L47: Pulmonary Hypertension Flashcards
Criteria for pulmonary hypertension
Mean Pulmonary Artery Pressure > 25 mmHg (at rest measured by right heart catheterisation)
Normal systolic: 15-30 mmHg
Normal diastolic: 4-12 mmHg
Normal MPAP: <=20 mmHg
Classification of pulmonary hypertension
According to Pulmonary Artery Wedge Pressure (PAWP) (estimate of left atrial pressure)
<=15 mmHg: Precapillary —> Right heart-related
> 15 mmHg: Postcapillary —> Left heart-related
Group 1: Pulmonary arterial hypertension (Primary pulmonary hypertension)
- Idiopathic
- Secondary to systemic disorders
Group 2: Left heart cause (pulmonary venous hypertension)
Group 3: Respiratory cause / Hypoxia
- COPD, Interstitial lung, obstructive sleep apnea
Group 4: Thromoboembolic/embolism
Group 5: Unclear Multifactorial mechanism
Group 1 Primary pulmonary arterial hypertension
- Progressive disease (50% survival rate at 2.8 years)
- sudden death
- Young adults (mean age: 45)
- Rarely familial
- Localised to small pulmonary arterioles
- Idiopathic (IPAH) and Heritable (PAH)
- clinically indistinguishable unless genetic defects identified
- Heritable (6-10%): BMPR2 genetic mutation - Secondary to systemic disorder
Causes:
- Connective tissue disease: Scleroderma, Systemic Lupus Erythematosus (SLE)
—> Scleroderma: obliteration of alveolar capillaries and arterioles (10-15% of all PH)
—> SLE: fibrous obliteration of pulmonary vascular bed
—> female
—> Raynaud phenomenon
- Liver, congenital heart, drugs (appetite suppressant aminorex - definite, amphetamines -possible), HIV
Group 2 Left heart cause (25%)
- Elevated Left atrial and pulmonary venous pressure
Causes:
- Left ventricular dysfunction (heart failure with preserved ejection fraction)
- Mitral / aortic valve disease
Group 3 Respiratory cause / Hypoxia
Causes:
- COPD
- Interstitial lung disease
- Combined Pulmonary Fibrosis and Emphysema (CPFE)
- Obstructive sleep apnea (15-20% of all PH)
Group 4: Thromoboembolic/embolism
Thromboembolic occlusion of pulmonary vasculature —> Thromoboendarterectomy
Group 5: Multifactorial Unclear mechanism
- chronic haemolytic anaemia (sickle cell, beta-Thalassaemia)
- systemic disorder
- CKD
Signs and Symptoms of pulmonary hypertension
Early: Dyspnea with activity
Late: Syncope, chest pain, leg oedema (right heart failure)
Signs of systemic disease:
- Scleroderma
- Respiratory: cyanosis
- Left heart: heart murmur
- Right heart hypertrophy: parasternal heave
- Right heart failure: ankle oedema, hepatic congestion
- Tricuspid regurgitation: elevated JVP
Cause of death in pulmonary hypertension (Right heart failure)
Right heart failure (with circulatory collapse, superimposed respiratory failure)
Pulmonary hypertension —> ↑ RV afterload —>
- RV hypertrophy —> RV ischaemia —> ↓ RV output
- RV dilation —> tricuspid insufficiency / septal shift / ↓ LV compliance —> ↓ RV and LV output
Pulmonary hypertension CXR
- elevated cardiac apex (R ventricular hypertrophy)
- enlarged R atrium
- prominent pulmonary outflow tract
- pruning of peripheral pulmonary vessels
ECG abnormalities in pulmonary hypertension
- Right heart strain (RV and RA enlargement)
- Right axis deviation
- ST depression and T wave inversion V1-V3 (Right bundle branch block)
- Large P wave
Screening for pulmonary hypertension
Transthoracic echocardiography
- estimate RV systolic pressure
- determine RV size
Diagnosis for pulmonary hypertension
Right heart catheterisation
Evaluation for secondary cause
Exclude group 2-5 to confirm group 1 pulmonary hypertension
- oximetry (OSA)
- VQ scan (lung function)
- CT chest (thromboembolism)
- HIV serology
Treatment for pulmonary hypertension
All groups
- Diuretics (oedema)
- Oxygen (hypoxia)
- Anticoagulation (group 4 thromboembolism)
- Digoxin (group 3: improve right ventricular ejection fraction due to COPD)
- Exercise
***vasodilator not recommended
Group 2:
Treat left heart disease e.g. Antihypertensive
Group 3:
Oxygen
Group 4:
Anticoagulant
Surgical thromboendarterectomy
