Sinoatrial Node Dysfunction Differential Diagnosis Table

Sinoatrial Node Dysfunction Differential Diagnosis Table:

Sinoatrial node (SAN) dysfunction is the inability of the SAN, which is the pacemaker of the heart, to make rhythms that match the physiological needs of the heart’s demands.
SAN dysfunction can lead to abnormal heart rhythm like bradycardia and sinus pause, making the patient feel fatigue, dizziness, and can lead to syncope. These symptoms can be exaggerated by exercise and stress. In some cases, alternating episodes of bradycardia-tachycardia can occur too.
SAN dysfunction can be diagnosed by ECG that shows missing P waves. Devices like Holter monitor can be used too, to show your heart activity throughout your day.

How to Distinguish Sinoatrial Node Dysfunction from Other Diseases

Distinguish Atrial Fibrillation from Sinoatrial Node Dysfunction – Diagnosis

Atrial fibrillation (AF) is an irregular heart rhythm, an increase in heart rate in the atrium. AF doesn’t usually cause any symptoms, but some patients may feel heart palpitation or fatigue. AF can either be paroxysmal where it will go away on its own or it can be a chronic condition that needs treatment. Most AF patients need anticoagulant to prevent the risk of blood clotting or stroke. Chronic AF can lead to sinoatrial node dysfunction.

• Diagnosis of atrial fibrillation is based initially on ECG where it will show missing P waves and irregular QRS complex.
• AF can be seen on echo, where stagnation of blood and abnormal heart muscle contraction can be evidence of atrial fibrillation.

“If diagnosis of Atrial fibrillation is made, other tests may be needed to know the cause of the disease like thyroid tests or blood pressure measurement.”

Distinguish Atrial Flutter from Sinoatrial Node Dysfunction – Diagnosis

Atrial flutter is an increased heart rate like atrial fibrillation, but the electrical impulses in atrial flutter are more organized and regular than that of atrial fibrillation. This condition, although leading to the risk of blood clotting and strokes, can have a heart rate of up to 300 beats per minute.

• Diagnosis of atrial flutter by ECG shows “flutter waves or F-waves,” which are very characteristic of atrial flutter, and the baseline shows a saw-tooth appearance.
• Echo is needed to show any forming thrombi that may develop in the heart because of the disease itself.

Distinguish Ventricular Tachycardia from Sinoatrial Node Dysfunction – Diagnosis

Ventricular tachycardia is an increased abnormal heart rate in the lower chambers of the heart (ventricles), and this condition can lead to a life emergency and cardiac arrest if progressed to ventricular fibrillation.

• ECG can diagnose ventricular tachycardia as it shows a wide QRS complex, unlike atrial arrhythmia.
• Echo can detect an abnormality in the heart or structural heart disease that may have caused the symptoms.

Distinguish Sick Sinus Syndrome from Sinoatrial Node Dysfunction – Diagnosis

Sick Sinus syndrome (SSS), now known as sinus node dysfunction, is a group of heart rhythm problems characterized by sinoatrial node dysfunction, leading to the same symptoms of bradycardia, dizziness, and fatigue.

• Intracardiac electrophysiology study (EPS) is a very diagnostic test for SSS; it helps detect electric signals in the heart and any abnormality in them.
• Holter monitors are very effective methods for diagnosis too, as they can monitor your heart rate and episodes of pause or sometimes tachycardia that might occur with this condition.

Distinguish Heart Block from Sinoatrial Node Dysfunction – Diagnosis

Heart block is when there’s a problem in conduction in your heart that prevents signals from transferring from atrium to ventricles to make it contract and pump blood to the body. Usually, these conduction problems don’t lead to a complete stop of signal transfer but rather slow it down. There are three types of heart block from mild to severe.

• ECG is the main diagnostic test in heart block, and it helps distinguish different types of heart block from each other.
• Holter monitor to monitor your heart signals throughout the day.

Distinguish Carotid Sinus Hypersensitivity from Sinoatrial Node Dysfunction – Diagnosis

Carotid sinus hypersensitivity is a condition in which applying pressure to the carotid artery leads to stimulation of carotid baroreceptors, which leads to bradycardia, dizziness, hypotension, and sometimes syncope.

• A simple carotid sinus massage monitor is the best diagnostic test; it’s a simple bedside maneuver that leads to stimulation of the carotid artery and monitors the occurrence of symptoms.
• Holter monitor and cardiac electrophysiologic study are usually used in diagnosis to assess your heart activity and bradycardia throughout the day.

Important Red Flags in Sinoatrial Node Dysfunction

Sinoatrial node dysfunction is a progressive disease, and without treatment, it has a low survival rate.
Most problems of sinoatrial node dysfunction come from developing arrhythmia, which can be life-threatening and fatal. Another common complication is the risk of developing a stroke, so it’s important if the patient feels any chest pain to go immediately to the emergency department.
Any unusual feeling of palpitations or dizziness during exercise should be checked, since this condition is exaggerated by exercise when cardiac demand is high.