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
- 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
Diagnosis
History
- Fatigue
- Failure to thrive/weight loss
- Dizziness
- Syncope
- Exercise intolerance
- Chest pain (secondary to RV ischemia)
- Palpitations
- Hemoptysis
Alert
Hemoptysis is a life-threatening emergency and heralds a poor prognosis for any patient with PH.
Physical Exam
- Tachycardia
- Parasternal RV impulse
- Cyanosis may be evident.
- Hepatomegaly, jugular venous distention, peripheral edema
- A loud, narrowly split or single 2nd heart sound (P2); RV gallop; holosystolic murmur right of the sternum (tricuspid regurgitation); and/or diastolic murmur at the left upper sternal border (pulmonary insufficiency)
Alert
In the newborn period to puberty, an abnormally increased RV impulse is best felt under the xiphoid sternum.
Diagnostic Tests & Interpretation
Lab
- Brain-type natriuretic peptide is an excellent biomarker of RV diastolic dysfunction and is elevated with worsening cor pulmonale.
- Decreased PaO2, increased PaCO2, and a compensatory metabolic alkalosis
- Polycythemia may be consistent with chronic hypoxemia.
Imaging
- Chest radiograph: cardiomegaly from RV dilation and main pulmonary artery enlargement
- Echo: RV dilation, tricuspid annular plane systolic excursion (TAPSE), RV hypertrophy, pulmonic insufficiency, RV pressure estimate from tricuspid regurgitation, and/or intraventricular septal position
- Ventricular/perfusion (V/Q) scan is beneficial to rule out thromboembolic disease.
- Chest CT scan: volumes to assess lung hypoplasia, interstitial lung disease, thromboembolic disease, and large pulmonary vein disease
Diagnostic Procedures/Other
- ECG: may show right atrial enlargement, RV hypertrophy, and T-wave inversion
- 6-minute walk: measures functional capacity and limitations; 2 minute tests are reliable for those younger than 6 years old.
- Cardiac catheterization, although invasive, remains the gold standard.
- Lung biopsy is usually contraindicated in the face of PH and significant lung disease.
Pathologic Findings
- Vascular lesions (plexiform lesions)
- Parenchymal fibrotic lesions
- Concentric and eccentric remodeling
Differential Diagnosis
- Congenital heart disease with PH and right-to-left shunt (Eisenmenger syndrome)
- Obstruction of pulmonary venous return, both anatomic obstruction and left ventricular failure
- Pulmonary veno-occlusive disease
- Alveolar capillary dysplasia
Treatment
Medication
First Line
- Oxygen to keep saturations >90%
- Anticongestive medications (digoxin, diuretics)
Second Line
Vasodilator therapy with care not to worsen the intrapulmonary shunt
Additional Treatment
General Measures
- The primary goal is reduction of the abnormally elevated pulmonary artery pressure and the RV workload.
- If at all possible, address the primary etiology (i.e., tonsillectomy/adenoidectomy in a patient with obstructive upper airway disease).
- Fluid boluses are poorly tolerated and rarely augment systemic BP.
- Oxygen (nocturnal oxygen)
- Diuretics (if pulmonary congestion)
- Bronchodilators (theophylline)
- Digoxin (may improve RV contractility)
- Anticoagulants
- Pulmonary vasodilators
- Nitric oxide
- Calcium channel blockers (only if >1 year of age and cardiac output is not compromised)
- Phosphodiesterase-5 inhibitors
- Endothelin receptor antagonists
- Prostanoid
- Atrial septostomy (in select cases, may improve cardiac output but at the expense of hypoxemia)
- Lung or heart-lung transplantation
- Usually self-limited activity
- No competitive sports
- Arginine, a nitric oxide donor, has been used; however, the increased amino acid concentrations are proliferative and may worsen the long-term prognosis.
Surgery/Other Procedures
Consider tracheostomy, Nissen fundoplication, and gastrostomy tube (G-tube) early
Ongoing Care
Follow-up Recommendations
Patient Monitoring
Home oxygen saturation monitoring is indicated when night oxygen is necessary to keep saturations >90%.
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, growth, or febrile illnesses.
- Numerous medical therapies and lung transplantation may improve long-term survival.
- Long-term survival is variable and depends on the age at onset of pulmonary changes and the underlying conditions (e.g., Down syndrome) that may adversely affect survival.
- Death often occurs in the 2nd or 3rd decade of life.
Complications
Aside from the underlying lung process, the chronic hypoxia results in polycythemia, decreased systemic oxygen delivery, and RV failure secondary to the inability of the RV to handle the excessive afterload.
Additional Reading
- Bandla HP, Davis SH, Hopkins NE. Lipoid pneumonia: a silent complication of mineral oil aspiration. Pediatrics. 1999;103(2):E19. [View Abstract]
- Brouillette RT, Fernback SK, Hunt CE. Obstructive sleep apnea in infants and children. J Pediatr. 1982;100(1):31-40. [View Abstract]
- Cerro MJ, Abman S, Diaz G, et al. A consensus approach to the classification of pediatric pulmonary hypertensive vascular disease: report from the PVRI Pediatric Taskforce, Panama 2011. Pulm Circ. 2011;1(2):286-298. [View Abstract]
- Koestenberger M, Revekes W, Everett AD, et. al. Right ventricular function in infants, children and adolescents: reference value of the tricuspid annular plane systolic excursion (TAPSE) in 640 healthy patients and calculation of z score values. J Am Soc Echocardiogr. 2009;22(6):715-719. [View Abstract]
- Perkin RM, Anas NG. Pulmonary hypertension in pediatric patients. J Pediatr. 1984;105(4):511-522. [View Abstract]
- Proceedings of the 4th World Symposium on Pulmonary Hypertension, February 2008, Dana Point, California, USA. J Am Coll Cardiol. 2009;54(1)(Suppl):S1-S117. [View Abstract]
- Rashid A, Ivy D. Severe paediatric pulmonary hypertension: new management strategies. Arch Dis Child. 2005;90(1):92-98. [View Abstract]
- Simonneau G, Robbins M, Beghetti M, et al. Updated clinical classification of pulmonary hypertension. J Am Coll Cardiol. 2009;54(1)(Suppl):S43-S54. [View Abstract]
Codes
ICD09
- 416.9 Chronic pulmonary heart disease, unspecified
- 415 Acute cor pulmonale
ICD10
- I27.81 Cor pulmonale (chronic)
- I26.09 Other pulmonary embolism with acute cor pulmonale
SNOMED
- 83291003 Cor pulmonale (disorder)
- 49584005 Acute cor pulmonale (disorder)
- 79955004 Chronic cor pulmonale (disorder)
FAQ
- Q: Is cardiac catheterization indicated in all patients with cor pulmonale?
- A: Yes. Although a great deal of information can be learned from echocardiogram, 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.