Fiser Chapter 26 CARDIAC Flashcards
Shunt causing cyanosis
R to L shunt
Children squatting does what
Increases SVR and decreases R to L shunt
Cyanosis from R to L shunt can lead to what
Polycythemia, stroke, brain abscess, endocarditis
Eisenmenger’s syndrome
L -> R shunt switches to R -> L shunt
Sign of increasing pulmonary vascular resistant and pulmonary HTN, and is generally irreversible
Shunt causing CHF
L to R shunt
Manifests as failure to thrive, tachycardia, tachypnea, hepatomegaly
First sign of CHF in children
Hepatomegaly
Causes of L to R shunts
VSD
ASD
PDA
PDA causes what kind of shunt
L to R
Causes of R to L shunts
Tetralogy of Fallot
Ductus arteriosus
Connection between descending aorta and Left pulmonary artery; blood shunted away from lungs in utero
Ductus venosum
Connection between portal vein and IVC; blood shunted away from liver in utero
Fetal circulation at placenta
2 umbilical arteries (take blood away from fetus)
1 umbilical vein (brings blood to fetus)
Most common congenital heart defect
VSD causing a L -> R shunt
80% close spontaneously by 6 months
Large VSDs usually cause symptoms after 4-6 weeks old, as PVR decreases and shunt increases
Cx: CHF (tachypnea, tachycardia) and FTT (failure to thrive)
Tx: Diuretics, digoxin, repair
VSD timing of repair
FTT: most common reason for earlier repair
Medium (shunt 2-2.5): 5yo
Large (shunt > 2.5): 1yo
ASD types
Ostium secundum is most common; centrally located
Ostium primum (or atrioventricular canal defects or endocardial cushion defects); can have mitral valve and tricuspid valve problems; frequent in Down’s syndrome
ASD
L -> R shunt
Usually symptomatic when shunt > 2 -> CHF (SOB, recurrent infections)
Can get paradoxical emboli in adult hood
Tx: Diuretics and digoxin
ASD timing of repair
1-2yo
If canal defects: 3-6 months old
Tetralogy of Fallot
PROV:
- Pulmonic stenosis
- R ventricular hypertrophy
- Overriding aorta
- VSD
R to L shunt -> cyanosis
Tx: Beta blocker, repair at 3-6 months old
Most common congenital heart defect that results in cyanosis
Tetralogy of Fallot
Tetralogy of Fallot repari
-RV outflow tract obstruction removal, RVOT enlargement, and VSD repair
PDA
L to R shunt
Tx: indomethacin to close, rarely successful beyond neonatal period, requires L thoracotomy for repair if persists
MCC death in US
CAD
CAD risk factors
- Smoking
- HTN
- Male
- Family hx
- HLD
- DM
CAD medical tx
-Nitrates, smoking cessation, weight loss, statins, ASA
Coronary arteries
LMA branches into LAD and LCx
Where are most atherosclerotic coronary lesions?
Proximal
MI complications
- Ventricular septal rupture
- Papillary muscle rupture
3-7 days after MI, patient has hypotension, pansystolic murmur, and a step-up in O2 content between R atrium and pulmonary artery
Ventricular septal rupture
Dx: Echo
Tx: IABP and patch over septum
3-7 days after MI, patient has severe mitral regurgitation with hypotension and pulmonary edema
Papillary muscle rupture
Dx: Echo
Tx: IABP, replace valve
Incidence in restenosis in CAD revascs
Drug-eluting stent: 80% at 1 year
Saphenous vein graft: 80% at 5 years
Internal mammary artery (off subclavian): 95% 20 year patency when placed to LAD; collateralizes with superior epigastric artery
What do you use to cause arrest of heart in diastole and keep heart protected and still while grafts are placed during CABG?
Potassium and cold solution cardioplegia
CABG indications
Left main > 50% stenosis or at other site > 70% stenosis
- Left main disease
- 2-vessel disease involving LAD
- 3 vessel disease (LAD, Cx, RCA)
- Lesion not amenable to stenting
High mortality risk factors for CABG
Pre-op cardiogenic shock is #1 risk factor
Emergency operations
Age
Low EF
Mechanism of aortic stenosis
Degenerative calcification
Benefit of bioprosthetic tissue valves
- Do not require anticoagulation
- But not as durable, last 10-15 years
- Use for patients who want pregnancy, have contraindication to AC, are older >65, and unlikely to require another valve in their lifetime, or have frequent falls
- Contraindicated in children and young patients d/t rapid calcification
DOE, angina, syncope
Aortic stenosis
Syncope is the worst with mean survival 3 years (versus 4 and 5 for angina and DOE)
AS indications for operation
Symptomatic (usually have peak gradient > 50 mm Hg and valve area < 1.0 cm^2)
Key index of disease progression in patients with MR
Ventricular function. Usually becomes dilated.
Other symptoms: A fib, pulmonary congestion
MR indications for operation
Symptomatic or severe MR
Pulmonary edema, dyspnea, hx of rheumatic fever
MS
MS indications for operation
Symptomatic (usually have valve area < 1 cm^2)
Balloon commissurotomy to open valve often used as 1st procedure
Patient with fever, chills, sweats, and heart murmur
Endocarditis, usually Staph aureus and Left sided (except drug users: pseudomonas? and Right sided)
Most common site of native valve vs prosthetic valve infections
Native: mitral
Prosthetic: aortic
Endocarditis tx
Medical tx successful in 75%, sterilizes valve in 50%
Surgery if failure of abx, severe valve failure, peri
