Pulmonary Vascular and Sleep Disorders

≥25 mmHg

Earlier detection and intervention improve prognosis.

Low-pressure system

Remodeling and constriction of pulmonary vasculature

Increased pulmonary vascular resistance and pressure

Primary lung disease

Dyspnea

Chest pain and syncope

A distinct PH subtype characterized by narrowing of pulmonary arteries

Primary pulmonary hypertension

Idiopathic

Apoptosis resistance; cell proliferation; dysregulated metabolism; increased oxidant stress

Pulmonary vascular cells and adventitial fibroblasts

Hypertrophic, fibrotic, and plexogenic remodeling

Ability of a structure to distend

Vascular stiffness and difficulty expanding

Only a small volume passes despite high pressure.

In situ thrombosis

Thickening

A complex vascular lesion associated with pulmonary arterial hypertension

It enlarges and weakens due to increased workload.

The RV works harder against increased pulmonary vascular resistance.

Pumps blood to the lungs for oxygenation

Blood congestion increases pulmonary vascular pressure.

Dyspnea and/or fatigue

Edema; chest pain; syncope

Difficulty pumping blood through narrowed pulmonary arteries

Elevated JVP; pedal edema; ascites

Blood flow stasis and increased preload

$0.5$

Ventricular hypertrophy

Blunting of the costophrenic recess

It does not directly measure mPAP; it measures sPAP.

RV dilation

Mean pulmonary artery pressure

>20 mmHg

Femoral or subclavian access → jugular vein → tricuspid valve → RV → pulmonary artery

Vascular histopathological changes without hemodynamic changes; asymptomatic

PVR, PAP, and RAP increase while CO begins to decline.

Further increases in PVR and RAP with decreasing CO due to decompensation

Cardiac output

Pulmonary artery pressure

Pulmonary vascular resistance

Right atrial pressure

It may eventually cause PAP to decrease.

Nonspecific; may show obstructive or restrictive disease

Controlled inhalation of carbon monoxide followed by measurement of absorption

Diffusing capacity of the lungs for carbon monoxide

Isolated reduction in DLCO

Yes

Enlarged main pulmonary artery

Typically similar in size

Primary pulmonary hypertension

Progressive disease that can lead to right heart failure and early mortality

Thickening and narrowing of pulmonary arteries

Congenital heart disease

Generally favorable

Systemic sclerosis

HIV

PRIMARY = ONE

WHO Group 2: left heart disease

LV systolic dysfunction; aortic or mitral valve disease; HFpEF

Heart failure with preserved ejection fraction

Preserved ejection fraction

Reduced ejection fraction

Backward transmission of pressure from left heart dysfunction

No

IT TAKES TWO PEOPLE TO FALL IN LOVE

WHO Group 3: lung disease

COPD and interstitial lung disease

Chronic obstructive pulmonary disease

Interstitial lung disease

Modest

Alveolar hypoxia

To divert blood toward better-oxygenated lung segments

Ventilation-perfusion matching and systemic oxygen delivery

OXY HAS 3 LETTERS

Around 3–7%

25%

Persistent clots form scar tissue that obstructs pulmonary blood flow.

Chronic obstructive pulmonary clots

CLOT HAS 4 LETTERS

Miscellaneous diseases affecting the pulmonary vasculature

Sarcoidosis; sickle cell disease; schistosomiasis

Granulomatous inflammation of pulmonary vessels

Abnormally shaped RBCs obstruct blood vessels.

Hemolysis; hypoxemia; thromboembolism; chronically high CO; chronic liver disease

Schistosomiasis

Hepatosplenic disease in portal hypertension

Pulmonary vasodilation

Epoprostenol; treprostinil; selexipag

Activate adenylate cyclase, increasing cAMP and causing vasodilation.

Prostacyclin

Drugs that block endothelin receptors to cause vasodilation

Bosentan and macitentan

Ambrisentan

A vasoconstrictor and vascular smooth muscle mitogen

ETA and ETB

Phospholipase C activation and calcium mobilization cause vasoconstriction.

