| Life-threatening cardiac conditions |
| Supraventricular tachycardia (SVT) |
| Ventricular tachycardia (VT) |
| Other arrhythmias (eg, torsades de pointes, atrial flutter) |
| Hypertrophic cardiomyopathy (HCM) |
| Myocarditis, cardiomyopathy |
| Pericardial effusion |
| Life-threatening noncardiac conditions |
| Substrate deficiency (hypoxemia, hypoglycemia) |
| Hypovolemic shock |
| Anaphylaxis |
| Toxic exposure |
| Sepsis |
| Electrolyte imbalance (hyperkalemia, hypocalcemia, hypomagnesemia) |
| Pheochromocytoma |
| Common conditions |
| Fever |
| Exercise |
| Crying |
| Pain |
| Anxiety, hyperventilation syndrome |
| Anemia |
| Drug-induced (caffeine, herbal medications, dietary supplements, illicit drugs) |
| Other conditions |
| Kawasaki disease |
| Acute rheumatic fever |
| Hyperthyroidism |
