Cardiac carnitine leakage is promoted by cardiomyopathy

We investigated whether a damaged heart with cardiomyopathy (CM) influences cardiac-stored carnitines. A sensitive, specific, carnitine-requiring yeast was used to determine blood carnitine concentration in 116 healthy subjects. For comparison with blood carnitine concentrations from patients with CM, we selected 33 male patients, ages 29 to 67 y, with evidence of CM and 24 male patients, ages 31 to 66 y, with no CM as categorized by cardiac catheterization. During catheterization, significantly higher concentrations of arterial blood levels of carnitines leaked from hearts of patients specifically with CM; no arterial blood carnitines leaked from hearts of patients without CM. Venous blood carnitine concentration for all patients was within the normal range. Carnitine did not accumulate in venous blood and was not a source of large amounts of leaked blood carnitines in patients with CM. CM causes leakage of carnitines from heart stores, possibly making cardiac tissue vulnerable to damage. We do not know whether cardiac carnitine leakage leads to CM or if established CM promotes cardiac carnitine leakage.