A recent case has captured attention: a woman, living a healthy life, began experiencing dizziness every time she swallowed food. This eventually escalated to a severe situation where she would lose consciousness and faint during every meal. The cause of these symptoms was a rare condition known as cardiac inhibitory syncope of deglutition.

What is Cardiac Inhibitory Syncope of Deglutition?

Cardiac inhibitory syncope of deglutition is a condition where heart rate drops drastically or the heart temporarily stops, leading to fainting during the act of swallowing food. With fewer than 150 documented cases worldwide, it is an exceptionally rare condition. Patients may experience symptoms such as dizziness, cold sweats, blurred vision, and loss of consciousness when they swallow.

How Does It Occur?

The primary cause of this condition lies in an exaggerated vagal reflex triggered by swallowing. Normally, when we swallow, nerve signals are sent to the brain, and the vagal nerve activates to aid digestion. However, in individuals with cardiac inhibitory syncope of deglutition, this response is excessively strong, suppressing the sinoatrial (SA) node and atrioventricular (AV) node, which regulate heart rate. This causes the heart rate to slow down significantly or stop temporarily. Consequently, blood pressure also drops, leading to reduced blood flow to the brain and subsequent fainting.

Symptoms and Diagnosis

Symptoms can vary depending on the type of food consumed. For instance, symptoms might worsen when eating cold beverages, carbonated drinks, hot foods, or large chunks of food. Patients experiencing these symptoms can face significant disruptions in their daily lives.

• Dizziness
• Cold sweats
• Blurred vision
• Loss of consciousness

Diagnosis is typically made through electrocardiogram (ECG) tests and 24-hour Holter monitoring, which help identify the correlation between food intake and changes in heart rhythm.

Treatment Methods

Treatment varies depending on the severity of symptoms, and may involve avoiding trigger foods or attempting medication. However, the effectiveness can be limited in many cases. In the past, the implantation of a pacemaker was the primary treatment. More recently, cardioneural ablation has emerged as a promising new therapeutic approach. This procedure involves removing nerve cells that transmit excessive vagal signals to the heart, thereby reducing the abnormal reflex. Recent studies have reported a significant decrease in fainting episodes among patients who have undergone this procedure.

While cardiac inhibitory syncope of deglutition is a rare condition, it can be managed with proper diagnosis and treatment. Remember that even patients with rare symptoms can find positive changes and hope.