ABSTRACT

Sinus tachycardia In sinus tachycardia, the rate is 100-150 beats per minute with normal P-waves and PR interval. It may be physiological, for example in response to exercise or anxiety, or pathological, for example in response to pain, left ventricular failure, asthma, thyrotoxicosis or iatrogenic causes (e.g. β-agonists). If pathological, treatment is directed at the underlying cause.