Atrial Septal Defects Dr Nithin P G

Preview 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 Abraham M. Rudolf. Congenital diseases of the heart. Third Edition Moss & Adams’ Heart diseases in infants, children & Adolescents. Seventh Edition Nadas' Pediatric Cardiology. Second Edition ACC/AHA 2008 Guidelines for the Management of Adults With Congenital Heart disease 6.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

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

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 history Effects 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/m 2 ….34 women (85%) and 6 men… < 19 years of age no PVOD. Circulation 1987;76: 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, 2 nd space pulsations Auscultation – Loud T1 – Wide fixed split S2 – Pulmonary ESM – Tricuspid MDM Features of PAH in some cases

Differential diagnosis Mitral 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 mm Hg in infants & mm Hg in Adults, diff of 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 then PVR 1.5] (6)

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 [ %] 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