Subendocardial Ischemia Vs Transmural: Know the Differences

Subendocardial Ischemia vs Transmural Ischemia: Subendocardial Ischemia and Transmural Ischemia are two types of Myocardial Ischemia that indicate varied degrees of impaired blood flow to the heart muscle. Subendocardial ischemia occurs when the deepest layer of the heart muscle, known as the Subendocardium, does not receive enough oxygen due to partial blockages or constriction of the coronary arteries. This disorder may cause brief chest pain or discomfort, which is usually precipitated by exertion or stress. In contrast, Transmural Ischemia affects the full thickness of the heart muscle, from the endocardium to the epicardium, and is frequently caused by significant blockages or complete occlusion of the coronary arteries.

Difference between Subendocardial Ischemia and Transmural Ischemia

Subendocardial Ischemia affects the inner heart layer, generating brief chest discomfort, whereas Transmural Ischemia affects the entire heart muscle, resulting in more severe and chronic chest pain, which frequently indicates a heart attack. The table below outlines the differences between Subendocardial Ischemia and Transmural Ischemia.

Browse The Best Scrubs Collection!

What is Subendocardial Ischemia?

Subendocardial Ischemia is defined as insufficient blood supply to the innermost layer of the heart muscle, known as the subendocardium. This disorder is frequently caused by partial blockages or narrowing of the coronary arteries, resulting in symptoms such as temporary chest pain or discomfort, particularly during exercise or stress. 

Features of Subendocardial Ischemia 

• Area of effect: It primarily affects the heart's innermost layer, known as the subendocardium.
• Cause: Subendocardial Ischemia is frequently caused by partial blockages or constriction of coronary arteries, which reduce blood supply to the affected area.
• Symptoms: Common symptoms include temporary chest pain or discomfort, which is usually caused by effort or stress.
• Risk Factors: Risk factors for Subendocardial Ischemia include coronary artery disease, hypertension, diabetes, smoking, and excessive cholesterol.
• Complications: If not addressed, Subendocardial Ischemia can proceed to more serious disorders including unstable angina or myocardial infarction.

• Treatment: Management involves medications to improve blood flow, lifestyle modifications (such as diet and exercise), and interventions to address underlying risk factors.

Causes of Subendocardial Ischemia 

• Coronary Artery Disease (CAD): The most prevalent cause, CAD is the accumulation of plaque within the coronary arteries, resulting in partial blockages or narrowing of these blood channels.
• Atherosclerosis: Atherosclerosis is characterized by the formation of fatty deposits (plaque) in the artery walls, which can restrict blood flow to the heart muscle and contribute to Ischemia.
• Coronary Artery Spasms: Coronary artery spasms or contractions can briefly restrict blood flow to the heart, resulting in Ischemia.
• Other Causes: Other causes of Subendocardial Ischemia include hypertension, diabetes, smoking, hyperlipidemia, and vasospastic diseases.

Symptoms of subendocardial ischemia 

• Angina Pectoris: Chest pain or discomfort that occurs during physical activity or mental stress and is relieved by rest or medication.
• Shortness of Breath: Difficulty breathing, particularly after effort or when resting flat, due to a decrease in oxygen flow to the heart muscle.
• Fatigue: Feeling exhausted, even after moderate physical effort, as the heart strains to pump adequately.
• Nausea or Indigestion: During subendocardial ischemia, some people may suffer nausea, indigestion, or a sense of fullness in their stomach.

What is Transmural Ischemia?

Transmural Ischemia is defined as insufficient blood supply affecting the entire thickness of the heart muscle, from the inner endocardium to the outside epicardium. This disorder is often caused by severe obstructions or full occlusion of the coronary arteries, which results in a considerable reduction in oxygen flow to the affected portion of the heart.

Features of Transmural Ischemia

Transmural Ischemia affects the entire thickness of the heart muscle, from the inner endocardium to the outside epicardium.

• Severe Blockages or Occlusion: It is typically caused by severe blockages or complete occlusion of the coronary arteries, resulting in a considerable reduction in blood flow to the affected area of the heart.
• Prolonged Chest Pain: Symptoms commonly include chest pain lasting more than 20 minutes and described as crushing, squeezing, or pressure-like. This chest pain is indicative of a myocardial infarction (heart attack).
• Radiating Pain: Pain or discomfort may radiate to the neck, lips, shoulders, arms (often the left arm), and back.

Causes of Transmural Ischemia

• Coronary Artery Occlusion: The complete blockage or occlusion of one or more coronary arteries caused by blood clots, atherosclerotic plaques, or debris.
• Atherosclerosis: Atherosclerosis is the progressive development of plaque within coronary arteries, resulting in narrowing and, finally, full blockage, limiting blood flow to the heart.
• Coronary Artery Thrombosis: Coronary Artery Thrombosis Coronary Artery Thrombosis is the formation of blood clots within the coronary arteries, which restrict blood flow and cause transmural ischemia.
• Coronary Artery Embolism: Coronary Artery Embolism is the blockage of the coronary arteries caused by the passage of clots or debris from other sections of the circulatory system.
•  Vasospasm: A vasospasm is a sudden constriction or spasm of the coronary arteries, which reduces blood flow to the heart muscle and causes transmural ischemia.

Symptoms of Transmural Ischemia

• Prolonged and Intense Chest Pain: Described as crushing, squeezing, or pressure-like, chest pain that lasts more than 20 minutes is an indication of a heart attack.
• Radiating Pain: Pain or discomfort might spread to the neck, jaw, shoulders, arms (often the left arm), or back.
• Shortness of Breath: Difficulty breathing, particularly during effort or at rest, may result from the heart's decreased capacity to pump adequately.
• Sweating Profusely: Cold and clammy sweat may accompany chest pain or discomfort.
• Weakness and Weariness: Reduced blood flow and oxygen supply to the heart muscle can cause feelings of weakness, weariness, and lightheadedness.

Shop Best Lab Coats From Here!

Similarities between Subendocardial ischemia and transmural ischemia

Subendocardial Ischemia and Transmural Ischemia are both kinds of Myocardial Ischemia, which occur when the heart muscle does not receive enough blood supply. There are several similarities between the two.

• Cardiac Event: If left untreated, both diseases can cause serious cardiac events such as unstable angina, myocardial infarction (heart attack), and sudden cardiac death.
• Risk Factors: They have similar risk factors, such as hypertension, diabetes, smoking, obesity, high cholesterol, sedentary lifestyle, and a family history of cardiovascular disease.
• Symptoms: While the degree and length of symptoms vary, both can include chest pain or discomfort, shortness of breath, nausea, sweating, and exhaustion.

In conclusion, while both Subendocardial Ischemia and Transmural Ischemia are types of myocardial ischemia caused by insufficient blood flow to the heart muscle, they differ in terms of depth of involvement, severity of symptoms, and therapeutic options. Subendocardial Ischemia affects the heart muscle's innermost layer and is frequently connected with coronary artery partial blockages, which cause brief chest pain or discomfort. Transmural Ischemia, on the other hand, affects the full thickness of the heart muscle and is generally caused by major blockages or complete occlusion of the coronary arteries, resulting in more severe and protracted chest discomfort, indicating a heart attack. Prompt detection and effective management are critical for preventing complications and improving outcomes for patients with either illness.

Order the Best Jogger Scrub From Here!