October8
There are lots of misunderstanding regarding heart attacks & chest pain in general. In this post, I will be clarifying some of the major points regarding heart attacks for non-medicals.
Angina Pectoris (Heart attack) is chest pain due to heart disease characterized by inadequate blood supply to an area of the heart muscle, usually happens due to stress, exercise, after meals or cold, & resolved by rest or nitrates.
The chest pain is usually compressing like a huge rock on the chest in the middle of the chest, can’t be pinpointed with a finger “i.e. diffuse” and radiating to left arm, left shoulder, jaw, epigastrium “stomach area” or back. Classical description of cardiac chest pain necessitated further investigations whenever there’s pain from the eyebrow to the umbilicus “belly button/navel”.
Sometimes the cardiac chest pain “heart attack” can be silent, without any pain in certain conditions like: diabetic patients, heart transplant patients and some other uncommon diseases. Sometimes it might present with shortness of breath “dyspnea” instead of chest pain, we call that Angina equivalents.
A heart attack is almost always accompanied by shortness of breath “dyspnea”, sense of impending doom “Angor animi”, Sweating, palpitation “conscious sensation of heart beats” & fatigue.
Other characteristics of chest pain cannot fully exclude a heart attack, for example:
- Chest pain that increase & decrease with respiration: That would point to a chest cause more often
- Chest pain that can be pinpointed: more commonly a chest cause
- Chest pain that would last for hours without signs of hemodynamic collapse “i.e. low blood pressure, loss of consciousness and immediate hospitalization” that would commonly be not cardiac in origin
- Chest pain that happens after and not during exercise
- Chest pain that resolve when continuing exercise.
- Non-radiating chest pain
Those types of chest pain would rather point to a cause that is not cardiac, but can not fully exclude cardiac origin, 4% of heart attacks present with atypical forms.
The mechanisms behind a heart attack is a clot in one of the coronary arteries that is obstructing the blood from flowing to the heart muscle OR a spasm in the coronary artery causing transient shortage of blood supply OR incomplete obstruction of a coronary artery that lowers blood supply and manifest when more oxygen is needed by the heart as in exercise.
Who would get a heart attack? There are a huge array of risk factors that would be a cause of atherosclerosis “fat deposition in the artery walls which cause narrowing & maybe clot formation” like: Diabetes, Hypertension, Obesity, Male gender, Stressful personality, lack of exercise, old age, smokers, among other uncommon risk factors.
What to do? First, you need to rest and stop the exercise immediately “that way you’re lowering your heart need for oxygen”. Next, use a nitrate tablet under the tongue “sublingual nitrates” as dinitra to dilate the coronary artery & allow more blood to flow. It’s worthwhile to take 300 mg of aspirin (4 tablets of 75 mg) as well if you were not already on aspirin, this alone improves survival rate by 30%. Then seek medical advice immediately even if the pain subsided.
What do doctors do? First, we ensure there’s no on-going chest pain by giving nitrate drip intra-venous and oxygen supply to increase blood oxygenation. Meanwhile, we run an ECG to detect total obstruction of the coronary artery as well as cardiac biomarkers which increase when there’s heart cells damage “Myocardial infarction”.
It must be noted that normal ECG will not exclude a heart attack. A doctor has to differentiate between a heart attack due to partial coronary narrowing without heart cells damage & a heart attack due to partial or total coronary narrowing with heart cells damage for it will decide the treatment modality chosen.
So Heart attacks can be classified to:
- Simple Angina Pectoris: due to partial obstruction, with no heart cell damage or cardiac biomarkers level increase. Treated by drugs only
- Myocardial Infarction: due to partial or total obstruction, with heart cell damage and cardiac biomarkers level increase. Treated by drugs &/or intervention.
A total coronary obstruction would mean that the part of the heart that is supplied by this artery is not getting any oxygen, rapid action need to be taken to dissolve that clot, otherwise, this part of the heart muscle will die resulting in decrease in overall heart function “i.e. heart failure” & maybe death.
In setting of total occulsion, depending on the situation, Either we dissolve the clot by applying clot-dissolving drip streptokinase or alteplase OR we do coronary intervention by insertion of a catheter through the femoral artery “thigh” up to the clogged artery, remove the clot, dilate the artery & apply a stent “this procedure is called Per-cutaneous coronary intervention PCI”. also multi-slice CT scan should be able to show the obstructed vessels, however it lacks sensitivity on heart rates more than 85/minute and also lacks the intervention aspect of PCI.
