Acyanotic Congenital Heart Disease Flashcards
Treatment of ASD
Up to 62% of secundum ASDs may spontaneously close in the first year of life, especially ASD < 8 mm.
Closure of ASD is indicated when ASD is anatomically large >10 mm with one of the following hemodynamic features:
• Qp/Qs ≥1.5 in patients older than 1 year, including asymptomatic patients, as soon as possible. In infants < 1 year old, wait to see if
spontaneous closure occurs.
• Right‐sided enlargement or failure. The calculation of Qp/Qs is particularly needed when ASD seems anatomically small and needs to be
confirmed as the cause of RV failure, or when the shunt is bidirectional.
• In case of pulmonary hypertension, ASD closure remains indicated if there is still a net left-to-right shunt (Qp/Qs ≥1.5) and PVR is <1/3 SVR
and <5 Wood units.
ESC contraindicates
closure when PVR ≥5 Wood units. However, ESC allows a trial of PAH therapy followed by re-evaluation of PVR (goal <5) and Qp/Qs (goal>1.5)
Percutaneous closure of ASD
ASD that is ≤ 38 mm in diameter with 5 mm rims (except aorta) and without severe TR or anomalous pulmonary venous return
Effect of closure of ASD on survival
ASD closure improves survival and functional status, especially when performed at an early age. Closure before the age of 25 estab
lishes a normal longevity (Mayo registry).3 Closure after the age of 40 in patients with right heart failure or Qp/Qs >1.5 does not
re‐establish normal longevity but still reduces long‐term mortality by 70% and improves functional status.4 The reduction of right heart
volume starts early after closure, within 24 hours, and may continue for over a year. This reverse remodeling is more complete in younger
patients.
Ecg findings of ASD
• Ostium secundum ASD: RBBB (usually incomplete), right axis deviation, R‐wave notching in the inferior leads (crochetage), right atrial
enlargement
• Ostium primum ASD: RBBB + left axis deviation ± prolonged PR interval (primum ASD damages the infra‐Hisian conduction system)
• Sinus venosus ASD: ectopic atrial rhythm (non‐sinus P waves)
• AF or atrial flutter may be present
Auscultation and exam of ASD
• Fixed split S2
• Scratchy systolic ejectional murmur at the pulmonic area (left upper sternal border) due to the increased right‐sided flow. The murmur
may mimic pulmonic stenosis. P2
allows the distinction: P2
is attenuated in PS but part of a loud split S2
in ASD. Systolic TR murmur
may also be heard.
• RV heave
• Increased JVP with a large V wave indicative of RV failure ± TR
Consequences of ASD
- A significant ASD is an ASD with a prominent left‐to‐right shunt leading to a pulmonary flow (Qp) 1.5 times larger than the systemic
flow (Qs): Qp/Qs ≥1.5/1.0.
A large ASD is characterized by a Qp/Qs ≥2. - A significant ASD causes RA/RV volume overload, dilatation, and failure. This may, rarely, occur in childhood if the ASD is large. Most
patients are minimally symptomatic in the first three decades; exercise intolerance and hemodynamic compromise occur later in adulthood
(30s to 40s), and most patients are symptomatic by the age of 50. AF and right heart failure develop by the age of 40 in ~10% of patients,
then become more prevalent with age. In fact, for the same ASD size, left‐to‐right shunting may become more severe with age, as LV
diastolic dysfunction occurs and LA pressure rises. Also, LA enlargement that occurs with age stretches and widens the ASD. ASD does not,
by itself, lead to LA enlargement unless AF occurs.
A complete AV canal defect, on the other hand, leads to a severe shunt and Eisenmenger syndrome early in infancy if not corrected.
Paradoxical embolism may be seen. - Pulmonary hypertension (PH) may occur but is rarely severe, because the RV usually fails before severe PH develops. In a way, the
failing RV constitutes a barrier that protects the pulmonary arteries from volume overload. If PH is severe and ASD is <2 cm, a second
causative diagnosis should be considered. Under 10% of ASDs develop significant pulmonary vascular disease with PVR >5 Wood units.3,4 Cyanosis
and reversal of the shunt to a right‐to‐left shunt often result from RV failure and the consequent rise of RA pressure, even without any PH.
Treatment of VSD
Surgical closure (direct closure or patch closure) is indicated as soon as possible for:
• Significant VSD (moderately restrictive or large non‐restrictive) with a Qp/Qs ≥1.5 and without severe pulmonary vascular disease (as
under ASD treatment).
• Large VSD with LV or LA dilatation or LV dysfunction.
• Outlet VSD with progressive AI, regardless of its size.
