Cor Pulmonale Disease

BASICS

DESCRIPTION

Right ventricular enlargement/dysfunction and failure caused by pulmonary hypertension (increased right ventricular afterload) secondary to diseases of the lung, thorax, and pulmonary vasculature.

Acute cor pulmonale: acute dilatation or overload of the right ventricle secondary to massive pulmonary embolism
Chronic cor pulmonale: hypertrophy and dilatation of the right ventricle resulting from diseases of the pulmonary parenchyma and/or pulmonary vasculature (most commonly COPD)
System(s) affected: Cardiovascular, Pulmonary, Renal/Urologic
Genetics: No known genetic pattern
Incidence/Prevalence in USA: 5-10% of adult heart diseases
Predominant age: >45
Predominant sex: Male > Female

SIGNS AND SYMPTOMS

Acute cor pulmonale:
- Severe dyspnea
- Pallor
- Diaphoresis
- Jugular venous distention with inspiration (Kussmaul's sign)
- Systolic murmur loudest at left sternal border (tricuspid regurgitation)
- Distended, tender, pulsatile liver
- S3 gallop
- Hypoxemia
- Cardiovascular collapse because of right ventricle's low output state
Chronic cor pulmonale:
- Tachypnea/shortness of breath not relieved by sitting upright
- Productive or nonproductive cough
- Chest pain secondary to pulmonary artery root dilatation and right ventricular ischemia
- Hepatomegaly
- Peripheral edema
- Cyanosis
- Right ventricular systolic heave
- Pulmonary ejection click
- S3 gallop that increases with inspiration
- Jugular venous distention with prominent a- and v-waves
- Systolic murmur of tricuspid regurgitation
- Diastolic murmur of pulmonary regurgitation
- Right ventricular failure (indicated by increased venous pressure, edema, hepatojugular reflux, worsening tricuspid regurgitation, right ventricular pulsus alternans, development of S3 and S4).

CAUSES

Disease affecting pulmonary air spaces
- Diffuse interstitial lung diseases: idiopathic pulmonary fibrosis, radiation induced fibrosis
- Pulmonary resection
- Chronic obstructive pulmonary diseases (chronic bronchitis, emphysema, asthma)
- Granulomatous and connective tissue diseases: sarcoidosis, rheumatoid arthritis, systemic lupus erythematosus, eosinophilic granuloma, mixed connective tissue disease
- Bronchiectasis
- Cystic fibrosis
- Malignant infiltration
- Chronic hypoxia at high altitude
- Congenital structural defects
Diseases affecting the pulmonary vasculature
- Primary pulmonary hypertension
- Pulmonary embolism
- CREST
- Tumor embolism
- Amniotic fluid embolism
- Schistosomiasis
- Sickle cell disease
- Pulmonary vascular disease secondary to systemic illness
- Human immunodeficiency virus
- Granulomatous pulmonary arteritis
- Chronic liver disease
- Intravenous drug abuse
Diseases affecting thoracic cage function
- Obesity
- Kyphoscoliosis
- Neuromuscular diseases
- Sleep apnea
- Pleural fibrosis
- Idiopathic hypoventilation
Pharmacologic induction
- Appetite suppressants, including aminorex, fenfluramine, dexfenfluramine

RISK FACTORS

Tobacco abuse
Living at high altitudes
Industrial exposures

DIAGNOSIS

LABORATORY

Acute cor pulmonale: ventilation/perfusion mismatch with hypoxia and hypocarbia
Chronic cor pulmonale: pulmonary function testing shows airflow obstruction with reduced pO2 and possibly elevated hematocrit

Drugs that may alter lab results: N/A
Disorders that may alter lab results: N/A

PATHOLOGICAL FINDINGS

Evidence of underlying etiology
Dilated, hypertrophic right ventricle

SPECIAL TESTS

ECG: often normal, but findings can include:

RVH: most common in primary pulmonary hypertension. Indicated by clockwise rotation of electrical axis, right axis deviation, and P pulmonale (increased P wave amplitude in II, III, and AVF)
Right-sided heart failure suggested by:
- R/S in V1 > 1
- R/S in V6 < 1
- R wave in V1 > 5mm
- P wave in II > 2.5 mm, consistent with right atrial enlargement
Transient changes with hypoxia (arterial O2 saturation 25 mm Hg) which may include:
- Rightward mean QRS axis (shift of 30° or more from former position)
- Biphasic, flattened, or inverted T waves in the precordial leads
- ST segment depression in II, III and aVF
- Incomplete or complete (rare) right bundle-branch block

