Congenital Heart Disease + Valvular Heart Disease Flashcards
What does Left to right shunt and right to left shunt mean
NOTE:
- The left atrium receives oxygenated blood from the lungs to the rest of the body - SYSTEMIC CIRCULATION
- The right atrium receives deoxygenated blood returning from other parts of the body, and transports to lungs - PULMONARY CIRCULATION
- A left-to-right shunt allows the oxygenated, pulmonary venous blood to return directly to the lungs rather than being pumped to the body.
- A right-to-left shunt allows the deoxygenated, systemic venous return to bypass the lungs and return to the body without becoming oxygenated
What congenital heart disease is down syndrome associated with?
VSD - ventricular septal defect
AVSD - atrioventricular septal defect - ostium primum ASD (MOST COMMON IN DS)
Endocardial cushion defect: Ostiurn primum defects (15%-20% of cases) are located in the
lowest portion of the atrial septum; they are commonly associated with a cleft mitral valve, ventricular septal defect, and subaortic stenosis, a collection of abnormalities termed endocardial
cushion detect.
What congenital heart disease is associated with Di George (22q deletion)?
great artery malformation
tetralogy of fallot
What congenital heart disease is associated with lithium
Ebstein anomaly (tricuspid valve is in the wrong position and the valve’s leaflets are the incorrect shape) , TV anomaly
What congenital heart disease is associated with rubella?
Rubella - peripheral PA (pulmonary artery) stenosis
PDA
What defect is common in adults presenting with Eisenmenger syndrome?
VSD or PDA
Shunt Volumes
Qp/Qs ratio = 1:1
Qp/Qs >1
Qp/Qs < 1
The ratio of total pulmonary blood flow to total systemic blood flow, the Qp/Qs ratio, is a useful tool for quantifying the net shunt.
- A Qp/Qs ratio of 1:1 is normal and usually indicates that there is no shunting.
- A Qp/Qs ratio of >1:1 indicates that pulmonary flow exceeds systemic flow and defines a net left-to-right shunt.
- A Qp/Qs ratio of < 1:1 indicates a net right-to-left shunt.
ASD (atrial septal defect)
- Clinical Features
- Physical Exam
- Communication between atria, left and right shunt
- Ostium secundum (75%) are most common, ostium primum (15-20%)
Clinical Features
- Fatigue
- Exertional dyspnoea
- Atrial fibrillation
- PARADOXICAL EMBOLISM
Physical Exam
- Jugular venous distension
- Parasternal heave
- Mild systolic ejection murmur over LEFT sternal edge
- FIXED SPLITTING of S2
Can present with pulmonary HTN (rare)
Summary
- FIXED S2 SPLITTING
- Small atrial septic defect (Qp:Qs < 1.5) with no associated symptoms or right heart enlargement can be followed clinically
- SYMPTOMS AND RIGHT SIDED HART CHAMBER ENLARGEMENT = ATRIAL SEPTAL DEFECT CLOSURE
Symptoms: Platypnea-orthodeoxia (P-O) syndrome is an under-diagnosed condition characterized by dyspnea and deoxygenation when changing from a recumbent to an upright position (worse when upright). It is usually caused by increased right-to-left shunting of blood on assuming an upright position, with normal pressure in the right atrium
What examination finding is found in aortic stenosis?
Aetiology
Aetiology
- > 70yo: degenerative
- <70yo: bicuspid, rheumatic
Clinical: - Crescendo decrescendo ejection systolic murmur over right sternal murmur radiating to carotids - May progress to biventricular failure Paradoxically split S2 Single S2
Progression
- Angina
- Syncope
- Failure
TTE
Mean Gradient > 40
Aortic valve area < 1cm
Dobutamine stress echo can be done to determine pseudo AS vs true AS
Ventral septal defect murmur
- Most common at birth but frequency decrease by adulthood because of spontaneous closure
- Most commonly type - perimembranous
Clinical Features
Loud holosytolic murmur located at the left sternal border and often obliterates the S2 and may be palpable
- Small VSD do not cause left enlargement or PAH
- A moderate sized VSD with moderate left to right shunt may cause left ventricular volume overload and PAH
- Worsening PAH results in Eisenmenger syndrome and right to left shunt reversal
- Can present with symptoms of heart failure
Murmur, HF (dilated LV), endocarditis, cyanosis (pulmonary HT)
Closure when Qp:Qs > 2 and evidence of left ventricular volume overload or a history of endocarditis.
