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Pulmonary Hypertension (PH). By: Ahmad Al-Masri. Definition. defined as mean pulmonary artery pressure of ≥ 25 mmHg at rest , as measured at right heart catheterisation. N ormal mean pulmonary artery pressure?! 15 mm Hg. Classifications. Pulmonary arterial hypertension
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Pulmonary Hypertension(PH) By: Ahmad Al-Masri
Definition • defined as mean pulmonary artery pressure of ≥ 25 mmHg at rest, as measured at right heart catheterisation. • Normal mean pulmonary artery pressure?! 15 mm Hg
Classifications • Pulmonary arterial hypertension • Pulmonary venous hypertension • PH caused by respiratory disorders & /or hypoxaemia • PH caused by chronic thromboembolic disease • Miscellaneous
Pulmonary arterialhypertension found in: 75% of the familial cases 25% of sporadic cases • Primary(Idiopathic) : sporadic & familial… (BMPR2 gene)!! Typically young female (20-30) • Secondary: • connective tissue disease (systemic sclerosis) • congenital systemic to pulmonary (left to right) shunts (VSD,ASD,PDA) • portal hypertension • HIV infection • various drugs or toxins • persistent pulmonary hypertension of the newborn
Cont. Pulmonary arterial hypertension will cause damage to Endothelial cells in pulmonary a. release (Less production) Endotheline-1 Serotonin Thromboxan Nitric Oxide Prostacyclin Pulmonary artery dilatation Inhibit smooth muscle Hypertrophy Pulmonary artery constriction Smooth muscle Hypertrophy Worsening the Pulmonary hypertension Vicious cycle
Pulmonary venoushypertension • Left-sided atrial or ventricular heart disease (eg. hypertrophy, atrial myxoma ,etc..) • Left-sided valvular heart disease(eg. Mirtal stenosis) • Pulmonary veno-occlusive disease • Pulmonary capillary haemangiomatosis(very rare)
Cont. Left Heart Disease (Pulmonary BVs are normal & undamaged) Left-side of heart unable to pump blood efficiently Backup of blood in pulmonary veins and capillary beds ↑ Pressure in pulmonary artery
PH caused by respiratory disorders & /or hypoxaemia • COPD • Diffuse parenchymal lung disease • Sleep-disordered breathing • Alveolar hypoventilation disorders • Chronic exposure to high altitude • Neonatal lung disease • Alveolar capillary dysplasia • Severe kyphoscoliosis
Cont. respiratory disorders & /or hypoxaemia Hypoxic vasoconstriction of pulmonary arterioles ↑ Pulmonary vascular resistance (harder for Rt. Ventricle to pump blood)
PH caused by chronic thromboembolic disease • Thromboembolic obstruction of the proximal pulmonary arteries • In situ thrombosis • Sickle cell disease Emboli BLOCK pulmonary vessels Endothelial cells will release ↑ resistance to blood flow ↑ pulmonary BP Constrict pulmonary arterioles Histamine Serotonin
Miscellaneous • Inflammatory conditions • Extrinsic compression of central pulmonary veins… eg. Tumour
Pathological features • hypertrophy of the media of the vessel wall • Intimal fibrosis • plexiform lesions?! (group of capillaries placed together, that arise as complication of long standing pulmonary hypertension)
Consequences • Lung pulmonary edema • Heart Rt. Ventricle hypertrophy O2 Demand exceeds O2 supply Rt. Sided heart failure (CorPulmonule) Blood backup in venous system: ↑JVD Hepatomegaly Ascites Legs edema Left ventricle receive less blood To compensate it will pump harder & faster
Clinical features • Symptoms: - Breathlessness - chest pain - Fatigue - palpitation - Syncope (with severe disease) • Signs: • accentuation of pulmonary component of the second heart sound (S2) m.c. • Right ventrical heave (right ventricular hypertrophy) • elevation of the jugular venous pulse (prominent ‘a’ wave if in sinus rhythm) • right ventricular third heart sound. • Tricuspid regurgitation
Investigations • CXR?! Enlarged pulmonary arteries • ECG?! right axis deviation due to Rt. Ventricle hypertrophy • Echocardiogram?! 1) Dilated pulmonary artery 2) Dilatation/hypertrophy of RA and RV 3) Abnormal movement of IV septum (due to increased right ventricular volume) • Right heart catheterization?! increased pulmonary artery pressure • V/Q scan… when?! If the cause is not revealed (neither heart nor lung), to know is it due PE or is it primary pulmonary hypertension
Cont. • PFT?! most pulmonary function parameters are normal in PH (if it’s not caused by respiratory disorders), but the DLCO (Diffusing capacity of the lungs for carbon monoxide) decreases. Know that a very low DLCO is associated with a poor prognosis in patients with PH. • What are the 1st tests you order when you suspect PH?! • What follow-up test is done if the 1st tests are suggestive?! ECG& an echocardiogram. Right heart catheterization to confirm the diagnose
Management 1) Exercise : improve the functional class of patients greatly but does not change the hemodynamics. 2) Unless there is an increased risk of bleeding anticoagulants mainly warfarin. Our goal is to reach INR of 2.0. 3) Diureticsare recommended for fluid retention. 4) Oxygen for those with chronic hypoxaemia. 5) Vasodilators 6) Lung transplantation
Vasodilator agents 1) Oral Calcium Channel Blockers.. vasodilators of choice (eg. ifedipine, amlodipine & diltiazem) 2) Oral Endothelin Receptor Antagonists(eg. Bosentan) 3)IV Prostacyclin(eg. Epoprostenol) 4) Inhaled PDE(phosphodiesterase)Inhibitors type 5