Reply Mitral valve prolapse and left ventricular systolic function First published online: 6 March 2015 We thank Dr Yiğiner et al 1 for their interest in our study regarding the left ventricular function in young adults with mitral valve prolapse without significant mitral regurgitation. 2 Their commentary emphasised the importance of the aetiological distinction of mitral valve prolapse for medium- and long-term prognosis and reconstructive surgery timing decision. Indeed, myxomatous Barlow’s disease – syn.: classic mitral valve prolapse – and fibroelastic deficiency are the two dominant forms of degenerative mitral valve disease, and have unique differentiating character- istics on clinical and echocardiographic assessment. 3 In our study, myxomatous changes in mitral leaflets were identified only by transthoracic echocardio- graphy and have not been confirmed by histological examinations. At present, despite the introduction of three-dimensional trans-oesophageal echocardio- graphy in routine practice, transthoracic echocardio- graphy is the optimal non-invasive technique to determine the morphology and to identify aetiologies of mitral valve prolapse compared with surgical and pathological findings. 4 Some previous pathology studies in myxomatous mitral valve prolapse provided evidences for intramyo- cardial extracellular matrix changes as a specific reflec- tion of a general myxomatous alteration in cardiac connective tissue. 5,6 These changes may cause both left ventricular enlargement and systolic dysfunction in classical mitral valve prolapse. The low longitudinal deformation in septal seg- ments revealed in our study is only the first sign of future deterioration of the left ventricular systolic function by mitral valve prolapse progression. The significantly worse contractile function of the septum compared with other left ventricular regions was demonstrated by MRI-based strain analysis in patients with mitral valve prolapse and moderate-to-severe chronic mitral regurgitation. 7 In patients with severe chronic mitral regurgitation, we found significant decrease of the global longitudinal systolic strain in myxomatous Barlow’s disease compared with fibro- elastic deficiency. 4 Importantly, the subclinical regional and global left ventricular systolic dysfunction in mitral valve prolapse were not revealed by conventional echocardiography and required a novel echocardiography- based or MRI-based strain technique. Myxomatous Barlow’ s disease leads to the anterior or bileaflet prolapse, requires a more complex type of repair, and greater surgical expertise. Lower pre-operative left ventricular systolic function in myxomatous mitral valve prolapse may demand the earlier repair procedure for severe mitral regurgitation and affect the post-operative medium- and long-term survival. Thus, left ventricular dysfunction is an integral part of myxomatous mitral valve disease, and may affect even young patients without significant mitral regur- gitation and influence their long-term prognosis. Eduard Malev Department of Connective Tissue Disorders, Federal North-West Medical Research Centre, Saint-Petersburg, Russia Eduard Zemtsovsky Department of Propaedeutic of Internal Diseases, State Pediatric Medical University, Saint-Petersburg, Russia References 1. Yiğiner O, Degirmencioglu G, Doğan M, Sitki Cebeci B. Mitral regurgitation: many reasons, multiple myocardial conditions and several surgical options. Cardiol Young 2015. 2. Malev E, Reeva S, Vasina L, et al. Cardiomyopathy in young adults with classic mitral valve prolapse. Cardiol Young 2014; 24: 694–701. 3. Anyanwu AC, Adams DH. Etiologic classification of degenerative mitral valve disease: Barlow’s disease and fibroelastic deficiency. Semin Thorac Cardiovasc Surg 2007; 19: 90–96. 4. Malev E, Kim G, Mitrofanova L, Zemtsovsky E. Preoperative left ventricular function in degenerative mitral valve disease. J Cardiovasc Med (Hagerstown) 2014; 15: 222–229. 5. Morales AR, Romanelli R, Boucek RJ, et al. Myxoid heart disease: an assessment of extravalvular cardiac pathology in severe mitral valve prolapse. Hum Pathol 1992; 23: 129–137. 6. Dollar AL, Roberts WC. Morphologic comparison of patients with mitral valve prolapse who died suddenly with patients who died from severe valvular dysfunction or other conditions. J Am Coll Cardiol 1991; 17: 921–931. 7. Maniar H, Brady B, Lee U, et al. Early left ventricular regional contractile impairment in chronic mitral regurgitation occurs in a consistent, heterogeneous pattern. J Thorac Cardiovasc Surg 2014; 148: 1694–1699. Cardiology in the Young (2015), 25, 1232 © Cambridge University Press, 2015 doi:10.1017/S1047951115000232