Cardiac Flashcards
Physiological causes of cyanosis in a neonate
- R to L ventricular shunt (tetralogy of Fallout)
- R to L partial shunt (severe pulmonary stenosis)
- Complex mixing ( single ventricle disease)
- Transposition physiology (transposition of the great arteries)
Determinants of arterial O2 saturation (5)
1- Pulmonary venous oxygen saturation (V/Q)
2- Pulmonary to systemic flow ratio (Qp:Qs)
3- Systemic blood flow (slow flow=longer extraction)
4- Hgb
5- Total body O2 consumption (VO2)
What is Eisenmenger syndrome
- condition presenting in older children as a result of pulmonary hypertension secondary to a chronic ASD (30%) VSD (33%) or PDA (14%) “ communication between systemic and pulmonary blood flow”
- features: fingernail clubbing, syncope, heart failure
Which CHD will present with significant pulmonary edema on CXR
Total anomalous pulmonary venous connection
Total anomalous pulmonary venous connection
- 4 pulmonary veins fail to connect to LA
4 types
- supracardiac
- cardiac
- infraacardiac
- mixed
cause of higher pre ductal vs post ductal saturations
- **Severe PPHN (PVR too high, blood preferentially circulating through PDA)
- Aortic coarctation
cause of lower pre ductal vs pre ductal saturations
Transposition of great arteries ( high PVR = blood flowing through LV into pulmonary artery crosses PDA and mixes with oxygenated blood)
Possible causes of a right displaced aorta
ToF
snowman
TAPVR
egg on a string
Tans-position of the great arteries
approach to cadiomypathy
- reversible cause? (infection/structure)
- manage (after-load reduction (milrinone, ace, BB) , HR control, diuresis)
what cardiac pathology should you consider in viral infections
myocarditis 7-28% of sudden death in peds if survive can lead to cardiomyopathy
presentation
ecg (tachy with low voltage QRS)
fever
heart block
tachycardia (persistant not responding to conventional therapy)
resp distress
older children ( exercise intolerance, abdominal pn)
management
diuretics, anticoagulant, steroids, IVIG, after-load reduction
definition of htn in ped
BP > 95th percentile for age, gender and height
hypertensive emergency vs urgency
emergency: severely elevated BP + end-organ damage
S/S HTN in peds
HTN’ive encephalopathy
DLOC
HA
nausea
Vomiting
DDX for hypertensive enceph
acute neuro event renal disease hepatorenal syndrome steroid OD AMI LV failure with pulmonary edema microangiopathic hemolytic anemia Dissecting AA coarctation
Tx for HTN’ve crisis
- Labetolol 0.25 mg/kg bolus then 0.25-3 mg/kg/hr
Recommended reduction MAP by 20-25% over 6-8hrs) (below 95th preventive
-*** signs of ICP osmolar therapy is paramount prior to BP reduction -
AAA drop BP faster
- try to get an art line, 2 lines
size of heart on CXR
50-60% of chest
SVT TX
- ice
- adenosine (.1 mg/kg, .2 mg/kg)
- cardioversion (.5J/kg - 1J-2J) (+ sedation ketamine)
consideration for pacemakers
- bicarb in setting of arrythmia
common arrhythmia complication cardiac surgery
JET
junctional ectopic tachycardia
common cause of bradycardia in peds
hypothermia
Post cardiac arrest goal
- PaO2 > 60 < 300
- PaCO2 35-40
- tight glycemic control
- norothermia
- BP > 5th percentile
high lying UV on CXR
above diaphragm lateral film is easier to view diaphragm
