CARDIOVASCULAR JOURNAL OF AFRICA • Vol 24, No 8, September 2013
AFRICA
e5
Case Report
Left ventricular rupture after double valve replacement
in a patient with myocarditis due to myasthenia gravis
MIHALIS ARGIRIOU, VASILIS PATRIS, NIKI LAMA, SOTIRIOS KATSARIDIS, ORESTIS ARGIRIOU,
CHRISTOS CHARITOS
Abstract
Myasthenia gravis is an autoimmune disease characterised
by a weakness of the skeletal muscles, with remissions and
exacerbations due to antibodies acting on the acetylcholine
receptors. This leads to the characteristic defect transmission
in the neuromuscular junction. Treatment includes anticho-
linesterase agents, thymectomy, and immunosuppression.
Surgical thymectomy can induce remission or improvement,
allowing for reduction in the immunosuppressive treatment.
The case of an 84-year-old female patient with myasthenia
gravis, aortic valve stenosis, mitral valve regurgitation and
myocarditis is described. The development of myocarditis
was related to inflammatory cell infiltration, and progressive
and additive focal cellular necrosis associated with reactive
myocardial fibrosis. After replacement of the mitral valve,
complications arose whereby a rupture of the left ventricular
posterior wall occurred, which caused massive bleeding and
sudden death on the operating table.
Keywords:
left ventricular rupture, double valve replacement,
myasthenia gravis, thymectomy, myocarditis
Submitted 6/1/13, accepted 14/8/13
Cardiovasc J Afr
2013;
24
: e5–e7
DOI: 10.5830/CVJA-2013-056
Myasthenia gravis (MG) is an acquired autoimmune disease
with remissions and exacerbations due to antibodies acting
on the acetylcholine receptors (AChR). This leads to the
characteristic defect transmission in the neuromuscular
junction,
1
usually resulting from a decreased number of active
acetylcholine receptors (AChR) at the neuromuscular junction. It
is characterised by a weakness of the voluntary skeletal muscles.
2
MG patients have been suggested to have a higher-than-normal
prevalence of heart disease. Antibodies against
β
-adrenergic
receptors in patients with MG bind to both
β
1
- and
β
2
-adrenergic
receptors and may be implicated in the few patients with MG
who have heart disease.
3
It is speculated that the heart and
skeletal muscles are also autoimmune targets in MG.
4
However,
inflammatory myopathies, autoimmune-mediated myocarditis
and/or myositis have developed in a few patients with MG,
especially thymoma-associated MG.
4
Treasure
et al
.
5
classified the complications on the basis of
the location of the tear: ruptures located in the posterior atrio-
ventricular groove are type I, ruptures in the posterior wall of
the left ventricle at the base of the papillary muscles are type
II, and ruptures posterior to the atrio-ventricular area are type
III. The ruptures have also been classified by time pattern of
presentation: early, delayed and late rupture.
This report presents a rare case of early left ventricular rupture
after mitral–aortic valve replacement in a patient with MG and
myocarditis. The exact rupture could not be classified on the
basis of the location because it was not possible to determine its
precise location. However, it is postulated that the rupture may be
classified as a type III in accordance with Sersar
et al
.
6
Case report
An 84-year-old female patient with a history of MG who was on
medication for over two years was admitted to our department
with an echocardiographic diagnosis of severe aortic valve
stenosis (max Gr 84 and AVA 0.65–0.7 cm
2
), mitral valve
regurgitation (3
+
), the ECG showed T-wave abnormality, atrio-
ventricular dissociation, arrhythmias [chronic atrial fibrillation
(AF)], and wide QRS complex. It is important to note that the
patient was not treated with Cox-Maze IV (ablation) due to her
chronic AF.
The patient’s clinical status was classified as NYHA class III
and her MG status was Osserman IIB, so her symptoms were
not further investigated considering her severe double valvular
disease. She was scheduled for an elective aortic–mitral valve
repair with simultaneous thymectomy.
Initially, a trans-sternal thymectomy was carried out and
the hyperplastic thymus tissues were completely removed and
sent for histological analysis. The ascending aorta and both
venae cavae were cannulated, and cardiopulmonary bypass was
instituted.
After aortic cross-clamping, myocardial protection was
achieved with antegrade and retrograde intermittent cold blood
cardioplegia. A longitudinal left atrial incision parallel to the
atrial septum was performed to expose the mitral valve. The
valve leaflets were fragile and myxomatous, and the chordal
structures of the anterior leaflet were ruptured. After excision
Cardiac Surgery Department, Evaggelismos General
Hospital, Athens, Greece
MIHALIS ARGIRIOU, MD,
VASILIS PATRIS, MD
NIKI LAMA, MD
SOTIRIOS KATSARIDIS, MD
ORESTIS ARGIRIOU, MD
CHRISTOS CHARITOS, MD
