IT is often assumed that when someone faints, the reason is due to stress, fatigue or excessive sun exposure.
However, a sudden blackout or fainting spell – syncope in medical terminology – should never be ignored, particularly when it occurs without an obvious explanation.
Such conditions can potentially lead to serious complications if left untreated.
Recognising when a fainting episode requires medical attention can make the difference between early intervention and a potentially life-threatening event.
More than just a dizzy spell
Syncope refers to a temporary loss of consciousness caused by a sudden reduction in blood flow to the brain.
Cardiac Vascular Sentral Kuala Lumpur consultant cardiologist Dr Abdul Raqib Abd Ghani says that unlike feeling dizzy or unsteady, a person experiencing syncope loses consciousness, even if only briefly.
“It’s a transient loss of consciousness, lasting from a few seconds to less than one to two minutes,” he explains.
“Harmless blackouts are a result of vasovagal syncope, where the body’s autonomic nervous system overreacts to a trigger, which leads to a temporary drop in blood pressure and reduced blood flow to the brain.
“The result is a brief loss of consciousness. Triggers could be dehydration, stress, pain, exhaustion, heat exposure, emotional distress,” he adds.
These episodes are generally not dangerous and often resolve without long-term consequences.
Another benign cause is orthostatic hypotension when blood pressure drops upon standing.
More serious causes include cardiac syncope due to heart rhythm disorders or structural heart diseases, for example, a narrowed heart valve disease called aortic stenosis or patients with heart failure caused by previous heart attacks, as well as less common cerebrovascular conditions affecting blood flow to the brain.
As syncope may occasionally be the first sign of a potentially life-threatening cardiac condition, especially when accompanied by palpitations, chest pain, shortness of breath, or occurring during exercise, prompt medical evaluation is important, warns Dr Abdul Raqib.
Certain symptoms before a fainting episode may suggest a cardiac cause. These include:
> Palpitations or a racing heartbeat
> Chest pain or chest tightness
> Sudden light-headedness
> Recurrent episodes of unexplained fainting.
“We should also be particularly concerned when fainting occurs during physical exertion, or without any warning symptoms at all.
A family history of unexplained sudden death, heart disease or serious arrhythmias should also raise alarm and prompt further investigation,” explains Dr Abdul Raqib.
How arrhythmias cause fainting
The heart relies on a complex electrical system to coordinate heartbeat. When this system malfunctions, the heart may beat too slowly, too quickly or irregularly – what is termed as arrhythmia.
If the heart beats too slowly – a condition known as bradycardia – it may not pump enough blood to meet the body’s needs, resulting in dizziness or loss of consciousness.
On the other hand, very rapid heart rhythms (tachycardia) can also be problematic. Although the heart is beating quickly, it may not have sufficient time to fill properly between beats, reducing the amount of blood being pumped to the brain, leading to syncope, says Dr Abdul Raqib.
Syncope in younger patients can occasionally be the first sign of an inherited or structural heart condition that leads to arrhythmias.
An example is the inherited electrical disorder, Brugada syndrome, notes Dr Abdul Raqib.
Such inherited conditions may remain undetected for years and can sometimes present with fainting, palpitations, or even sudden cardiac arrest, he warns.
In older patients, conditions such as hypertension, diabetes, hyperlipidaemia and underlying heart disease can increase the risk of structural heart changes, coronary artery disease and cardiac arrhythmias.
Therefore, any unexplained blackout in these patients should be taken seriously, investigated thoroughly and treated according to the underlying cause.
There are many different types of arrhythmias. Suffice to say, a definitive diagnosis has to be made in order for effective treatment, and to prevent catastrophic complications from occurring, especially with some types of tachycardias.
The importance of early assessment
The diagnostic process often begins with relatively simple investigations.
According to Dr Abdul Raqib, a detailed history is important – symptoms before the event, how long the loss of consciousness lasted, whether there were witnesses, and how quickly recovery occurred.
A physical examination and a standard 12-lead electrocardiogram (ECG) may provide some clues to the underlying cause.
“One of the challenges in diagnosing arrhythmia-related syncope is that the abnormal rhythm may not occur frequently, hence the ECG performed in the clinic could appear completely normal. This is where longer-term monitoring is needed,” explains Dr Abdul Raqib.
