In patients with severe left ventricular hypertrophy (LVH), levels of C16, C18:1, C18, and C26 acylcarnitines are significantly elevated (but C18:2 acylcarnitine is not). In patients with left ventricular systolic dysfunction (defined as a left ventricular ejection fraction [LVEF] of 45% or less), levels of C18:2 acylcarnitine, kynurenine, and choline are significantly reduced. Diamond shapes indicate mean values, circles indicate outlying values, and bars indicate interquartile ranges.