FM Radiology Case - Congestive Heart Failure Flashcards
What are the characteristic pathologic features of the heart in CHF?
- Enlarged heart
- Changes in cardiac chambers and myocardium (depending on etiology)
- Irregular fibrosis replaces myocardium
What are the characteristic pathologic features of the lungs in CHF?
- Severe, chronic passive congestion of the lungs
- Vessels, including alveolar capillaries, are congested as a result of pulmonary venous hyeprtension
- Alveoli contain numerous hemosiderin laden macrophages
What causes the frothy liquid seen from the cut surface of the lung in CHF?
Air moving through water in the respiratory tree
List some of the anticipated CXR findings in a patient with CHF.
- Cardiomegaly
- Vascular Phase (phase 1) - cephalization, hilar fulness with haziness
- Interstitial Phase (phase 2) - kerley lines
- Alveolar phase (phase 3) - butterfly distribution, pulmonary edema
- Pleural effusions
Define cardiomegaly on CXR.
If the transverse diameter of the heart is larger than the diameter of the hemithorax; cardiothoracic ratio >0.5
What are the phases of congestive heart failure?
- Vascular phase
- Interstitial phase
- Alveolar phase
What happens pathophysiologically in the vascular phase of CHF?
Pulmonary venous hypertension
What is cephalization?
The vessels in the upper chest are more prominent due to pulmonary venous hypertension (opposite of normal); increased (>1) artery:bronchus ratio at hilar level
What causes hilar fulness with haziness?
Enlarged pulmonary veins with perivascular fluid collection
What happens pathophysiologically in the interstitial phase of CHF?
Interstitial edema and increased lymphatic drainage
What are kerley lines?
2-3cm long horizontal lines in the base of the lungs close to the chest wall
What is seen on CXR in the Alveolar phase?
Bilateral diffuse soft fluffy alveolar infiltrates coalescing with each other in a butterfly distrubtion
What happens pathophysiologically in the alveolar phase of CHF?
Pulmonary edema
Why might a normal sized heart be seen on CXR during CHF?
CHF secondary to an acute MI
Compare the CXR of acute vs. chronic CHF.
Acute - pulmonary edema (alveolar phase)
Chronic - all 3 phases + pleural effusions
What is gravity-dependent accumulation of fluid in the lungs and alveoli?
Basal congestion
What causes pleural effusions?
Increased hydrostatic pressure
Compare CHF and pulmonary edema.
CHF - basal congestion (dependent)
Pulmonary edema - diffuse white out of lungs
What are the steps in reading a CXR suspected to have CHF (chronic)?
- Determine PA vs. AP view - many of the findings will change in AP film
- Decide on the transverse diameter of the heart
- Look for pleural effusion.
- Compare the diameter of the vessels in the upper 1/3 of the lungs to the lower 2/3.
- Comapre the size of the end on view of vessel to the adjacement bronchus
- Look for hilar fullness and congestion
- Look for kerley lines
- Look for basal congestion
What are the steps in reading a CXR suspected to have CHF (acute)?
- Heart may be of normal size
- Diffuse white out of lungs
- Butterfly pattern - medullary or central distribution of density
- Will NOT see findings noted in chronic CHF
How to distinguish CHF CXR from other acute alveolar disease? - Hemorrhage
Hemoptysis, sudden drop in Hgb
How to distinguish CHF CXR from other acute alveolar disease? - ARDS
- Prior major event (trauma, bleeding, sepsis, etc.), progressive hypoxia resistant to therapy requiring ventilator management
- Normal heart size, no pleural effusion
How to distinguish CHF CXR from other acute alveolar disease? - Pneumonia
High fever, oddball infections (influenza, mycoplasma, pneumocystis)