Inhibition of vasoconstriction and promotion of vasodilation

Sildenafil and tadalafil

Prevent hydrolysis and inactivation of cGMP

Pulmonary hypertension

Increases bioactive cGMP

NO activates soluble guanylyl cyclase → cGMP activation → vasodilation

Upregulate nitric oxide

Obstruction of pulmonary arteries by an embolus

Deep veins of the legs

Clot dislodges → travels to heart → lodges in pulmonary artery

Lung parenchyma

Patent foramen ovale (PFO)

Factor V Leiden and prothrombin gene mutation

Resistance to activated protein C

Anticoagulant that inactivates clotting factors V and VIII

Increased plasma prothrombin concentration

An acquired prothrombotic state

Recurrent spontaneous abortions

Cancer; obesity; smoking; vaping; long-haul travel; hypertension; COPD; CKD; estrogen; pregnancy; surgery; trauma; coronavirus

Vasoconstriction promotes a prothrombotic state.

Prolonged seating causes venous stasis in the legs.

Stand up occasionally and use medical-grade compression socks.

Prolonged immobility

It promotes a procoagulant state.

They are normally matched.

Decreases

It is maintained relative to reduced perfusion.

More blood flow relative to ventilation can also cause V/Q mismatch.

5–10%

Extensive thrombosis affecting at least half of pulmonary vasculature

An embolus lodged at the pulmonary artery bifurcation

Hypotension; cyanosis; dyspnea; syncope

20–25%

RV dysfunction despite normal systemic arterial pressure

No

65–75%

Excellent; it usually resolves on its own.

Assess disease severity

Subclinical; incidental and asymptomatic

Symptomatic with low clinical severity score

Symptomatic with elevated clinical severity score

Incipient cardiopulmonary failure with transient hypertension responsive to treatment

Cardiopulmonary failure with persistent hypertension despite management

The Great Masquerader

Pulmonary tuberculosis

≥3

≥4

Signs or history of DVT

Deep vein thrombosis

Pulmonary vascular obstruction by material other than a blood clot

Fat; tumor; air; amniotic fluid; hydatid cyst; septic embolism

Bone marrow entering the circulation after pelvic or long-bone fracture

Up to 100 cc

Breakdown of fibrin by plasmin

Endogenous thrombolysis

No; other diseases can also elevate it.

PE is unlikely.

Prominent S wave in lead I

Q wave in lead III

Inverted T wave in lead III

Tachycardia

No

Focal oligemia due to reduced pulmonary blood volume

Reduced or absent lung markings

Pleural-based opacity representing hemorrhage and necrotic lung tissue

Enlarged right descending pulmonary artery

No

Normal findings in most patients

RV free-wall hypokinesis with normal or hyperkinetic RV apex motion

Anticoagulation alone

Binds to and accelerates antithrombin activity

Continuous intravenous drip

Constant monitoring of blood parameters

Fragments of UFH with greater bioavailability

Predictable dose response; longer half-life; convenient administration

Enoxaparin and tinzaparin

Subcutaneously

An anti-Xa pentasaccharide

No

Subcutaneously

Heparin-induced thrombocytopenia

They do not cause HIT.

Dabigatran; rivaroxaban; apixaban

Edoxaban

They are expensive.

DOACs

LMWH

LMWH and consideration of UFH

Surgical removal of a pulmonary embolus

As a last resort for Group D and E patients

Low-dose UFH or LMWH

Patients with malignancy, immobility, or trauma history

Prevent DVT and potential PE

Symptoms and overnight polysomnography

Snoring; snorting; gasping; breathing pauses

Sleepiness and fatigue despite adequate sleep opportunity

Apnea-hypopnea index

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≥5 episodes per hour

Complete cessation of breathing for ≥10 seconds

Yes, despite blocked airflow

≥30% reduction in airflow with ≥3% oxygen desaturation, lasting ≥10 seconds