Cardiology Flashcards
Symptoms of cardiac murmur
Physiological murmur or congenital abnormality
Poor performance - rare - considerable cardiac reserve so unless at maximal performance dont need all
Collapse/sudden death - rare - concurrent (secondary ventricular dysrrhythmias)
Congestive heart failure - rare
Jugular distention + heart murmur indicates..
Reduced cardiac return
- Right sided cardiac failure - reduced RHS cardiac output into lungs - backs up
- Thoracic disease - mediastinal mass, pressure on vessels - drainage
- Pericardial disease - pressure of fluid in pericardium - reduced fill so RHS reduced pressure so squeezed so right sided failure
Peripheral oedema + heart murmur indicates..
Right sided heart failure
Hypoproteinaemia
Vascular diseases
Jugular pulsation + heart murmur
Normally visible in distal 1/3 neck, dependant on head and neck position
Shouldnt see this further up neck
Dysrrhythmias
Left sided heart failure
Pulmonary oedema
- Ruptured chordae tendonae
- Bacterial endocarditis
- Congenital cardiac disease
Right sided heart failure
Peripheral oedema
- Chronic endocardial disease
Can see liver engorgement, fluid within abdominal, pleural cavity, peripheral interstitial tissue
Left sided quickly progresses to right sided - so miss the pulmonary oedema phase
Where to listen to heart
Start on left
Listen just behind triceps
- Halfway between shoulder and elbow - ICS 5 mitral valve
- Under triceps - ICS 4 - aortic and pulmonic valve
Listen on right under triceps - move leg forward
What is s4 shh sound
Onset of atrial systole - audible in 60% TB
What is S1 lub sound
Onset of ventricular systole
Closure of AV valves, opening of semilunar valve
Loudest over LICS5
- Hypertension, adrenaline, MVD
What is S2 dub sound
Onset of diastole
Closure of semilunar valves, open AV
Loudest over LICS4
- Fever, adrenaline, anaemia
What is S3 de sound
Rapid ventricular filling
Loudest over cardiac apex - Low LICS5
40% TB
What makes the heart sounds
Causes by turbulence
Closure of cardiac valves
High velocity flow - young excitable or fit
Rapid outflow through aorta - normal
Murmurs - forward or reverse flow
2nd degree AV block
2nd degree AV block – associated with high vagal tone to control HR, should go away with exercise
- Significance? Only when in advanced 2nd degree AV block – blocking multiple in a row so not contracting for long periods or not going away with exercise so cannot meet requirements – collapse
Assessment of cardiac murmurs
Timing - systole or diastole and PMI - point maximal intensity
Determine valve affected
Determine a tentative diagnosis
LICS 5 murmur indicates …
Mitral valve (Left AV valve) regurgitation
LICS 4 murmur indicates…
Aortic (left semi lunar) valve regurgitation
RICS5 murmur indicates…
Tricuspid regurgitation
Which horses with a cardiac murmur need further investigation?
