MMVD
Bacterial Endocarditis
Pericardial DZ
Congenital Heart DZ
Syncope
100
3 etiologies of Mitral Valve Disease (Explain w/ detail)
Genetic- Cavaliers and Dashunds predisposed to poly geneticcs w/ incomplete penetrence
Mechanical- Flatter mitral valve rather than saddle shaped
Inflammatory/Environmental- Increased serotonin and TGFb (transformation of quiescent valve interstitial cells to myofibroblasts)
100
Valve Most Affected
3 predisposing Factors
Dog: Mitral and Aortic
Horse: Aortic then Mitral
Cattle: Tricuspid
PF: Catheter Endothelial damage, Iatrogenic Immunosuppression, Congenital Heart Defects (SAS, PDA, VSD)
100
Common Cardiac Cancers (3)
Heart Base Mass (Chemodectoma)- well circumscribed mass that is roughly hypoechoic to the myocardium located at the aortic root (brachyephalics)
Right atrial mass (hemangiosarcoma)
Cardiac Lymphoma- thickened myocardium; infiltrative tumor throughout myocardium – pale cream discoloration
100
innocent or flow murmur
Intesity
Location
Timing
Shape
No structed heart dz and no obvious physiologic explanation.
Soft(grade I-II/VI)
Location: Left basilar
Timing: Ejection (early systolic/protosystolic)
Shape: Sweet(not harsh)
also described as being sensitive(position and heart rate) and small(localized to a small area)
100
List the three main categories of etiologies of syncope and give examples in each category.
Syncope- sudden, but brief loss of consciousness from which recovery is spontaneous and complete
Reflex (Neurally mediated): Exaggerated or inappropriate cardiovascular reflexes
-Neurocardiogenic: reflex is triggered by the heart or pulmonary vessels and the stimulus is adrenergic
-Vasovagal: triggered by the brain in response to emotional shock, phobias and pain
-Situational: vagal surge due to coughing, vomiting or urination; not reported in cats
-Carotid sinus: Mechanical stimulation of the carotid sinus
Orthostatic: Orthostatic hypotension (form of low blood pressure that happens when standing after sitting or lying down.) not seen in animals
Cardiogenic (arrhythmias and structural heart disease):
-Bradycardia, Tachycardia, Structural Heart Dz
200
Pathophysiology of Mitral Valve Regurgitation
Increased preload (diastolic volume)-> increased L ventricle diastolic pressure -> increase L wall strain -> Eccentric Hypertrophy over time-> cardiac remodeling
Extra Points for what kind of procees this is and why!
200
Pathogenesis of Bacterial Endocarditis (6)
Bacteremia+Eroded Valve Endothelium-> Colonize/ Ulcerate valve leaflets-> Platelet aggregation and vegetation forms-> Bacteria enveloped in fibrin (evades immune system)-> Valves shorten/deform-> Valves damaged irreversibly (leak or stenosis)
200
Constrictive pericarditis and its systemic Effects
Fibrosis of the pericardium from sub-acute to chronic pericarditis that limits ventricular filling (diastolic impairment)
Lowers Cardiac Output leading to Systemic Congestion
Bonus: How do this look on Echo?
200
Congenital Cardiac Defects Without Murmurs
•Vascular ring anomalies*
•Endocardial fibroelastosis (rare)
•Peritoneopericardial diaphragmatic hernia*- liver, stomach intestines in pericardial sac
•Ectopia cordis (rare)
•Eisenmenger Syndrome (right to left shunting)- Reverse patent ductus arteriosus, VSD, ASD (rare)
200
Indication for Permanent pacemaker implantation and complication
high grade 2nd degree AV block and complete AV block (aka 3rd degree AVB)
Major complications: Lead dislodgement, fracture and malfunction, infection
Minor: Seroma and Thrombus
300
Stage B1 vs B2 stages and management
Stage B1:Dogs with a murmur and no or minimal changes on radiographs; Echocardiography: LA/Ao <1.6 and left ventricle not
dilated. Management: No drugs or lifestyle change (diet/exercise). Auscultate ev. 6 to 12 mo (6 in L. dogs)
Stage B2: moderate, loud, or loud thrilling, left apical holosystolic murmurs (grade >III/VI), Significant changes (mild to moderate enlargement) – cardiomegaly (radiographically or echocardiographically) (are we in CHF?) Management: 6 mo. aus and rads, echo, MONITOR resting RR. Start Pimobendan.
