If supraventricular tachycardia occurs in someone who has significant coronary artery disease, the heart may not receive enough blood to keep up with the demands of the increased heart rate. If this occurs, the heart may not get enough oxygen, potentially causing chest pain (angina) or a heart attack.

Mild supraventricular tachycardia, with short episodes that don't happen often, doesn't typically weaken the heart or lead to heart failure. But some people have a higher risk of getting heart failure, such as those who have a heart valve disease. If tachycardia is left untreated, repeated and long episodes of tachycardia can lead to heart failure (known as a tachycardia-mediated cardiomyopathy). But this heart failure might be stopped, or reversed, if the supraventricular tachycardia is stopped with treatment.