Atrial Septal Defects
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Transcript of Atrial Septal Defects
Atrial Septal Defects
Dr Nithin P G
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• Introduction
• Embryology & Types of ASD
• Physiology, natural history & clinical features
• Investigations -salient features
• Management
References 1. Joseph Perloff. The clinical recognition of congenital heart disease. Fifth
Edition 20032. Abraham M. Rudolf. Congenital diseases of the heart. Third Edition 2009 3. Moss & Adams’ Heart diseases in infants, children & Adolescents.
Seventh Edition 20084. Nadas' Pediatric Cardiology. Second Edition 2006 5. ACC/AHA 2008 Guidelines for the Management of Adults With
Congenital Heart disease6. ESC Guidelines for the management of grown-up congenital heart
disease 2010
Introduction
• 6-10% of all cardiac anomalies(3)
• M:F = 1:2 [ sinus venosus defects 1:1](1)(4)
• 1 in 1500 live births(3)
• Most common congenital abnormality in adult > 40yrs [30-40%]
Embryology & types of ASD
• Embryology [video]
• Types of ASD– Secundum ASD
– Primum ASD
– Sinus venosus ASD
– Coronary Sinus type
– PAPVC
Embryology & types of ASD
Embryology & types of ASD
Associated anomalies(5)
• 30% cases have associated anomalies
– Secundum- Valvular PS, MVP, PAPVC
– Primum- Cleft MV, Discrete subaortic AS
– SV- PAPVC
– Coronary Sinus- PAPVC, PLSVC
Embryology & types of ASD
Inherited disorders- secundum ASD(3)
• Holt-Oram syndrome [AD] – TBX5
• Familial syndromes– NKX2.5 and GATA4– missense mutation in myosin heavy chain 6
Physiology, natural history
Physiology, natural history
Shunt (2)
• Size of defect– As large as mitral valve orifice
• Ventricular compliance [ most important]
Physiology, natural history
Effects of changes in SV of left and right ventricles associated with changes in PVR and with changes in compliance of the respective ventricles after birth in the presence of an ASD(2)
Physiology, natural history
ASD shunt flow during cardiac cycle(3)
Physiology, natural historyEffects of L to R shunt(2)
• RA/RV dilation, volume overload RV, RVF • Atrial arrhythmias
• Increased PBF
• +/- PAH
Physiology, natural history
ASD & PAH• Not all individuals develop PAH
702 pts isolated ASDs [Secundum or SV]. 40 (6%) had PVOD, defined as a TPR of >7 U/m2 ….34 women (85%) and 6 men… < 19 years of age no PVOD. Circulation 1987;76:1037-1042
• Why others are spared?
• Factors– Increased PBF– Coexistant PAH– Concominant adult heart diseases
Physiology, natural history
Clinical course(1) (2) (3) (4) (5)
• Infancy
• Child hood
• Adults
Clinical Findings
• G/E- thin, upper limb abnormalities• JVP- mean normal, a=v• Pulse & BP- no change in pulse volume and BP during valsalva,
square wave response • Prominent RV pulsations, 2nd space pulsations• Auscultation
– Loud T1– Wide fixed split S2– Pulmonary ESM– Tricuspid MDM
• Features of PAH in some cases
Differential diagnosisMitral Stenosis
Dyspnea, orthopnea
AF
RV impulse
Loud T1 vs Loud M1
A2-P2 vs S2-OS
MDM Tricuspid vs MDM mitral
Increased pulmonary vasc.
Mitral Regurgitation
AF
TR murmur vs MR murmur
Wide split S2
MDM Tricuspid vs MDM mitral
S3
Acquired heart diseases
CAD
Atrial arrhythmias
Special situations
• Lutembacher- RHD MS/MR + secundum ASD
• PAPVC & Scimitar syndrome
• Raghib’s syndrome- coronary sinus ASD + PLSVC
PAPVC & Scimitar syndrome(1)
Investigations- salient features ECG• SN dysfunctions
– AF, AFL, SVT– Absence of sinus arrhythmia
• AV conduction – Increased PR interval– CHB
• rsR’ or rSr’ pattern in V1
• Crochetage [notched R II,III,aVF]
Investigations- salient features
CXR
• RAE
• RV Apex
• Prom MPA
• Increased PBF
Investigations- salient features
Echo
– Most important Ix for confirmation of diagnosis, location and type of ASD, severity, need for intervention & planning further Mx/ Follow up
– RA, RV Volume overload
– Associated abnormalities
– Abnormal venous connections
– Suitability for device closure, rims
Investigations- salient features
Bi-caval view for IVC & SVC rims [subcoastal sagittal & TEE]
Investigations- salient features AV rim & Postero-
superior (atrial) rim[Suboastal coronal & TEE 4C]
Aortic rim[TTE PSX & TEE BSX]
Investigations- salient features
• MRI
Investigations- salient features
CATH• Main indication is assessment of PVR in doubtful cases &
anomalous venous connections not visible on echo• Oximetry
– SVC step up 10% or 5% in 2 serial samples [AVSD, RSOV/LV to RA, VSD + TR, PAPVC, Systemic AVF]
– SVC sat >75-80% [RPV to SVC, LPV to L inominate vein]– CS sat > 45% PLSVC or anomalous PV connections to CS
• Pressures– RA, LA mean normal, RA a=v– RVSP 35-40 mm Hg in infants & 25-30 mm Hg in Adults, diff of 15-30
mm b/w RVSP & PAP noted
Management
• In whom, When & How should you close the defect ?
– RV volume overload [+/- symptoms]– Paradoxical embolism
• Surgical vs Device closure
Management(5) (6)
• <5 mm, no volume overload [unless paradoxical embolism] followed up
• Secundum ASD>5 mm, <38 mm size with a rim of 5 mm all around except towards aorta Device closure [Larger ASD, associated tricuspid repair, sinus venosus, coronary sinus, or primum ASD for Sx]
• PAP <5 WU, if>5 WU then PVR<2/3 SVR, PAP<2/3 SYS Pressure [baseline or when challenged with vasodilators with net Qp: Qs>1.5] (6)
Devices
Devices
Occluder diameter 2-4mm size larger than the maximum strechable defect size
Complications
Procedural success rate 95%-98%
Very rare complication (<0.5%) Rev Esp Cardiol Cardiol. 2003;56:383; (5) (6)
• Entrapment in RA structures & PV, impingement of aorta • Inability to release, withdraw• Twisting of device• Dislodgment & embolization• Thrombosis Very rare [0.05-0.2%] J Am Coll Cardiol 2004;43:302
Related to– Poor implant apposition – Poor device endothelialization– Underlying prothrombotic
Follow up
• Issues(5) (6) – Atrial arrhythmias- OAC, RF ablation– RV & LV dysfunction [Pre intervention- balloon occlusion and
reassessment of hemodynamics in poor LV function(6)]– PAH– Coexistant valvular or other cardiac lesions
• IE prophylaxis upto 6m after procedure • Aspirin atleast 100mg daily upto 6 m (6) • Echo f/up at 24 hrs, 1 m, 6m, 1 yr & then at regular intervals
Thank you
Embryology