[Changes in fatty acid metabolism in dilated cardiomyopathy and hypertrophic cardiomyopathy in childhood].

The aetiology and the pathomechanisms in both types of cardiomyopathy (CM) are still unknown. In vivo measurements of myocardial metabolism in CM may be useful, but there is hardly any information on this subject. Free fatty acids (FFA) are the main source of energy for the normal myocardium. A method for external measurement of the FFA extraction rate (FFA-ER) in different myocardial regions by the simultaneous use of two isotopes has been developed. 201 TI indicates the myocardial perfusion and 15-(p-123 I-phenyl)-pentadecanoid acid (IPPA) represents the FFA uptake. The relation of IPPA/TI reflects the FFA-ER. 8 patients with hypertrophic CM (HCM), age 0.2-20 years, and 8 patients with dilated CM (DCM), age 0.2-18 years were investigated. 12 healthy adults and 4 infants after an arterial switch operation were used as a control group. All patients with HCM showed normal myocardial perfusion but the FFA uptake was strongly diminished, resulting in a reduction in FFA-ER to 42 +/- 12% of the normal value. The maximal influx rate (IR) of FFA was diminished too. In patients with DCM both the myocardial perfusion and the FFA uptake were globally reduced, resulting in a virtually normal FFA-ER. The IR was slightly increased. In HCM and DCM FFA utilisation was disturbed. The alterations were significantly different in both types of CM and different pathomechanisms can be assumed.