"String sign": a mismatch of currently available self-expandable valve and the annulus sizing?

@article{Vavuranakis2014StringSA,
  title={"String sign": a mismatch of currently available self-expandable valve and the annulus sizing?},
  author={Manolis Vavuranakis and Maria Kariori and Konstantinos A. Aznaouridis and Carmen Moldovan and Konstantinos Kalogeras and Christodoulos Stefanadis},
  journal={International journal of cardiology},
  year={2014},
  volume={171 2},
  pages={e28-30}
}