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ATRIALSEPTALDEFECT
EditedbyP.SyamasundarRao
Atrial Septal Defect
Edited by P. Syamasundar Rao
Published by InTech
Janeza Trdine 9, 51000 Rijeka, Croatia
Copyright © 2012 InTech
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First published April, 2012
Printed in Croatia
A free online edition of this book is available at www.intechopen.com
Additional hard copies can be obtained from orders@intechopen.com
Atrial Septal Defect, Edited by P. Syamasundar Rao
p. cm.
ISBN 978-953-51-0531-2
Contents
Preface IX
Section 1 General Review of Atrial Septal Defects 1
Chapter 1 Atrial Septal Defect – A Review 3
P. Syamasundar Rao
Chapter 2 Pregnancy Issues in Women with Atrial Septal Defect 21
Duraisamy Balaguru
Section 2 Natural History 29
Chapter 3 Prevalence of Secundum Atrial
Septal Defect and Associated Findings 31
Mark D. Reller
Section 3 Creation of ASDs 37
Chapter 4 Computer-Aided Automatic Delivery System
of High-Intensity Focused Ultrasound
for Creation of an Atrial Septal Defect 39
Hiromasa Yamashita, Gontaro Kitazumi,
Keri Kim and Toshio Chiba
Section 4 Transcatheter Closure of ASD 55
Chapter 5 Historical Aspects of Transcatheter
Occlusion of Atrial Septal Defects 57
Srilatha Alapati and P. Syamasundar Rao
Chapter 6 Role of Transesophageal
Echocardiography in Transcatheter
Occlusion of Atrial Septal Defects 85
Gurur Biliciler-Denktas
VI Contents
Chapter 7 Role of Intracardiac Echocardiography (ICE)
in Transcatheter Occlusion of Atrial Septal Defects 99
Ismael Gonzalez, Qi-Ling Cao and Ziyad M. Hijazi
Section 5 ASD Closure in Adults and Elderly 119
Chapter 8 Why, When and How Should Atrial
Septal Defects Be Closed in Adults 121
P. Syamasundar Rao
Chapter 9 Atrial Septal Defect Closure in Geriatric Patients 139
Teiji Akagi
Section 6 Patent Foramen Ovale 153
Chapter 10 Atrial Septal Defect/Patent
Foramen Ovale and Migraine Headache 155
Mohammed Tawfiq Numan
Chapter 11 Transcatheter Occlusion of Atrial
Septal Defects for Prevention of
Recurrence of Paradoxical Embolism 167
Nicoleta Daraban, Manuel Reyes and Richard W. Smalling
Preface
Defectsintheatrialseptumareonethemostcommontypesofcongenitalheartdefects
(CHDs)inchildrenandsuchadefectisthemostcommonCHDinadults.Atrialseptal
defects(ASDs)causeleftto right shunt beca use the left atrial pressure is higher than
that inthe right atrium. Th
iscausesvolume overloadingofthe right ventricle. While
thisisgenerallywelltoleratedduringinfancyandchildhood,developmentofexercise
intolerance and arrhythmias in later childhood, adolescence and adulthood, and the
risk for development of pulmonary vascular obstructive disease in adulthood make
thesedefectsimportant.Themajortypesofatrialdefectsareostiumsecundum,ostium
primum,sinusvenosusandcoronarysinusASDsandpatentforamenovale(PFO).
In the first chapter, I review the clinical features and management of ASDs. Patients
with small defects are usually asymptomatic while moderate to large defects may
presentwithsymptoms. Physicalfindingsincludehyperdynamicprecor
dium,widely
split and fixed second heart sound, ejectionsystolicmurmur at the left upper sternal
border and a mid‐diastolic flow rumble at the left lower sternal border. In patients
withostiumprimumASDs,anapicalholosystolicmurmurmayalsobeheard.Clinical
diagnosis is not difficult and the diagnosis can be confirmed and quantified by
echocardiographic studies. While surgical intervention was used in the past,
transcatheter methods are currently used for closure of ostium secundum ASDs.
Surgical correction is necessary for the ostium primum, sinus venosus and coronary
sinusdefects.PFOispresentinnearlyonethirdofnormalpopulationandislik
elyto
beanormalvariantandsuchisolatedPFOsdonotneedintervention. Whenassociated
with other CHDs, the PFO facilitates intra‐cardiac shunt to allow appropriate egress
and/or mixing of blood flow. Hypoxemia in post‐surgical residual defects including
Fontan fenestrations, right ventricular infarction and platypnea‐orthodexia syndrome
maybesecondarytorighttoleftshuntacrossPFOandthesedefectsmayneedclosure.
