CHRONIC COR PULMONALE

Cor pulmonale 1. Acute cor pulmonale 2. Chronic cor pulmonale

Cor pulmonale Acute cor pulmonale usually refers to the development of acute pulmonary hypertension and right ventricular overload from a massive pulmonary thromboembolic event, with subsequent development of right ventricular dilation

Chronic cor pulmonale: Definition Pulmonary arterial hypertension resulting from diseases affecting the structure and/or the function of the lungs; pulmonary arterial hypertension results in right ventricular enlargement (hypertrophy and/or dilatation) and may lead with time to right heart failure (Weitzenblum, 2003)

Chronic cor pulmonale: key-point - Right ventricular dilation or hypertrophy in chronic cor pulmonale is a direct compensatory effect of chronic pulmonary vasoconstriction and subsequent pulmonary artery hypertension that leads to increased right ventricular work and stress. - When the right ventricle can no longer compensate through dilation or hypertrophy, right ventricular failure occurs.

Chronic cor pulmonale: Old Definitions Hypertrophy of the right ventricle resulting form diseases affecting the structure and/or function of the lungs (WHO, 1963) Hypertrophy  alteration in the structure and function of the right ventricle (revision, 1970)

Pulmonary hypertension: Definition Pulmonary hypertension complicating chronic respiratory disease is generally defined by the presence of a resting mean pulmonary artery pressure (PAP) > 20 mm Hg. This is slightly different from the definition of primary pulmonary hypertension (PAP> 25 mmHg).

Definition In young (< 50 years) healthy subjects PAP is most often between 10–15 mm Hg.With aging there is a slight increase in PAP, by about 1 mm Hg/10 years. A resting PAP > 20 mm Hg is always abnormal.

In the “natural history” of COPD, pulmonary hypertension is often preceded by an abnormally large increase in PAP during exercise, defined by a pressure> 30 mm Hg for a mild level of steady state exercise. The term “exercising” pulmonary hypertension has been used by some authors, but the term “pulmonary hypertension” should be reserved for resting pulmonary hypertension.

Aetiology

There are three major groups of diseases which may lead to cor pulmonale: those characterised by a limitation to airflow (COPD and other causes of chronic bronchial obstruction) those characterised by a restriction of pulmonary volumes from extrinsic or parenchymatous origin (restrictive lung diseases) those where the relatively well preserved mechanical properties of the lungs and chest wall contrast with pronounced gas exchange abnormalities which are partially explained by poor ventilatory drive (respiratory insufficiency of “central”origin).

Aetiology Obstructive lung diseases: COPD (chronic obstructive bronchitis, emphysema and their association) (80-90% of cases) Asthma with irreversible airway obstruction Bronchiectasis Bronchiolitis obliterans

Aetiology Restrictive lung diseases: Kyphoscoliosis Idiopathic pulmonary fibrosis Pneumoconiosis

Aetiology Respiratory insufficiency of “central” origin: Central alveolar hypoventilation Obesity-hypoventilation syndrome (formerly, “Pickwickian syndrome”) Sleep apnea syndrome

All of the following diseases are relatively frequent causes of cor pulmonale, EXCEPT: A.Idiopathic pulmonary fibrosis B.Bacterial pneumonia C.Pneumoconiosis D.Sleep apnea E.Kyphoscoliosis

All of the following diseases are relatively frequent causes of cor pulmonale, EXCEPT: A.Idiopathic pulmonary fibrosis B.Bacterial pneumonia C.Pneumoconiosis D.Sleep apnea E.Kyphoscoliosis

Some COPD patients with pulmonary hypertension will never develop right heart failure: A.True B.False

Some COPD patients with pulmonary hypertension will never develop right heart failure: A.True B.False

Pathophysiology Anatomic factors Destruction or obstruction of the pulmonary vascular bed Functional factors Alveolar hypoxia Acute hypoxic pulmonary vasoconstriction Remodeling of the vascular bed due to chonic hypoxemia Hypercapnia and acidosis Hyperviscosity Hypervolemia secondary to polycythemia Mechanical factors Compression of alveolar vessels

Recognized mechanisms of pulmonary hypertension in chronic obstructive pulmonary disease are all of the followings, EXCEPT: A.Pulmonary vascular remodeling resulting from chronic alveolar hypoxia B.Increased pulmonary vascular resistance C.Elevated pulmonary capillary wedge pressure

Recognized mechanisms of pulmonary hypertension in chronic obstructive pulmonary disease are all of the followings, EXCEPT: A.Pulmonary vascular remodeling resulting from chronic alveolar hypoxia B.Increased pulmonary vascular resistance C.Elevated pulmonary capillary wedge pressure

Clinical Assessment  The clinical signs occur late, being observed at an advanced stage of the disease far after the development of pulmonary hypertension.  Peripheral (ankle) oedema is the best sign of RHF but it is not specific and can arise from other causes; in some patients with pulmonary hypertension, it does not occur at all.  A murmur of tricuspid regurgitation, suggesting right ventricular dilatation, is a very late sign in respiratory patients.  Accentuation of the pulmonary component of the second heart sound is only observed in patients with severe pulmonary hypertension.

