Plasma brain natriuretic peptide in takotsubo cardiomyopathy

Background: Takotsubo cardiomyopathy is a reversible left ventricular dysfunction with symptoms resembling acute myocardial infarction, but without coronary lesions. Patients have wall motion abnormalities (apical akinesis and basal hyperkinesis), and characteristic left ventricular morphology. Aim: To investigate plasma brain natriuretic peptide (BNP) concentrations in takotsubo cardiomyopathy. Methods: Ten consecutive patients with takotsubo cardiomyopathy underwent cardiac catheterization on their first hospital day, and blood was collected to measure BNP. To evaluate acute basal hyperkinesis, the difference in diameter between systole and diastole was measured at 10 mm below the aortic valve (the deltaBase value). Results: Coronary angiography revealed no significant stenosis in any patient. Initial ejection fraction was 42.2 +/- 7.3%, cardiac index was 1.90 +/- 0.39 l/min/m(2), and plasma BNP was 522.5 +/- 632.9 pg/ml. Ventricular contraction and the ejection fraction were normalized on echocardiography after 17.9 +/- 6.3 days. BNP was significantly correlated with deltaBase, but not with other cardiac parameters. Discussion: Initial deltaBase value seems to be a good indicator of the severity of basal hyperkinesis in patients with takotsubo cardiomyopathy. In contrast to other diagnoses, a high BNP concentration is not associated with a poor prognosis in this condition.