PFO, presumed to be the seat of paradoxical embolism resulting in stroke/transient
ischemic attacks is the subject active investigation. Similarly the role of PFO in
Caisson’s disease and migraine is not well‐establi
shed. There is varying degrees of
evidenceforbenefitoftranscatheterocclusionofthesePFOs.
In the second chapter, Dr. Balaguru from the University of Texas Medical School,
Houston, Texas discusses issues related to ASD in pregnant women. There are
remarkable changes in cardiovascular physiology during pregnancy; the cardiac
X Preface
output increases, related to increased stroke volume and heart rate. The systemic
vascular resistance decreases; however, concurrent increase in cardiac output keeps
blood pressure stable. The blood volume increases (by 1.5 times) by raise in plasma
volume; however, this is out of proportion to the increase in red cell mass with
consequent relative anemia. These changes are tolerated well because the changes
occu
r gradually. During the third trimester, enlarging uterus compresses the inferior
vena cava (IVC) in supine posture leading to decrease in cardiac output and
predisposestodeepveinthrombosis.InpregnantwomenwithASD,thereisagreater
increase in rig
ht atrial and right ventricular size (compared to pregnant women with
no heart defect) and a higher incidence of supraventricular tachycardia. The
probability of paradoxical embolism via the ASD is high given the predisposition to
deep vein thrombosis and hypercoagulable state.If the diagnosis is known prior to
pregnancy and the ASD is larg
e and associated with moderate or severe right heart
enlargement and is a potential candidate for supraventricular tachycardia and
thromboembolic events during pregnancy, labor or postpartum, the ASD should be
closed prior to planned‐pregnancy. Transcatheter or surgical closure could be
performedbasedonthesizeoftheASDandadequacyofseptalrims.WhentheASD
is diagnosed during pregnancy but, the patient is asymptomatic without functional
compromise (NYHA Class I and II) and has no heart failure, atrial arrhythmia,
pulmonary hypertension or history of stroke, the these women are likely to do well
throughout pregnancy and do not require transcatheter or su
rgical closure. On the
contrary, in the presence ofany of these issues, transcatheteror surgicalclosuremay
be performed. If transcatheter is opted, second trimester (13‐28 weeks) is preferred
instead of first trimester to avoid irradiation to the fetus. Local anesthesia with
conscious sedation, intracardiac echocardiography to aid balloon sizing and device
deployment and use of long venous sheath; the latter two to avoid or reduces
radiation, may be appropriate. If the ASD is unsuitable for transcatheter closure,
surgicalclosureofASDmaybeperformedinthesecond trimesterwith thefollowing
precautions: infusion of high‐concentration of gl
ucose (to provide energy for fetus),
fetal monitoring, maintenance of high‐flow, high mean arterial pressure (60 mmHg)
and high hematocrit (> 25%) and hyper oxygenation. The author concludes that the
need for closure of ASD during pregnancy is rare and if possible avoided. When
closure is indicated transcatheter or surgical closure may be performed, taking
appropriateprecautions.
InthethirdchapterRellerfromOregonHealth&ScienceUniversity,Portland,Oregon
reviews data on the prevalence, associated cardiac and non‐cardiac findings and
naturalhistoryofsecundumASDs,definedassizegreaterthan4mm.Theprevalence
ofsecu
ndumASDisestimated to be10.3per10,000births, prevalence comparable to
thatofperi‐membranousventricular septaldefects.Theincreaseinthe prevalenceof
secundumASDwasattributedtoevaluationbycolorflowDoppler‐echocardiography.
Theassociationof secundumASDwithperi‐membranous VSDandvalvar pulmonary
stenosisiswellrecognized.The cau
se(s)ofsecundumASDremain largely unknown.
Genetic syndromes associated with secundum ASD include Trisomy 21, 13 and 18;
. ATRIAL SEPTAL DEFECT Edited by P. Syamasundar Rao Atrial Septal Defect Edited by P. Syamasundar Rao Published by InTech Janeza Trdine. Septal Defect, Edited by P. Syamasundar Rao p. cm. ISBN 978-953-51-0531-2 Contents Preface IX Section 1 General Review of Atrial Septal Defects 1 Chapter 1 Atrial Septal. Occlusion of Atrial Septal Defects 57 Srilatha Alapati and P. Syamasundar Rao Chapter 6 Role of Transesophageal Echocardiography in Transcatheter Occlusion of Atrial Septal Defects 85 Gurur
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