title: Breathing maneuvers as a coronary vasodilator for myocardial perfusion imaging.
abstract: A combined breathing maneuver of hyperventilation, followed by a long voluntary breathhold leads to coronary vasodilation. We investigated the impact of breathing maneuvers on MR first-pass cardiac perfusion imaging and its potential clinical utility.
  
  
  
  We studied 24 healthy volunteers (37 ± 12 years; 62.5% men) on a clinical 3 Tesla MRI system and performed first-pass perfusion MR at rest, during a short breathhold (S-HVBH) following 60 s of hyperventilation, and at the end of a long breathhold (L-HVBH) following the hyperventilation, performed in random order. A blinded reader analyzed signal intensity upslope, upslope index, and time between 20 and 80% of maximal signal.
  
  
  
  All volunteers tolerated the breathing maneuvers well and completed the study protocol. The upslope of the signal-intensity-over-time curve was increased during S-HVBH (1.86 ± 0.70 units/s, P < 0.05) and at the end of L-LVBH (1.77 ± 0.82 units/s), when compared with baseline results (1.34 ± 0.58 units/s). Corrected for the arterial input, the upslope was higher at the end of the L-HVBH (0.095 ± 0.019 units/s versus 0.077 ± 0.016 units/s at rest, P < 0.01) as was the myocardial perfusion reserve index (1.25 ± 0.22 versus 1.09 ± 0.17; P < 0.001). In a multiple regression model, only gender, rate-pressure product, and breathhold time were independently and significantly related to the upslope (R = 0.771; P < 0.001).
  
  
  
  In conclusion, a voluntary long breathhold after hyperventilation leads to an increase of the myocardial perfusion reserve index. This may impact findings from current practice of first-pass perfusion imaging. The clinical utility of breathing maneuvers as a vasodilatory stimulus for first-pass perfusion imaging may warrant further research. J. MAGN. RESON. IMAGING 2016;44:947-955.
authors.affiliation: Montreal Heart Institute, Departments of Cardiology and Radiology, Université de Montréal, Montréal, Canada.|Lenitudes Medical Center and Research, Sta Maria da Feira, Portugal.
authors.forename: Tiago
authors.initials: T
authors.lastname: Teixeira
authors.affiliation: Montreal Heart Institute, Departments of Cardiology and Radiology, Université de Montréal, Montréal, Canada.
authors.forename: Gobinath
authors.initials: G
authors.lastname: Nadeshalingam
authors.affiliation: Montreal Heart Institute, Departments of Cardiology and Radiology, Université de Montréal, Montréal, Canada.
authors.forename: Kady
authors.initials: K
authors.lastname: Fischer
authors.affiliation: Montreal Heart Institute, Departments of Cardiology and Radiology, Université de Montréal, Montréal, Canada.
authors.forename: François
authors.initials: F
authors.lastname: Marcotte
authors.affiliation: Montreal Heart Institute, Departments of Cardiology and Radiology, Université de Montréal, Montréal, Canada. mgwfriedrich@gmail.com.|McGill University Health Centre, Departments of Cardiology and Diagnostic Radiology, McGill University, Montreal, Canada. mgwfriedrich@gmail.com.
authors.forename: Matthias G
authors.initials: MG
authors.lastname: Friedrich
mesh_terms: D000328:Adult; D062485:Breath Holding; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000502:physiology*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D015203:Reproducibility of Results; D015656:Respiratory Mechanics / Q000502:physiology*; D012680:Sensitivity and Specificity; D014664:Vasodilation / Q000502:physiology*
keywords: breathing maneuvers; cardiac MR; coronary vasculature; first-pass perfusion; myocardial perfusion