Multifocal Atrial Tachycardia - Symptoms, Causes, Diagnosis, and Treatment

Introduction

MAT, or multifocal atrial tachycardia, is a kind of arrhythmia, which means an abnormal rhythm of the heart caused by the strange electrical activity of the atrium. Generally, it occurs due to excessive signals sent to the upper part of the heart that may occur due to various underlying conditions or even a pacemaker malfunctioning. The heart is divided into four chambers. The above two chambers are the left and right atrium, and the lower two are called the left and right ventricles. A normal heartbeat originates due to an electrical impulse arising from the sinus node.

When this is altered, an unusual electric signal keeps repeating, leading to the atrium beating way too rapidly. The sinus node is a zone of peculiar cells in the upper right chamber of the heart (right atrium). This particular region is responsible for the heart to beat in a standard rhythm by creating a stable pace of electrical impulses. This steady pace can alter according to physical or emotional activity, for instance, exercise, stress, or rest. Multifocal atrial tachycardia can be understood as a repeated short circuit taking place in the sinus node as well as other foci points in the atrium resulting in the atrium contracting abnormally fast and thus raising the heartbeat to dangerously high readings. When multifocal atrial tachycardia happens for a brief period of time and halts immediately, it is referred to as paroxysmal atrial tachycardia. But if this is continuous, it is claimed as persistent atrial tachycardia.

What Is the Etiology of Multifocal Atrial Tachycardia?

Multifocal atrial tachycardia (MAT) is usually seen in patients with other medical conditions more often in respiratory and cardiac diseases. The common causes include:

• Chronic Obstructive Pulmonary Disease (COPD): MAT is most often diagnosed in patients with severe pulmonary diseases such as COPD. Chronic lung disease, hypoxia, and acidosis may cause a change in the electrical activity of the atria.

• Electrolyte Imbalances: Hypokalemia (decreased potassium levels), hypomagnesemia (reduced magnesium levels), or hypercalcemia (increased calcium levels) are known to cause MAT, though their levels may vary.

• Heart Conditions: Some of the pre-existing diseases, which increase the risk of MAT include coronary artery diseases, congestive heart failure, and valvular heart diseases.

• Medications: There are various causative agents of MAT including digitalis, theophylline, or beta-agonist drugs.

• Other Conditions: Sepsis (a condition in which the body responds differently to infections), metabolic disturbances such as hyperthyroidism, and systemic diseases are also some of the factors that may contribute to the same.

What Is the Epidemiology of Multifocal Atrial Tachycardia?

MAT is relatively rare, but certain populations are more prone to it:

• Age Group: MAT is most often seen in elderly patients and those with pre-existing medical conditions.

• Association with Lung Disease: More than 60 percent of the patients with MAT have comorbid lung disease of which chronic obstructive pulmonary disease is the most prevalent, they are not very common in people who do not have respiratory problems.

• Hospitalized Patients: More than half of the patients developed MAT during hospitalization especially the ones with severe respiratory illness or other comorbidities.

• Gender: Gender predilection is not very high, however, some of the studies point towards slightly higher frequency in the male gender, probably because of higher susceptibility to lung diseases.

What Are the Signs And Symptoms of Multifocal Atrial Tachycardia?

Few clinical manifestations are presented by a patient suffering from multifocal atrial tachycardia. On the other hand, seldom can this condition go unnoticed since it also has the tendency to not show any signs or symptoms. Below are some of the signs of atrial tachycardia.

• Weight loss.

• Abnormal functioning of the lungs.

• A fluttering feeling in the chest.

• Blacking out.

• Dizziness.

• Lightheadedness or fainting.

• Chest discomfort or chest pain.

• Palpitations.

• Shortness of breath.

• Lethargy and fatigues.

• Rapid breathing.

• Nausea and vomiting.

• Cardiomyopathy is due to the heart turning weak.

• Heart failure is a result of a combination of the above symptoms.

• Infants fail to thrive.

• Syncopal episodes.

• Tightness of the chest.

• Angina pectoris.

• Heart failure.

Who Is at Risk of Developing Multifocal Atrial Tachycardia?

