Flashcards in Module 6 CVS continued- Congenital Heart Deck (44):
What are congenital heart diseases?
Abnormalities of the heart or great vessels that are present from birth
What are the two physiologic shunts?
1. Foramen Ovale
2. Ductus Arteriosus
What is the normal fetal to adult circulation transition?
At birth baby breathes --- lungs inflate and pulmonary resistance (right sided pressures) fall
---blood flow stops through foramen ovale (flap valve)
---ductus arteriosus closes by 15 hr of life
---prostaglandins (PGs) (main patency, produced in placenta, metabolized in lungs, at birth decreased production and increased breakdown)
What are some causes of congenital heart defects?
Main known causes: sporadic genetic abnormalities
---trisomy 13,18,21 and monosome X
What are the right to left shunts (cyanotic), called the terrible T's
1. Tetralogy of Fallot
2. Truncus arteriosus
3. Tricupsid atresia
4. Total anomalous pulmonary venous connection
5. Transposition of great vessels
What are the left to right shunts (non cyanotic), called the D's
1. Atrial Septal Defect( ASD)
2. Ventricular Septal Defect (VSD)
3. Patent Ductus Arteriosus (PDA)
What is the reason for cyanosis in right to left shunts?
Deoxygenated blood mixes with oxygenated blood --- flows into the systemic circulation
--if caused by congenital heart defect, requires R- sided circulation to flow to L-sided
circulation bypassing the lungs
Tetralogy of Fallot is the most common form of cyanotic congenital disease (NOTCH2 mutation), what are the 4 defining features in order
1. Right ventricular hypertrophy
4. Pulmonary stenosis (most important for patients)
What is the pathogenesis for tetralogy of fallot?
Antero-superior displacement of the infundibular septum
What is the presentation for an infant with tetralogy of fallot?
Becomes apparent at 6 months after birth -- decreased fetal Hb decreases (holds onto more oxygen due to high affinity) --- finger clubbing
Tet spells (squatting) -- increased after load to reverse the shunt -- left to right --- cyanosis transiently improves
(increases peripheral or systemic vascular resistance and this is what makes the shunt switch)
What are the complications of tetralogy of fallot?
DVT: paradoxial embolism -- bypasses pulm circulation and goes to the systemic circulation (aka legs or brain)
Jet lesions: right to left ventricle-- lands on left endocardial surface and damages it
Chronic hypoxia: (Because bypassing the lungs) so in response to low oxygen levels kidney makes Erythropoietin (EPO) and this leads to secondary polycythemia (increased RBCs)
What investigations are done for tetralogy of fallot?
Boot shaped heart on CXR
The next T is truncus Arteriosus, what is involved in this shunt?
Failure of partitioning of embryologic truncus into aorta and pulmonary artery
--Single great artery gets blood from both ventricles
--blood from both ventricles mixes
The third T is tricuspid atresia, what is involved in this shunt?
Complete occlusion of the tricupsid valve oriffice
--mitral valve is larger than normal
--R to left shunt though ASD (bypass obstruction)
---L to right shunt through VSD (get blood from RV)
--cyanotic from birth
The fourth T is Total Anomalous Pulmonary Venous Connection (TAPVC)
Pulmonary veins fail to join the left atrium
--pulmonary return vessels drain into the left innominate vein or coronary sinus
--ASD always present
---R to left shunting through ASD due to lower left atrial pressure
--left to right through ASD (No normal return) results in cyanosis
The fifth and final T is transposition of the great arteries, what does this involve?
Aorta off RV and pulmonary artery off LV
---AV connections normal (2 isolated systems)
--LV to the lung and LA from the lung
---RV to the body and RA to the body
--incompatible with life unless a shunt is present
VSD is the first L to R shunt what is affected in this shunt?
Membranous VSD -- most common congenital heart disease (Asymptomatic)
---associated with trisomy 21,13,18
---incidental finding on examination or ECG
What is the pathogenesis for VSD?
--defect in the ventricular septum allowing left to right shunting of the blood
--ventricular septum normally is formed by the fusion of muscular ridge that grows upward from the apex of the heart to a thinner membranous partition that grows downward from the endocardial cushion
---the basal (membranous) region is the last part of the septum to develop and this is the site of approximately 90% of VSDs
--although more common at birth, most VSDs close spontaneously in infancy or childhood
What are the common site for VSD?
The size and locations of VSDs are variable, ranging from minute defects in the membranous septum to large defects involving the entire interventricular wall
What is the pathogenesis for Large VSDs?
Result in chronic severe left to right shunting, often leads to complications
pulmonary HTN (overtime this growing RV due to volume increase and pressure increase) --- Right heart failure, nutmeg liver and jet lesions (vegetations that develop where a regurgitant jet of turbulent blood flow strikes the endocardium , blood going from high to low pressure region) ----damaging RV ---- sub acute infective endocarditis (Which is a bulky mass of thrombotic debrie and organisms hanging off a valve) --- embolizes and goes through the lungs
What is Eisenmenger's Syndrome?
Chronic pulmonary HTN --- shunt reversal (R to L) --- jet lesions on left ventricle ---embolize and goes to systemic
(When you have a reversal of a left to right shunt due to chronic pulmonary overload may cause a new onset cyanosis (all the blood going to left ventricle and the lungs are starved for oxygen)
What are some complications of VSD?
