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| Cor Pulmonale | ||
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Mitchell I. Cohen
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Database Differential Diagnosis Data Gathering Physical Examination Laboratory Aids Therapy Follow-Up Common Questions and Answers Bibliography |
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DEFINITION
Cor pulmonale is right ventricular (RV) failure secondary to an altered cardiopulmonary process, resulting in excessive pulmonary artery pressure and resistance (PVR). Cor pulmonale is not the result of a primary congenital heart defect.
CAUSES
PATHOPHYSIOLOGY
Chronic hypoxia is the principal factor, resulting in a cascade of endothelial dysfunction with pulmonary vasoconstriction, followed by the development of pulmonary hypertension. A variety of vasoactive mediators may be responsible for the effect on vasomotor tone. Alveolar hypoventilation, hypoxemia, hypercarbia, and acidemia all result in increased RV afterload and decreased RV systolic function.
EPIDEMIOLOGY
Cor pulmonale may be found at any age, but is typically due to a long-standing pulmonary process. PPHN is most often diagnosed in the second or third decade of life. There is a female predominance, and it is often diagnosed during pregnancy.
COMPLICATIONS
Aside from the underlying lung process, the chronic hypoxia results in anemia, polycythemia-decreased systemic oxygen delivery, and RV failure secondary to the inability of the RV to handle the excessive afterload.
PROGNOSIS
Patients with reversible lung disease usually have a better prognosis. Patients with cor pulmonale are at risk for sudden death because of the inability to augment cardiac output with exercise secondary to a relatively fixed PVR. Numerous medical therapies and lung transplantation may improve long-term survival.
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Congenital heart disease with pulmonary hypertension and right-to-left shunting (Eisenmenger syndrome) should be ruled out.
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HISTORY
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NONSPECIFIC TESTS
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PROGNOSIS
Long-term survival is variable because of the age of onset for pulmonary changes and the underlying conditions (e.g., Down syndrome) that may adversely affect survival. Death often occurs in the second or third decade of life.
PITFALLS
In newborns, the RV muscle mass is comparable to the LV. RV failure from pulmonary hypertension is rare in newborns. RV failure in newborns is usually a consequence of hypoxemia, ischemia, and metabolic acidosis (e.g., persistent fetal circulation).
| COMMON QUESTIONS AND ANSWERS | ||
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Q: Is cardiac catheterization indicated in all patients with cor pulmonale?
A: Yes. While a great deal of information can be learned from echocardiography, direct pulmonary artery pressure/resistance measurements require an invasive procedure. In addition, assessment of the reactivity of the pulmonary vascular bed to various agents (oxygen, prostacyclin, and calcium channel blockers) is best performed in the catheterization laboratory.
Q: Is nocturnal oxygen therapy beneficial?
A: Nocturnal oxygen has been speculated to delay the progression of cor pulmonale in some select patients with obstructive sleep hypoxemia.
ICD-9-CM 416.9
Chronic 415.0
| BIBLIOGRAPHY | ||
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Brouillette RT, Fernback SK, Hunt CE. Obstructive sleep apnea in infants and children. J Pediatr 1982;100:31.
Perkin RM, Anas NG. Pulmonary hypertension in pediatric patients. J Pediatr 1984;105:511.
Wessel DL, Adatia I, Thompson JE, Hickey PR. Delivery and monitoring of inhaled nitric oxide in patients with pulmonary hypertension. Crit Care Med 1994;22(6):930–938.
Copyright © 2000 Lippincott Williams & Wilkins
M. William Schwartz, Louis M. Bell, Jr., Peter M. Bingham, Esther K. Chung, David F. Friedman and Andrew E. Mulberg, The 5 Minute Pediatric Consult