What is the Difference Between Massive and Submassive Pulmonary Embolism

The key difference between massive and submassive pulmonary embolism is that massive pulmonary embolism is the obstruction of the pulmonary artery with systemic hypotension, while submassive pulmonary embolism is the condition where individuals suffer from pulmonary embolism with right ventricular dysfunction or myocardial necrosis but without systemic hypotension.

Pulmonary embolism is a disease condition caused by the blockage of a pulmonary artery in the lungs due to a blood clot generated from deep veins in the legs that travel up to the lungs. This clot will prevent blood flow to the lungs and cause severe life-threatening conditions.

1. Overview and Key Difference
2. What is Massive Pulmonary Embolism
3. What is Submassive Pulmonary Embolism
4. Similarities – Massive and Submassive Pulmonary Embolism
5. Massive vs Submassive Pulmonary Embolism in Tabular Form
6. Summary – Massive vs Submassive Pulmonary Embolism

What is Massive Pulmonary Embolism?

Massive pulmonary embolism is the obstruction of the pulmonary artery exceeding more than 50% of the cross-sectional area, causing severe cardiopulmonary failure derived from right ventricular overload with systemic hypotension. This condition has a high mortality rate. With prompt diagnosis and therapy, the risk is reduced.

Massive and Submassive Pulmonary Embolism - Side by Side Comparison

Figure 01: Massive Pulmonary Embolism

Systemic hypotension is the key parameter in massive pulmonary embolism. Systemic hypotension is defined as systolic arterial blood pressure, which is less than 90 mmHb, or reduction in systolic arterial blood pressure for 15 min with a value of 40 mmHg. Apart from that, shock due to tissue hypoperfusion and hypoxia, including a level of altered consciousness, is also a minor parameter in the context of massive pulmonary embolism. Patients with massive pulmonary embolism are required to undergo immediate resuscitation in an intensive care management system. Patient’s vital signs and signs of clinical shock will determine the initial treatment options.

What is Submassive Pulmonary Embolism?

Submassive pulmonary embolism is the condition where individuals suffer from pulmonary embolism with right ventricular dysfunction or myocardial necrosis but without systemic hypotension. Submassive pulmonary embolism causes organ failure. Compared to massive pulmonary embolism, submassive pulmonary embolism causes minor risks in severity and mortality. Even though patients develop organ failure, they are hemodynamically stable while presenting symptoms.

Massive vs Submassive Pulmonary Embolism in Tabular Form

Figure 02: Pulmonary Embolism

Disease management is comparatively easy with no immediate requirement for resuscitation or care at intensive care management systems. However, it is vital to observe symptoms and proceed with treatment options accordingly. Thrombolytics are the primary type of treatment option available for initial phase treatment. With the onset of hemodynamic instability and worsening of prognosis, the use of thrombolytics is risky since they could induce a high risk for bleeding. Parenteral and oral anticoagulants are other pharmacological options for treatment.

What are the Similarities Between Massive and Submassive Pulmonary Embolism?

Massive and submassive pulmonary embolism occur due to a blockage of the pulmonary artery of the lung.
Blood clots are the main cause of the blockage in both conditions.
They cause severe life-threatening conditions.
Both types prevent blood flow to the lungs.
Apart from blood clots, part of a tumor, air bubbles, and fat from a portion of a long bone could be a cause for pulmonary embolism.

What is the Difference Between Massive and Submassive Pulmonary Embolism?

The key difference between massive and submassive pulmonary embolism is the presence of hypotension to bring out the symptoms. During massive pulmonary embolism, hypotension causes severe cardiopulmonary failure derived from right ventricular overload, whilst during submassive pulmonary embolism, hypotension does not cause right ventricular dysfunction or myocardial necrosis. Moreover, massive pulmonary embolism has a higher mortality rate than submassive pulmonary embolism.

The below infographic presents the differences between massive and submassive pulmonary embolism in tabular form for side by side comparison.

Summary – Massive vs Submassive Pulmonary Embolism

Pulmonary embolism is a life-threatening severe disease condition caused by a blockage of the pulmonary artery in the lung due to a blood clot. It is of two types: massive pulmonary embolism and submassive pulmonary embolism. Massive pulmonary embolism is characterized by the development of systemic hypotension. Submassive pulmonary embolism does not develop systemic hypotension. The most severe condition with a high mortality rate is massive pulmonary embolism. With prompt treatment, the risk of death can be reduced. Severe cardiopulmonary failure and ventricular dysfunction or myocardial necrosis are the effects of massive and submassive pulmonary embolism, respectively. So, this summarizes the difference between massive and submassive pulmonary embolism.

Reference:

1. Farkas, Josh. “Submassive & Massive Pe.” EMCrit Project, 29 Nov. 2021.
2. Maria Leibfried, BS. “Treatment of Pulmonary Embolism.” U.S. Pharmacist, 13 July 2018.