Clinical Assessment: features of frank right heart failure - Ascites and peripheral edema - Pulsus paradoxus (a decrease of >10 mm Hg in systemic systolic BP during inspiration) - Prominence of the jugular veins - Sustained impulse along the lower left sternal margin (arising from RV enlargement) NB. Cardiac findings may be obscured during auscultation by chest hyperinflation and by rotation of the heart in patients with COPD

Diagnostic techniques  Chest radiography  ECG  Echo  Radionuclide assessment of RV EF  RV dimensions measured by MRI

Diagnostic techniques  Chest radiography ↑ Diameter of the right descending PA on posteroanterior projection ↑ Diameter of the left descending PA on left lateral projection Loss of retrosternal airspace on lateral films (owing to RV hypertrophy) RV silhouette often assumes lobular appearance

Diagnostic techniques: chest radiography

Diagnostic techniques  Chest radiography  ECG  Echo  Radionuclide assessment of RV EF  RV dimensions measured by MRI

ECG (high specifity, but low sensitivity) - Right ventricular hypertrophy: R.A.D. R or R’>S in V1 R<S in V6 R in V1 + S in V5 or V6 = 10 mm R in V1 = 7 mm (15 mm with RBBB) RA enlargement -S 1 S 2 S 3 syndrome -Incomplete or complete RBBB -Inverted, biphasic, or flattened T waves in precordial leads - Depressed ST segments in leads II, III, aVF

Case 1 A 76-year old man admitted for dyspnea

Case 2 A 60-year old woman with dyspnea and pulmonary hypertension in the setting of sarcoidosis

Peripheral (ankle) oedema is the best clinical sign of cor pulmonale: A.True B.False

Peripheral (ankle) oedema is the best clinical sign of cor pulmonale: A.True B.False

A normal ECG does not exclude the presence of cor pulmonale : A.True B.False

A normal ECG does not exclude the presence of cor pulmonale : A.True B.False

The non-invasive diagnosis of pulmonary hypertension is presently based on Doppler echocardiography : A.True B.False

The non-invasive diagnosis of pulmonary hypertension is presently based on Doppler echocardiography : A.True B.False

Treatment

FEV 1 (% of value at age 25) Age (years) Adapted from Fletcher C et al. Br Med J. 1977;1:1645–1648. COPD Risk and Smoking Cessation Death Disability Never smoked or not susceptible to smoke Smoked regularly and susceptible to effects of smoke Stopped smoking at 45 (mild COPD) Stopped smoking at 65 (severe COPD)

Treatment Long-term oxygen therapy (LTOT) Vasodilator treatment Other (diuretics, digitalis, phlebotomy)

Indications Absolute Pa O 2 ≤55 mm Hg or Sa O 2 ≤88% In patients with cor pulmonale Pa O 2 55–59 mm Hg or Sa O 2 ≥89% ECG evidence of P pulmonale, hematocrit >55%, and CHD Specific Indications Nocturnal hypoxemia Sleep apnea with nocturnal desaturation not corrected by constant positive airway pressure or bilevel positive airway pressure No hypoxemia at rest, but desaturation during exercise or sleep (PaO 2 <55 mm Hg) Treatment Goals Pa O 2 ≥60 mm Hg or Sa O 2 ≥90%; Appropriately adjusted O 2 dose during sleep and exercise Same as above Appropriately adjusted O 2 dose during sleep Long-Term Oxygen Therapy: Guidelines Appropriately adjusted O 2 dose during sleep Same as above

Treatment Long-term oxygen therapy (LTOT) Vasodilator treatment Other (diuretics, digitalis, phlebotomy)

Treatment Vasodilator treatment : ACEI - ARB (captopril, enelapril, losartan): despite reductions in Ppa, no improvements in RV function and exercise tolerance were detected CCB (nifedipine, diltiazem):only one third demostrated any reduction in Ppa Nitrates, prostaglandins (E 1 and I 2 i.v.), theophylline

Treatment Long-term oxygen therapy (LTOT) Vasodilator treatment Other (diuretics, digitalis, phlebotomy)

Treatment Digitalis : contraindicated unless left-sided congestive heart failure present The cardiac glycosides have been used to manage cor pulmonale for many years. The evidence, however, does not support (!) the use of digoxin in patients with cor pulmonale unless they have concurrent LV failure or arrhythmia (rapid AF).

Treatment Phlebotomy : In polycythemic patients who undergo phlebotomy, the mean Ppa decreases but the cardiac output is generally unaffected. Although rarely indicated as the sole therapy for cor pulmonale, phlebotomy might be considered for acute decompensation of cor pulmonale accompanied by severe polycythemia, or for patients who remain markedly polycythemic even after continuous oxygen therapy. Nonetheless, it is not known whether repeated phlebotomies lead to any definite long-term benefits in pulmonary hemodynamics.

LTOT has not significantly modified the life expectancy of COPD patients with cor pulmonale : A.True B.False

LTOT has not significantly modified the life expectancy of COPD patients with cor pulmonale : A.True B.False

LTOT is at present the best treatment of cor pulmonale in COPD patients: A.True B.False

LTOT is at present the best treatment of cor pulmonale in COPD patients: A.True B.False