POM I - Pulmonary HTN - Exam 3

pulmonary hypertension

pathological elevation in pulmonary artery pressure (vessels in the lungs)

pulmonary artery HTN

-fatal dz characterized by an increase in pulmonary arterial pressure w/ subsequent RV failure and death

-caused by destruction of small blood vessels in the lungs

-NOT caused by lung dz, primary L-sided heart dz, or large pulmonary emboli

Group 1: PAH

-pulmonary arteries themselves are diseased (thickened, narrowed, or remodeled)

-idiopathic PAH, connective tissue dz, congenital heart dz, drug-induced

-arteries are the issue

Group 2 - LHD

-left heart disease

-pressure backs up from the left side of the heart into the lungs

-left sided HF, mitral/aortic valve disease

-traffic jam from left heart

Group 3: lung dz/hypoxia

-chronic lung or low-oxygen conditions strain pulmonary vessels

-COPD, ILD, sleep apnea

-bad lungs, high pressure

Group 4: Chronic Thromboembolic PH

-old or recurrent blood clots block lung vessels and increase pressure

-chronic pulmonary emboli

-clots clog flow

Group 5: multifactorial/unclear

-mixed or rare causes that do not fit neatly elsewhere

-blood, systemic, or metabolic d/o

Pre-capillary HTN

-primary elevation of pressure in the pulmonary artery system alone --> caused by pulmonary vascular remodeling leading to increased pulmonary vascular resistance

Primary pre-capillary PAH

rare, disease of unknown etiology, idiopathic; vascular

Secondary Pre-capillary PAH

-complication of pulmonary, cardiac, and extrathoracic conditions

-often associated with emphysema, collagen vascular dz, congenital heart dz, pulmonary embolism, HIV, liver dz, diet drugs

Postcapillary HTN

-elevations of pressure in the pulmonary venous and pulmonary capillary systems --> result of an increase in pulmonary venous pressure in left-sided heart dz

-think group 2

Pulmonary HTN incidence

-general pop w/ primary PH = 1-2 per 1 million persons

-scleroderma = 10-15%

-COPD (severe) --> 90% have mild to mod PH, 3-5% have severe PH

-OSA = 15-20%

-HIV = 1 per 200 (0.5%)

Uncontrollable pulm HTN RF

-age --> most dxs: 30-60; idiopathic PAH is common in younger adults

-FH --> PAH, PE

-blood clotting d/o

-genetic d/o --> incl congenital heart dz

Controllable pulm HTN RF

-overweight

-asbestos exposure

-high altitude

-drug use --> certain weight loss drugs, illegal drugs, SSRIs

Anesthesia and PH

-PH significantly increases risks d/t anesthesia

-increases perioperative mortality d/t: severe hypoxemia, acute RIGHT heart failure, circulatory collapse

PH prognosis

-highly variable

-could take 2+ years to correctly dx

-severe and progressive dz: emphasizes the importance of early dx and aggressive therapy

PH mortality

-survival rate (w/o tx from time of R-sided heart catheterization) --> median 2.8 years

-common cause of death: lower resp infxn, cor pulmonale (right heart failure)

-life expectancy has improved d/t dx techniques and specialized therapies

PH Triad

-atypical chest pain (pleuritic pain, pain w/ moving)

-syncope

-increasing DOE

PH S/S

-early: chest pain, DOE, fatigue, tachycardia, RUQ abd pain, decreased appetite

-Late sx: light-headed, esp during activity, syncope, LE edema, cyanosis

-result from inability to increase CO during demand

PH DDx

-aortic stenosis

-ASD

-Cardiomyopathies

-mitral regurg

-mitral stenosis

-VSD

-COPD

-PE

-Emphysema

-ILD

-OSA

-restrictive lung dz

Chest XR - PH

-m/c finding --> enlarged hilar vessels that rapidly prune into periphery and RVH

-right ventricle fills anterior airspace on lateral view

ECG - PH

-higher the PA pressure = more sensitive the ECG

-may demonstrate signs of RV hypertrophy

Transthoracic Echocardiogram - PH

-make a preliminary dx by estimating the pressures in the R heart and assessing heart function

-used to r/o other heart conditions w/ similar sxs

PFTs - PH

-may identify PH cause

V/Q Scan - PH

-test for PE

-helps distinguish CTEPH from other causes of PH

CT scan - PH

-helps dx lung dzs that may lead to PH like COPD, pulmonary fibrosis

Cardiac Catheterization - PH

-gold standard for PH dx (right heart cath)

-directly measures the pressure inside the pulmonary arteries

-should be done in all pts at least 1x to confirm a pt's PH dx

serum Lab Eval - PH

-BNP can assess strain on heart and may monitor response to tx

-most predictive noninvasive variable of survival

Sleep Studies - PH

-help dx sleep apnea, which can be a cause of PH

Lung Biopsy - PH

-establish dx of primary PH and determine grade and reversibility

ABGs - PH

-hypocapnia is an independent marker of mortality, esp in PH

PH - Dx Approach

-Group 2/3 dz --> TTE to screen, then PFT w/ ABG --> if these don't reveal anything --> do V/Q Scan to check for Group 4 dz --> if defect is present, do pulm angiography or CT

-Findings from hx, PX, CXR, ECG

-2D R sided cardiac catheterization - gold standard

-pts should also be screened for OSA

-lastly, lab studies to check for group 1 dz (PAH)

PH - Dx Use and Sequence

-start with noninvasive, then can do more invasive if necessary

-refer to PH center if severe

-echocardiogram - most useful initial imaging test

-serum lab tests

-CXR, ECG, V/Q scan, High res CT, Cardiac catheterization

PH Tx Goal

-improve: NYHA heart functional class by 1-2 classes, 6MWD to >400m, CO (baseline and exercise), QOL, survival

-decreased RAP and BNP

General PH Tx

-early tx recommended for underlying cause

-supportive tx

-advanced vasodilatory tx

-preventive care

-balloon atrial septostomy

-lung or heart transplant --> severe PAH

lung or heart transplant

-reserved for pts with severe PAH (only hope for some)

-typically, only NYHA functional class 4 after 3 months of tx with epoprostenol (50% survival after 5 years)

PH - Tx meds

-oxygen --> reduce hypoxemic pulmonary arterial vasospasm

-anticoagulation --> decrease clot formation

-diuretics --> makes breathing easier

-K+ --> to replace what may be lost while taking diuretics

-inotropic agents --> improve pumping ability of heart

PH - vasodilator

pts with PH produce less nitric oxide (vasodilator), so they may need a vasodilator to help them out