163: Assessment of uraemic cardiomyopathy in childhood by systolic time intervals

Systolic time intervals (STI) are recorded in 48 children with chronic renal failure (CRF) for quantitative determination of impaired myocardial performance as a result of uraemic cardiomyopathy under conservative treatment or on haemodialysis (HD). Duration of total systole (DTS), pre-ejection-phase (PEP), ejection time (ET) and systolic quotient (SQ = ET/PEP) are estimated from simultaneous high speed tracings of the EKG, PKG and the external carotid pulse. The measured values are compared to the calculated values related to age and heart rate according to GOLDE. In non-dialysed children (mean SCR 9 mg%) there is a prolongation in PEP of 32% above normal (p < 0.05), indicating a reduced myocardial performance. The SQ is found shortened to 80% of normal (p < 0.05) corresponding to a diminished left ventricular ejection fraction. A correlation is also found between PEP, SQ and serum haemoglobin (r = 0.75/0.76). Following administration of digitalis PEP decreases (p < 0.05) and SQ increases (p < 0.05). On HD PEP and SQ improve significantly (p < 0.05) in the case that they have indicated a negative inotropic myocardial state before HD.