Four cases of venous thrombosis in athletes with silent hereditary defects of the protein C system.

We report four cases of athletes, carriers of a defect of theprotein C (PC) anticoagulant system, who developeddeep vein thrombosis (DVT) after strenuous physicalexercise. These cases suggest that there could be a relationshipbetween post-exercise hypercoagulability and the onset of DVT.A retrospective study of cases of DVT associated with hereditarythrombophilia evaluated in our laboratory over a period ofabout three years (1995–1997) revealed four cases of DVT thatoccurred in athletes soon after strenuous exercise. The firstsymptoms of DVT (pain, oedema and cyanosis at variable extent)occurred in the legs of all athletes between 1–3 h after exercise(swimming, rowing or football; see Table 1). DuplexDoppler ultrasound was positive for DVT. Thrombosis was localizedin the femoral vein in all subjects except subject 2, in whomit occurred in the popliteal vein. All subjects practised sport at acompetitive level, and one was an elite athlete.