Cardiology Flashcards
Characteristics of a VSD on examination?
Loud, harsh, blowing pansystolic/holosystolic murmur, best heard at LLLE with thrill (should be L–>R shunt)
What is Eisenmenger syndrome?
Reversal of shunt through a defect to R–> L due to pulmonary hypertension - Cyanosis - murmur may disappear - accentuated S2 - cubbing
Normal foetal cardiac physiology x 4
1) Right –> Left shunting at the atrium through patent foramen ovale and from the arterial level thorugh the ductus arteriosis 2) High pulmonary vascular resistance 3) Low pulmonary blood flow 4) Ventricles work in parallel
What is this?
Ebsteins anomaly, cardiomegally, lung hypoplasia
TAPVD = total anomalous pulmonary venous drainage
Most commonly infra-cardiac and below the diaphragm
If also an obstruction to flow into LA = BAD, needs urgent surgery
Pulmonary blood flow goes into RA so RA saturations will be high
Causes of murmurs in first 24 hours of life?
Semi-lunar valve stenosis AV / tricuspid valve regurtiation Usually NOT ASD/VSD
Causes of cyanosis in the first 24 hours of life
Transposition of the great arteries single ventricle physiology
When do duct dependent lesions appear?
24 hrs –> 2 weeks of life
Cardiac lesions dependent on blood flow to lungs?
Present with cyanosis when duct closes eg) Critical pulmonary stenosis, pulmonary atresia, single ventricle with PS/PA
Cardiac lesions dependent on blood flow to body?
Present with low cardiac output (shocked) when duct closes eg) critical aortic stenosis, critical coarctation of the aorta, hypoplastic left heart syndrome
What is the hyperoxia test?
Place child in high oxygen environment - if sats / pO2 >150mmHg, likely lung pathology - If low sats / poor pO2, likely to be a cardiac issue with mixing of oxygenated and deoxygenated blood
Transposition of the Great Arteries (describe)
CXR - narrow upper/anterior mediastinum as aorta and pulmonary vessels are on top of each other, heart not huge, Present with cyanosis, M>F Mx - prostaglandin (keep duct open), septostomy (open ASD larger to mix blood, may need atrial switch procedure
Cyanotic neonate, what does this ECG show?
Small RV/TV large R waves
= ECG of pulmonary atresia
Management of pulmonary atresia
Mx: prostaglandin to keep duct open, If septum intact, associated with fistula to coronary artieries which when corrected, drop in pressure can cause myocardial ischaemia
Describe Truncus arteriosis
Large VSD
Single large outflow tract
CXR - pulmonary plethora
Well until pulmonary vascular resistance drops
Tetraology of fallot + pulmonary atresia
Large VSD
No pulmonary outflow tract (atresia) - maintain bronchial arteries from aorta
ADD INFO
Main signs and symptoms of heart failure in infants
*** Poor feeding
tachypnoea
tachycardia
**** poor growth
diaphoresis
hepatomegally
What percentage of children will have a systolic heart murmur?
+ most common
Up to 50%
15% will have a >2/6 murmur
Most do not have CHD and dont need any other investigation
- Most commonly “functional” murmur, ASD, small VSD, AS/PS, rarely PDA or coart if child is well
- minor lesions can wait until >3yrs
Older childen - common causes of heart murmurs?
1) innocent murmur
2) ASD - lound second heart sound, hyperdynamic praecordium, ,systolic flow murmur
Characteristics of coarctation of aorta?
Murmur heard best posteriorly (b/w scapular)
Hypertension
Difficult to palpate femoral pulses
associated with bicuspid aortic valve
Characteristics of an innocent murmuer in older kids? (x 5)
Healthy child, no exercise intolerance
No signs of heart failure / cyanosis
Normal praecordium
Murmur intensity varies with posture and fever
Normal second heart sound
* Pathological murmurs are almost never intermittent *
What is still’s murmur?
Vibratory murmur
A twanging sound, like that made by a piece of string
= aortic leave vibration
Almost always resolves when sitting
What is a venous hum and how can you elicit it?
Benign phenomenon
Heard loudest above the right clavicle
Continous, if loud, often confused with PDA
Assess my occluding ipsilateral internla juglar vein (if is disapears = venous hum)
Rheumatic heart disease
Mitral / aortic regurg
Valve thickening and deformity
pancarditis (pericardium, myocardium, epicardium)
Follow guildelines
* Can present in complete heart block *
Causes of Cardiomyopathy in a structurally normal heart (x 6)
Myocarditis
Familial dilated cardiomyopathy
Tachycardia induced
Mitochondrial
Myopathies
Metabolic
Heart failure management
Diuretics
ACE inhibitors
Spironolactone
betablockers
* may need inotropes eg) dobutamine, milrinone
What is the bernouli equation?
Change in pressure = 4 x (distal velocity2 - proximal velocity2)
Assume promimal velocity is low (except in coart)
therefore:
Change in pressure = 4 x (distal velocity2) mmHg
What is the noral expected fractional shortening?
30%
= diameter of ventricle in diastole minus diameter of ventricle in systole divided by VDD