Increased oxygen demand | Noncardiac | Hyperthermia | Hyperthyroidism | Sympathomimetic toxicity (eg, cocaine use) | Hypertension | Anxiety | Arteriovenous fistulae | Cardiac | Hypertrophic cardiomyopathy | Aortic stenosis | Dilated cardiomyopathy | Tachycardia | Ventricular | Supraventricular | | Decreased oxygen supply | Noncardiac | Anemia | Hypoxemia | Pneumonia | Asthma | Chronic obstructive pulmonary disease | Pulmonary hypertension | Interstitial pulmonary fibrosis | Obstructive sleep apnea | Sickle cell disease | Sympathomimetic toxicity (eg, cocaine use) | Hyperviscosity | Polycythemia | Leukemia | Thrombocytosis | Hypergammaglobulinemia | Cardiac | Aortic stenosis | Hypertrophic cardiomyopathy | |