ASD Flashcards
Types of ASD
Secundum ASD
Sinus venosus defect (superior or inferior)
Primum ASD
Coronary sinus defect
Secundum ASD anatomic sub-types
Central defect Deficient aortic rim Deficient posterior rim Deficient IVC rim Multi-fenestrated Multiple
What is a secundum ASD?
Defect of septum premium in the area of the fossa ovalis
Result of deficiency of the flap valve tissue of the oval foramen so the flap valve does not completely cover the oval fossa or there are fenestrations
What percentage of all atrial level defects do secundum ASDs account for?
70%
What is a sinus venous ASD?
Defect in the posterior atrial septum
What percentage of all atrial level defects do sinus venosus ASDs account for?
5-10%
What are sinus venosus defects commonly associated with?
Anomalous pulmonary veins
What ECG change do you notice in sinus venosus defects?
Abnormal P wave axis (left atrial p waves)
What is a primum ASD?
Deficiency in endocardial cushion tissue - inferior atrial septum (just above AV valve)
What percentage of all atrial level defects do primum ASDs account for?
5-10%
What is primum ASD associated with?
Cleft anterior leaflet of the MV causing MR
What determines shunt magnitude of ASD?
Size of defect
Ventricular diastolic compliance
ASD Complications
Mortality
Atrial arrhythmias
Pulmonary hypertension
Frequency of atrial arrhythmias in patients with ASD
10% unoperated will develop by 40 yrs age
20-50% by 55-60 yrs age
How can prevalence of atrial arrhythmias be reduced?
Surgery before 40 yo
What affects your risk of atrial arrhythmias after ASD closure?
Male
Age>40
Hx of atrial arrhythmias
Factors that increase risk of pHTN in patients with ASD
Type of defect
Size of defect
Shunt magnitude
Age
Post-ASD closure factors that increase risk of pHTN
Type of defect Size of defect Shunt magnitude Age at repair Patient age PA pressure
ASD Indications for Closure
RA and RV dilatation with 1 or more of the following:
ASD minimum diameter >10 mm on echocardiography
Qp:Qs >1.5:1 by echo or CMR flow assessment or from oxygen saturation runs when cardiac catheterisation is performed (for other reasons)
Management of Sinus venosus defect
Patch closure
Re-routing pulmonary veins
Management of primum ASD
Patch closure
Repair of cleft in AV valves
When should surgery be considered for Secundum ASD?
Surgery only for the extremely large >38-40mm
Deficient inferior rim
Device interferes with adjacent cardiac structures
Which ASD should be considered for percutaneous device closure?
Only secundum ASDs <38mm and sufficient rim of 5mm (except towards the aorta)
Effects of ASD device closure
Right heart will reduce in size
Contraindications to ASD Closure
PHTN
- Elevated PVR > 8U
Systemic desaturation at rest or exercise
LV diastolic dysfunction with high LA pressure and left sided heart failure
Eisenmenger physiology
When is annual clinic follow-up recommended?
Watch for PAH, atrial arrhythmias, valvular disease, device complications or residual shunts.
How do you calculate ether Qp:Qs ratio with saturation data?
Qp:Qs = (systemic artery saturation (SpO2) - mixed venous saturation (SVC/IVC)) / (PV saturation(SpO2) - PA saturation)
What causes ASD murmurs?
Increased flow over the pulmonary and tricuspid valves
Symptomatic presentation in Adults
SOBoE or palpitations usually in 30-40s
ASD Examination findings
RVH
Pulmonary ESM
Fixed splitting of S2 during all respiration phases
Tricuspid diastolic flow murmur (with large defects)
ASD CXR findings
Normal or mildly increased CTR with prominent pulmonary vascular markings and enlargement of central pulmonary artery
ASD ECG Findings
RAD; RVH; RSR in right precordial leads with QRS <120ms (incomplete RBBB)
Ostium primum: LAD with RVH
After ASD closure at a young age what happens to the right heart?
RV size and function return to normal and patients do well Improves left heart filling Improves functional class Improves exercise capacity Improves survival
Are there restrictions in physical activities in patients after successful ASD closure?
No
Is pregnancy well tolerated in patients after ASD Closure?
Yes, but contraindicated in patients with severe PAH or Eisenmenger
What lesions are associated with ASDs?
anomalous PV connection
Persistent left SVC
PV stenosis
MVP
What syndrome can secundum ASD be associated with?
Holt-oram syndrome
What is Holt-oram syndrome?
AD disorder that affects bones in the arms and hands and often causes heart problems (ASD/VSD, cardiac conduction disease)
What does the ASD shunt volume depend on?
RV/LV compliance
Defect size
LA/RA pressure
What can increase left to right shunt?
Reduction in LV compliance or any condition with elevation of LA pressure (HTN, IHD, Cardiomyopathy, AV or MV disease)
What can reduce L-R shunt or cause shunt reversal (leading to cyanosis)?
Reduced RV compliance (PS, PAH, other RV disease) or TV disease
What is the best imaging modality to diagnose sinus venosus defect?
TOE
What patients should undergo ASD closure?
Significant shunt (Signs of RV volume overload) and PVR <5WU should undergo ASD closure REGARDLESS of symptoms
What patients should be considered for ASD closure?
All patients with suspicion of paradoxical embolism (regardless of size)
Patients with PVR>/= 5 WU but <2/3 SVR or PAP <2/3 systemic pressure (baseline or when challenged with vasodilators, preferably nO or after targeted PAH therapy) and evidence of net L-R shunt (Qp:Qs >1.5)
How long should patients be on anti platelet therapy for post-device closure for secundum ASD?
6/12 Aspirin 100mg od
What is a modified Maze procedure?
Surgical AF ablation (laparoscopic or open heart)
They create scar tissue to direct electrical signals through a controlled path
Which patients with repaired ASDs do not require regular follow-up?
Repaired <25 yo without relevant sequelae or residual shunt, normal PAP, normal RV, no arrhythmias
After device closure, how often is follow-up recommended?
Regular during first 2 years and then, depending on results, every 2-4 years
When is IE prophylaxis recommended?
For 6/12 after device closure
What different types of percutaneous ASD devices exist?
Figulla
Amplatzer
