CARDIOVASCULAR JOURNAL OF AFRICA • Vol 23, No 9, October 2012
AFRICA
e7
Case Report
Acute ST-elevation inferior myocardial infarction in a
patient with a non-obstructive mechanical mitral valve
thrombosis
AHMET CAGRİ AYKAN, MEHMET ÖZKAN,NİLUFER EKSİ DURAN, MUSTAFA YİLDİZ
Abstract
The risk of systemic embolisation in patients with pros-
thetic heart valves who are receiving anticoagulation ther-
apy is 0.5 to 1.7% per patient year and most cases present
with cerebrovascular events. Here we report the case of a
42-
year-old woman who was uneventfully treated with a
low dose, prolonged infusion of tissue plasminogen activator
because of non-obstructive prosthetic mitral valve thrombo-
sis. It presented as coronary embolism and resulted in acute
ST-elevation inferior myocardial infarction.
Keywords:
coronary embolism, prosthetic valve thrombosis,
thrombolytic theraphy, prosthetic heart valve, acute coronary
syndrome
Submitted 26/12/10, accepted 5/6/12
Cardiovasc J Afr
2012;
23
:
e7–e8
DOI: 10.5830/CVJA-2012-047
On warfarin therapy, the incidence of major thromboembolism
(
resulting in death or persistent neurological deficit) in patients
with prosthetic valve thrombosis (PVT) is 0.5 to 1.7%.
1-3
Multiple prosthetic valves, cage ball valves and aortic valve
prostheses increase the risk of embolisation.
1,2
Age over 70
years, atrial fibrillation and depressed left ventricular functions
also increase the risk of embolisation with prosthetic valves.
4
Acute pulmonary oedema, circulatory collapse or progressive
dyspnoeas (NYHA class III and IV) may be the presentation of
PVT.
5
Up to 25% of patients suffer from systemic embolism before a
diagnosis ismade.
6
The typical findings arediminishedmechanical
valve sounds, decreased valve area on Doppler and increased
transvalvular gradients. Both obstructive and non-obstructive
PVTs are best diagnosed by transoesophageal echocardiography
(
TEE).
7,8
Generally, patients with non-obstructive PVT are in
NYHA class I and II.
5
An autopsy series of coronary embolism cases reported 14%
incidence of mitral valve disease with atrial fibrillation and 8%
with prosthetic heart valves.
9
Because of haemodynamic factors
favouring diastolic blood flow into the left coronary artery, the
embolic myocardial infarctions mostly affected the anterior wall.
Seventy-five per cent of cases were typical transmural infarcts
while 25% were atypical.
Case report
A 42-year-old woman was admitted to the emergency department
with a history of sudden-onset retrosternal chest pain radiating to
the left arm. Her physical examination was normal with audible
mechanical heart valve sounds. She had a history of rheumatic
mitral stenosis and had received a mechanical mitral valve (27
St Jude, bileaflet) three years earlier. She was on 5 mg warfarin
therapy and her international normalised ratio (INR) was 1.9 two
months prior to admission and 1.5 at presentation.
Her electrocardiogram revealed normal sinus rhythm and
2-
mm ST-segment elevation in leads DII, DIII and AVF. She
was started on unfractioned heparin, and immediate coronary
angiography demonstrated an occlusive thrombus in the distal
Department of Cardiology, Kosuyolu Kartal Heart Training
and Educational Hospital, Istanbul, Turkey
AHMET CAGRİ AYKAN, MD,
MEHMET ÖZKAN, MD
NİLUFER EKSİ DURAN, MD
MUSTAFA YİLDİZ, MD, PhD
Fig. 1. The arrow shows cessation of the blood flow in
the distal segment of the left anterior descending artery,
which is a sign of thrombotic occlusion of the coronary
artery.
