Day 8 - cardiac diseases Flashcards
General steps of exam of cardiac diseases
- Detailed physical examination at rest
- Exercise test/performance analysis (is the cardiac problem the cause?, subclinical and transient problems)
- Echocardiography: murmurs, pericardial effusion
- ECG: arrythmias (exercise test)
- Laboratory parameters (hematology, biochemistry, microbiology, cytology (pericardial effusion))
Left-sided congestive heart failure (CHF)
acute: lung-edema,
chronic: cardiac cachexia
Right-sided heart failure:
ventral oedema, venous pulsation
consequence of unilateral HF
will become bilateral
Most common congestive HF
Valvular heart disease (+ atrial fibrillation)
CS of HF
Exercise intolerance
Slow return to resting values
Weight loss
Cough
Tachycardia
Tachypnoea
Ventral edema
Pulmonary congestion, edema
Colic-like signs
CHF - Tx (4)
- Digoxin
- Furosemide
- Potassium chloride
- ACE inhibitors
Congenital diseases
- Ventricular septal defect, atrial septal defect
- Abnormal valves
- Complex cardiac defects
- Vascular malformations (Patent ductus arteriosus)
Vascular septal defect - Tx
- Most common, Inherited
- Basal area
- Signs depend on size: > 2,5 cm: Left to right shunt
- Cardiac murmur: Holo- or pansystolic, grade 3-5/6, point of maximum intensity (PMI) below tricuspid opening
- Dx: 2D and Doppler echocardiography
- Tx: as CHF or euthanasia
Ventricular septal defect - Eisenmengers syndrome
right to left shunt
Acquired heart diseases - Endocardium and valves
Bacterial/vegetative endocarditis (infective)
Degenerative thickening of the valves
Valvular dysfunction, secondary to myocardial disease Ruptured chordae tendinea
Prolapse of valves
Aortic regurgitation
Mitral regurgitation
Tricuspid regurgitation
Pulmonary regurgitation
Acquired heart diseases - Myocardium
- Myocarditis (equine influenza, herpesvirus, rhinopneumonitis, bacterial)
- Myocardial fibrosis (Ischemic or strongylosis)
- Myocardial degeneration/necrosis (Toxic or Se/Vit E def.)
Acquired heart diseases - Neoplasia and Dilated cardiomyopathy
Lymphosarcoma, melanoma, haemangio(sarco)ma
(idiopathic) - rarely
Acquired heart diseases - Arrhytmias
- Atrial, junctional and ventricular premature complexes
- Atrial tachycardia, flutter, fibrillation
- Ventricular tachycardia, flutter, fibrillation
- Second and third degree atrioventricular blocks: 1st degree always physiological
Grade 5 L-sided murmur (holosystolic)
mitral regurgitation/aortic stenosis –> a. stenosis Ø common in adult horses
Grade 5 L-sided murmur (holodiastolic)
Ø have to think about mitral stenosis
Bacterial endocarditis - Pathogens and CS
o Streptococcus Equii ssp equi, Streptococcus Equi ssp zooepidemicus, Actinobacillus equuli, Rhodococcus equi
- Mitral, aortic, tricuspid, pulmonary (high to low)
CS: Bacreremia, Resp signs, Cardiovasc signs (grade 3-6/6 murmur)
Bacterial endocarditis - ancillary and lab
o ECG, phonocardiography, echocardiography
o Aortic regurgitation —> diastolic, decrescendo murmur
o Leukocytosis, neutrophilia, hyperfibrinogenemia, hypergammaglobulinemia
o Blood culture (aseptic venous blood sample before starting AB treatment)
Bacterial endocarditis - Dx and Tx
o Suspicion based on clinical signs, echocardiography
o AB: initially broad spectrum
o Treatment of congestive heart failure
o Antiarrhythmic drugs if necessary
o Flunixin meglumine
o Low molecular weight heparin
o Strict box rest
Aortic valve insufficiency
- Most common, older horses
- Not always leading to exercise intolerance
- Prolapse, nodules, thickening, fenestrations of valve leaflets
- Holodiastolic, decrescendo, grade 3-6/6 murmur on left side
- Strong, short pulse
- Compensation: hypertrophy (stronger contraction stronger pulse), MVI, left atrial dilation, AF
- Mosaic pattern = regurgitation
Mitral valve insufficiency
- Pan- or holosystolic murmur on left side, PMI: 5th ICS
- Can continue to diastole: enhancement of 3rd heart
sound, fast early filling - Acute/peracute MVI: ruptured chordae tendinea
- Left atrial dilation, jet lesions (erosion development in
atrial endocardium / endothelial abnormalities) - Echo on left side due to large heart and thickened chest
wall
Rupture of chorda tendinea
- Peracute cardiac failure
- Pulmonary edema: Can give huge amounts of digoxin - help pump function of the heart + large dose of furosemide
- Grave prognosis
Tricuspid and pulmonary valve insufficiency
- Tricuspid valve insufficiency
o Bacterial or secondary together with MVI
o Systolic, grade 3-5 murmur of right side
o Dilated jugular vein, positive venous pulse (due increased pressure/regurgitation into RV –> vena cava —> jugular vein) - Pulmonary valve insufficiency
Atrial premature complex - Tx
Ausc, ECG
abnormal P-wave, narrow QRS,
Tx: Box rest, Arrhytmic drug (Quinidine, procainamide),
Dexamethadone
Correction of electrolytes
Atrial fibrillation - Tx
Myocardial disease, not alter CO, cons of other cardiac disease
ECG: Variable, irregular RR intervals, No P wave, F wave instead
Tx: Quinidine, Digoxin
Atrial flutter
- Can be a stage after atrial fibrillation
- Higher P wave
- Lower contraction rate of atria compared to fibrillation
- Can go to normal sinus rhythm
Ventricular tachycardia - Tx
- 4 or more consecutive VPCs, life-threatening, Fast HR
ECG: Abnormal QRS complex and T wave, QRS is independent from preceding P-wave, P wave may merge into QRS or T wave o “R-on-T” phenomenon - Torsades de pointes
Tx:
o Lidocaine IV
o Procainamide IV/PO
o Propranolol IV/PO
o Propafenone IV/PO
o Flecainide acetate IV
o Magnesium sulphate IV/nasogastric tube
o Bretylium IV
