Study Limitations
There were some limitations identified in this systematic review and
meta-analysis. Firstly, the severity of the disease in the patients
included from the included studies were variable which may potentially
impact test performances. Secondly, strain assessment reported in the
included studies were all acquired using four different vendor-specific
software, which may potentially also impact the external validity of 2D
LV-GLS across different settings. Thirdly, different aetiologias of
myocarditis were included which can also bias the overall results.
Lastly, the included studies were all single-centre studies, which are
typically limited by greater inherent bias due to the greater variation
and generalisability between diagnostic work-up and protocols between
different centres in different studies. However, we did assess for
potential small-study effects on the individual parameters studied using
Egger’s tests which did not demonstrate any evidence of small study
effects confounding the results.