Pulmonary HTN TEST ONLY.pdf

Pulmonary Hypertension Pulmonary Hypertension • Increase in mean pulmonary artery ≥ 25mm Hg (rest) or > 30mm Hg (exercise) • Mechanism: Increased pulmonary vascular resistance leads to R ventricular failure Epidemiology • Initially it is asymptomatic: silent • Female/male ratio: 1.8 to 1 WHO hyperte...

Pulmonary Hypertension Pulmonary Hypertension • Increase in mean pulmonary artery ≥ 25mm Hg (rest) or > 30mm Hg (exercise) • Mechanism: Increased pulmonary vascular resistance leads to R ventricular failure Epidemiology • Initially it is asymptomatic: silent • Female/male ratio: 1.8 to 1 WHO hypertension classification: • Group 1: pulmonary arterial hypertension (PAH) • Group 2: PH secondary to L heart disease – heart failure, valvular heart dz • Group 3: PH from chronic lung disease and/or hypoxia – Obstructive lung dz, restrictive lung dz • Group 4: PH from pulmonary artery obstruction-chronic thromboembolic PH • Group 5: PH from unclear/multifactorial mechanisms (systemic, metabolic disorders) Group 1 (Pulmonary Arterial Hypertension) • Arteries become narrow, thick • Less blood passing through, raises pressure in pulmonary arteries • PAH causes high mortality: o Increased vasoconstrictors (thromboxane, endothelin-1) o Decreased vasodilators (prostacyclin, nitric oxide) o (PVR) Pulmonary vascular resistance increased o (PH) Pulmonary hypertension increased o (RVH) R ventricular hypertrophy o (RHF) R heart failure • Subgroups of PAH o Idiopathic PAH (primary) Unknown cause; primary pulmonary HTN o Heritable PAH (10-20%): Bone morphogenetic protein receptor 2 (BMPR2) mutation § Normally, BMPR2 signaling inhibits vascular smooth muscle cell proliferation and favors apoptosis § Vascular remodeling - Endothelial proliferation - SM proliferation - Chronic inflammation § Injured endothelium § Activate coagulation: produce blood clots § Obstruct blood flow o Drug/toxin induced PAH o Congenital heart disease (VSD, ASD, PDA): L to R shunt o Eisenmenger’s complex (RàL shunt) § Pressure in the pulmonary circulation gets higher than systemic blood pressure, leading to shunt reversal (VSD will reverse into a R-to-L shunt) Group 2 PH: PH secondary to L heart disease - heart failure, valvular heart disease o When L heart is compromised, blood backs up in lungs, causing congestion and increased pulmonary pressure o Fluid leaks from blood vessels to lung tissue, resulting in pulmonary edema Group 3 PH: Chronic pulmonary diseases/hypoxia Group 4 PH: From pulmonary artery obstructions Group 5 PH: PH from unclear/multifactorial mechanisms 3 subgroups cause Pulmonary vascular HTN • Increased pulmonary vascular resistance (PVR): o Occlusive vasculopathy of arterioles (group 1 PAH) o Decrease cross-sectional area diseases of pulmonary vascular bed such as: § Group 3 including interstitial lung diseases, COPD and § Group 4 -pulmonary emboli § Other diseases resulting in vessel destruction or obliteration o Hypoxia-induced vasoconstriction (group 3) • Increased flow through pulmonary bed leads to endothelial injury causing vascular changes (group 1) • Increased pulmonary venous pressure - group 2 PH Symptoms • The most common symptoms initially are dyspnea on exertion • Chest pain on exertion or at rest • Dizziness • Palpitations • Syncope usually exertional Diagnostic Testing • Echo – initial screening • R heart catheterization: o Peripheral hypovascularity o R descending pulmonary artery o Central pulmonary artery is prominent o RV enlargement ECG findings • ECG may be normal in some patients • Incomplete or complete R bundle branch block • Tricuspid regurgitation • R ventricular hypertrophy • R ventricular dilation • R atrial dilation • Elevated systolic pulmonary artery pressure (>30 mmHg for adults) Pulmonary Function Tests: Helps identify lung disease causing pulmonary hypertension o Spirometry and flow volume loops may show restrictive or obstructive lung disease 6 minute walk test: Marker for physical function, Measures meters walked. Normal healthy patient is 400-700 meters CT of chest findings for PH: Increased pulmonary artery to ascending aorta diameter ratio ≥ 1 R hypertensive heart disease: o Pulmonary HTN: “Cor pulmonale”: pressure overload in RV due to pulmonary HTN of various etiologies o Pathologic findings of R heart failure: Cardiac sclerosis of the liver, sometimes progressing to cirrhosis, which may result in portal HTN and splenomegaly Stages of PH (by WHO) • Class I o No limitation with functional activity • Class II o Comfortable at rest but has slight limitations with activity • Class III o Comfortable at rest but has significant limitations with activity • Class IV o Symptoms at rest. Signs and symptoms suggestive of R-sided congestive heart failure. Quiz Which one of the following is most accurate about the etiology and epidemiology of PAH? a. Worldwide, the most common cause of PAH is collagen-vascular disease b. PAH is typically diagnosed in elderly patients, with a mean age at diagnosis of >70 years c. The most common drug that leads to PAH is metformin d. Women are more likely than men to develop PAH d Which one of the following is more commonly associated with PAH? a. Family history of PH b. Syncope without any exertion c. Pulmonary hypertension from chronic lung diseases or hypoxia d. Hypothyroidism a