Cardiac Syncope

21st March 2023 | Dr Boon Lim


Cardiac syncope is a type of fainting caused by various underlying heart conditions. Conditions such as bradycardia, tachycardia, and structural heart diseases like hypertrophic cardiomyopathy, aortic stenosis, and inherited cardiac diseases can lead to cardiac syncope. This article provides an overview of cardiac syncope, covering its definition, diagnosis, management options, and the overall outlook for patients with these specific cardiac conditions.

What is Cardiac Syncope?

Cardiac syncope occurs when there is a temporary interruption in blood flow to the brain due to a heart-related problem. It is primarily caused by underlying heart conditions that affect heart rhythm or structure. For abnormalities in rhythm, the heart may be pumping too fast (tachycardia) or slow (bradycardia), and both of these heart rhythm abnormalities can lead to loss of consciousness. If there is a structural problem with the heart, most commonly aortic valve stenosis, this may lower your heart’s ability to generate adequate blood flow particularly during exercise, which may lead to symptoms of exertional breathlessness, chest pain or loss of consciousness.

Understanding the specific diagnoses associated with cardiac syncope is crucial for appropriate management.

Diagnosing Cardiac Syncope

Diagnosing cardiac syncope involves a thorough evaluation by a healthcare professional, often a cardiologist. The diagnosis process may include:

– Detailed Medical History: The doctor will inquire about your fainting episodes, whether you are experiencing palpitations, shortness of breath, whether there is a past history of heart attack or heart failure, , and family history of heart disease. 

– Physical Examination: A physical examination will be conducted to assess blood pressure, heart rate, and signs of any structural abnormalities or irregular heart rhythms.

– Diagnostic Tests: Additional tests will be performed based on the suspected cardiac condition, which may include electrocardiogram (ECG), echocardiogram, exercise stress test, Holter monitor, cardiac magnetic resonance imaging (MRI),  blood pressure monitoring, and sometimes, an implantable loop recorder.

If a genetic diagnosis is suspected, your doctor may refer you to an expert in inherited heart rhythm abnormalities for genetic testing for specific conditions.

Management of Cardiac Syncope


– Pacemaker Implantation: In cases of bradycardia, where the heart beats too slowly, a pacemaker may be implanted to regulate the heart rate and prevent syncope episodes.


– Medications: Antiarrhythmic medications may be prescribed to regulate heart rhythm and prevent tachycardia-induced syncope.

-Catheter Ablation: For certain types of tachycardia, a catheter ablation procedure may be performed to selectively destroy the abnormal heart tissue causing the rapid heart rate.

Structural Heart Diseases:

– Medications: Medications may be prescribed to manage symptoms associated with structural heart diseases, such as hypertrophic cardiomyopathy or aortic stenosis.

– Surgical Interventions: Depending on the severity and specific condition, surgical procedures like myectomy, valve repair/replacement, or other corrective surgeries may be considered.

Inherited Cardiac Diseases:

– Genetic Counseling and Testing: For individuals with suspected or known inherited cardiac diseases, genetic counseling and testing can provide valuable information about the condition, risk assessment, and potential management strategies.

Outlook for Patients

The outlook for individuals with cardiac syncope varies depending on the underlying cardiac condition and its management. 

It is important to see your doctor urgently if you suspect you may have cardiac syncope, as this form of syncope can be dangerous.

With appropriate diagnosis and targeted treatments, many individuals can effectively control or reduce the frequency of syncope episodes. It is important to adhere to the prescribed treatment plan, follow lifestyle modifications, attend regular follow-up appointments, and communicate any changes in symptoms to the healthcare provider for optimal management.


Cardiac syncope is a type of fainting caused by underlying heart conditions such as bradycardia, tachycardia, and structural heart diseases like hypertrophic cardiomyopathy, aortic stenosis, and inherited cardiac diseases. By understanding the specific diagnoses associated with cardiac syncope and following the recommended management strategies, individuals can improve their quality of life and minimize the risk of syncope episodes. Seeking appropriate medical evaluation, working closely with a cardiologist, and following the prescribed treatment plan are essential for effectively managing cardiac syncope in these specific cardiac conditions.

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