PANCE Blueprint Pulmonary (10%)

Right ventricular enlargement and eventually failure secondary to lung disorder that causes pulmonary artery HTN

• Etiology: COPD (most common), pulmonary embolism, vasculitis, asthma, ILD, acute respiratory distress syndrome
• Physical Exam: Lower extremity edema, neck vein distention, hepatomegaly, parasternal lift, tricuspid/pulmonic insufficiency, loud S2

DX: The diagnosis of cor pulmonale is usually made with an echocardiogram → increased pressure in the pulmonary arteries and right ventricle

• Spirometry can be done to look for chronic lung disease
• The gold standard diagnostic test to directly measure pulmonary pressures and assess for response to vasodilating medications is a right heart catheterization

TX: Diagnose and treat the underlying condition before cardiac structure change becomes irreversible

• • Diuretics are not helpful and may be harmful!

Pathophysiology of cor pulmonale (Image by Lecturio)

ReelDx Virtual Rounds (pulmonary embolism)

pulmonary embolism

You are called to see a 51 y/o male with an acute onset of shortness of breath x 24 hours

Patient

• Gender: Male
• Age: 51 years
• Weight: 253.5 lb/115 kg
• Height: 73 in/185.4 cm

Vitals

• Temperature: 97.7 F/36.5 C
• Blood Pressure: 139/98
• Heart Rate: 113
• Respiratory Rate: 20
• Pulse Oximetry: 96% RA

Signs and Symptoms

• Acute onset of shortness of breath the previous night

Click here to work through this patient case simulation.

A pulmonary embolism is a blockage in one of the pulmonary arteries in the lungs

• More than 90% originate from clots in the deep veins of the lower extremities
• Presents with dyspnea (most common) and pleuritic chest pain
• R/F: Virchow’s triad = hypercoagulable state, trauma, venostasis (surgery, cancer, oral contraceptives, pregnancy, smoking long bone fracture/fat emboli)
• Homan’s sign: (Dorsiflexion of the foot causes pain in calf) indicative of deep vein thrombosis
• EKG: TACHYCARDIA (most common), S1Q3T3 (rare), non-specific ST wave changes

Diagnosis: Well’s Score is used to assess the probability of pulmonary embolism

• Spiral CT = initial method of identifying
• Pulmonary angiography = gold standard definitive
• CXR: Westermark sign or Hampton hump (triangular or rounded pleural base infiltrate adjacent to hilum)
• VQ scans are "old school"= perfusion defects with normal ventilation (normal VQ rules out PE; abnormal – non-specific)
• Venous duplex ultrasound of lower extremities (normal test does not exclude PE)
• ABG = respiratory alkalosis secondary to hyperventilation
• D-dimer

Tx: Heparin is the anticoagulant of choice for the acute phase with factor Xa inhibitors (e.g., rivaroxaban, apixaban, edoxaban) and oral direct thrombin inhibitors (dabigatran) thereafter

Blood pressure in the lungs is usually extremely low 15/5. In pulmonary hypertension, the pressure increases > 20 mmHg at rest

• Usually caused by an underlying disorder (constrictive pericarditis, mitral stenosis = MC, LV failure, mediastinal disease compression pulmonary veins)
  • Mitral stenosis: mitral valve = tight so blood can’t pass into left ventricle ⇒ pressure backs up to lungs
• When the right heart can’t pump against vascular resistance ⇒ right heart failure = Cor pulmonale
• Presentation: Dyspnea on exertion, fatigue, chest pain, edema
• Physical Exam: Loud pulmonic component of second heart sound (P2); Jugular venous distension; Ascites; Hepatojugular reflux; Lower limb edema

Diagnose with a right heart catheterization (gold standard) → most accurate measure of pressures

• CXR
  • Enlarged pulmonary arteries
  • Lung fields may or may not be clear, dependent on the underlying cause
• Echocardiogram
  • Increased pressure in pulmonary arteries, right ventricles → dilated pulmonary artery
  • Dilatation/hypertrophy of right atrium, right ventricle
  • Large right ventricle → bulging septum
• ECG → Right heart strain pattern: T wave inversion in right precordial (V1–V4) and inferior leads (II, III, aVF)

TX: identify and treat the underlying cause

• Pulmonary hypertension secondary to left ventricular failure → optimize left ventricular function
  • Diuretics (cautiously—individuals may be preload dependent)
  • Digoxin
  • Anticoagulants
• Cardiogenic pulmonary arterial hypertension
  • Relax smooth muscle (promote vasodilation), reduce vascular remodeling, improve exercise capacity with prostanoids, phosphodiesterase inhibitors, endothelin antagonists
• Pulmonary arterial hypertension
  • Endothelin receptor antagonists
  • Prostanoids

The classic findings on chest radiography in a patient with pulmonary arterial hypertension include enlarged central pulmonary arteries that taper distally (peripheral pruning), attenuated peripheral vessels, and oligemic lung fields.