Stroke volume(SV) at rest and during exercise measured using magnetic resonance imaging before and after treatment with sildenafil
| Healthy controls# | COPD patients¶ | |||||
| Before treatment with sildenafil | After 3-month treatment with sildenafil | |||||
| Rest | Exercise | Rest | Exercise | Rest | Exercise | |
| Cardiac frequency beats·min−1 | 71±8 | 96±12+ | 78±13* | 94±15+ | 79±10 | 99±8+ |
| SV mL·beat−1 | 81±22 | 101±28+ | 62±12* | 70±15*,+ | 64±12 | 73±21+ |
| Cardiac output L·min−1 | 5.7±1.5 | 9.6±2.6+ | 5.1±1.4 | 6.7±2.0*,+ | 5.3±1.4 | 7.3±2.2+ |
Data are presented as mean±sd. COPD: chronic obstructive pulmonary disease. #: n = 8; ¶: n = 15. *: p<0.05 versus healthy controls; +: p<0.05 versus rest in same treatment.