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 1015 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 centralorigin). 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 R55%, 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