Multifocal atrial tachycardia is a moderately common phenomenon seen in the senile group of society. The majority of the newly recorded cases are paroxysmal in nature. Multifocal atrial tachycardia can occur in any individual. It is equally reported in both men and women. It should be noted that there are some age factors that result in particular kinds of multifocal atrial tachycardia. Additionally, there are also some kinds of atrial tachycardia that run in families. Thus genetics can play a crucial role in acquiring this condition. Several other factors, such as underlying cardiovascular disease or a history of cardiac disorders, also play a pivotal role in getting affected.

What Are the Causes of Multifocal Atrial Tachycardia?

There are numerous reasons that have the potential to result in multifocal atrial tachycardia. Below are some of them.

• A history of cardiovascular disease.

• Congenital heart disorders.

• Episodes of a heart attack.

• Disproportionate electrolyte levels.

• Increased alcohol consumption.

• Digoxin toxicity.

• Increased intake of caffeine and caffeine-related foods and beverages.

• Methamphetamine, cocaine, and other recreational drugs.

• Stress.

• Strenuous exercise.

• Acute illness.

• Hypertension, meaning high blood pressure.

• Patients suffering from diabetes or chronic heart failure.

• COPD or chronic obstructive pulmonary disease.

• Aging.

How Is Multifocal Atrial Tachycardia Diagnosed?

The signs and symptoms of a patient generally give the idea of an underlying problem with the heart rhythm. Several medical tests are conducted to diagnose this condition.

• Recording a patient's medical history is essential to give an idea of the patient's ongoing cardiovascular condition.

• Physical examination reveals any risk factors that may be present.

• Electrocardiography measures the heart's electrical activity with the help of sensors and electric pads in the chest.

• A Holter monitor is similar to an electrocardiograph, but it records the heart activity for over two days.

• Ambulatory monitors, such as event monitors or implantable monitors, which can be taken home for up to a month, can also help diagnose atrial tachycardia.

• To understand the type of atrial tachycardia, a detailed electrophysiological heart study may be conducted by the healthcare professional. This study is generally combined with catheter ablation.

What Is the Differential Diagnosis of Multifocal Atrial Tachycardia?

MAT has clinical features that are very similar to other types of tachycardia (increased heart rate), and thus it is crucial to distinguish between MAT and other types of arrhythmias. Some key differentials include:

• Atrial Fibrillation (AFib): AFib also has a similar effect as MAT which is to induce an irregular heart rhythm. However, in AFib, the pattern of P-wave is not present while in MAT, although the pattern is present, the morphology of P-waves is different due to atrial foci.

• Atrial Flutter: Atrial flutter has a more uniform rate and a saw-tooth pattern on ECG (electrocardiogram) as compared with the irregular P wave activity in MAT.

• Sinus Tachycardia: Sinus tachycardia has a regular rhythm and all the P waves look similar and all originate from the sinus node which is not so in MAT.

• Multifocal Atrial Rhythm: This condition is like MAT but the patient has a slow pulse which is normally below 100.

A normal ECG is very helpful in diagnosing these conditions and therefore differentiation between the two. MAT is diagnosed by abnormal rhythm and at least three different P wave appearances, with a rate of more than 100 bpm.

What Is the Treatment for Multifocal Atrial Tachycardia?

The chief step toward treatment is to manage any underlying cardiac condition. This is followed by correcting the specific part of the heart that produces the wrong electrical signals. This can be done only after multiple diagnostic tools determine and locate the precise abnormality. Correction of the present cardiovascular condition generally tends to cure atrial tachycardia as well. Medications and therapy that aid in improving irregular heartbeats may then be prescribed by the healthcare professional. This is done only after a fine-tuned electrophysiological study of the heart. A surgical route is decided only if there is no alternative way to treat atrial tachycardia.

Conclusion

Multifocal atrial tachycardia is a fairly common but treatable condition where the heart produces irregular rhythms. It can cause anxiousness in the patient, but if diagnosed early, it is easily cured. Any signs or symptoms should not be ignored, and medical care must be immediately sought. Generally, atrial tachycardia goes away on its own, and people return back to their everyday lives. Alternatively, there are multiple treatment modalities present that eradicate this condition altogether. Diet and exercise play a critical role in heart health. Thus, keeping track of one’s health and weight can reduce the risk of developing atrial tachycardia.