Effects of knee surgery on cardiac function in soccer players

OBJECTIVE: To evaluate the effects of knee surgery on hematocrit and hemoglobin concentration and on resting cardiac parameters as measured by echocardiography. DESIGN: Ten soccer players who underwent knee surgery were evaluated before (T1) and after (T2) hospitalization within a 7-day interval. RESULTS: After hospitalization, end diastolic volume and stroke volume were significantly reduced (P < 0.05) by 14 and 22%, respectively. Despite a significant increase in resting heart rate (T1: 68 +/- 3.3 beats/ min, T2: 72 +/- 3.1 beats/min, P < 0.05), cardiac output was significantly decreased (T1: 4.89 +/- 0.56 liters/min; 3.95 +/- 0.62 liters/min, P < 0.05). The ejection fraction was 65% at T1 and fell to 58% at T2 (P < 0.05). After hospitalization, significant decreases in hemoglobin concentration and hematocrit were observed, suggesting a fall in blood volume. CONCLUSION: In soccer players, knee surgery leads to resting cardiac deconditioning, which is characterized by a significant reduction in stroke volume.