It should be noted that there’s only 8 – 12 hours window to dissolve the clot by drugs from the onset of pain. The ideal door-to-balloon time is 90 minutes from the time you reach the hospital to removing the clot & dilating the coronaries which emphasize the importance of the time spent to seek medical advice from the onset of the heart attack.
However in setting of not total occlusion, We resort to drugs only to improve the heart oxygenation, for example:
- Long-acting nitrates: usually taken in the morning and afternoon, leaving an 8-hour nitrate-dree period to prevent tolerance. It dilates the coronary arteries & also decrease the load of the heart, it also causes headache that is resolved by aspirin, it might cause hypotension “low blood pressure” and the dose should be adjusted immediately. It is to be noted that Viarga & Cialis are totally contraindicated with nitrates for the risk of life-threatening hypotension.
- Aspirin: Cornerstone of treatment of heart attacks, it blocks the blood clotting on the platelet level and improve the survival by 30%.
- A Beta blocker: those drugs reduce heart rate & output of the heart, they’re given in a very careful dosage to avoid depression of cardiac function, although they might seem injurious, but they improve outcomes by 17%.
- A Lipid-lowering agent “Statin”: They lower blood cholesterol levels to block more atherosclerosis, moreover they have extra effects by stabilizing the present lipid plaques avoiding their rupture & so, clot formation.
- Heparin: Used only in the acute stage or during the first 24 hours in hospitalized patients only, it is another blocker of the blood clotting system and should be given intra-venous or subcutaneous.
- Clopidogrel “Plavix”: another blocker of blood clotting on the level of the platelets, showing synergy with aspirin and improve the outcome even more than aspirin alone
Other drugs may be added according to the state of your coronary arteries whether it is total or partial occlusion as well as associated condition as hypertension or diabetes.
As you see, those are not on-the-counter medicaments that can be used casually, The management plan has to be custom-tailored to every patient according to his condition.
What should you do after?
- Avoid saturated fat as in butter & ghee and use oils only to cook food, only 2 eggs are allowed per week, red meats should be avoided “duck and pigeons are considered red meat”, sea food in general is beneficial in lowering cholesterol except shrimps, lobster & calamari.
- Make sure your blood pressure & sugar are within the safe margin: BP lower than 130/80 mmHg & Blood sugar lower than 200 randomly.
- Apply exercise cautiously unless your doctor advises otherwise: when chest pain takes place, you should rest immediately.
- Cease smoking.
- If you’re hypertensive, eat low-salt diet. if you’re diabetic, eat low-sugar and low-carbohydrate diet.
- Adhere to your medicament, your heart is dependent on them.
- Always carry sublingual nitrate tablets “taken under the tongue” with you in case you suffered an attack, if you needed more than 3 tablets separated by 5 minute interval, seek medical advice immediately. Chest pain that is not controlled by 3 consecutive nitrate tablets might be an ominous sign of total occlusion.
- If you sensed shortness of breath on minimal exercise, consult your doctor immediately, this might be caused by decrease in heart function that would necessitate adjustment of your treatment plan.
- Fainting might be a sign of heart rate irregularities, although not common when you’re not in need for hospitalization, it should be addressed immediately because it might be life-threatening.
- Bleeding is not a common complaint when using aspirin & clopidogrel, but should be managed as soon as possible to avoid life-threatening internal bleeding.
Further investigations may be required from you including:
- Exercise ECG: to assess your response to exercise.
- Echocardiography “Echo”: to assess the heart function & observe any not-moving heart walls “Segmental wall motion abnormalities”
- Exercise Echocardiography: to assess heart function during stress, we use drugs to induce an exercise-like state
- Thallium scan: injecting a radioactive dye and use a gamma camera to observe uptake during rest & exercise, dead heart tissue will not take the heart at all, while tissues with low oxygen supply will take the dye on exercise when the coronary artery dilates, this test is used to assess the viability of heart tissue if you need late PCI or CABG “bypass open-heart surgery”.
- Multi-slice CT scan of the heart
I hope this discussion helped you understand the basics of mechanisms and treatment of heart attack as well as immediate management and further lifestyle modifications needed, please if you have any inquiries, write them in the comment field and I will try to respond as soon as I can.