Large VSD with right to left shunt reversal and PAH (Eisenmenger syndrome) should not be closed as closure will result in clinical deterioration
During ventricular contraction, or systole, some of the blood from the left ventricle leaks into the right ventricle, passes through the lungs and reenters the left ventricle via the pulmonary veins and left atrium. This has two net effects. First, the circuitous refluxing of blood causes volume overload on the left ventricle. Second, because the left ventricle normally has a much higher systolic pressure (~120 mmHg) than the right ventricle (~20 mmHg), the leakage of blood into the right ventricle therefore elevates right ventricular pressure and volume, causing pulmonary hypertension with its associated symptoms.
In serious cases, the pulmonary arterial pressure can reach levels that equal the systemic pressure. This reverses the left to right shunt, so that blood then flows from the right ventricle into the left ventricle, resulting in cyanosis, as blood is by-passing the lungs for oxygenation.
This effect is more noticeable in patients with larger defects, who may present with breathlessness, poor feeding and failure to thrive in infancy. Patients with smaller defects may be asymptomatic. Four different septal defects exist, with perimembranous most common, outlet, atrioventricular, and muscular less commonly.
Patent ductus arteriosus
- Patent ductus arteriosus (PDA) is the persistence of the arterial duct that connects the aorta and the pulmonary artery in the fetus.
- Maternal rubella and neonatal prematurity predispose to PDA.
- Continuous murmur that envelops the S2 - a continuous “machinery” murmur heard beneath the left clavicle
- Bounding pulses and wide pulse pressure may be noted
- A large PDA causes a large left to right shunt and if unrepaired can cause PAH with eventual shunt reversal from right to left (Eisenmenger syndrome)
- Characteristic feature of Eisenmenger PDA is differential cyanosis/clubbing - cyanosis and clubbing that affects the feet but not the hands owing to desaturating blood reaching the lower part of the body preferentially (differential cyanosis)
Tx
- Closure of PDA is indicated for left sided cardiac chamber enlargement in the absence of severe PAH
- A large PDA with severe PAH and shunt reversal should be observed as closure can be detrimental
- VERY HIGH RISK for endocarditis - intervention in almost all cases
Pulmonary valve stenosis
- Usually isolated congenital cardiac lesion causing obstruction to right ventricular outflow
- Associated with Noonan syndrome
Noonan syndrome, an autosomal dominant disorder, is often associated with isolated pulmonary valve stenosis or other congenital cardiac defects. Additional features of Noonan syndrome include short stature, variable intellectual impairment, unique facial features, neck webbing, and hypertelorism
- Ejection systolic murmur (crescendo-decrescendo), heard at the left sternal border
- R ventricular S1 heard in severe pulmonary valve stenosis
Severe if peak gradient > 60mm Hg - pulmonary balloon valvuoplasty
Treatment of pulmonary valve stenosis
- Pulmonary balloon valvuloplasty
- Complications: increased risk for pulmonary valve regurgitation
What is aortic coarctation associated with?
- 50% of patients with aortic coarctation have bicuspid aortic valve
- Turner syndrome
Others:
- Aortic valve stenosis
- Parachute mitral valve
- VSD
- Cerebral artery aneurysms
Aortic coarctation pathophysiology
Pathophysiology: Aortic coarctation is a discrete aortic narrowing, usually located just beyond the LEFT SUBCLAVIAN artery, causing hypertension proximal and reduced blood pressure distal to the aortic narrowing
Physical examination findings of aortic coarctation
Treatment + complications
- Upper extremity HTN and reduced BP and pulse amplitude in low extremities
- Radial-femoral delay
- Systolic murmur in left infraclavicular region or over the back
- Aortic coarctation + bicuspid aortic valve = ejection click or systolic murmur, S4 often audible
CXR: figure 3 sign - dilatation of the aorta above and below the coarctation. Dilatation of intercostal arteries = rib notching
Treatment: when systolic peak pressure gradient > 20
Angioplasty/stenting
Main side effect after repair is hypertension
Tetralogy of fallot
It consists of 4 main defects:
- Pulmonary stenosis: narrowing of the exit from the right ventricle
- Ventricular septal defect
- Right ventricular hypertrophy: thickening of the right ventricular muscle
- Overriding aorta which allows blood from both ventricles to enter the aorta
Most common cyanotic congenital cardiac lesion
- ~15% with TOF has 2211q.2 chromosome microdeletion (Di George)
- Also seen in Down Syndrome
