Prognosis

Recurrent episodes are common in patients with paroxysmal atrial flutter ^b

Patients who are cardioverted are more likely to remain in sinus rhythm if they have ^a  

• non-rheumatic mitral valve disease
• low NYHA functional class

Supraventricular tachycardia

Ventricular arrhythmias

Many patients die, particularly suddenly. ^b     

The risk is increased with ^b

• severe heart failure
• left ventricular aneurysm
• a poor response to antiarrhythmics on electrophysiologic testing