300
Signalment/ Hx/ Clinical Findings
middle aged or older male, large-breed dogs, > 15 kg (+/- lamness, fever, prev. antibiotic courrse. weight loss lethargy etc.)
NEW murmur (diatolic) w/ bounding pulses; fever, polyarthritis, Arrythmias (VT, SVT, AVB)
Thromboembolism (large vegetative lesions from mitral valve) kidney, spleen, joints, CNS
300
Cardiac tamponade
pathophysiology
Beck's Triad
1. PE develops rapidly,the pericardial sacis unable to stretch, and pressures rise rapidly
2. Intra-pericardial pressures exceed intra-cardiac pressures
3. Filling is impaired and reduced stroke volume
4. Initially effects right side of the heart (R atrial collapse then ventricular collapse during diastole)and then left side (underfilling)
5. Severe form (acute) - cardiac output drops → life threatening (Does not require a large volume to have dramatic effect)
Becks triad: Low arterial BP, increased jugular pressure, muffled heart sounds'
bonus pts: when to do pericardiocentesis? When don't you?
300
murmur, the grading based on echocardiography and pathology, and the hemodynamic
consequences of sub-aortic stenosis (SAS) in the dog
Murmur: left basilar, holosystolic crescendo-decrescendo
Echo/Grading: Narrow turbulent LVOT, accelerated AV, aortic insufficiency; Bernoulli equation= 4V^2 (Severe: > 4.5 m/s (80 mmHg))
Pathology and Hemodynamic Conseq.: Increased filling pressure/ strain of the left ventricle and left atrial pressure rises leading to left
sided congestive heart failure. Advanced cases have coronary artery disease and myocardial necrosis and fibrosis→ arrhythmias and Sudden Cardiac Death (SCD)
300
Arrhythmias that cause syncope in Large Breed Dogs and Treatment
Ventricular Premature Complexes (VPCs)
-In case if ARVC, only if symptomatic: Sotalol, Mexiletine. Omega 3 Fatty Acids (Monitor w/ Holtor)
Ventricular Tachycardia
- Hospital: IV Lidocaine Chronic: Sotalol, Mexiletine, Amiodarone
Ventricular fibrillation
400
Signalment and clinical findings
Rads
Echo (What are the views?)
Labs/Biomarkers
Geriatric small breed w/ incidental murmur (Stage 3 or 4 left apical, plateau-shaped, holosystolic)
Dyspnea or tachypnea(Might be in what stage of HF?); Cyanosis
Rads: L atrial enlargement and ventricular dilation (Whats VHS?)
Echo: Nodular deformity, prolapse of valve into the L atrium w/; thicker chordae tendineae; Increase L Ventricle diameter; 1LA: Ao >1.6; turbulence at MV during systole (RPLAX, SAX, RPSAX, L apical 4 chamber)
Labs/Biomarkers: Resp. Alkalosis, Prerenal Azotemia (due to reduced CO), Inc. Liver Enzymes w/ dec. plasma proteins and albumin(R HF), NTproBNP(indirect measurement of magnitude of cardiac mm stretch) test issues?