“Patients might wear a Holter monitor to assess heart rhythm for a longer duration. These days, it entails a small wearable patch, in contrast to the bulky equipment of the past. This can be kept on for up to two weeks However, if symptoms occur even more infrequently, the likelihood of capturing the arrhythmia during that time may be low.
“Modern technology has introduced implantable loop recorders – small devices inserted just beneath the skin that continuously monitor the heart rhythm.
“These can be left in the patient from two to five years depending on the make of the loop recorder.
“These devices function much like a surveillance camera for the heart, recording electrical activity around the clock.
“When symptoms occur, doctors can review the stored recordings and determine whether an arrhythmia was responsible,” says Dr Abdul Raqib.
For patients with recurrent unexplained fainting, implantable monitoring devices have significantly improved the ability to reach an accurate diagnosis.
Dr Abdul Raqib observes that modern smartwatches are increasingly becoming useful tools for detecting potential heart rhythm abnormalities.
Many devices can continuously monitor heart rate and alert users to unusually fast, slow or irregular rhythms.
Although they do not replace medical-grade tests or a doctor’s evaluation, smartwatches can help capture intermittent symptoms such as palpitations that might otherwise go undocumented.
This prompts for earlier medical assessment and aids in the diagnosis of conditions such as atrial fibrillation and certain other arrhythmias.
Modern treatment options
Treatment depends on the underlying cause.
“For patients whose symptoms result from excessively slow heart rates or prolonged pauses, implantation of a permanent pacemaker may be recommended. Pacemakers continuously monitor heart rhythm and provide electrical stimulation whenever the heart rate falls below a safe level,” says Dr Abdul Raqib.
“When the problem involves excessively fast heart rhythms that are life-threatening such as ventricular tachycardia or ventricular fibrillation, both of which may lead to sudden cardiac arrest, patients may require an implantable cardioverter-defibrillator (ICD).
“Unlike a pacemaker, which treats slow heart rhythms, an ICD continuously monitors the heart and can deliver life-saving electrical therapy when dangerous arrhythmias occur.
“In effect, the device acts as an internal emergency response system, capable of detecting and treating potentially fatal rhythm disturbances within seconds.
“For other types of fast heart rhythms, treatment may require catheter ablation. This minimally invasive procedure targets and eliminates abnormal electrical pathways in the heart responsible for the arrhythmia.
“Catheter ablation can be highly effective for a few different types of arrhythmia, and for many patients, it offers the possibility of a long-term solution without the need for lifelong medication,” he explains further.
According to Dr Abdul Raqib, in younger patients (less than 40 years old) with recurrent fainting caused by excessive autonomic nervous system activity rather than disease of the heart’s electrical system itself, a newer procedure known as cardioneural ablation (a form of catheter ablation that targets specific nerve clusters within the heart) reduces excessive vagal activity and helps reduce abnormal reflex responses and prevent recurrent syncope.
Treatments continue to evolve for the better, and that can only benefit patients who require such therapy, notes Dr Abdul Raqib.
Protecting those at risk
Most fainting episodes are not caused by dangerous heart conditions. Nevertheless, unexplained syncope should never be dismissed as simple stress or exhaustion without proper assessment.
Modern medicine offers a wide range of diagnostic and treatment options, from implantable monitoring devices to pacemakers, implantable defibrillators and catheter ablation.
The key is recognising that a blackout may sometimes be more than just a passing episode. When it comes to unexplained fainting, seeking timely medical attention could save a life.
“Do not ignore fainting during exertion, fainting accompanied by palpitations, or fainting when you have an underlying heart condition, or you have a family history of heart disease, arrhythmia or sudden death.
“Consult a doctor to make sure there’s no underlying harmful cause for the fainting episode. It may save your life or the lives of your loved ones,” emphasises Dr Abdul Raqib.
Cardiac Vascular Sentral Kuala Lumpur
Jalan Stesen Sentral 5,
Kuala Lumpur Sentral,
50470 Kuala Lumpur.
KKLIU 2736 / EXP 31.12.2028
