The phenotypic characteristic observed by cardiac magnetic resonance in a PLN-R14del family

Abstract

Phospholamban (PLN) is an important regulator for sarcoendoplasmic reticulum (SR) calcium transport ATPase (SERCA), which uptakes Ca2+ to SR during the diastolic phase of cardiomyocytes to maintain intracellular calcium homeostasis. Mutations on PLN result in intracellular calcium disorder, myocardial contraction defect, and eventually heart failure and/or malignant ventricular arrhythmia. Since 2003, several kinds of PLN mutations have been identified in familial dilated cardiomyopathy (DCM) patients, illustrating a few clinical characteristics that differs from classical DCM patients. Herein, we report a large PLN-R14del family with typical clinical characteristics reported including relatively late-onset clinical symptoms, low-voltage in ECG, as well as frequent ventricular arrythmias. Moreover, members underwent cardiac magnetic resonance (CMR) examination showed a strikingly similar pattern of late gadolinium enhancement (LGE)—Sub-epicardial involvement in the left ventricular (LV) lateral wall with or without linear mid-wall enhancement in the interventricular septum. The former one can also present in younger PLN-R14del carriers despite completely normal LV structure and function. Meanwhile, T1 mapping also found significantly increased extracellular volume (ECV) in PLN-R14del carriers. These findings highlight the special role of CMR to phenotyping PLN-induced cardiomyopathy patients and distinguish them from other types of cardiomyopathy.