Pulmonary hypertension Flashcards
Definition of pulmonary hypertension
Nice 6th World Symposium on PH 2019
1. Mean pulmonary arterial pressure (mPAP) > 20mmHg at rest (with 20mmHg being ULN)
2. Emphasis on pulmonary arterial wedge pressure (PAWP) and pulmonary vascular resistance (PWR)
What are the normal values of mPAP?
Normal mPAP 14 +/- 3mmHg
(Upper limit normal 20mmHg)
mPAP increases with exercise:
At HR 100/min - 32mmHg
Maximal exercise - 37mmHg
Exercise in > 50 years old - 47mmHg
Significance of mPAP 21-24mmHg
Risk of mortality in patients with elevated PAP is incrementally noted with mPAP between 19 and 24 mmHg and not necessarily restricted to patients with mPAP 25 mmHg or more
What is pulmonary vascular resistance?
PVR = (mPAP - mPCWP) / Cardiac output
PVR ULN ~2 Wood units (WU)
What is pulmonary arterial wedge pressure (PAWP)?
Current consensus ULN 12mmHg
(But most therapeutic studies of PAH used PAWP 15mmHg as threshold)
What are the symptoms of PH?
Right ventricular dysfunction symptoms
What are the clinical signs and examination findings of PH?
What are the ECG changes in PH?
- P pulmonale (P > 0.25mV in lead II)
- Right axis deviation
- RV hypertrophy (R/S >1, R>0.5 in V1; RV1 + SV5 >1)
- RBBB
- RV strain pattern (ST-depression or TWI in right precordial (V1-V4), inferior (II, III, AVF) leads)
- Prolonged QTc
What are the abnormal CXR findings in PH?
What are the normal haemodynamic values during right heart catheterisation?
What is the function of vasoreactivity testing?
What groups of PH are recommended for vasoreactivity testing?
What are the medications used in vasoreactivity testing
Vasoreactivity testing in PAH to identify acute vasoresponders as candidates for treatment with high dose calcium channel blockers
Vasoreactivity testing in group 1 PAH:
1. Idiopathic PAH (IPAH)
2. Heritable PAH (HPAH)
3. Drug-induced PAH (DPAH)
Medications used:
1. Inhaled nitric oxide (INO)
2. Inhaled iloprost
3. IV epoprostenol
Diagnostic algorithm of patients with unexplained dyspnoea and/or suspected pulmonary hypertension
Summary of findings for different classification groups of PH
Pathophysiology of PAH
- Right heart failure
- RV remodelling
- RV dysfunction - Progressive pulmonary vasculopathy and obstruction
- Intimal proliferation and fibrosis
- Medial hypertrophy
- Plexiform lesions
- Vasoconstriction
- Prone to thrombosis
WHO-FC of PAH
- Strongest predictors of survival
- Worsening classification most alarming indicators of disease progression
FC1 - PAH without limitation of physical activity, and activity does not cause symptoms
FC2 - PAH with slight limitation of physical activity. Comfortable at rest, normal activity causes undue symptoms
FC3 - PAH with marked limitation of physical activity. Comfortable at rest, less than normal activity causes undue symptoms
FC4 - PAH with inability to carry out any activity without symptoms, symptomatic even at rest.
Symptoms: dyspnoea, fatigue, chest pain, near syncope