Poor performance and new murmur or new loud murmur
Use echocardiography to confirm, prognosis, and safety
Electrocardiography - concurrent dysrrhythmias and safety
Look for structural secondary changes
Grade murmurs
1, 2, 3, 4, 5, 6
1 - Quiet murmur hard to identify
2 - Murmur quieter than heart sounds
3 - Murmur as loud as S1 and S2
4 - Murmur louder than S1 and S2
5 - Loud cardiac murmur with pericardial thrill
6 - Murmur audible with stethescope off thoracic wall
Holo systolic murmur (or diastolic)
Timings
Between cardiac sounds
Lub-shhh-dub
Pan systolic murmur
Timings
Across heart sounds
Lshhhh Lshhhh
Mid systolic murmur timings
Lub shh dub
How to assess cardiac function
ECG
Blood pressure
Cardiac output
- Ultrasound
- VO2 max
Maximum tissue uptake - high speed treadmill with expired gas analysis
What causes murmurs in the heart
Normal blood flow - ejection type - normal - rapid outflow through major vessels
Valvular regurgitation - valvular disease - endocarditis, endocardiosis
Cardiac defects - ventricular septal defect
Endocardiosis
Valvular degeneration - progressive - mitral, aortic, tricuspid
Endocarditis - what causes it
Clinical signs
Treatment
Bacterial, secondary to bacteraemia
Cattle - liver abscesses, TRP, mastitis
Equine - dental, respiratory, thrombophlebitis
Other causes
- Valve dysplasia
- Valvulitis
- Valve prolapse
- Ruptured chordae tendonae
Clinical signs
- Acute onset cardiac failure
- Fever, cardiac murmur, tachycardia, tachypnoea
Hyperfibronogenaemia, anaemia, leukocytosis,
Blood culture - sterile procedure
US
Treatment
Broad spectrum antibiotics then based off C+S
Prognosis
- Guarded even after bacteriological cure - permanent damage
Septic emboli to distant sites - lungs if RHS, kidney, joints LHS - younger
Pericarditis
Clinical signs
Diagnosis
Treatment
Prognosis
Aitiology
- Idiopathic, equine viral arteritis, equine influenza, strep pneumoniae, e.coli, actinobacillus
Clinical signs
- Echocardiogram - fluid and fibrin within pericardial sac - compression of cardiac chambers
- Electrocardiogram -small complexes, main differential for this is obesity
Cytology of pericardial fluid - pericardiocentesis
Treatment
- Pericardial drainage and lavage if right atrium is collapsing - cardiac tamponade
Indwelling drain and BID lavage with antibiotic fluid (gentamicin) improves prognosis
Systemic penicillin
Care with IVFT - dont overload heart
Prognosis - early and aggressive - good
Constrictive disease with chronic - fibrin and fibrous tissue with chronic disease and not enough treatment
Full performance possible
Jugular thrombosis
Septic and non septic
Aitiology
Clinical signs
Diagnosis
Treatment
Non septic - thickening of vein and reduced patency
Septic - hot, painful, discharging tracts - chronic
Venous occlusion possible - swelling in supraorbital area, cheek, lips, tongue - dysphagia - URT obstruction - tracheostomy
IV catheters or injection
Predisposing
- SIRS, MODS, irritant drugs, poor placement, use, care of catheters
Use US to assess thrombus, identify cavitation (sepsis), patency, site for aspiration
Diagnosis
Culture - catheter tip that was in
- US guided, swab from discharging tract, blood
Treatment
- Broad spectrum - penicillin, gentamicin
- NSAIDs
- Systemic aspirin, heparin
Vasodilators - glyceryltrinitrate
Raise head
Embolic disease - lodge elsewhere - bacterial endocarditis, septic pneumonia
Recurrent laryngeal neuropathy
Upper airway oedema
Aortoiliac thrombosis
Partial or complete occlusion of terminal aorta, and external and internal iliac arteries by thrombus - unknown cause
Poor performace, exercise associated hindlimb lameness - differential for exertional rhabdomyolitis
Breeding failure in stallions
After exercise - cold limbs with weak pulses
Diagnosis
- Palpation or US of thrombus on rectal
Treatment
- NSAIDs - flunixin
- Aspirin
- Fenbendazole
Prognosis - guarded
Vascular aneurisms and rupture
Aitiology
Diagnosis
Management
Prognosis
Vascular rupture - sudden death
Vascular rupture and haemoperitoneum - differential with severe distress post exercise with colic pain
DDx - stress fractures, exertional rhabdomyolisis, arrhythmias
Pre-existing aneurism, medial degeneration, congenital, parasitic
Manage - conservative, support circulation, analgesic
Limit movement - dislodge clots
Tranexamic acid
Uterine bleeds - poor prognosis
Aorto-cardiac fistula
Defect of aortic wall to right atrium, intact males
Rupture during exercise or breeding
Sudden death, distress, ventricular tachycardia, loud continuous murmur
Echo diagnosis
Hopeless prognosis
