Cardiac abnormalities in girls with Turner syndrome: ECG abnormalities, myocardial strain imaging, and karyotype-phenotype associations.

Turner syndrome (TS) is a chromosomal condition which is associated with an increased prevalence of cardiac morbidity and mortality. In this cross-sectional study, Minnesota-based electrocardiographic (ECG) abnormalities, aortic dimensions, routine- and myocardial strain echocardiographic parameters, and karyotype-cardiac phenotype associations were assessed in girls with TS. In total, 101 girls with TS (0-18 years) were included. The prevalence of major ECG abnormalities was 2% (T-wave abnormalities) and 39% had minor ECG abnormalities. Dilatation of the ascending aorta (z-score > 2) was present in 16%, but the prevalence was much lower when using TS-specific z-scores. No left ventricular hypertrophy was detected and the age-matched global longitudinal strain was reduced in only 6% of the patients. Cardiac abnormalities seemed more common in patients with a non-mosaic 45,X karyotype compared with other karyotypes, although no statistically significant association was found. Lowering the frequency of echocardiography and ECG screening might be considered in girls with TS without cardiovascular malformations and/or risk factors for aortic dissection. Nevertheless, a large prospective study is needed to confirm our results. The appropriate z-score for the assessment of aortic dilatation remains an important knowledge gap. The karyotype was not significantly associated with the presence of cardiac abnormalities, therefore cardiac screening should not depend on karyotype alone.