What changes occur in stages II and III of circulatory insufficiency?

In stage II circulatory insufficiency, signs of disorders (dyspnea, tachycardia, etc.) are detected at rest, ranging from moderate to severe. In stage III (terminal stage), significant cardiac and hemodynamic impairments occur at rest, along with dystrophic and structural changes in organs and tissues.

Which rheological properties of blood influence the development of circulatory insufficiency?

Impairments in blood viscosity and fluidity affect the development of circulatory and microcirculatory insufficiency. Increased viscosity, aggregation of formed elements (erythrocytes and platelets), and the sludge phenomenon lead to impaired capillary perfusion, microthrombosis, stasis, and tissue hypoxia.

What is the difference between compensated and uncompensated circulatory insufficiency?

In the compensated form, signs of disorders are detected exclusively under exertion. In the uncompensated stage, hemodynamic disturbances are detected even at rest.

How fast does acute circulatory insufficiency develop?

The acute form of pathology develops extremely rapidly—within a few hours or up to one day. The chronic form requires months or years.

What changes in heart function are characteristic of the first stage of the pathology?

The initial stage (Stage I CI) is characterized by a decrease in the rate of myocardial contraction and relaxation, as well as a reduced ejection fraction.

What determines the adequate level of circulatory system functioning in health?

Optimal blood supply depends on three components: normal cardiac activity, adequate vascular tone, and blood status (its volume and rheological properties).

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Pathology of the Circulatory System

Insufficientia circulatoria

For medical students2 min readUpdated 2026-10-10

Circulatory insufficiency is a typical pathological state in which the cardiovascular system fails to provide organs and tissues with an optimal volume of blood. The development of this condition is associated with impaired cardiac function, altered vascular tone, or blood pathology.

Main criterionInability of the system to provide tissues with adequate blood supply

Risk factorsImpaired cardiac function, vascular tone, and blood properties

Acute formDevelops rapidly: from a few hours up to one day

Initial stageDecreased ejection fraction and myocardial contraction velocity

Physiological Norm and System Components

Under normal physiological conditions, the circulatory system ensures the optimal and uninterrupted supply of organs and peripheral tissues with adequate blood flow. For this complex mechanism to function without failure, coordinated work of several key components is required.

There are three fundamental components that strictly determine the adequate functioning of the entire hemodynamic system:

Cardiac activity. The myocardium acts as the primary pump, and any deviations in its contractility instantly affect systemic blood flow.
Vascular tone. The vascular bed must adequately respond to the body's demands by altering its lumen to redistribute blood flow.
Blood status. Two aspects are critical here: first, the total and circulating blood volume; second, its rheological properties (fluidity, viscosity).

Essence of Circulatory Insufficiency

Any impairment in even one of the aforementioned links (cardiac, vascular, or blood-related) inevitably triggers a cascade of pathological reactions. The result of such a failure is the development of circulatory insufficiency (CI).

From the perspective of pathophysiology, circulatory insufficiency is defined as a typical form of pathology of the circulatory system. The main characteristic of this condition is that the system fully or partially loses its ability to meet the metabolic needs of tissues and internal organs for optimal blood supply.

Classification Criteria

For accurate diagnosis and understanding of pathogenesis, circulatory insufficiency is differentiated according to several strict criteria. In modern practice, four main classification vectors are distinguished:

By the degree of compensation for the resulting disorders.
By the acuteness of the pathological process and its clinical course.
By the severity of clinical and functional signs (stages).
By the predominant involvement of specific structures within the circulatory system.

Types of Circulatory Insufficiency

Depending on the rate of development and the degree of adaptation, the pathology is divided into several forms.

By degree of compensation:

Compensated CI. In this form, signs of circulatory disorders do not manifest at rest. They are detected only under exertion, when tissue demand increases and the system cannot meet it.
Uncompensated CI. A more severe variant where signs of circulatory impairment are clearly detected in the patient even at rest.

By acuteness of the course:

Acute form. Characterized by extremely rapid development. Pathological changes develop within a few hours or days.
Chronic form. Characterized by gradual development. The pathology forms over several months, or in some cases, years.

Characteristics of the Initial Stage

Based on symptom severity, three sequential stages of insufficiency are traditionally distinguished.

Stage I (Initial, or Stage I CI) At this stage, pathological changes are just beginning to form, but they already affect myocardial performance indicators. The first stage is characterized by the following functional deviations:

Decreased rate of myocardial contraction.
Decreased rate of myocardial relaxation.
Decreased ejection fraction—an indicator reflecting the heart's pumping efficiency.

Mnemonic

To remember the three main causes of circulatory insufficiency, use the "Three C's" rule: Cardiac function (myocardium), Caliber/tone of vessels (vascular tone), and Circulating blood (status, volume, and rheological properties of blood).

Frequently asked questions

What changes occur in stages II and III of circulatory insufficiency?: In stage II circulatory insufficiency, signs of disorders (dyspnea, tachycardia, etc.) are detected at rest, ranging from moderate to severe. In stage III (terminal stage), significant cardiac and hemodynamic impairments occur at rest, along with dystrophic and structural changes in organs and tissues.
Which rheological properties of blood influence the development of circulatory insufficiency?: Impairments in blood viscosity and fluidity affect the development of circulatory and microcirculatory insufficiency. Increased viscosity, aggregation of formed elements (erythrocytes and platelets), and the sludge phenomenon lead to impaired capillary perfusion, microthrombosis, stasis, and tissue hypoxia.
What is the difference between compensated and uncompensated circulatory insufficiency?: In the compensated form, signs of disorders are detected exclusively under exertion. In the uncompensated stage, hemodynamic disturbances are detected even at rest.
How fast does acute circulatory insufficiency develop?: The acute form of pathology develops extremely rapidly—within a few hours or up to one day. The chronic form requires months or years.
What changes in heart function are characteristic of the first stage of the pathology?: The initial stage (Stage I CI) is characterized by a decrease in the rate of myocardial contraction and relaxation, as well as a reduced ejection fraction.
What determines the adequate level of circulatory system functioning in health?: Optimal blood supply depends on three components: normal cardiac activity, adequate vascular tone, and blood status (its volume and rheological properties).

Go deeper

Characteristics of stages II and III of circulatory insufficiency
Predominant involvement of specific structures of the circulatory system
Influence of blood rheological properties on pathology development
Mechanisms of changes in total and circulating blood volume
Pathogenesis of reduced ejection fraction in the initial stage of CI