Natural history of VSD
Small perimembranous or trabecular VSDs have a high closure rate (50–80%) by 2–10 years of age. A perimembranous VSD may close
by the apposition of the septal tricuspid leaflet, which sometimes forms a pouch at the level of the sealed defect.
A small VSD is hemodynamically insignificant, and remains so as the patient ages, but is associated with a risk of endocarditis.
Large VSDs (non‐restrictive, Qp/Qs >2) have a low spontaneous closure rate and lead to left HF, then Eisenmenger syndrome in infancy or childhood. They are typically corrected early on, before 1 year of age.
Moderately large VSDs (Qp/Qs 1.4–2) may be tolerated for years
before leading to hemodynamic compromise later on, in adulthood, as LV systolic and diastolic pressures rise and increase L-R shunting.
infective endocarditis
and AI may be seen later in life with a small, seemingly insignificant adult VSD.
Types of VSD
- Perimembranous VSD is the most common VSD (70–80% of VSDs). It involves the membranous septum and extends a bit into one of the
three muscular regions (inlet, trabecular, or outlet). An entirely membranous VSD is rare, as the membranous septum is a small fibrous center. - Muscular trabecular VSD is the next most common VSD.
- Inlet VSD. The inlet septum separates the septal cusps of the mitral and tricuspid valves. Inlet VSD is mainly a defect of the muscular inlet
septum, but the membranous septum is frequently involved. A gross deficiency of the inlet septum is associated with AV canal defect.
Conversely, a small inlet VSD is not usually associated with AV canal defect.13 - Outlet VSD (subarterial or infundibular VSD). Outlet VSD is mainly a defect of the muscular outlet septum, but the membranous septum
is frequently involved. When outlet VSD is very high and abuts both arterial valves, it is called supracristal VSD or doubly committed VSD
(the crista supraventricularis being a muscular ridge in the RV outflow)
Why does VSD dilate uniquely left heart
A hemodynamically significant VSD leads to LV and LA dilatation and LV failure from volume overload. Since the LV‐to‐RV
shunt is systolic, the RV does not get overloaded in diastole and therefore RV failure does not occur. Even when pulmonary
hypertension develops, right‐sided enlargement and tricuspid regurgitation are very unusual because the VSD allows decompression of the RV.
This is in contrast to ASD, which leads to RV diastolic volume overload, RV dilatation and failure, and tricuspid regurgitation;
in ASD, the LV is protected by the unloading that occurs at the LA level
Gerbode defect
A Gerbode defect is a perimembranous VSD extending more proximal to the tricuspid insertion, leading to a high‐velocity LV‐to‐RA shunt
and RV failure, in addition to the LV‐to‐RV shunt
Patent ductus arteriosus severity
Spontaneous closure of a PDA is unlikely in term infants older than 3 months or pre‐term infants older than 12 months.
A large shunt (Qp/Qs >2) is symptomatic in infancy and leads to Eisenmenger syndrome early on, as early as 8 months, if untreated.
A moderate shunt (Qp/Qs 1.5–2) may lead to hemodynamic compromise at a later age (childhood or adulthood, up to the third
decade).
A small shunt (Qp/Qs <1.5) presents as an isolated murmur.
Indications for repair of CAo
- Repair of coarctation or re-coarctation (surgically or catheter based) is indicated in hypertensive patientsc with an increased non-invasive
gradient between upper and lower limbs confirmed with invasive measurement (peak-topeak >_20 mmHg) with preference for catheter
treatment (stenting), when technically feasible. - Catheter treatment (stenting) should be considered in hypertensive patientsc with >_50% narrowing relative to the aortic diameter at the
diaphragm, even if the invasive peak-to-peak gradient is <20 mmHg, when technically feasible. - Catheter treatment (stenting) should be considered in normotensive patientsc with an
increased non-invasive gradient confirmed with invasive measurement (peak-to-peak >_20 mmHg), when technically feasible. - Catheter treatment (stenting) may be considered in normotensive patientsc with >_50% narrowing relative to the aortic diameter at the
diaphragm, even if the invasive peak-to-peak gradient is <20 mmHg, when technically feasible.
Associated anomalies with CAo
mitral valvular disease (parachute mitral valve, part of Shone complex), VSD, PDA, and intracranial berry
aneurysm (10%)
When to perform surgery in VSD
Perform the surgery soon in infancy if needed (at the age of 3–6 months). Postoperative patch leaks may be seen but rarely require reopera
tion. Occasionally, if VSD closure cannot be immediately performed, PA banding is performed to reduce the pulmonary flow and the risk of
Eisenmenger syndrome before definitive surgery.
