Myocardial Infarction (MI) presenting as acute limb: an extremely rare presentation of MI
1Jersey City Medical Center, Jersey City, NJ, USA
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Case Report
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Abstract
Acute embolic occlusion of the bilateral lower limbs from the left ventricular thrombus is an extremely rare medical condition that is not only
limb threatening but also potentially life threatening. Several strategies are available but not even a single treatment modality is clearly the
best. Here, we present an interesting case that presented with bilateral lower limb ischemia and was later found to have a big thrombus in the
left ventricle as the source of the emboli.
Key words
Myocardial Infarction; LV thrombus; Emboli
J Thorac Dis 2010;2:57-59. DOI: 10.3978/j.issn.2072-1439.2010.02.01.021
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The association between acute myocardial infarction and thrombus
formation is well known. Acute embolic occlusion of bilateral
limbs is very rare phenomenon from the left ventricular thrombus
due to hypokinetic left ventricle. It requires prompt diagnosis and
emergent intervention.
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Case report
A 38 year old male significant past medical history of chronic
smoking presented with the chief complaint of pain in both lower
legs for last two weeks. He was a construction worker and was
completely asymptomatic till 2 weeks back. He developed pain in
both lower extremities, more prominent in the calves, sudden in
onset, aggravated on walking and relieved with rest. The pain was
getting worse over the course of last 2 weeks. He denied any chest
pain and shortness of breath. He denied any IV drug abuse. On
physical examination, he was not in any acute distress and was
hemodynamically stable. Examination of the lower extremities
showed no muscle wasting, no chronic ischemic changes like loss
of cutaneous hair, thinning of the skin or dry gangrenous changes.
Dorsalis pedis, Posterior Tibial and Poplitial pulses were absent but
femoral pulses were strongly palpable bilaterally. Cardiac examination
showed normal heart sounds with no murmur or gallop.
Chest x ray was normal. Ultrasound Doppler showed occluded
right poplitial artery. CT angiogram showed acute occlusion of both right and left poplitial, tibial and peroneal arteries. EKG was
significant for ST segment elevation in V3 and T wave inversions
in V2 and V4.
2D Echo at this stage showed apical akinesis and a huge clot at
the apex of the left ventricle.
Immediate consult for vascular surgery and cardiology was
called. Patient went for emergency cardiac angiogram which
showed 60-80% occlusion of LAD. Cardio-thoracic surgery was
called and he was taken to the operating room for left ventricular
thrombectomy (Fig 1 & 2). LIMA bypass was also done. Subsequently,
percutaneous Mechanical thrombectomy was done to save
both the lower limbs. Patient responded very well to the whole
treatment plan.
Figure 1 ventriculostomy
Figure 2 Thrombus removed from the left ventricle
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Discussion
Inflammation of the endocardium resulting from myocardial
necrosis in any location may cause a layered mural thrombus (1,2).
More extensive thrombi with protruding appearance are at increased
risk for systemic embolization (2,3). Echocardiography has
been instrumental in refining our understanding of patho-physiology
of LVT and is a useful tool in identification of patient who
would benefit from continued anticoagulation and assessing the
status of the LVT by serial echocardiographies (4).
Left ventricular mural thrombus (LVT) is a well recognized
consequence of acute myocardial infarction. LVT formation often
occurs early after anterior myocardial infarction (AMI). As suggested
in our patient, acute anterior wall thrombus leads to decreased
anterior wall motion leading to a big thrombus formation
in the left ventricle (5). The absence of symptoms of acute coronary
syndrome in our patient led to the delay in the diagnosis of the
AMI which subsequently led to the formation of a big left ventricular
thrombus.
The highest rate of occurrence of LVT was found among patients
with anterior MI and an LV ejection fraction of less than
40%. The incidence of LVT in the pre-thrombolytic era is reported
between 20 and 56%, but the Healing and Early After-load Reducing
Therapy (HEART) study assessed the prevalence of LVT as
only 0.6% at day 1, 3.7% at day 14, and 2.5% at day 90 (6).
The role of activated protein C resistance (APC-R) is under
study as a possible predictor of those who would develop LVT. In
a recent study, smoking and APC-R were significantly greater in
those with LVT than those without. Multivariate regression analysis
showed APC-R as an independent risk factor for LVT, whereas
protein S and antithrombin III concentrations were not significantly
different in the two groups (7). The mainstay of treatment is anticoagulation
and it leads to a successful resolution in a large number
of cases. In a study carried out to follow the course of LVT, echocardiography
was done serially at day three of admission, then
before patient discharge, and again at one, three and twelve months
after discharge. The results were that at discharge only 30% had
the LVT still seen and at one, three and twelve months 81%, 84%
and 90% of LVTs respectively had resolved completely (8). But
due to extensive emboli to both the lower limbs in our patient, it
was decided to perform ventriculostomy and thrombectomy to prevent
further embolic phenomenon.
A recent epidemiologic study showed that peripheral artery obstruction
occurs in 14 of every 100,000 people in the general population (9). The heart is the major source of emboli in patients with
valvular disease with or without atrial fibrillation or ventricular
mural thrombus after myocardial infarction. Thrombotic obstructions
of the peripheral arteries are generally associated with
atherosclerotic progression. However, differentiating these two
pathologies clinically is difficult in most cases, and impossible in
10-15% of cases (10).
Classically, the symptoms of acute limb ischemia are dominated
by the six Ps (pain, pallor, paralysis, poikilothermia, paresthesias,
and pulselessness) or 'blue toe syndrome' which was the main presenting
complaint of our case (11). Patients in whom acute limb
occlusion is suspected are evaluated using digital subtraction angiography
(DSA), duplex ultrasonography, CT angiography, and
magnetic resonance angiography. Although DSA is regarded as the
gold standard for limb ischemia imaging, CT angiography has recently
come into wider use (12,13,14)
Various options have been proposed for the management of acute
embolic limb ischemia. For years, surgical procedures such as
embolectomy, bypass, and amputation were considered the gold
standard treatment for total common iliac artery occlusion. However,
early operative intervention has several procedural limitations
and is characterized by a high mortality rate, with a 30-day mortality
rate of 15-25% (15,16).
Randomized studies have shown that thrombolysis is generally
as effective as surgery. Therefore, local thrombolysis has become a
treatment modality in appropriately selected patients (17,18).
Moreover, several recent studies have reported that percutaneous
mechanical thrombectomy has a high success rate, with low amputation
and mortality rates (19,20). Primary endovascular stenting is
not usually considered for the treatment of acute embolic limb lesions
due to the fear of distal embolization (21). Therefore, instead
of using surgery or stenting, we decided to combine treatment with
intra-arterial thrombolysis and percutaneous thrombectomy.
In short, our case has myocardial infarction leading to large
thrombus formation in the left ventricle which then sent emboli to
both the limbs leading to acute ischemia of both the limb which is
an extremely rare phenomenon. The case was treated successfully
with ventriculostomy and thrombectomy followed by percutaneous
thrombectomy and lysis of the clot in the lower limbs.
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References
Cite this article as: Aziz F, Doddi S, Kallu S, Penupolu S, Alok A. Myocardial Infarction (MI) presenting as acute limb: an extremely rare presentation of MI. J Thorac Dis 2010;2:57-59. doi: 10.3978/j.issn.2072-1439.2010.02.01.021
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