400
6 Potential Outcomes of BE
1. Irreversible valve damage (ulcerative endocarditis)
2. Polypoid endocarditis (obstruction)
3. Myocarditis
4. Perivalvular abscess(involvement of AV node / Hiss
bundle – arrhythmias, including an AV block or premature ventricular depolarizations)
5. Septic Emboli
6.Immune complex deposition
400
Diagnosis of Pericardial Effusion (Clinical Signs, ECG, Echo, Fluid Analysis)
Clinical Signs: May find incidentally. Poor CO(Pallor, Long CRT, Weak Pulse, Tachycardia, Muffled Heart Sounds) and/or R CHF (Jugular distension, Ascites, Hepatomegaly)
ECG: Small complexes, electrical alterans, ST segment elevation, Arrythmias (based on location)
Echo: Will show fluid in pericardial sac (100% sens. and spec); Normal image in constrictive pericarditis but restrictive filling pattern
Bonus: What would you see in the event of tamponade?
Bonus: Can we diagnose with thoracic rads?
400
embryologic role of a ductus arteriosus, state the age at which it should close, the result of the duct remaining patent - the hemodynamic consequences in the puppy
Embryo: serves as a shunt between the pulmonary artery and the aorta . fetal lungs are filled with amniotic fluid and, therefore, cannot be used to oxygenate the blood and oxygenated blood is received through the placenta.
Stage: @ 1st breath; prostaglandins are triggered to cause vasoconstriction of DA on the pulmonary aspect 1st and then the arterial side. Closed by dday 7 in most species.
Remaining: 60% of dogs that are not treated will develop
congestive heart failure by 1 year of age
Hemodynamic Conseq.: Continuous turbulence in the pulmonary artery distal to the bifurcation. Volume overload of the left ventricle.
Bonus: Treatment options?
400
Explain how oxygen therapy improves pulmonary hypertension.
O2 corrects hypoxia but also dilates pulmonary capillaries reducing vascular resistance
500
Dogs with a murmur that cough are more likely to have
primary___________
Vertebral Heart Score (VHS) < _____ are
likely to have a cough that is unrelated to their MMVD
___________could be the cause of coughing in a dog with MMVD
allergic airway disease (chronic bronchitis)
12.8
Left mainstem bronchus collapse from left atrial dilation
500
Negative prognosticators (5)
- Aortic location
– Treatment with glucocorticoids
– Renal failure/azotemia
– Pulmonary hemorrhage
– Neurological signs
500
Treatment and Prognosis
(Therapies and Definitive Tx)
Pericardiocentesis (Describe technique), Yunnan Baiya(for bleeding), Diuretics, Antibiotics (not effective alone), Magnets for cows
Can't give Digitalis, Pimobendan, Furosemide
Definitive Tx: sub-total pericardiectomy
Prognosis: Recurrence 50% for idiopathic PE (Pericardiectomy is recommended). If the effusion recurs quickly, neoplasia is likely, and prognosis is guarded (likely hemangiosarcoma). Constrictive pericarditis and septic pericarditis also guarded but hope w/ surgery and and intensive therapy.
500
Describe the pathology of mitral (MVD) and tricuspid dysplasia (TVD), the echocardiographic
changes and the hemodynamic consequences of each disease
Pathology/ Echo?:
-MVD: thickened valve cups w/ short chordae tendineae; Enlarged left atrium/auricle and ventricle
-TVD: thickened valve cups w/ short chordae tendineae, R atrium and ventricular enlargement
-MVD:
Hemodynamic consequences:
MVD: Signs of heart failure at 6-12 months
TVD: Severe tricuspid regurgitation; heart failure by 1-5 year old; ascites, arrythmias
500
Diagnostic Approach to Syncope
1. Consider Likely diagnoses based on signalment
2. History (drugs, toxins, event description, triggers, breed dispositions)
3. Cardiovascular examinations & Blood pressure measurement (murmurs, Irr. Rhythm)
4. Laboratory testing
5. ECG (resting ECG (irreg. rhythm), 24 ambulatory ECG (arrythmia) )
6. Echo (examine for structural heart disease, irrespective of whether a murmur is detected )
7. Holstor analysis
8. Fix/Treat