Congenital mumurs in puppies and kittens Flashcards
Define pathological (cardiac) murmurs
Incompetent or stenotic valve
Flow through shunts
Define physiological (functional) murmurs
Changes in blood viscosity or velocity
E.g. Anemia/Hypoproteinaemia/Atheletes
Define Innocent (Flow) murmurs
Soft (Maximum grade 1-2), systolic, short, variable, localised
Outline murmur grade classification
Grade 1: difficult to hear
Grade 2: quieter than heart sounds
Grade 3: equal to heart sounds
Grade 4: louder than heart sounds
Grade 5: palpable thrill
Grade 6: thrill and can hear with stethoscope off the chest wall
State 4 causes of murmurs in puppies and kittens
Innocent (“flow”) murmur
Systemic disease e.g. anaemia
Acquired disease - RARE
Congenital anatomical defect
When do Innocent murmurs go away in puppies and kittens
Usually gone by 16 to 20 weeks of age
Top three most common congenital heart diseases in dogs
Aortic stenosis
Patent ductus arteriosus
Pulmonary stenosis
Top three most common congenital heart diseases in cats
Ventricular septal defect
Mitral valve dysplasia
Tricuspid valve dysplasia
Aortic stenosis
Narrowing of the exit of the left ventricle of the heart
Patent ductus arteriosus
Oxygenated blood from the left heart flows back to the lungs through the aorta, which has a higher blood pressure, to the pulmonary artery, which has a lower blood pressure
Pulmonary stenosis
Obstruction of flow from the right ventricle of the heart to the pulmonary artery
Ventricular septal defect
Defect in the ventricular septum, the wall dividing the left and right ventricles of the heart.
Majority of congenital heart murmurs in dogs and cats are? Systolic OR diastolic. What congenital disease is the exception
Systolic
Patent ductus arteriosus- Continuous
Murmurs when auscultating the left heart base may be due to?
Patent ductus arteriosus (continuous)
Aortic stenosis (systolic)
Pulmonary stenosis (systolic)
Innocent/functional murmurs (systolic)
What murmurs can you hear when you auscultate the Left heart apex
Mitral valve dysplasia (systolic)
Hearing murmurs when auscultating the Right side of thorax could be a cause of?
Tricuspid valve dysplasia (systolic)
Ventricular septal defect (systolic)
Tetralogy of Fallot (systolic)
What can one expect to see on a thoracic radiograph of a patient with patent ductus ateriosus
Left sided enlargement, vascular congestion, aorta and pulmonary artery enlargement
What can one expect to see on a thoracic radiograph of a patient with Pulmonic stenosis
Right sided enlargement, decreased vascularity, pulmonary artery enlargement
Dog breeds predisposed to Aortic stenosis
Boxer
Golden retriever
German shepherd
Rottweiler
Newfoundland
Clinical history of aortic stenosis
Asymptomatic
Exercise intolerance
Syncope
Sudden death
Left sided congestive heart failure (dyspnoea, tachypnoea, cough)
Clinical examination of aortic stenosis
Weak pulse
Harsh systolic murmur left heart base
+/- left sided CHF
Treatment for mild cases of aortic stenosis
no treatment, good prognosis
Treatment for severe cases of aortic stenosis
beta-blockers, calcium channel blockers (diltiazem) will reduce HR, reduce outflow gradient, reduce risk of arrhythmias and may improve quality of life but no proven impact on survival
Pathophysiology of aortic stenosis
- Aortic valvular or sub valvular narrowing
- Pressure overload of left ventricle
- Decreased CO resulting in forward failure resulting in exercise intolerance
- Concentric hypertrophy of left ventricle resulting in arrhythmias/diastolic dysfunction/LSCHF
Explain why patent ductos arteriosus can cause Caudal cynanosis and hindlimb weakness
- Excessive circulation of blood through the lungs
- Irreversible changes to lung
- Pulmonary hypertension and reverse shunting
Explain why patent ductos ateriosus can cause LSCHF
- Blood shunts from artery to pulmonary atery
- Excessive circulation of blood through lungs
- Volume overload of left ventricle and atrium
Dog breeds predisposed to PDA
German Shepherd
Border Collie
Springer Spaniel
Poodle
Chihuahua
Clinical examination of a dog with PDA
Dynamic pulse ‘water hammer pulse’
Continuous murmur left heart base ‘machinery murmur’
+/- signs of left sided congestive heart failure
Clinical findings of patients with Reverse PDA
Weakness hindquarters
Caudal cyanosis
+/- murmur
Diagnosis for reverse PDA
Echocardiography- May require contrast echo to diagnose with simultaneous imaging of aorta
Pulmonary hypertension
Treatment for reverse PDA
Non-surgical
Develop right heart failure if occluded
Sildenafil for pulmonary hypertension
Phlebotomy if develop polycythaemia
Dog breeds predisposed to Pulmonic Stenosis
Boxer
Cocker spaniel
Beagle
Bull dog
Westie
T/F Pulmonic Stenosis is common in cats
False!
History of dog with Pulmonic stenosis
Asymptomatic
Exercise intolerance
Syncope
Sudden death
Right sided CHF (ascites, dyspnoea)
Clinical examination of dog with pulmonic stenosis
Weak pulse
Harsh systolic murmur left heart base
+/-ascites/pleural effusion
Treatment for severe pulmonic stenosis
Beta-blockers
Balloon valvuloplasty – works best if fused valves
Stent
Pathophysiology of Ventricular septal defect
- LARGE ventricular septal defect
- Shunting from left to right
- Overcirculation of lungs
- Left sided CHF OR Pulmonary hypertension causing RCHF
Dog Breeds predisposed Ventricular Septal Defect:
Bulldog
Keeshound
Springer Spaniel
T/F Ventricular septal defect is the most common congenital cardiac defect in cats
True!
History of Ventricular septal defect
Asymptomatic
Exercise intolerance
Left sided congestive heart failure (dyspnoea, tachypnoea, cough)
Clinical examination of Ventricular septal defect
Strong pulse
Systolic murmur right ventral thorax
+/- left sided CHF
What is the most common cyanotic congenital heart disease
Tetralogy of fallot
Tetralogy of fallot
- Ventricular septal defect.
- Pulmonary stenosis.
- The aortic valve, which opens to the aorta, is enlarged and seems to open from both ventricles. In this defect, the aortic valve sits directly on top of the ventricular septal defect.
- Right ventricular hypertrophy
Physical examination of patient with tetralogy of fallot
+/- murmur depends on presence of polycythaemia
+/- cyanosis
+/- dyspnoea
T/F Tricuspid dysplasia cases and animals with small VSDs cannot have a normal life span
False
