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Pulmonary Hypertension. Katie DePlatchett M.D. AM Report June 29, 2010. Pulmonary Hypertension. Elevated Pulmonary Artery pressure Secondary R Ventricular failure Mean Pulm Artery Pressure of >25mmHg at rest Pulmonary capillary wedge pressure (PCWP) <15mmHG
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Pulmonary Hypertension Katie DePlatchett M.D. AM Report June 29, 2010
Pulmonary Hypertension • Elevated Pulmonary Artery pressure • Secondary R Ventricular failure • Mean Pulm Artery Pressure of >25mmHg at rest • Pulmonary capillary wedge pressure (PCWP) <15mmHG • Diagnosed by Right Heart Catherization (RHC)
Pathogenesis • Ohm’s Law: P = Q x R Pa- Pv = CO (right sided) x PVR Pa = (CO x PVR) + PCWP • PVR: occlusion of small arterioles, hypoxic vasoconstriction • CO: congenital defects (shunts), cirrhosis • PCWP: systolic HF, valvular dx
Pathogenesis • intimal hyperplasia and fibrosis, medial hypertrophy, and in situ thrombi of the small pulmonary arteries and arterioles
Classification • Previously idiopathic PAH vs secondary PAH • Amended to groups (Group 1-5) based on etiology
Causes, Group 1 • Idiopathic • Heritable • Disease which localize to small pulm arterioles • connective tissue disease, HIV, portal htn, chronic hemolytic anemia, congenital • Drug or toxin induced • amphetamines, cocaine, appetite suppressants (fen-fen), chemotherapies, St. John’s wort, SSRIs
Causes • PH secondary to L heart disease (G2) • systolic, diastolic, valvulardx • PH secondary to lung dx or hypoxemia (Group 3) • COPD, ILD, OSA, Hypoventilation • Chronic thromboembolic PH (Group 4) • PH due to “unclear multifactorial mechanisms” (Group 5) • Heme, systemic (sarcoidosis), metabolic (glycogen storage dx)
Physical Exam • Increased intensity of pulmonic component of 2nd heart sound or split P2 • Systolic ejection murmur over LSB • Diastolic murmur over LSB (d/t pulmregurg) • R-sided S3 or S4 • Elevated JVP • Peripheral edema • Hepatomegaly, ascites
Work-Up • CXR: enlargement of the central pulmonary arteries with attenuation of the peripheral vessels • ECG R heart strain, RAD • Echo estimate the pulmonary artery systolic pressure and to assess right ventricular size, thickness, and function • PH is likely if the PASP is >50 and the TRV is >3.4
Work-up • Labs: HIV, LFTs, ANA, RF, ANCA, ? evidence of chronic hemolytic anemia • PFTs to identify and characterize underlying lung disease that may be contributing • Overnight oximetry to assess nocturnal oxyhemoglobindesaturation • Sleep study for eval of OSA • V/Q scan for chronic thromboemboli
Work-up…yes, let the $$$ roll • Right Heart Catherization • necessary to confirm the diagnosis of PH and accurately determine the severity of the hemodynamic derangements • 6 min walk • To determine functional status • Assist with prognosis • Some cases are exercised induced
WHO Functional Classification • Class: I Ordinary physical activity does not cause undue fatigue or dyspnea, chest pain, or heart syncope. • Class II: Slight limitation of physical activity. Ordinary physical activity results in undue fatigue or dyspnea, chest pain, or heart syncope. • Class III: Less than ordinary physical activity causes undue fatigue or dyspnea, chest pain, or heart syncope. • Class IV: Inability to carry on any physical activity without symptoms. Usually manifest signs of right heart failure. Dyspnea and/or fatigue may be present even at rest.
Treatment • Oxygen • Diuretics • Anticoagulation for groups 1 & 4 • intrapulmonary thrombosis & thromboembolism, due to sluggish pulmonary blood flow, dilated right heart chambers, venous stasis, and a sedentary lifestyle • Warfarin therapy w/ INR target of 2.0 • Exercise…get off that couch! • Improved functional status
Treatment, (PAH, group 1) • Phosphodiesterase 5 inhibitors (sildenafil) • prolong the vasodilatory effect of nitric oxide • SUPER trial, improved HD & exercise capacity, no change in mortality • Class III • Endothelian receptor antagonist (Tracleer) • Endothelin-1 is a potent vasoconstrictor and smooth muscle mitogen • BREATHE-1 trial, improved symptoms, the six-minute walking distance, and the WHO functional class • Class II & III • CCB • Class II & III
Advanced therapy for Classes III-IV • Vasoreactivity testing during RHC • Measures HD response to nitric oxide or Flolan • If Pulm artery pressure decreases by 10mm Hg & is <40mm Hg w/o a significant change in CO, then trial of CCB (Diltiazem 120mg daily & titrate) • If negative (no response) Prostanoids (Flolan, Remodulin) • Prostanoids = prostacyclins • Potent vasodialator & inhibitor of platet aggregation
Prognosis • Symptomatic IPAH w/o treatment have a median survival of ~ 3 years • Symptomatic w/ PAH that is associated with another disease generally have a worse prognosis • Severe PAH or right CHF median survival of 1 year w/o treatment