When supraventricular tachycardia occurs in someone with 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 (ischemia), potentially causing a heart attack (myocardial
infarction).
Supraventricular tachycardia may result in heart failure, especially
in people with diseases of the heart valves (particularly aortic stenosis or
mitral stenosis) or with a weakened heart muscle (cardiomyopathy).
Additionally, if supraventricular tachycardia persists for a long period of
time, it may cause a normal heart to weaken and heart failure to develop (known
as a tachycardia-mediated cardiomyopathy), although it is often reversible if
the supraventricular tachycardia is corrected.