The orthogonal Frank electrocardiogram in 70 well-trained athletes.

Interpretation of the vectorcardiogram in athletes requires normal values based on quantitatively analyzed data obtained in large groups of athletes. Frank electrocardiograms of extensively trained white athletes aged 23 +/- 5 years were analyzed by computer. Different sport disciplines were included. Tables are provided describing the results for the complete group of 70 athletes (A), respectively indicating the difference between 27 footballers (F) and 16 endurance athletes (E). A critical comparison with two control groups is also discussed, as for other purposes, vectorcardiograms had been collected in healthy non-trained young men, respectively 68 medical students (MS) and 63 nurse students (NS). The following figures may serve as an example to illustrate the difficulty of constituting and using similar normal limits in athletes: mean QRS spatial maximal amplitude (mV.) was respectively 1.82 (MS), 2.03 (NS), 2.17 (A), 1.97 (E), 2.29 (F). It can often be hazardous to attribute certain deviations of electrocardiological measurements to training effects in the athlete.

High-performance liquid chromatographic determination of metoprolol in plasma.

A high-performance liquid chromatographic method is presented for the determination of metoprolol in human plasma. Metoprolol was extracted from plasma by a single extraction procedure with 4-methylpropranolol as the internal standard. Chromatography was done on a reversed-phase column with fluorescence detection. The minimum detectable concentration was 5.0 ng/ml of plasma. The standard curve was linear in the range evaluated, 10-300 ng/ml. The within-run coefficient of variation was 2.3-6.0%, and the day-to-day variation was 6.8%. The method is free from interference by major metoprolol metabolites.

Non-invasive evaluation of cardiac function in professional cyclists.

Cardiac dimensions and left ventricular function were investigated at rest with non-invasive methods in 14 professional road race cyclists and in 11 age-matched sedentary control subjects. The electrocardiographic findings were in agreement with previous studies in endurance athletes and the vectocardiographic data showed anterior displacement of the electrical forces. Echocardiographic dimensions at end-diastole showed higher values in the cyclists for left ventricular internal diameter, left ventricular posterior wall thickness, and interventricular septal thickness. Derived values for left ventricular volume and left ventricular mass were also much larger in the cyclists and there was excellent agreement between total heart volume measured with radiology and total measured by echocardiography. There was a significant correlation between maximal oxygen consumption and end-diastolic left ventricular diameter.