[Cardiac and metabolic investigations during 24 hour endurance skiing (Pinzolo, Italy)].

In the "24-hour Cross Country Ski Race of Pinzolo" skiers attempt to cover as long as possible distances within 24 hours. Cardiac and metabolic changes of 6 volunteer cross country skiers, aging 29 to 39 years, participating to the individual competition, were analysed. All skiers had negative clinical examination and resting standard 12-lead ECG, except for one who had a midsystolic click on auscultation suggesting the presence of mitral valve prolapse. They were submitted to 48-hour Holter monitoring (HM) going from 3:00 p.m. of the day before the race up to one hour after the end of competition. The period of HM going from 3 p.m. of the day before to 1.00 p.m. of the day of race (one hour before the start) was utilized as control as concerns arrhythmias, ST-T wave and QT interval changes observed during the period of competition. In all 6 skiers, standard 12-lead ECG was again recorded on completion of race. The following serum indexes were obtained in basal conditions and within one hour after the end of race: electrolytes (Na+, K+), Myoglobina (MG) and the enzymes GOT, GPT, LDH, CK and CK-MB. Complete urine analysis was also obtained before and immediately after the race. The distance covered by the skiers ranged from 189 to 260 Km, except for the skier with systolic click who covered 95.7 Km within 12 hour and then retired from the race for acute pain of knee.(ABSTRACT TRUNCATED AT 250 WORDS)