Sinus tachycardia may be caused by a variety of stimuli.
Pharmacologic causes:
(1) caffeine
(2) alcohol
(3) albuterol (salbutamol) or other beta-adrenergic agonists
(4) high doses of amphetamine (heart rate shows reflex slowing at lower doses)
(5) theophylline
Endocrine causes:
(1) thyrotoxicosis
(2) epinephrine (pheochromocytoma)
Pathophysiologic:
(1) fever
(2) anemia
(3) hypovolemia (associated with hemorrhage or other cause)
(4) hypoxemia (including pulmonary embolism)
(5) exertion or exercise
(6) fear or anxiety
(7) pain
(8) myocardial infarction
Other:
(1) re-entry phenomenon within the sinoatrial node (may have an abrupt onset and can be terminated by a vagal stimulus)
