What are the causes of hyperdynamic circulation?

From the Guidelines

Hyperdynamic circulation is primarily caused by conditions that lead to decreased peripheral vascular resistance, triggering compensatory increases in cardiac output, heart rate, and stroke volume, with anemia being a key factor, as seen in patients with β-thalassemia major, where chronic anemia results in increased cardiac index, heart rate, and stroke volume 1. The causes of hyperdynamic circulation can be categorized into several groups, including:

• Systemic vasodilation, which can be caused by liver cirrhosis, pregnancy, sepsis, and certain medications, such as calcium channel blockers and nitrates
• Conditions that reduce blood viscosity and oxygen-carrying capacity, such as anemia, which is a common cause of hyperdynamic circulation, as seen in patients with β-thalassemia major 1
• Arteriovenous fistulas or malformations, which create low-resistance pathways that increase cardiac workload
• Thyrotoxicosis, which causes hyperdynamic circulation through increased metabolic demands and direct cardiac stimulation by thyroid hormones
• Beriberi (thiamine deficiency), which leads to peripheral vasodilation and high-output cardiac failure
• Other conditions, such as Paget's disease of bone and severe anxiety states These conditions lead to a decrease in peripheral vascular resistance, which triggers a compensatory increase in cardiac output, heart rate, and stroke volume, resulting in the characteristic bounding pulses, wide pulse pressure, and warm extremities seen in hyperdynamic states, as described in the European Society of Cardiology guidelines for the diagnosis and treatment of acute and chronic heart failure 1. Key points to consider in the management of hyperdynamic circulation include:
• The importance of addressing the underlying cause of the condition
• The need to carefully manage cardiac output and peripheral vascular resistance to prevent complications, such as heart failure and cardiac arrhythmias
• The potential benefits of treatments that reduce cardiac workload and improve peripheral vascular resistance, such as beta blockers and vasopressors, although these should be used with caution in patients with certain underlying conditions, such as β-thalassemia major 1.

From the FDA Drug Label

The increased peripheral vascular resistance, an underlying cause of hypertension, results from an increase in active tension in the vascular smooth muscle. Studies have demonstrated that the increase in active tension reflects an increase in cytosolic free calcium.

The causes of hyperdynamic circulation are not directly stated in the provided drug labels. However, the labels do mention that increased peripheral vascular resistance is an underlying cause of hypertension, which can be related to hyperdynamic circulation. The increase in peripheral vascular resistance is caused by an increase in active tension in the vascular smooth muscle, which is due to an increase in cytosolic free calcium 2.

• Key points:
  • Increased peripheral vascular resistance is an underlying cause of hypertension
  • Increase in active tension in vascular smooth muscle causes increased peripheral vascular resistance
  • Increase in cytosolic free calcium causes increase in active tension in vascular smooth muscle However, the FDA drug label does not directly answer the question about the causes of hyperdynamic circulation.

From the Research

Causes of Hyperdynamic Circulation

The causes of hyperdynamic circulation can be attributed to various factors, including:

• Chronic iron deficiency anemia, which triggers physiologic adjustments leading to hyperdynamic circulation and enhanced hypoxic pulmonary vasoconstriction 3
• Portal hypertension due to chronic liver disease, which leads to increased resistance to flow and altered hepatic vascular morphology, resulting in dilatation of the portal vein and increased blood flow 4
• Splanchnic vasodilation and the opening of collateral circulation, which worsen and maintain portal hypertension, leading to the onset of the hyperdynamic circulatory syndrome 5
• Anemia, which aggravates the hyperdynamic circulation of portal hypertension, with hemoglobin concentration being an important variable for evaluating the degree of hemodynamic disturbance in patients with portal hypertension 6

Associated Factors

Other factors associated with hyperdynamic circulation include:

• Higher hepatic venous pressure gradient (HVPG) and higher hepatic blood flow (HBF), which are independently associated with higher cardiac output 7
• Presence of ascites and higher HVPG, which are independently associated with higher heart rate 7
• Lower systemic vascular resistance, which is independently associated with lower HVPG 7
• Increased levels of vasodilators such as nitric oxide, and the development of an autonomic neuropathy, which may explain the presence of vasodilatation in the presence of highly elevated levels of circulating vasoconstrictors 4