Fainting Spells – When is it Cardiovascular related?

Article contributed by Dr Teo Wee Siong, Consultant Cardiologist and Eletrophysiologist at Mount Elizabeth Hospital.

Is it a fainting spell?
It is important to differentiate a fainting spell from vertigo, which is more of a spinning sensation with no loss of consciousness and is usually related to the position of the head. Fits and other neurological disorders may also be excluded.

Is it a fainting spell if it’s associated with transient loss of consciousness?
For most people, fainting spells may mean a near loss of consciousness or a near blackout. When there is a complete loss of consciousness, albeit transient, the person is often described as having fainted or having syncope. It is important to differentiate if the patient has a fainting spell associated with syncope or not, as the outcome is worse in those who have fainting spells associated with loss of consciousness.

How common are fainting spells?
Fainting spells are not uncommon and occur frequently. As much as 10-20% of the general population will have had some fainting spells and they occur more commonly in females.

What are the causes of fainting spells?
Fainting spells related to cardiovascular disease may be related to reflex syncope, orthostatic hypotension (fall in blood pressure on standing up), cardiac related heart disease or arrhythmias (abnormal heart rhythm). Reflex syncope is also commonly referred to as simple faint or vasovagal syncope.

Are there any other associated symptoms?
When the fainting spell is preceded by exercise or rapid palpitations, care should be taken for further examination.

How does it happen and what are the common causes?
It is not uncommon to have fainting spells during severe emotional stress or after prolonged squatting or sitting, and getting up suddenly after that. In fact, this is common especially in young women who already have a relatively low resting blood pressure or older patients who are on drugs for their high blood pressure or prostate problem.

Reflex syncope patients often have a long history of recurrent fainting occurring before the age of 40 and is associated with unpleasant sights, sounds, smells or pain. They are often triggered by prolonged standing especially in crowded and/or hot places or during school assemblies. They recover very quickly and are usually not associated with any head injuries. These patients (other than their fainting spells) do not have any underlying heart disease. Sometimes, there may be a history of other family members also having had fainting spells. In some reflex syncope, certain situations such as micturition (passing urine) and prolonged coughing can trigger a fainting attack.

A less common cause of fainting episodes occurs in patients with arrhythmias, due to supraventricular (abnormal rhythm arising from the upper chambers of the heart) or ventricular arrhythmias (abnormal rhythm arising from the lower chambers of the heart). These may occur in young or old patients who may or may not have underlying structural heart disease. Patients with ventricular arrhythmias and underlying heart disease are at risk for sudden cardiac death, if they have associated fainting spells.

Near fainting episodes in older patients may be associated with the sick sinus syndrome (see figure below). Classically, these patients have palpitations due to atrial fibrillation (type of rapid irregular rhythm) with a rapid ventricular response which on termination, is followed by a pause lasting for a few seconds. Occasionally, fainting episodes are due to underlying heart disease such as valvular heart disease (e.g. aortic stenosis (narrowing of the valve) in elderly patients) or cardiomyopathies (disorders of the muscles of the heart). Fainting episodes are rarely related to underlying ischemic heart disease, due to blockages of the arteries of the heart.

Fainting due to orthostatic hypotension is usually because of drugs or dehydration, but rarely due to neurological disorders affecting the autonomic nervous system such as Parkinson’s disease.

How to diagnose the cause of fainting spells?
The difficulty in patients with fainting episodes is the diagnosis of the cause of these symptoms. They are usually so transient and unwitnessed that it is difficult to determine the exact cause. Regular blood pressure (both lying down and standing), ambulatory blood pressure monitoring, pulse and Electrocardiogram (ECG) monitoring may be helpful. A 24 to 48 hours Holter ECG monitoring can also be helpful. More prolonged event recording ECGs or the new wearable
smartwatch devices (such as ECG watches) can help to monitor any associated arrhythmia.

In some patients with recurrent vasovagal syncope especially those associated with injuries, an upright tilt test may be useful.

Finally, when it is vital to monitor the cause, an insertable loop recorder which is injected just under the skin over the left chest region provides monitoring for 2-3 years.

It is also important to determine if there is any underlying heart disease on the ECG and echocardiogram if needed. Any fainting spells associated with an underlying heart disease needs further investigations.

What are the possible treatments available?
Once the diagnosis is obtained, appropriate treatment can be done. For the majority who have slightly low blood pressure (BP) with or without vasovagal syncope, reassurance that it is benign is very helpful to allay fears that it may be more sinister. Increased salt intake and hydration is very important. Patients who are taking blood pressure medication may need to monitor their BP regularly and if there is a demonstration of low blood pressure, they should have a discussion with their doctors to reduce the dose of their medication.

In patients who have rapid arrhythmias, drug treatment or catheter ablation can be considered. Patients with underlying heart disease need treatment of the disease and if there is an arrhythmia associated with fainting spells, an implantable cardioverter defibrillator may be needed. In older patients with sick sinus syndrome, a permanent pacemaker may be needed.

Can it be prevented?
Patients who tend to have low blood pressure should avoid getting up suddenly after prolonged sitting or lying down. When fainting spells are associated with near vasovagal syncope, physical manoeuvers such as crossing one’s legs and arms may help. If not, lying down immediately with the legs up may abort the full fainting episode.

Maintaining a healthy lifestyle and prevention of heart disease and heart failure is very important, as failure to do so can often lead to arrhythmias later on in life which can result in fainting spells.