Myocardial Infarction With Non-Obstructive Coronary Arteries

Introduction:

The heart is the most important organ in the human body. It plays an inevitable role in pumping blood throughout the body. Any damage to the heart could have serious implications for the overall health of an individual. In recent times, many heart conditions have become more prevalent in both the younger and older populations. It could be due to the changing lifestyle, food habits, and lack of exercise that are responsible for these changes. Over the years, heart attacks and coronary artery diseases have been commonly observed in people from different geographic locations across the world.

In the initial days, most heart attacks occur due to a medical condition called myocardial infarction, in which the blood supply to the heart is drastically compromised. Due to poor blood supply, the heart may gradually lose its functionality, resulting in heart failure. The causes of poor blood supply may vary in each individual. However, obstruction to the coronary arteries is not the only cause of myocardial infarction. Non-obstructive coronary arteries also play a role in myocardial infarction. It could be due to fat deposits in the arterial walls or constant anxiety and stress contributing to the heart condition. A proper evaluation of the heart is a must to rule out all the possible causes of the improper functioning of the heart.

In most industrial countries, myocardial infarction accounts for 10 to 25 percent of all deaths, and the incidence is high in elderly people. About five percent occurs in individuals less than 40 years. Males have a higher risk than females. This article explains in detail the causes, symptoms, and treatment of myocardial infarction with non-obstructive coronary arteries (MINOCA).

What Is Myocardial Infarction?

Myocardial infarction is characterized by decreased blood flow to the heart, which is caused due to coronary artery disease. It could be due to atherosclerosis or occlusion of an artery, which is caused by an embolus (a free-floating blood clot). Myocardial infarction is irreversible damage of the myocardial tissue, which is probably caused due to poor blood flow or lack of oxygen.

What Are the Symptoms of Myocardial Infarction?

The symptoms of myocardial infarction may manifest differently in each individual. The commonly experienced symptoms are listed below:

• Chest pain.

• Discomfort spreads from the shoulder.

• Cold sweat.

• Fatigue.

• Heartburn.

• Sudden dizziness.

• Nausea.

• Shortness of breath.

• Indigestion.

What Is Myocardial Infarction With Non-obstructive Coronary Arteries (MINOCA)?

Myocardial infarction with non-obstructive coronary arteries is characterized by minimally obstructed coronary arteries. It contributes to almost ten percent of myocardial infarctions. The condition is usually determined by angiography.

What Are the Causes of Myocardial Infarction With Non-obstructive Coronary Arteries (MINOCA)?

MINOCA occurs due to coronary and non-coronary causes. The coronary causes of MINOCA are:

• Vasospastic angina.

• Coronary microvascular disorder:

  1. Coronary slow flow.

  2. Microvascular angina.

  3. Microvascular spasm.

• Coronary plaque disruption.

• Spontaneous coronary thrombosis.

• Missed obstructive coronary artery disease.

The non-coronary causes of MINOCA are:

• Myocarditis.

• Cardiomyopathy.

• Pulmonary embolism.

• Stroke.

• Sepsis.

• Renal impairment.

What Are the Symptoms of Myocardial Infarction With Non-obstructive Coronary Arteries (MINOCA)?

The symptoms of MINOCA are listed below:

• Chest pain.

• Pain in arms, neck, and jaw.

• Nausea.

• Vomiting.

• Heartburn.

• Indigestion.

• Coughing.

• Wheezing.

• Anxiety.

• Shortness of breath.

• Lightheadedness or dizziness.

What Are the Risk Factors Associated With Myocardial Infarction With Non-obstructive Coronary Arteries (MINOCA)?

Some of the risk factors associated with MINOCA are listed below:

• Increased risk of blood clotting.

• Anxiety.

• Depression.

• Cancer.

• Autoimmune diseases.

• Infectious diseases.

• Pneumonia.

• Sepsis.

• Respiratory infection.

• Hormone replacement therapy.

How Is Myocardial Infarction With Non-obstructive Coronary Arteries (MINOCA) Diagnosed?

MINOCA is usually an accidental finding when diagnosing patients with acute myocardial infarction. The doctor may advise routine blood tests. Special radiography may be performed by the doctor to confirm the condition. It is called coronal radiography, which uses a contrasting dye to help detect blockages. Other tests to confirm MINOCA include:

• Electrocardiogram - A test done to check the rhythm of the heart and electrical activity. It comprises various sensors that are attached to the skin. These sensors detect the electrical signals produced by the heart. It helps to identify abnormal functioning of the heart.

• Magnetic Resonance Imaging - An imaging technique that uses a magnet and radio signals to create radiographic images of the tissues in the body. The heart is thoroughly imaged at different levels to identify the level of obstruction and the extent of the disease. It creates a magnetic field around the body.

• Echocardiogram - An echocardiogram helps to scan the heart and the blood vessels around the heart. It is a type of ultrasound scan that produces high-frequency waves. It helps to find any blocks in the coronary arteries, which are the major blood vessels of the heart. Any obstruction to the blood flow to the heart will increase the heart rate and the overload of the heart. Hence if the doctor suspects such obstruction, he may suggest a few medications or surgeries correct the blockage and allow free blood flow.

• Coronal Optima Coherence Tomography - It is a non-invasive imaging method to obtain high-resolution images. It produces cross-sectional images of the heart. The various layers of the heart and their thickness is measured to aid in the early diagnosis of heart diseases.

What Is the Treatment for Myocardial Infarction With Non-obstructive Coronary Arteries (MINOCA)?

Depending on the underlying cause, MINOCA will be managed accordingly. The doctor may prescribe a drug or a combination of drugs to help with treatment and better recovery. Some of the commonly prescribed drugs are mentioned below:

• Beta-blockers.

• Statins.

• ACE inhibitor.

• Calcium channel blockers.

• Aspirin.

• Clopidogrel.

What Is the Prognosis for Myocardial Infarction With Non-obstructive Coronary Arteries (MINOCA)?

Although the outcome of MINOCA depends on the underlying causes, the overall prognosis of the condition is serious, with one-year mortality of about 3.5 percent. Hence, it is important that patients with MINOCA receive the same clinical attention as a single or double-vessel disease and are not merely dismissed as an insignificant clinical condition.

Conclusion:

Myocardial infarction with non-obstructive coronary arteries is one of the causes of irreversible heart damage. Management of MINOCA with medications and frequent follow-ups is essential for the betterment of the condition. Early diagnosis can aid in long-term life and better recovery of an individual and prevents further damage to the heart.