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Atrial Septal Aneurysm and Stroke – A Report of Two Cases
LAURA POANTĂ, D.L. DUMITRAŞCU, DANIELA FODOR, ADRIANA ALBU
“I. Haţieganu” University of Medicine and Pharmacy, Department of Internal Medicine, Cluj-Napoca, Romania
Atrial septal aneurysm (ASA) is an uncommon lesion which often associates other cardiac
abnormalities such as patent foramen ovale or mitral valve prolapse. More than half of the cases with ASA
associate an interatrial shunt which can explain cerebral embolism and consecutive ischemic stroke.
Case summary. We present two cases which were admitted to our hospital with minor
complaints. Personal histories excluded cardiac disease, high blood pressure, smoking, and included
ischemic stroke in both cases. Physical examination revealed no abnormalities. Electrocardiogram
showed right bundle branch block in one case, lab findings were in normal limits.
Cardiac ultrasound (transthoracic and transesophageal) revealed in both cases an ASA, one
with bidirectional equidistant excursion without visible interatrial shunt, and one with unilateral
excursion and a small shunt.
Conclusion. The ASA diagnosis should be remembered as an alternative cause in a patient with a
history of stroke, or with developing stroke, and without risk factors for cerebrovascular disease.
Key words: atrial septal aneurysm, stroke.
Atrial septal aneurysm (ASA) is an uncommon
lesion with a varying prevalence in studies with
transthoracic echocardiography (TTE), transesophagian
echocardiography (TEE) and autopsies [1][2]. The
prevalence of ASA varies with the examination
method: transthoracic echocardiographic studies
estimate the rate to be between 0.08% and 1.2%, in
autopsies the prevalence reported was 1%, and in
more recent studies using TEE the prevalence was
between 2% and 10% [1][3][4].
It often associates other cardiac abnormalities
such as patent foramen ovale, atrial septal defects,
ventricular septal defects, valvular prolapse, patent
ductus arteriosus, Ebstein’s anomaly, and tricuspid
and pulmonary atresia, as well as acquired heart
diseases including valvular disease, cardiomyopathy,
systemic and pulmonary hypertension, ischemic heart
disease, arrhythmias and thrombus formation [1][2][4].
More than half of the cases with ASA
associate an interatrial shunt which can explain a
consecutive ischemic stroke.
Atrial septal aneurysm has been considered a
potential cardiac source of embolism in recent
years (transient ischemic attacks and cerebrovascular
accidents), but the role of atrial septal aneurysm as
a risk factor is not very well defined [2–4]. In a
multicentric study, the authors concluded that atrial
septal aneurysm could be considered a risk factor
for cardiogenic embolism in a significant subgroup
ROM. J. INTERN. MED., 2008, 46, 4, 357–360
of patients [5]. The report from the Stroke
Prevention: Assessment of Risk in a Community
(SPARC) study demonstrated that atrial septal
aneurysm is associated with an increased risk of
stroke. This study established the prevalence of ASA
in the general population at 2.2%. The true
prevalence of ASA was underestimated before the
routine use of echocardiography, especially TEE. It
seems that paradoxical embolism is the predominant
mechanism of cardioembolism in ASA, according to
SPARC [6]. In contrast, a prospective long-term
study suggested that the risk of cerebrovascular
events is low in a patient population with incidental
atrial septal aneurysm [7].
Atrial septal aneurysm was defined as a bulging
over 15 mm beyond the plane of the atrial septum as
measured by transoesophageal echocardiography.
Atrial septal aneurysm was classified according to
Hanley’s diagnostic criteria, modified by Pearson to
include type 1C [8]. The type of aneurysm was
determined according to morphology and bulging in
four or five types [8][9].
CASE ONE
MI, fifty years old, female, was admitted in
our hospital with dyspepsia. Her personal history
excluded ischemic heart disease, high blood
pressure, and smoking.
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358
She had an ischemic stroke seven years ago
which was CT diagnosed at the time. Physical
examination revealed no abnormalities. Blood
pressure was 120/70 mmHg in supine position, on
admission in the hospital. Rest electrocardiogram
and lab findings were in normal limits. The patient
had normal carotid arteries on Doppler ultrasound.
2
Cardiac ultrasound found an atrial septal
aneurysm, confirmed by TEE (ASA type 5
according to [9]), with a base width of 2.2 cm, with
bidirectional and equidistant excursion throughout
the cardiac cycle, without interatrial shunt or intra
atrial thrombi (Fig. 1).
Fig. 1. – Apical four chambers view, atrial septal aneurysm (arrow).
