Congenital defects Flashcards
(44 cards)
What are the 3 most common congenital heart defects in dogs?
Patent ductus arteriosus
Subaortic stenosis
Pulmonic stenosis
What are the 2 most common congenital defects in cats?
Mitral dysplasia
Ventricular septal defect
What 5 things can you use to commonly help diagnose a congenital heart disorder?
Signalment/history/exam Chest radiographs ECG Echocardiography PCV/TPP
What 2 things will you find during a clinical exam in a dog with patent ductus arteriosus?
Machinery murmur in left heart base
-no silence
Hyperkinetic pulses
-diastolic pressure is low
Over time what will turbulence in an artery lead to?
Arterial dilatation
In PDA what direction is the blood usually shunted?
Left-to-right
From LV - lungs - LA - LV
-over circulation
What type of dog is PDA most common in?
Young small dogs
What things may you see on a radiograph for a dog with PDA?
Over-circulation of the lung fields
Dilated main pulmonary artery and descending aorta
Enlarged left atrium
Pulmonary oedema with congestive heart failure
3 ‘knuckles’ on VD - Aortic arch, pulmonic artery and oracle
How do you treat a left-to-right shunting PDA?
Surgery as early as possible
Treatment for congestive heart failure if needed
What surgical method is used to fix left-to-right shunting PDA?
Trans-arterial ductal occlusion with coils
-Coil with fluff on it promotes clotting, fibrosis and healing of area
What direction does the blood flow in a reversed PDA?
Right-to-left
RV-Body-RA-RV
-bypasses the lungs and left side of heart
How do you treat a dog with right-to-left shunting PDA?
Not surgery - has turned into a pressure release valve Phlebotomy - blood letting \+/- hyroxyurea to hit marrow Enforced rest Avoidance of stress
What is the most common site for sub-aortic stenosis?
Sub-valvular 95%
What is the most common signalment for a dog with subaortic stenosis?
Large breed dog
-It is autosomal dominant with other genes influencing phenotype
What is the pathophysiology of subaortic stenosis?
Variable severity Subvalvular fibrous ring Develops within first months of life LV pressure overload Concentric hypertrophy Inadequate coronary perfusion Worsening outflow tract obstruction
What are 4 history findings for a dog with subaortic stenosis?
Exercise intolerance
Syncope
Left-sided heart failure
Sudden death
What are 2 findings you can get from a clinical examination of a dog with subaortic stenosis?
Slow-rising hypokinetic pulses
Harsh systolic heart base murmur which radiates widely
+/- low heart base thrill
-can hear murmur all over body and can be very loud
Why is echocardiography important in a dog with subaortic stenosis?
To confirm diagnosis
Determine the severity of narrowing
How do you treat a dog with subaortic stenosis?
Refer for surgery for balloon dilatation or open heart
Beta-1 blocker - Atenolol
Exercise restriction
Why should you give a dog with subaortic stenosis beta-1 blockers?
To stop the heart working so hard and to prevent worsening
Where does pulmonic stensosis usually occur?
Valvular
What type of animal does pulmonic stenosis most commonly occur in?
Small dogs
-Congenital defect
Rare in cats
What are some history findings for a dog with pulmonic stenosis?
Asymptomatic usually until over 1y.o
Poor exercise tolerance
Syncope
Right-sided heart failure
What are some clinical findings for a dog with pulmonic stenosis?
High left base systolic ejection murmur \+/- thrill there No radiation to carotids \+/- jugular pulse \+/- arrhythmias
