Left ventricular functional response to moderate and intense exercise
| Autor: | J M, Goodman, M J, Plyley, C A, Lefkowitz, P P, Liu, P R, McLaughlin |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
Adult
Male Anaerobic Threshold Pulmonary Gas Exchange Cardiac Volume Respiration Physical Exertion Blood Pressure Gated Blood-Pool Imaging Heart Stroke Volume Carbon Dioxide Myocardial Contraction Ventricular Function Left Oxygen Consumption Heart Rate Exercise Test Humans Female Sodium Pertechnetate Tc 99m |
| Zdroj: | Canadian journal of sport sciences = Journal canadien des sciences du sport. 16(3) |
| ISSN: | 0833-1235 |
| Popis: | The left ventricular (LV) volume and ejection fraction (EF) response to upright exercise was assessed on 15 normal subjects during cycle ergometry. Measures of cardiac function and gas exchange were made at rest, at 85% of the ventilatory anaerobic threshold (VAT; WL1), and at peak exercise (WL2). EF increased from rest (58 +/- 12%) during WL1 (66 +/- 10%), reaching significantly higher values at WL2 (69 +/- 8%; p less than .05). End-diastolic volume increased from rest during WL1 (136 +/- 36 ml vs. 118 +/- 32 ml; p less than .05), becoming significantly higher than rest during WL2 (141 +/- 41 ml). End-systolic volume was unchanged from rest (51 +/- 25 ml) during submaximal exercise (50 +/- 20 ml), but it decreased significantly during WL2 (44 +/- 21 ml; p less than .05). The systolic pressure/end-systolic volume ratio increased from 3.0 +/- 1.7 (rest) to 5.8 +/- 3.0 at WL2 (p less than .05). These results suggest that the Frank-Starling mechanism is operative throughout exercise, particularly during exercise below the VAT. LV performance after the VAT is further augmented by increased contractility with continued, yet diminished, utilization of the Frank-Starling mechanism. |
| Databáze: | OpenAIRE |
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