Strategic Approach - Syncope in Mid Life (Ages 35-65)

The approach to the assessment of any patient with syncope is influenced by the age of the patient and the presentation of the events.

Here we discuss the likley causes and an approach to assessment for patients presenting with syncope in MidLife. Indications for specialist referral are also indicated.

Likely Causes:

Patients presenting with syncope in midlife are begining to develop degenerative diseases.

We start to see more commonly disease of the conducting system, presenting with bradycardia and heart block. They are more likely to have arrhythmic syncope due to underlying structural heart disease than younger patients

Blood pressure control disorders continue to be common, however in addition to neurally mediated syncope we begin to see the side effects of medications with subsequent orthostatic hypotension. Postprandial hypotension can occur in patients taking multiple medications or in those with diseases such as diabetes that affect the autonomic nervous system.

Neurally Mediated Syncope

Neurally mediated syncope remains a very common cause of syncope throughout life. However it rarely presents for the first time after the age of 35 years. Patients however who experienced syncope in younger years - particularly adolescence - may have had a long period syncope free and then re-present in mid life with further events.

Orthostatic Hypotension and Postprandial Hypotension

Over the age of 50 years syncope due to Orthostatic Hypotension and Postprandial Hypotension begin to appear.

This is the result of :

• The effects of aging - See Syncope in Older People
• Side effects of medications
• Co-morbid illness with autonomic dysfunciton or impaired cardiovascular reflexes eg
  • Diabetes
  • Parkinsons disease
  • Poorly controlled hypertension

Carotid Sinus Hypersensitivity

Carotid Sinus Hypersensitivity has been implicated in syncope and unexplained falls. It rarely occurs before the age of 50 years, but should be considered as a cause of recurrent syncope or unexplained falls in this age group - particularly is episodes are occuring whilst out walking and in association with head turning (eg about to cross the street).

Structural Heart Disease

Syncope in this age group can present seconday to structural heart disease - either due to ventricular tachycarrhythmias or as a result of low cardiac output with associated orthostatic or postprandial hypotension.

These conditions include:

• Ischaemic heart disease - particularly if in association with impaired ventricular funciton
• Non-ischaemic dilated cardiomyopthy
• Hypertrophic Cardiomyopathy
• Arrhythmogenic Right Ventricular Dysplasia
• Aortic Stenosis - usually in association with a bicuspid aortic valve in this age group.

Bradyarrhythmias

As patients approach their 50's and 60's we see an increase in the incidence of syncope due to bradyarrhythmias. These can occur in otherwise normal hearts or with conducting system disease in association with underlying structural heart disease.

Patients presenting with syncope due to intermittent bradyarrhythmias tend to have a recent onset of episodes. Episodes tend to be abrupt, without warning and associated with very rapid recovery.

Uncommonly supraventricular arrhythmias can present with syncope in this age group.

• Supraventricular tachycardia resulting in syncope is generally the result of initiation of a neurally mediated syncopal response due to the tachycardia.
• Patients with atrial fibrillation can have sinus pauses on reversion to sinus rhythm that reslut in syncope - the 'Tachy-Brady syndrome'.

Inherited Conditions

Some inherited conditions can present for the first time in this age group. In particular:

• Arrhythmogenic Right Ventricular Dysplasia
• Brugada Syndrome

It is rare for Long QT syndrome or Catecholaminergic Polymorphic VT to present for the first time in this age group.

Other Considerations:

Epilepsy may present for the first time in this age group

Often on a background of previous head injury or stroke.

Psychogenic syncope

A Psychogenic cause is rare as an explanation for syncope beginning in this age group.

 

Approach to the Patient Presenting with Syncope in Midlife

Content under review