Primary carnitine deficiency cardiomyopathy International Journal of Cardiology What is the role of carnitine (L carnitine) in the management of heart failure? l Carnitine and heart disease ScienceDirect L carnitine is primarily synthesized in the liver from the amino acids lysine and methionine through a series of four enzymatic reactions, with the liver and kidneys converting the precursor butyrobetaine into active