The main difference between sinus tachycardia and atrial tachycardia is the difference in the pacing site. Sinus rhythm is a normal pacing site, and even in sinus tachycardia, the pacing site is normal and the number of beats is usually not too high. In general, sinus tachycardia is 110 beats per minute. However, atrial tachycardia can be very fast, usually exceeding 160 beats per minute. This is usually a paroxysmal atrial tachycardia. Because atrial tachycardia is so fast, it inhibits the onset of the sinus node. So this atrial tachycardia dominates the entire heartbeat. In this case, the patient may experience palpitations, or even severe chest tightness, weakness, or even dizziness, leading to changes in blood pressure and atrial tachycardia, and this condition requires prompt treatment.