Sinus bradycardia is seen in:

Sinus tachycardia is associated with a sinus rate of more than 100/min. The various causes are, Anxiety Fever Exercise Emotion Anaemia Thyrotoxicosis Beta adrenoceptor agonists Sinus bradycardia is associated with a sinus rate of less than 60/min and is seen commonly in athletes. Myocardial infarction Hypothyroidism Cholestatic jaundice Raised intracranial pressure Beta-blockers Digoxin Verapamil