Arrhythmogenic Cardiomyopathy - An Overview

Introduction:

An uncommon hereditary condition known as arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) can result in ventricular tachycardia and unexpected heart mortality in young, seemingly healthy people. Ventricular arrhythmias are the disease's primary clinical feature, primarily originating from the right ventricle. Fibrofatty replacement of the right ventricle is the disease's pathological characteristic.

What Is Arrhythmogenic Cardiomyopathy (ACM)?

The disease known as arrhythmogenic cardiomyopathy (ACM) affects the myocardium, the heart's muscular wall. Myocytes, the cells that make up the heart muscle, perish when there is a deficiency in the proteins that link them. Fatty cells and scar tissue take their place. Arrhythmic right ventricular cardiomyopathy (ARVC) or Arrhythmogenic Right Ventricular Dysplasia (ARVD) is a subtype of ACM that disproportionately affects the right ventricle. The heart muscle weakens with age and finds it more difficult to pump enough blood that is rich in oxygen to the body's other organs. Arrhythmogenic cardiomyopathy over time may result in the following:

• Irregular heartbeat, heart rhythm, and arrhythmia.

• Heart attack.

• Unexpected cardiac death.

What Are the Causes of Arrhythmogenic Cardiomyopathy?

• Arrhythmogenic cardiomyopathy often runs in families, albeit there is a wide range in the severity of the disease in any given family.

• The term arrhythmogenic right ventricular cardiomyopathy originated from the long-held belief that arrhythmogenic cardiomyopathy exclusively affected the right ventricle.

• There were reports of multiple patients and families with the left ventricular dominant disease in 2008. Since then, scientists have discovered that desmoplakin is linked to the left-dominant version of the illness, and a protein known as plakophilin 2 is more frequently connected with AVRC.

What Are the Symptoms of Arrhythmogenic Cardiomyopathy?

In the early stages, ACM can not show any symptoms. Usually starting in adulthood, the symptoms get worse with time. Among them are:

• Arrhythmias include ventricular fibrillation, ventricular tachycardia, premature ventricular contraction, and atrial fibrillation.

• Weary.

• Palpitations, or a beating or fluttering sensation in the chest.

• Dizziness.

• A person was losing consciousness.

• Breathlessness due to the accumulation of fluid in the lungs.

• Swelling in the legs, belly, ankles, or feet.

What Is the Diagnosis?

The symptoms of arrhythmogenic cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy might be confused with those of other illnesses; diagnosis can be challenging. Frequently, dilated cardiomyopathy is the incorrect diagnosis. The doctors at Penn Medicine have decades of experience identifying ACM, ARVC, and other cardiomyopathies. Penn evaluation may consist of the following:

• Physical Examination and Medical History: The patient will be questioned in-depth regarding personal and family medical histories. Next, one perform a comprehensive analysis to detect ACM traits.

• Blood Tests: Laboratory tests can determine the amount of iron in the blood or identify indicators of infections, thyroid disorders, autoimmune diseases, and other illnesses.

• Cardiac Catheterization: This test gauges the pressure within and surrounding the heart's structure.

• Echocardiogram: An Echocardiogram, or "Echo," is a test that employs sound waves to image the heart's anatomy.

• Electrocardiogram (ECG): This test records the heart's electrical impulses and looks for irregular rhythmic or rate patterns.

• Study of Electrophysiology: An electrophysiologist passes a tiny tube into a blood vessel and the heart to assess electrical activity in the heart. This test can be used to estimate the chance of unexpected death.

• Genetic Testing and Counseling: ACM may include mutations in at least 13 genes, the most prevalent of which is PKP2. Genetic counseling ought to be provided to anybody undergoing genetic testing. A qualified counselor assists in comprehending the procedure and its potential implications for a family.

• Holter Monitor: This wearable technology tracks the heart's electrical activity while conducting regular business.

• Implantable Loop Recorder: This tiny gadget is inserted beneath the skin to identify arrhythmia and record the heart's electrical activity.

• Additional Imaging Tests: One can capture heart images using various techniques, such as radionuclide testing, CT, MRI, and more.

• Stress Test: Also known as an exercise test, this examination gauges the heart's performance while jogging or walking on a treadmill.

What Is the Role of Inflammation in Arrhythmogenic Cardiomyopathy?

Histopathologic examination of the ventricular myocardium after death or research on transgenic animals has revealed the presence of inflammatory infiltrates (primarily T-cells) among dying myocytes, raising concerns about the immune system's involvement in the condition's etiology.

• Early on in its course, arrhythmogenic cardiomyopathy may emerge as severe chest discomfort and a "Hot Phase" of troponin release, which is similar to the infarct-like appearance of certain clinically suspected myocarditis.

• Autoantibodies have been observed in both arrhythmogenic cardiomyopathy patients and their family members, with a positive status being more common in a familial pattern than in a sporadic one.

• It is unknown whether inflammation contributes to or results from cardiomyocyte apoptosis in arrhythmogenic cardiomyopathy. Pharmacologic research on the biological pathway causing cardiac inflammation has been spurred by the growing interest in the immune system's role in the disease's pathophysiology.

What Is the Treatment?

Regular monitoring can assist in spotting arrhythmogenic cardiomyopathy issues before the negatively impact health. Depending on illness and symptoms, several treatments are used. The following medications are used to treat ACM:

1. Angiotensin II receptor blockers or angiotensin-converting enzyme (ACE) inhibitors lessen the stress on the heart.

2. Antiarrhythmic drugs regulate the heartbeat's rhythm and pace. Beta-blockers decrease the heart's contraction force and rate.

3. Blood thinners to avoid stroke and clotting.

4. Diuretics, or water tablets, lower the accumulation of fluid.

Some ACM or ARVC patients require operations or surgery, including:

• Cardioversion is bringing the heart's pace and rhythm back to normal by shocking it with electricity.

• Radiofrequency ablation, also known as catheter ablation, is a technique that employs energy to eliminate damaged cardiac tissue and aberrant electrical signals that cause arrhythmias.

• Implantable cardioverter defibrillators (ICDs) and pacemakers are devices used to control the rhythm and rate of the heart.

• Advanced instances may require heart transplantation using a deceased donor's heart.

Conclusion:

Ventricular dilatation and dysfunction, along with progressive scarring of the ventricular myocardium, are the hallmarks of arrhythmogenic cardiomyopathy. Opportunities to redefine illnesses and test novel treatments are growing. With several hereditary and non-genetic etiologies, AC is a prime example of a heterogeneous family of illnesses that may be treated with current and future therapeutics that aim to halt, reverse, or even prevent disease.