IMAGING

Chest x-ray:
- Heart size may be normal in mild to moderate disease
- There may be counter-clockwise cardiac rotation and loss of aortic knob prominence with severe disease
- In the PA view, the left heart border is mostly comprised of the right ventricle
- Pulmonary hypertension gives rise to dilatation of the pulmonary trunk and hilar vessels
Echocardiography estimates right ventricular dimensions, right atrial pressure, systolic pulmonary artery pressure, and the severity of tricuspid regurgitation. In patients with chronic cor pulmonale secondary to COPD, there may also be late diastolic LV filling secondary to RV pressure/volume overload-induced structural distortion of the left ventricle.
Thallium-201 myocardial scintigraphy and MRI can be used to diagnose right ventricular hypertrophy
MRI can be used more specifically to characterize right ventricular ejection fraction and ventricular volume, including end-systolic and end-diastolic wall sizes

DIAGNOSTIC PROCEDURES

Right heart catheterization for quantitation of ventricular and pulmonary pressures and exclusion of congenital heart disease as etiology of right heart failure. Lung biopsy also helpful in discriminating among granulomatous and collagen-vascular diseases.

TREATMENT

APPROPRIATE HEALTH CARE

Acute cor pulmonale: ICU setting
Chronic cor pulmonale: outpatient

GENERAL MEASURES

Vigorous antibiotic treatment of acute respiratory tract infections
Avoidance of airway irritants (eg, tobacco smoke), sedatives and tranquilizers
Treatment of underlying pulmonary disease, for example:
- Chronic obstructive pulmonary disease
  - Bronchodilators to relieve obstruction
  - Supplemental oxygen to correct hypoxia and acidemia
  - Vasodilators, diuretics and phlebotomy (when HCT 55-60%) are possibly useful
  - Digoxin with concomitant left ventricular failure
- Ventilatory abnormalities, eg, sleep apnea
  - CPAP (continuous positive airway pressure) or BiPAP (biphasic positive airway pressure)
  - Progestins
  - Tracheostomy
Acute or chronic thromboembolic disease
- Appropriate anticoagulation and hemodynamic support

SURGICAL MEASURES

N/A

ACTIVITY

As tolerated

DIET

Moderate salt restriction

PATIENT EDUCATION

Signs of COPD exacerbation
Sudden unilateral swelling of lower extremity in patient with hypercoagulability
Diet restrictions
Signs of edema to watch for
Stress the need for adequate rest
Referral to social service agency for home care help (oxygen, suctioning, etc)
Report any signs of infections to physician
Avoid use of nonprescription medications, especially sedatives

FOLLOW UP

PREVENTION/AVOIDANCE

Discontinue tobacco use, limit exposure to inhalational irritants and allergens

POSSIBLE COMPLICATIONS

N/A

EXPECTED COURSE AND PROGNOSIS

Depends on underlying disease and degree of pulmonary hypertension. 50,000 deaths per year in US from acute pulmonary embolism. In more chronic forms of cor pulmonale, there is a 10-50% 5 year mortality which improves with supplemental oxygen. In COPD with cor pulmonale, 3 year mortality can approach 60%.
The development of an S1S2S3 on EKG, an alveolar-arterial gradient >48 mm Hg during oxygen therapy, and right atrial overload are all predictors of poor prognosis when chronic cor pulmonale is secondary to COPD

MISCELLANEOUS

ASSOCIATED CONDITIONS

Left heart failure

AGE-RELATED FACTORS

Pediatric: N/A
Geriatric: Metabolism of sedatives and narcotics may be slow, thus the respiratory drive of these patients may be affected for prolonged periods
Others: N/A

PREGNANCY

Cardiology consultation indicated as the consequences of increased demand for placental perfusion may be severe

OTHER NOTES

N/A

ABBREVIATIONS

N/A

Clinical Investigations

ROLE OF HOMOEOPATHY

Holistic healing that treats the person, not just the disease. Experience gentle, lasting wellness with expert constitutional care.