CASE TWO
DE, 55 years old, female, was admitted with
osteoarthritis. Her personal history also excluded
ischemic heart disease, high blood pressure, and
smoking; she also had an ischemic stroke three years
ago, CT confirmed and completely recovered.
Physical examination revealed no abnormalities.
Blood pressure was 135/78 mmHg in supine position
on admission. Rest electrocardiogram showed right
bundle brunch block. Laboratory findings were in
normal limits and she had normal carotid arteries.
Cardiac transthoracic ultrasound found an
atrial septal aneurysm, confirmed by TEE (ASA
type 1 R, according to [9]), with base width 1.8 cm,
with unidirectional excursion and interatrial left-toright shunt, without intra atrial thrombi, and with
normal heart chambers (Fig. 2).
The following parameters were also evaluated:
length of the atrial septal aneurysm, maximal
protrusion of the atrial septal aneurysm beyond the
plane of the atrial septum and the direction of the
maximal protrusion, oscillation of the atrial septal
aneurysm during a normal respiratory cycle,
thickening of the atrial septal aneurysm.
DISCUSSION
We choose to present those two cases because
this diagnosis is uncommon, although the incidence
of atrial septal aneurysm in the normal population is
still controversial. Many reasons explain this:
different diagnostic criteria, methodology used, and
age of patients and lack of recognition [1][3].
We cannot state for sure that there is a definite
connection between stroke and ASA in those two
cases, but the probability is high. The embolic
mechanism cannot be excluded in the first case,
despite the fact that the shunt is missing, as contrast
TEE is in fact more sensitive than TEE color Doppler
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Atrial septal aneurysm and stroke
Fig. 2. – Transthoracic view, atrial septal aneurysm (arrow).
alone in detecting interatrial shunt of small
dimensions [9]. So we cannot rule out the paradox
embolism in one case; other possible causes of
cardioembolic events are: thrombus formation inside
ASA, undiagnosed transient atrial arrhythmias, small
or rapidly resolving thrombi in ASA. Both cases
received medical treatment.
Many authors observed that a number of
patients with atrial septal aneurysm presented
cerebral ischemic events, which were otherwise
unexplained, as in our both cases [1][3][5]. A study
of Nighoghossian et al. found atrial septal
aneurysm in the 34.5% of the 79 patients who had
an unexplained stroke [10].
In subjects less than 55 years of age, a lower
prevalence of atherosclerosis makes a diagnosis of
“cryptogenic” stroke (stroke without other clear
cause) more frequent than in older subjects. Atrial
septal aneurysm has been described recently as the
only potential source of embolism in a significant
proportion of subjects who had sustained a transient
ischemic attack [11].
Mattioli et al. have also demonstrated that
patients who have sustained cryptogenic stroke, and
have atrial septal aneurysm, constitute a subgroup
which is at a higher risk of recurrent stroke [1].
CONCLUSION
The atrial septal aneurysm diagnosis should
be remembered as an alternative cause in patients
with a history of stroke, or with developing stroke,
and without risk factors for cerebrovascular
disease, especially under fifty five years old.
Anevrismul de sept interatrial (ASI) este o leziune mai puţin frecventă care se
asociază adesea cu alte anomalii cardiace cum ar fi foramen ovale patent sau
prolaps de valvă mitrală. Mai mult de jumătate dintre cazurile de ASI au asociat
un şunt interatrial care ar putea explica accidentele ischemice cerebrale
consecutive emboliei.
Prezentare de caz. Raportăm două cazuri internate în clinica noastră cu
simptome minore. Antecedentele personale patologice exclud bolile cardiace,
Laura Poantă et al.
360
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hipertensiunea arterială, fumatul, şi constau în accidente vasculare cerebrale
ischemice în ambele situaţii. Examenul obiectiv a fost în limite normale,
electrocardiograma arată bloc major de ramură dreaptă într-un caz, fiind normală
în celălalt, iar analizele de laborator au fost normale.
Ecocardiografia (transtoracică şi transesofagiană) a relevat în ambele
cazuri un ASI, unul cu excursie bidirecţională, echidistantă, fără şunt vizibil,
celălalt cu excursie unidirecţională şi un şunt mic.
Concluzie. Diagnosticul de ASI trebuie avut în vedere ca şi o posibilă cauză
de accident vascular cerebral ischemic la un pacient cu antecedente personale
patologice pozitive sau cu debut recent şi fără alţi factori de risc detectabili pentru
boala cerebrovasculară.
Corresponding author: Laura Poantă
2–4, Clinicilor Str., 400006, Cluj-Napoca, Romania,
Mobile phone: 0040744894190
E-mail address: [email protected]
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Received October 13, 2008