What is the cardiovascular pathophysiology of myxedema coma (crisis)?

Updated: Oct 10, 2018
  • Author: Mohsen S Eledrisi, MD, FACP, FACE; Chief Editor: George T Griffing, MD  more...
  • Print
Answer

Cardiac contractility is impaired, leading to reduced stroke volume, low cardiac output, bradycardia and sometimes hypotension. [6] Reduced stroke volume in severe cases may also be due to pericardial effusions caused by the accumulation of fluid rich in mucopolysaccharides within the pericardial sac. Congestive heart failure is rarely seen in the absence of preexisting cardiac disease.

Electrocardiographic findings may include bradycardia, varying degrees of block, low voltage, nonspecific ST-segment changes, flattened or inverted T waves, prolonged Q-T interval, and ventricular or atrial arrhythmias. [7]

The reduction of the effect of beta-adrenergic receptors leads to prevalence of the effect of alpha-adrenergic receptors, increased catecholamines, and increased systemic vascular resistance, causing some patients to have diastolic hypertension and a narrowed pulse pressure.  

Plasma volume is decreased, and capillary permeability is increased, leading to fluid accumulation in tissue and spaces and pericardial effusions. [8]


Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!