Section, Cardiovascular Division, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: David
authors.initials: D
authors.lastname: Lin
keywords: aortic root; cardiac magnetic resonance; catheter ablation; outflow tract; ventricular arrhythmias