Anaerobic threshold | HR response | BP response | Oxygen pulse | Oxygenation | Ventilatory efficiency | Other features | |
Normal | AT >40% predicted VO2max | Max HR >90% predicted (220–age) | SBP increase >20 to 30 mmHg; DBP increase <20 mmHg | Peak O2 pulse >80% predicted; O2 pulse plateaus late in exercise |
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Chronotropic incompetence | Low AT | Max HR <80% predicted chronotropic index <0.8* | Typically normal | Typically normal | Normal | Normal | Frequently on beta-blockers or Ca2+-channel blockers |
Cardiac ischemia | Low AT | Normal¶ | SBP may fall near peak exercise | ↓ or ↓↓ | Typically normal | Normal or mildly abnormal | Ischemic changes or arrhythmia on ECG |
Left-sided heart failure | Low AT | Normal¶ | In severe cases, SBP may fail to augment or fall at peak exercise | ↓↓ or ↓↓↓, early plateau | Normal at rest; ↓O2Sat and ↑peak A-a O2 difference w/exercise when severe (with pulmonary vascular remodeling) | Mildly-moderately abnormal, depending on severity of heart failure | Exercise oscillatory ventilation, in severe disease |
Peripheral vascular disease | Low AT | Normal¶ | DBP may increase >20 mmHg | ↓ or ↓↓ | Typically normal | Normal to mildly abnormal | |
Pulm HTN/right-sided heart failure | Low AT | Normal¶ | In severe cases, SBP may fail to augment or fall at peak exercise | ↓↓ or ↓↓↓, early plateau | ↓O2Sat (frequently at rest and always w/exercise); Peak A-a O2 difference >35 | Severely abnormal | |
Anemia | Low AT | Normal¶ | Normal | May be mildly reduced | Normal | Normal to mildly abnormal; OUES is usually more impaired than other measures | |
Deconditioning | Low AT | Normal¶ | Normal | May be mildly reduced | Normal | Normal to mildly abnormal; OUES is usually more impaired than other measures | |
Metabolic/mitochondrial myopathies | Low AT | Normal¶ | Normal | May be mildly reduced | Normal | Normal to mildly abnormal; OUES is often significantly impaired compared with other measures |
A-a O2 difference: difference between alveolar and arterial oxygen partial pressures (mmHg); AT: anaerobic threshold; DBP: diastolic blood pressure (mmHg); ECG: electrocardiogram; HR: heart rate (beats/min); O2 pulse: oxygen pulse, oxygen uptake/HR (mL/beat); O2Sat: oxygen saturation (measured by pulse oximetry); OUES: O2 uptake efficiency slope; PETCO2: end-tidal carbon dioxide tension (mmHg); RR: respiratory rate (breaths/min); SBP: systolic blood pressure (mmHg); VD/VT: proportion of dead space ventilation (VD) per tidal volume breath (VT); VE: minute ventilation (L/min); VCO2: measurement of carbon dioxide output from the lungs (mL/minute); VO2max: maximum rate of oxygen consumption with exercise (mL/kg/min).
* Chronotropic index is defined by [HRpeak–HRrest]/[(220–age)–HRrest], where HRpeak and HRrest are the heart rate at peak exercise and at rest, respectively. The normal range is 0.8 to 1.3.
¶ Unless concomitant chronotropic incompetence.آیا می خواهید مدیلیب را به صفحه اصلی خود اضافه کنید؟