Hello, welcome everybody, this is doctor Bolad, board certified physician in cardiology, interventional
cardiology and internal medicine, certified by the American Board of Internal Medicine.
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Heart attacks is the number one cause of death worldwide. Not all heart attacks are the same;
their causes and presentations are different. Sometimes when I inform my patients that they
suffered from a heart attack, they get surprised and most of the time they have lots of questions
about the diagnosis I just labelled them with. To me this is totally understandable, as the
public generally think of a heart attack as a sudden onset of severe chest pain, followed
by possible collapse. This belief is only partly true, as the description I just provided
you occurs in certain types of heart attacks, not all of them. I therefore made this video
to clarify the different types of Heart Attacks. When the heart is damaged due to a heart attack,
inflammation, trauma or other causes, certain proteins that are found in the heart muscle
leak into the blood. These proteins include TROPONIN T and TROPONIN I. The greater the
damage to the heart, the greater the level of these TROPONIN leaks into the blood. A
rise in troponin level in the blood followed by a fall is indicative of myocardial heart
muscle damage. There are FIVE MAIN TYPES of heart attacks, as defined by the Joint Task
Force of the American College of Cardiology, the American Heart Association, the European
Society of Cardiology, and the World Heart Federation. Heart attacks, also referred to
as ACUTE MYOCARDIAL INFARCTION, is defined as the presence of acute myocardial injury
detected by elevated troponin level in the setting of evidence of acute reduction of
blood flow to the muscle of the heart. The FIVE types of Acute Myocardial Infarctions
are: ●Type 1 myocardial infarction. This is caused
by acute clotting of the coronary artery, known as thrombotic occlusion. It is usually
precipitated by atherosclerotic plaque disruption, either rupture or erosion. This causes the
classic symptoms of acute severe chest pain, and leads to ST Elevation changes on the ECG
tracing and also leads to increase in the level of the cardiac troponin in the blood,
as measured by a blood test. This is an emergency situation and requires immediate intervention
to restore blood flow to the muscle of the heart.
●Type 2 myocardial infarction. This is caused by a mismatch between oxygen supply and demand,
and is caused by multiple mechanisms, the commonest is excessive work load of the heart
in the presence of coronary artery disease in addition to either drop in hemoglobin,
reduced oxygenation or irregularity of the heart beating. It can also occur in the ABSENCE
of coronary disease, in situations such as coronary dissection, coronary vasospasm, and
microvascular dysfunction. There is no ST elevation on the ECG, or there might be ST
depression. ● Type 3 myocardial infarction. This occurs
when patients present with typical myocardial ischemia or infarction symptoms and typical
ECG changes, followed by unexpected death before blood samples could be drawn for cardiac
troponins or before the appearance of cardiac troponins in the blood.
● Type 4 myocardial infarction. This is subdivided into A and B types. Type 4a myocardial
infarction is associated with percutaneous coronary intervention and requires an elevation
of cardiac troponin values to greater than FIVE times the upper limits of normal in addition
to evidence of new myocardial ischemia on the ECG tracing. Type 4b heart attack occurs
when a stent is placed in the coronary artery and the stent clots leading to a heart attack.
●Type 5 heart attack occurs after Coronary Artery Bypass Graft surgery, with elevation
of the cardiac troponins to levels more than TEN times the upper limit of normal in patients
with normal troponin levels before surgery. If you have any questions about what I presented
to you today, then subscribe to my channel and share your question in the comments section
below and I will reply to you. If you have a question that you would not like to share
in public, then follow me on twitter @DoctorBolad and then send me a private twitter Direct
Message and I will reply to you. Please like and share this video with family and friends.
This is Doctor Bolad, helping you with your heart health, thanks for watching, and talk
to you soon.