DVTs and embolizes --- lungs
Pansystolic murmur --- loudest at the lower sternal border at axilla
What investigation do you do for VSD?
ASD is the next left to right shunt and is the most common congenital cardiac malformation diagnosed in adults, what does the patient present with ?
Systolic (Contraction) ejection murmur --- loud S1 due to S2 splitting
Cyanotic Heart problems: blue baby syndrome occurs as a consequence of right to left shunt
Eisenmenger syndrome: right to left shunt due to pulmonary HTN (This can lead to paradoxical emboli)
No jet lesions
What are the three main types of ASD?
Ostium primum: associated with down syndrome (5%)
Ostium Secundum: Most common (90%)
Sinus Venosus: (5%)
What is the pathogenesis for ostium primum?
Ostium Primum: also commonly called an ASD, the opening is at the lower portion of the atria between the atrium and ventricle
What is the pathogenesis for ostium secundum?
Ostium Secundum: incomplete closure of the foramen ovale, inadequant growth of septum secundum or excessive absorption of the septum primum. note that this is only considered an ASD when the defect reaches a clinically appreciable size or promotes significant shunting
What is the pathogenesis for sinus venosus?
Sinus Venosus: occurs in the upper portion of the atrial septum and results in an abnormal connection between the pulmonary veins but in sinus venosus ASD ,one of these veins may drain into the right atrium
How would you differentiate between ASD and Patent foramen ovale (PFO)?
Normally, septum primum and secundum occlude ostium secundum (becomes foramen ovale) during development --- at birth ---- increased pressure in left heart = permanent fusion of septa against foramen
--in PFO flaps are good and fully developed but just not fused
--in ASD flaps are not fully developed
What is a complication of an ASD?
During transient increased pressure in right heart (ex:coughing) = flaps open = blood shunts Left to right through foramen ovale and get paradoxical emboli
Obstructive congenital anomalies involve obstruction of blood flow in the valves or great vessels. What are the three obstructive congenital abnormalities?
Coarctation of the aorta
Pulmonary stenosis and atresia
Aortic stenosis and atresis (hypoplastic left heart syndrome)
What is coarctation of the aorta?
is a congenital condition whereby the aorta narrows in the area where the ductus arteriosus inserts.
--aortic coarctation is considered when a section of the aorta is narrowed to an abnormal width
associated with turner syndrome
50% of cases associated with bicuspid aortic valve
The first type of coarctation of the aorta is Preductal (infantile) explain what symptoms you see?
The narrowing is proximal to the ductus arteriosus (PDA)
--blood flow to the aorta that is distal to the narrowing is dependent on the ductus arteriosus; therefore severe coarctation can be life threatening due to cyanosis of lower extremities
The second type of coarctation of the aorta is Postductal (adults), explain what symptoms you see?
The narrowing is distal to the insertion of the ductus arteriosus.
--even with an open ductus arteriosus, blood flow can be impaired to lower extremities (hypotension to LE)
---associated with notching of the ribs (Because of collaterals)
---hypertension in UE
The next obstructive congenital abnormality is pulmonary stenosis and atresia, explain the characteristics of this ?
--Hypoplastic RV and ASD
---blood reaches lung via PDA
The last obstructive congenital abnormality is aortic stenosis and atresia, explain the characteristics of this?
Hypoplastic left heart syndrome, need PDA
--valvular (Affects valve cusps)
--subvalvular (subaortic stenosis a ring of fibrous tissue below valve cusps)
---Supravalvular (inherited aortic dysplasia)
What is the most common secondary tumor of the heart?
Most common are metastatic neoplasms
What are clinical symptoms of tumors of the heart?
Sudden onset of severe, rapidly progressive heart failure w/o apparent cause and/or arrhythmia
What are cardiac atrial myxomas?
most common primary tumor in heart
myxoma: tumor (myxo= heart)
often calcify and can at times be seen on xray
most common in left atrium
micro: multinucleated stellate cells suspended in the edematous mucopolysaccharide --rich stroma
In a triple coronary artery bypass what artery is the most commonly used?
Internal Thoracic Artery also called internal mammary artery
---can hold up under high pressures (because its an artery also dont have to flip inside out because arteries dont have valves)
Long saphenous vein---less common (have to turn inside out due to the valves)
Pericardial diseases are based on type of exudate: serous, fibrinous, purulent and sanginous. what disease go with what exudate?
Serous: CHF and Hypoalbuminemia
Sero-Sanguineous: trauma or malignancy
Chylous: mediastinal lymphatic obstruction
Hemopericardium: cardiac tamponade
Pericarditis is inflammation of the pericardium, primary cause is unknown but what are secondary causes?
Secondary: Acute MI, cardiac surgery, radiation, Rheumatic fever (Fibrinous pericarditis), SLE
--uremia (renal failure): most common systemic disorder
--post MI: 2-3 days = fibrinous pericarditis and 2 weeks= Dressler's Autoimmune
--TB constrictive pericarditis
What are symptoms of all pericarditis?
Chest pain when you lie flat, relieved when you sit forward due to pericardial friction rub