title: Quantifying pulmonary regurgitation and right ventricular function in surgically repaired tetralogy of Fallot: a comparative analysis of echocardiography and magnetic resonance imaging.
abstract: BACKGROUND
  Patients with repaired tetralogy of Fallot are monitored for pulmonary regurgitation (PR) and right ventricular (RV) function. We sought to compare measures of PR and RV function on echocardiogram to those on cardiac magnetic resonance (CMR) and to develop a new tool for assessing PR by echocardiogram.
  
  
  RESULTS
  Patients with repaired tetralogy of Fallot (n=143; 12.5±3.2 years) had an echocardiogram and CMR within 3 months of each other. On echocardiogram, RV function was assessed by (1) Doppler tissue imaging of the RV free wall and (2) myocardial performance index. The ratio of diastolic and systolic time-velocity integrals measured by Doppler of the main pulmonary artery was calculated. CMR variables included RV ejection fraction, RV volumes, and pulmonary regurgitant fraction (RF). Pulmonary regurgitation was graded as mild (RF<20%), moderate (RF=20-40%), and severe (RF>40%). On CMR, RF was 34+17% and RV ejection fraction was 61+8%. Echocardiography had good sensitivity identifying cases with RF>20% (sensitivity 97%; 95% CI: 92-99%) but overestimated the amount of PR when RF<20% (false-positive rate 36%; 95% CI: 18-57%). The diastolic and systolic time-velocity integrals on echocardiogram showed moderate correlation with RF on CMR (R=0.60; P<0.0001). On CMR, RF of 20% and 40% corresponded with a diastolic and systolic time-velocity integral of 0.49 (95% CI: 0.44-0.56) and 0.72 (95% CI: 0.68-0.76), respectively. RV myocardial performance index correlated modestly with RV ejection fraction (r=-0.33; P<0.001).
  
  
  CONCLUSIONS
  This study suggests that the diastolic and systolic time-velocity integrals ratio may make a modest contribution to the overall assessment of PR in patients with repaired tetralogy of Fallot and warrants further investigation. However, echocardiography continues to have a limited ability to quantify PR and RV function as compared with CMR.
authors.affiliation: Division of Cardiology, Department of Pediatrics, The Children's Hospital of Philadelphia and the University of Pennsylvania Perelman School of Medicine, 34th and Civic Center Blvd, Philadelphia, PA 19104, USA. mercerrosal@email.chop.edu
authors.forename: Laura
authors.initials: L
authors.lastname: Mercer-Rosa
authors.forename: Wei
authors.initials: W
authors.lastname: Yang
authors.forename: Shelby
authors.initials: S
authors.lastname: Kutty
authors.forename: Jack
authors.initials: J
authors.lastname: Rychik
authors.forename: Mark
authors.initials: M
authors.lastname: Fogel
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Goldmuntz
mesh_terms: D000293:Adolescent; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D002648:Child; D003430:Cross-Sectional Studies; D003971:Diastole; D015150:Echocardiography, Doppler; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D015143:Philadelphia; D011237:Predictive Value of Tests; D011665:Pulmonary Valve Insufficiency / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D012720:Severity of Illness Index; D013318:Stroke Volume; D013599:Systole; D013771:Tetralogy of Fallot / Q000150:complications / Q000601:surgery*; D013997:Time Factors; D018497:Ventricular Dysfunction, Right / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D016278:Ventricular Function, Right