NAVLE theme → murmur character and signalment often narrow the list fast
Clinical mechanism — only what matters
Obstructive lesions → increase pressure load and can drive concentric remodeling
Shunts → alter blood flow and often create volume overload when left-to-right
Severe defects → can produce failure to thrive, exercise intolerance, or early CHF
Boards usually want practical hemodynamic grouping, not memorization of every defect variant.
Pattern recognition
Core pattern
Young dogCongenital murmurExercise intolerance or poor growth
Supporting clues
Breed predispositionContinuous vs systolic murmur cluesCardiomegaly pattern depends on lesionPulse quality may helpSome dogs remain asymptomatic early
NAVLE trigger: The stem often gives you age plus murmur type and expects you to think structurally rather than degeneratively.
Decision core — what NAVLE actually asks
Puppy with severe signs or CHF
→ Congenital disease moves from incidental murmur to hemodynamically important lesion
Stable young dog with characteristic murmur
→ Use murmur pattern and signalment to prioritize the lesion class
Defect-specific planning
→ Definitive options depend on the exact lesion, so broad “heart meds for all” thinking is weak
Key interpretation
Age
Very important
Congenital disease should rise in young dogs
Murmur type
High yield
Continuous, basilar, or sided clues help localize defects
Pulse quality
Sometimes helpful
Can support shunt or outflow lesion thinking
Cardiac enlargement
Pattern based
Depends on the lesion and shunt direction
CHF risk
Lesion dependent
Some congenital lesions decompensate much earlier than others
Breed
Useful clue
Boards often use predisposed breeds to support the diagnosis
⚠ “Congenital heart disease” is not a final answer on NAVLE unless the question truly asks for the category. Usually it wants the lesion class or hemodynamic logic.
Treatment
Step 1
Stabilize CHF or severe compromise if present
Some congenital lesions present as true clinical disease, not just murmurs.
Step 2
Match treatment and monitoring to the specific defect rather than assuming one generic cardiac plan
Lesion-specific reasoning is key.
Step 3
Consider interventional or surgical correction when appropriate for the lesion
This is especially important in correctable congenital defects.
NAVLE traps — where students lose marks
✕
Do not confuse congenital lesions with acquired degenerative valve disease in an older dog
Age is a major separator.
✕
A congenital murmur is not always benign just because the patient is young
Some lesions are hemodynamically important early.
✕
Do not treat every congenital lesion as a shunt
Outflow obstructions follow different logic.
✕
Definitive therapy depends on the exact defect
Generic “cardiac meds” is often a weak answer.
Differentials — how to separate these on NAVLE
Fast separator: Congenital cardiac disease is a young-dog structural lesion problem. Separate obstructive defects from shunts and from acquired heart disease.
Category
Typical clue
Load pattern
Board separator
Congenital heart abnormalities
Young dog + murmur
Lesion dependent
Structural congenital lesion
Degenerative mitral valve disease
Older small dog
Left-sided volume overload
Acquired, not congenital
Dilated cardiomyopathy
Larger adult breed
Systolic failure
Primary myocardial disease
Innocent murmur
Otherwise healthy youngster
No significant remodeling
No major hemodynamic consequence
Clinical application tools
These references support general clinical reasoning and monitoring while you work through murmur and hemodynamic patterns.
