Manganese-calcium contrast agents increased left ventricular developed pressure by up to 56% and reduced tissue manganese uptake compared to manganese alone, potentially reducing MR efficacy.
Does adding high calcium to manganese-releasing contrast agents affect cardiac function and magnetic resonance efficacy in perfused guinea pig hearts?
Adding high calcium to manganese-releasing contrast agents may be counterproductive by inducing strong positive inotropy and reducing magnetic resonance efficacy.
OBJECTIVES: Manganese ions (Mn) enter cardiomyocytes via calcium (Ca) channels and enhance relaxation intracellularly. To prevent negative inotropy, new Mn-releasing contrast agents have been supplemented with high Ca. The study aim was to investigate how this affects cardiac function and magnetic resonance efficacy. MATERIALS AND METHODS: MnCl2 based contrast agents, manganese and manganese-calcium (Ca:Mn 10:1), were infused during 4 repeated washin-washout sequences in perfused guinea pig hearts. Mn were 10, 50, 100 and 500 microM. RESULTS: During washin, manganese depressed left ventricular developed pressure (LVDP) by 4, 9, 17, and 53% whereas manganese-calcium increased LVDP by 13, 18, 25, and 56%. After experiments, tissue Mn contents (nmol/g dry wt) were control <40, manganese 3720, and manganese-calcium 1620. T1 was reduced by 85-92% in Mn-enriched hearts. CONCLUSIONS: High Ca supplements to Mn-releasing contrast agents may be counterproductive by inducing a strong positive inotropic response and by reducing the magnetic resonance efficacy.
Bruvold et al. (Tue,) reported a other. Manganese-calcium contrast agent (Ca:Mn 10:1) vs. Manganese contrast agent was evaluated on Left ventricular developed pressure (LVDP). Manganese-calcium contrast agents increased left ventricular developed pressure by up to 56% and reduced tissue manganese uptake compared to manganese alone, potentially reducing MR efficacy.