External evidence of a heart attack

No external signs ... they just keel over.

There is an enzyme that appears in the blood after a heart attack - it's one way that ER checks to see if patients who think they have suffered a heart attack actually have. Whether or not that could be determined after death - without a full autopsy - I don't know but maybe someone here will.

They might appear mottled

Yes, they will have a reddish flushed look to the skin from the nipples up. (This is not 100%, but death investigators and pathologists consider that distinctive flushing a strong sign of some sort of heart issue.)

Unfortunately, the enzyme is also released in massive quantities after death by any cause, so it's useless as a cause of death indicator.

The enzyme is released in the blood stream during/after the heart attack and will show up in a blood test.

tallus -
The problem is that dead and damaged heart muscle releases the enzyme. It's detected at high levels in all dead people, regardless of the cause of death.

with regard to the cardiac enzymes, there are subypings that can be specific to the heart and not other decaying tissue and if the heart is not pumping they won't reach the systemic circulation. On an autopsy they will take samples from different places to compare, however that is not an external sign. To the eye, someone might appear mottled, they might appear asleep. There are many variables.

The external signs of a heart attack are flushed face (cherry reddish colour) swollen jugular and carotid artery, there may also be a blueish grey tinge around nose, eyes and finger tips (referred to as cyanosis, caused by a lack of oxygen to the tissues), if the death is due to a heart attack (Acute Myocardial Infarction or AMI- acute = sudden onset, myo = muscles, cardial = heart, infarction = tissue death therefore literally meaning is sudden death of heart muscle).

A AMI is very painful and so it is not unusual to find the face clenched in pain, and the dominant hand -usually the right because most people are right handed- clutching at the chest. This is also the first outward sign most people see at the onset of the AMI that most people exhibit

Patients also report a crushing of the chest which radiates down the left arm and can be reported in the left jaw and left side of the neck. There will be clammy pale skin followed rapidly by flushing of the skin. The patient will sweat and feel both cold and heat alternating. Pulse will be erratic, and slow before stopping rapidly.

ECG (Electro Cardio Gram), called EKG by Americans but still mean Electro-cardiogram), changes will usually be to the P, Q and T waves- depending on the location of the infarct.

Immediate treatment is Nitroglycerine sub lingual (under the tongue), followed by Sodium bicarbonate/ calcium carbonate to counteract the unbalanced electrolytes (these are the chemicals which carry electric pulse), adrenaline (Epinephrine to Americans) and atropine to stimulate the heart. These drugs are usually given IV (intravenously) but can be given IC (intra cardiac or directly into the heart). IC is a stab with a long needle through the sternum (just a finger to the left). The patient will also have a ECG (12 lead) and be connected to a monitor which may be portable, called a Lifepak which is a brand but generally used to describe all forms of portable ECG defibrillator/ monitor

If the patient requires defibrillation (cardio shocking or "jump starting" like a car) the dose is 350 - 450 joules. The pads have to be applied direct to the skin, and requires some electrolytic jell or conducting pads. One on the sternum (Apex), the other to left side of the chest below the armpit about half way down the side. This provides a route directly across the heart.

Note each time you shock a patient you are sending a large electric shock into the body, is leaves a burn on the tissue which kills those cells. (See below)

A silent MI is where the patient shows no significant sign of the MI except a pain in the back or jaw / teeth- usually.

At post mortem (autopsy) the heart will show areas of black tissue which is dead tissue (infarct) caused by the MI or by the treatment. The vessel of the heart will have plaque (a thick viscous substance that looks like yellow nasal discharge) forming a blockage in one or more of the cardiac arteries. There will also be blood clots which look like semi set strawberry / raspberry jelly.

If your victim dies by an embolism (a air bubble in the blood) then there will be infarct but probably no plaque. The amount of air needed to induce an embolism is 30 -50 millilitres a very large syringe and has to be directly into a vein.

Then there will be a puncture site for the needle. The best, but most obvious place is the neck. The next would be through the arm pit into the baracial vein or the groin into the femoral vein. These would be obvious to even casual observation.

The easiest way to induce cardiac arrest is 150 - 200 units of insulin inject via the umbilicus (belly button) hard to trace and very effective, can use a small bore needle and so outward signs would be hard to detect.

The cardiac enzymes that have been mentioned are due to the breakdown of cardiac muscle fibre and the elevated enzymes caused by the limbic response to keep you alive.

Hope this helps. I was a Critical care RN for many ears if you are concerned about the veracity of the information.

I' am an avid basket ball player, and I play at a gym where a lot of guys who think they are in good enough shape to play the game come and try out. About 5 years ago a big fellow in his twenties came to play one evening and had a massive heart attack a few minutes into the game. Within moments we had paramedics and two doctors who were in the house trying to save this guys life to know avail. What I remember most is that he was fair skined and turned purple splotchy from the neck down while his face went from bright red to deep reddish purple as he expired on the floor. I never see anyone die in front of me, and it was the most horrifing thing I ever witnessed. Also, he seemed to come in and out of conscienceness with his body heaving in fits of agony whenever he came around then going still when he passed out.

David you are welcome.

Regarding the chap who witnessed the AMI. Unfortunately only 5 -7 % of all non hospital based heart attacks result in a successful resuscitation.

Where I live in New Zealand the government is external automated Lifepaks in Public places to try and increase the survival rate. All you have to do is turn it on and place the pads in place and the machine jump starts the person automatically.

Good point to bear in mind try and have your heart attack in or near to a hospital- preferably by the entrance.

There's a difference between a witnessed arrest, and simply finding someone already dead. Poohcat is describing a typical witnessed arrest in a patient with vascular disease, which is most of the time. (Do they really START at 350 joules in NZ? Is that in a post surgical cardiac unit? I am unfamiliar with how NZ organizes the hospitals. Without knowing specifics on a given patient, we'd start at 200).

If someone is simply found dead, then there won't be the clutching etc, since the body relaxes to default positioning at death. External signs are pretty much proportional to how fast they died, the faster, the fewer external signs. It also depends upon what part of the heart is affected. If it's the part of the heart that generates the electrical impulses as opposed to the muscle, then they are more likely to just keel over. A silent MI can produce no pain whatsoever, particularly in long term diabetics. Poohcat mentioned air emboli as a means of murder. That would require a compliant (probably unconscious) victim. If it's not a murder, a pulmonary embolus of a blood clot can happen to people who outwardly have no signs of an illness and a massive PE can result in someone dying before they hit the floor and have no outward sign of anything to the untrained eye. A long plane or car ride is a common precipitating event. A lot depends on the setting of your story and what you are trying to do.

You will have a lot of leeway in your story, particularly if you leave out medical jargon. That way, those in the know will assume one thing whereas those not in the know will assume another, but the result is the same. The one thing you don't want to do is use jargon incorrectly. I can't watch shows with a medical setting because it infuriates me when they do it so horribly wrong. They do things like (a quote from "ER" regarding a John Doe in the ER,) "He's bradicardic, quick get the lidocaine!" I'm sure Poohcat will laugh at that one.