Relation of B-type natriuretic peptide to left ventricular wall stress as assessed by cardiac magnetic resonance imaging in patients with dilated cardiomyopathy

• Published in: Canadian journal of physiology and pharmacology Vol. 85; no. 8; pp. 790 - 799
• Main Authors: Alter, P, Rupp, H, Rominger, M.B, Vollrath, A, Czerny, F, Klose, K.J, Maisch, B
• Format: Journal Article
• Language: English
• Published: Ottawa, ON National Research Council of Canada 01.08.2007; NRC Research Press
• Subjects: Adult; Aged; Biological and medical sciences; BNP; cardiac magnetic resonance imaging; Cardiomyopathy; Cardiomyopathy, Dilated - blood; Cardiomyopathy, Dilated - physiopathology; Diagnosis; Diastole; Female; Fundamental and applied biological sciences. Psychology; Heart; Heart diseases; heart failure; Humans; imagerie par résonance magnétique cardiaque; insuffisance cardiaque; left ventricular wall stress; Magnetic Resonance Imaging; Male; mechanical stress; Methods; Middle Aged; natriuretic peptide; Natriuretic Peptide, Brain - blood; Natriuretic peptides; peptide natriurétique; Physiological aspects; strain; Stress, Mechanical; tension mécanique; tension pariétale ventriculaire gauche; Ventricular Function, Left; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Germany; Heart failure; Wall; Peptides; Magnetic resonance; Cardiovascular disease; Myocardial disease; Nuclear magnetic resonance imaging; Stress; Vertebrata; Mammalia; Dilated cardiomyopathy; Mechanical stress; Heart disease
• ISSN: 0008-4212; 1205-7541
• DOI: 10.1139/Y07-076

Ventricular loading conditions are crucial determinants of cardiac function and prognosis in heart failure. B-type natriuretic peptide (BNP) is mainly stored in the ventricular myocardium and is released in response to an increased ventricular filling pressure. We examined, therefore, the hypothesis that BNP serum concentrations are related to ventricular wall stress. Cardiac magnetic resonance imaging (MRI) was used to assess left ventricular (LV) mass and cardiac function of 29 patients with dilated cardiomyopathy and 5 controls. Left ventricular wall stress was calculated by using a thick-walled sphere model, and BNP was assessed by immunoassay. LV mass (r = 0.73, p < 0.001) and both LV end-diastolic (r = 0.54, p = 0.001) and end-systolic wall stress (r = 0.66, p < 0.001) were positively correlated with end-diastolic volume. LV end-systolic wall stress was negatively related to LV ejection fraction (EF), whereas end-diastolic wall stress was not related to LVEF. BNP concentration correlated positively with LV end-diastolic wall stress (r = 0.50, p = 0.002). Analysis of variance revealed LV end-diastolic wall stress as the only independent hemodynamic parameter influencing BNP (p < 0.001). The present approach using a thick-walled sphere model permits determination of mechanical wall stress in a clinical routine setting using standard cardiac MRI protocols. A correlation of BNP concentration with calculated LV stress was observed in vivo. Measurement of BNP seems to be sufficient to assess cardiac loading conditions. Other relations of BNP with various hemodynamic parameters (e.g., EF) appear to be secondary. Since an increased wall stress is associated with cardiac dilatation, early diagnosis and treatment could potentially prevent worsening of the outcome.