Introduction Marfan syndrome is an inherited connective tissue disorder caused by mutations in the fibrillin-1 gene that encodes for the protein fibrillin-1. Fibrillin-1 has been identified as a regulator of transforming growth factor beta (TGFβ) bioactivity in the extracellular matrix. TGFβ dysregulation has been linked to reduced left ventricular stroke volume in the Marfan syndrome mouse model. Left ventricular dysfunction has also been demonstrated in humans but little attention has been paid to the right ventricle. We aimed to assess regional changes in right ventricular myocardial deformation in adult unoperated patients with Marfan syndrome using strain and strain rate imaging.
Methods Forty-three patients with Marfan syndrome, 25 men and 18 women (mean age 30 ± 12 years) and 49 controls without significant differences in age, sex and body surface area, were studied. No patient had more than mild tricuspid regurgitation. All subjects underwent an echocardiographic examination at rest. Dp/Dt was measured for all patients. Two-dimensional colour Doppler data were recorded using a four-chamber apical view to evaluate longitudinal systolic strain/strain rate (ϵSYS/SRsys) in the right ventricular free lateral wall. Diastolic strain rate was also assessed in the same region. Measurements were averaged over three consecutive cardiac cycles.
Results Values are presented as mean ± SD. Dp/Dt values were significantly lower in patients with Marfan syndrome compared with controls (746.79 ± 322.34 mm Hg vs 1086.20 ± 226.57 mm Hg, p<0.001). Both longitudinal ϵSYS and SRsys were significantly reduced in the basal, mid and apical segments of right ventricular free lateral wall in patients with Marfan syndrome when compared with controls (p<0.001). Diastolic strain rate values were also significantly lower in the Marfan syndrome group (p<0.001). In a multiple regression analysis including age, sex, heart rate and pulmonary systolic pressure, Marfan syndrome diagnosis was negatively associated with reduced right ventricular free lateral wall regional deformation (p<0.001; see fig).
Conclusion These findings showed reduced regional right ventricular systolic and diastolic deformation in patients with Marfan syndrome. This could be attributed to fibrillin-1 deficiency in the cardiac extracellular matrix. Treatment may need to be tailored to prevent further deterioration by supporting right ventricular function.