Syncope is the medical term for fainting, referring to a total loss of consciousness. In the context of a heart condition, it is known as cardiac syncope, though syncope in general may also be due to an extensive range of other causes. Arrhythmia, an abnormal heartbeat, is a common cause of cardiac syncope. Syncope can also be caused by low blood pressure, such as that caused by dehydration or medication.
Arrhythmia refers to a group of conditions characterised by an abnormal heartbeat, typically arising from a defect in the electrical signals that coordinate each contraction and relaxation of your heart muscle. Arrhythmias can be categorised based on your heart rate, the regularity of your heartbeat, and the origin of the abnormal electrical signal.
Some common types of arrhythmia include:
Not all types of arrhythmia are problematic. Some irregular heart rhythms, such as an ectopic heartbeat, where your heart skips a beat or adds an extra beat, are common and typically harmless. However, others present a life-threatening concern and need urgent attention.
Not all forms of arrhythmia present with noticeable symptoms, and may only be detected during a health check for something else. Some arrhythmic episodes, such as heart palpitations, an ectopic beat, or tachycardia, are transient and triggered by intense emotions, stress, or certain stimulating substances like caffeine. However, it can be difficult to know whether an abnormal heart rhythm is harmless or concerning, or if the arrhythmia is a symptom of another underlying condition.
It is recommended to see a doctor if you experience any arrhythmia symptoms such as:
Depending on the type of arrhythmia, you may also feel a pounding or fluttering sensation in your chest, a racing heartbeat, or a slow heartbeat.
Arrhythmia is associated with syncope because an abnormally beating heart is unable to pump blood effectively. Reduced oxygen supply to the brain, even for as short as five seconds, can cause it to temporarily shut down and result in a loss of consciousness. Syncope specifically associated with arrhythmia is known as arrhythmic syncope.
Other causes of fainting can range from simple emotional overwhelm or excitement to more serious conditions that cause a sudden reduced blood supply to the brain. Vasovagal syncope is a common cause of fainting, including among people with no health problems. Vasovagal syncope may be triggered by stressors such as intense emotions, dehydration, standing for too long, pain, or seeing blood. Syncope may also be caused by standing up too suddenly (postural hypotension), a blockage to blood flow to the brain such as from heart valve disease, or from a condition known as postural orthostatic tachycardia syndrome (POTS).
Syncope in itself is not harmful, though may cause injury if you lose consciousness during an activity such as driving or climbing a staircase. Although fainting is a common occurrence and as many as one in two people will experience an episode at some point in their lives, it is important to see a doctor to investigate the underlying cause if it is recurrent or associated with other symptoms.
Arrhythmia is associated with a number of medical conditions, both cardiovascular disease and other conditions not specific to the heart. Arrhythmia may also be a result of lifestyle factors, such as smoking, excessive alcohol consumption, and recreational drug use. Older adults are more likely to experience arrhythmia, as are individuals who are overweight.
Health conditions that can cause arrhythmia include:
Treatment for arrhythmic syncope is focused on managing the underlying heartbeat irregularity. Not all cases of arrhythmia require intervention, but if your type of arrhythmia is life-threatening or is causing severe symptoms that interfere with your daily life, your cardiologist may recommend treatment with medication, an implantable device, or a heart procedure.
Medications such as beta-blockers can help to slow your heart rate to a normal pace if you have tachycardia. Other anti-arrhythmic drugs may help keep your heart in a normal rhythm. If you have an elevated risk of stroke from arrhythmia, you may be prescribed blood thinners to mitigate this risk.
Electrical cardioversion involves delivering a controlled electric shock to your chest to reset the heart’s electrical activity and restore a normal rhythm. It is performed under sedation, and is often considered for atrial fibrillation and atrial flutter.
Catheter ablation is a minimally invasive procedure involving targeted destruction (ablation) of the area of the heart delivering the abnormal electrical signals. It may be helpful for treating atrial fibrillation, atrial flutter, supraventricular tachycardia, or ventricular tachycardia.
Implantable devices for arrhythmia include a pacemaker or an implantable cardiac defibrillator (ICD). A pacemaker delivers a continuous electrical signal to maintain a regular heartbeat while an ICD monitors your heart rhythm and provides an electrical impulse to reset the rhythm if it detects an abnormality. Both devices are implanted under the skin and are intended to remain long-term.
At Harbourside Cardiology, our team is dedicated to providing holistic, patient-centred care that aligns with the most recent clinical guidelines and research. We are with you every step of your health journey, providing continuity of care of all heart conditions from initial assessment through to treatment and recovery.
