Investigations including new ECG finding of arrhythmia, chest X-ray with foetal shielding (if required for diagnosis of pulmonary oedema) showing cardiomegaly, pulmonary venous congestion and interstitial oedema, and an elevated BNP or NT-proBNP level further suggest the presence of peripartum cardiomyopathy [89]. This evidence concerns the gene NPPB and peripartum cardiomyopathy.