Cor Pulmonale

Basics

Description

  • Cor pulmonale is right ventricular (RV) failure secondary to an altered pulmonary process that results in a loss of functional capillary vascular bed and in excessive pulmonary artery pressure and pulmonary vascular resistance (PVR).
  • Cor pulmonale is not the result of a primary congenital heart defect.
ALERT
  • In newborns, the RV muscle mass is comparable to that of the left ventricle.
  • RV failure from pulmonary hypertension (PH) occurs but is rare in newborns.
  • RV failure in newborns is usually a consequence of hypoxemia, ischemia, metabolic acidosis (e.g., persistent fetal circulation), and/or premature restriction/closure of the intrauterine ductus arteriosus.

Epidemiology

  • Cor pulmonale may be found at any age but is typically a result of a long-standing pulmonary process. However, severe bronchopulmonary dysplasia is an increasingly common cause of neonatal PH.
  • Primary pulmonary hypertension (PPHN) is most often diagnosed in the 2nd or 3rd decade of life with a female predominance, and it is often diagnosed during pregnancy.

Incidence

  • PPHN has an annual incidence of 2 per million.

Prevalence

  • Upward of 2 per 1,000 neonatal intensive care unit patients will develop significant cor pulmonale.
  • 2% of infants undergoing cardiac surgery will have PH, with an associated mortality of 10–20%.

Risk Factors

Genetics

  • Pediatric patients with trisomy syndromes are at high risk for PH.
  • Familial PH has been mapped to chromosome 2q32, but this is less frequently found in patients with secondary etiologies of PH.
  • Region 2q32 point mutations encode for a defective bone morphogenic receptor 2, a pulmonary vascular smooth muscle receptor that mediates proliferation.

Pathophysiology

  • Chronic hypoxia is the principal factor, resulting in a cascade of endothelial dysfunction with pulmonary vasoconstriction, followed by the development of PH.
  • A variety of vasoactive mediators may be responsible for the effect on vasomotor tone.
  • Alveolar hypoventilation, hypoxemia, hypercarbia, and/or acidemia all result in increased RV afterload and decreased RV systolic function.

Etiology

  • Parenchymal lung disease (most common)
  • Chronic obstructive pulmonary disease
    • Cystic fibrosis
    • Asthma
  • Restrictive lung disease
    • Infectious
    • Pulmonary toxins
    • Pulmonary fibrosis
    • Bronchopulmonary dysplasia (combined)
  • Upper airway diseases: tonsillar/adenoidal hypertrophy
  • Syndromes (Down, Treacher Collins)
  • Neuromuscular disorders: Duchenne muscular dystrophy
  • Chest wall deformities

Commonly Associated Conditions

  • Pulmonary vascular abnormalities
  • Collagen vascular diseases
  • Pulmonary veno-occlusive disease
  • Pulmonary thromboembolism
  • PPHN

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