Pulm HTN

##Defn
An elevation in pulm vasculr presur dat can b causd by an isolatd increas in pulm arterial presur / by increas in both pulm arterial & pulm venous presur

In practice, pulm HTN is usd for pulm arterial HTN & is dfined as a resting mean pulm artery presur greatr dan 25mm of Hg / a resting sytolic pulm artery presur greater dan 40mm Hg

##Etio & Clasn
1)Pulm arterial HTN
-sporadic
-familial
-related 2 colagen vasclr diseas, livr cirhsis, HIV infn, congenital systemic to pulm shunts
-asso wid significnt venous / capilary invo
-pulm venooclusive diseas

2)Pulm venous HTN
-left sided atrial / ventriculr heart diseas
-left sided valvulr heart diseas

3)Pulm HTN asso wid hypoxaemia
-COPD
-interstitial lung diseas
-obstructiv sleep apnoea

4)Pulm HTN due 2 chronic thrombotic / embolic diseas
-thromboembolism 2 proximl pulm arteries
-obstrctn of distl pulm arteries in pulm embolism, sickl cel disease

5)Miscelaneous
-sarcoidosis, histiocytosis X


##Pathophysiology
-norml pulm artery systolic presur at rest is 18-25mm of Hg, wid a mean of 12-16mm of Hg. Dis low presur is due 2 large cross sectionl area of pulm circulation, whch results in low resistenc
-increas in pulm vasculr resistenc
-increas in pulm bld flow


##C/F
1)symptoms of pulm HTN & its consequencs
-fatigue, dyspnea, syncop, angina due 2 reducd cardiac output
-haemoptysis uncomon & ocurs due 2 ruptur of distended pulm vessels
-peripheral edma, tender hepatomgaly, raised jugulr venous presur due 2 rt ventr failur

2)signs of pulm HTN
-cyanosis
peripherl cyno due 2 reducd cardiac output & skin bld flow

-pulse is low volum due 2 reducd cardiac output & left ventr strok volum

-JVP
prominent a wavs, JVP elevtd wid rt ventr failur, prominent v wavs & rapid y descent wid functional TR

-inspection & palpn
apicl impuls may b shiftd indicating rt ventr hypertrophy & dilatation
visibl & palpabl left parasternal heav & epigastrc pulsations indicating rt ventri hypertrophy
palpabl P2

-auscultatry
pulmo ejectn sound
abno S2
rt atrial 4th heart sound S4
rt ventr 3rd heart sound S3
pulm ejection systo murmur
pulm early diastolic murmur
tricuspid pansyst murmur


##Invst
1)ECG
rt axis deviation
rt atrial enlargmnt
rt ventr hypertrophy

2)Chest Xray
enlargment of pulm trunk & its main branches
peripherl pruning of vasculr shadows
enlargd rt atrium
enlargd rt ventr

3)Echocardiogrphy

4)Other
routin
autoantibodies if colagn vasc diseas
HIV ELISA
arterial bld gas 2 exclud hypoxia / acidosis
sleep studies
helical CT
high resolution chest CT
cardiac catheterisation


##Rx
-directed @ early recognition & Rx of undrlying caus
-pulm enarterectomy is curent mainstay of chronic thrombemblc pulm HTN
-Rx of hypoxaemia by low flow O2
-excesiv diuretics avoided
-drugs lik ilioprost, bosentan, sildenafil
-oral anticoagulants can b