Cardiovascular magnetic resonance tagging of the right ventricular free wall for the assessment of long axis myocardial function in congenital heart disease

• Main Authors: Chen Sylvia SM, Keegan Jennifer, Dowsey Andrew W, Ismail Tevfik, Wage Ricardo, Li Wei, Yang Guang-Zhong, Firmin David N, Kilner Philip J
• Format: Article
• Language: English
• Published: BMC 2011-12-01
• Series: Journal of Cardiovascular Magnetic Resonance
• Subjects: Right Ventricle; Ejection Fraction; Cardiac MRI; Tagging; Congenital Heart Disease; Reproducibility
• Online Access: http://www.jcmr-online.com/content/13/1/80

<p>Abstract</p> <p>Background</p> <p>Right ventricular ejection fraction (RV-EF) has traditionally been used to measure and compare RV function serially over time, but may be a relatively insensitive marker of change in RV myocardial contractile function. We developed a cardiovascular magnetic resonance (CMR) tagging-based technique with a view to rapid and reproducible measurement of RV long axis function and applied it in patients with congenital heart disease.</p> <p>Methods</p> <p>We studied 84 patients: 56 with repaired Tetralogy of Fallot (rTOF); 28 with atrial septal defect (ASD): 13 with and 15 without pulmonary hypertension (RV pressure > 40 mmHG by echocardiography). For comparison, 20 healthy controls were studied. CMR acquisitions included an anatomically defined four chamber cine followed by a cine gradient echo-planar sequence in the same plane with a labelling pre-pulse giving a tag line across the basal myocardium. RV tag displacement was measured with automated registration and tracking of the tag line together with standard measurement of RV-EF.</p> <p>Results</p> <p>Mean RV displacement was higher in the control (26 ± 3 mm) than in rTOF (16 ± 4 mm) and ASD with pulmonary hypertension (18 ± 3 mm) groups, but lower than in the ASD group without (30 ± 4 mm), P < 0.001. The technique was reproducible with inter-study bias ± 95% limits of agreement of 0.7 ± 2.7 mm. While RV-EF was lower in rTOF than in controls (49 ± 9% versus 57 ± 6%, P < 0.001), it did not differ between either ASD group and controls.</p> <p>Conclusions</p> <p>Measurements of RV long axis displacement by CMR tagging showed more differences between the groups studied than did RV-EF, and was reproducible, quick and easy to apply. Further work is needed to assess its potential use for the detection of longitudinal changes in RV myocardial function.</p>