(14,
26).
Additionally, the sub-endocardial layers of the myocardium with a
predominance of longitudinal myocardial fibers are typically impacted in
myocarditis. Hence the longitudinal left ventricular contractile
function is expected to be most impaired in acute myocarditis
(27, 28).
These are consistent with results from the study which demonstrated the
endo-GLS to be more impaired compared to mid- and epicardial-GLS(29). The distribution of LV-GLS
impairment in studies examining regional systolic dysfunction which
match areas of inflammatory response further strengthens the value of
measuring LV-GLS in the clinical setting.
Whilst the majority of the included studies included patients with acute
inflammatory myocarditis, one study included patients with immune
checkpoint inhibitor (ICI) myocarditis(14), an entity that is more
complex and multi-faceted than inflammatory myocarditis, despite similar
diagnostic criteria (30).Patients with ICI myocarditis may possibly have a greater impairment in
LV-GLS and LV systolic function compared to other subtypes, particularly
with the presence of confounding factors such as para-neoplastic
cytokines, and other mechanisms of treatment mediated toxicity