NPPB and heart failure: Cardiac investigation entails the performance of an electrocardiogram (ECG) and testing for QT prolongation, testing for biomarkers of cardiac injury such as cardiac troponin (cTnI), biomarkers of heart failure such as beta-natriuretic peptide (BNP), and reduced ejection fraction (EF) on a transthoracic echocardiogram (TTE).