No diagnosis of SMA or substantial doubts about diagnosis; diagnosis of non 5q-SMA (e.g.: SMARD, distal SMA); no cardiac pathology present; SMA with additional chromosomal abnormalities associated with (congenital) heart disease (e.g. trisomy 21); cardiac abnormalities due to medication or in moribund patients (e.g. bradycardia); redundant publication of previously reported case(s); congress reports; mouse model of non 5q-SMA (e.g. IGHMBP2 model); animal research other than mouse models; only abstract available with unidentifiable cases.