Prognosis

Recurrent syncope is more likely if: ^a  

• your patient is aged 45 or less
• 4 or more episodes of syncope in the last year
• 2 or more psychiatric diagnoses 

If no cardiovascular or neurological cause is found following investigation, recurrences are rare. ^a  

Cardiac arrhythmias are a common cause of unexplained syncope and are more likely with ^a

• no history of nausea or vomiting prior to syncope
• an abnormal ECG 

Death is more likely with

• age > 45 ^a
• heart disease ^a
• congestive heart failure ^a or left ventricular ejection fraction < 30% ^a
• a history of cardiac arrhythmias ^a
• serum creatinine > 177 µmol/l ^a
• an abnormal ECG  ^a  particularly
  • frequent (> 10/ hour ) or repetitive (≥ 2 consecutive) premature ventricular contractions ^a  
  • sinus pause > 2 sec ^a  

Use the following clinical prediction rule to rank patients for risk of cardiac arrhythmia or death ^a  

• aged > 45
• history of congestive heart failure
• history of ventricular arrhythmias

• abnormal ECG: any of

  • AF or flutter, or multifocal atrial tachycardia

  • junctional or paced rhythm

  • frequent or repetitive PVC (including VT)

  • PR interval < 0.10 mm

  • Mobitz I with other abnormalities, Mobitz II or complete heart block

  • conduction disorder: left-axis deviation, bundle-branch block, intraventricular delay

  • ventricular hypertrophy

  • old myocardial infarction