What is a heart attack?
A heart attack, clinically known as “Myocardial Infarction” (MI) occurs when there is reduced blood flow to the myocardium (the muscular layer of the heart). The depletion of oxygen causes necrosis of myocardial cells. The incident could be undetected or it can lead to eventful consequences followed by sudden death. Patients would usually display signs of chest discomfort which may spread to the arm, neck and shoulder.1
Causes
Acute MI is directly caused by the obstruction of coronary arteries for longer than 20-40 minutes, such occlusions are generally because of thrombosis (formation of blood clots in the heart) or plaque formation from atherosclerosis. Reduced blood and oxygen flow results in sarcolemma (muscle membrane) activity disturbance and myofibril relaxation, which creates a state of ischemia (restricted or reduced blood supply). Slowly, the associated necrosis would spread to other areas of the heart distressing the cardiac system. If the patient recovers from the event, then the infarcted areas will display internal scars due to the cardiac healing process.1
Risk factors
The non-modifiable risk factors are:
- Age – The risk of coronary heart disease increases with age.
- Sex – Males are slightly at higher risk of heart attack due to high prevalence of hypertension and stress in males.
- Race and Genetics – The offspring of parents with heart disease are more at risk to develop a cardiac condition. It was seen that African-Americans are likely to have a higher blood pressure compared to Caucasians, hence they are at a higher risk for a MI.2
Modifiable risk factors are :
- Tobacco smoke – Cigarette smoking is a major contributor to coronary heart disease since tobacco damages the walls of the arteries making them susceptible to plaque deposits.
- High cholesterol levels – Cholesterol levels are directly correlated to the risk of developing heart disease. It is also affected by the individual’s genetics, age and lifestyle. High levels of High-Density Lipoproteins (HDL) and low levels of Low-Density Lipoproteins (LDL) are important for good heart health.
- High blood pressure – With the cardiac muscle working at higher stress levels the muscles can become stiffer, increasing the risk of strokes and heart attacks.
- Physical inactivity – Regular exercise aids to reduce the risk of cardiovascular disease.
- Obesity – Overweight adults with high blood pressure and high cholesterol levels are at high risk of getting MI .
- Diabetes – Around 68% of diabetes patients over 65 years of age die of some form of heart disease.2
Common signs of heart attack for men
- Chest pain :Pain in the chest area is the most prevalent symptom of a heart attack. It manifests gradually with minor discomfort, then it progresses onto an unexpected period of intense pain, soon leading to an attack.
- Chest discomfort : There can also be a feeling of pressing weight onto the chest with various degrees of pain, which is usually located near the left side or centre of the chest. A scary misconception is that individuals might sometimes mistake the symptoms for heartburn. However, the pain experienced from a heart attack does not solely remain in the chest area, often in many cases, the pain would radiate towards the arms, stomach, back, neck and jaw, due to ischaemia.
- Other important symptoms can include dyspnoea, also known as shortness of breath, which can occur at any time which is not always related to activities performed by the individual or presence of other signs/symptoms. This happens due to fluid build-up in the lungs which may also cause wheezing and coughing.
Gender Differences in heart attack
Differences between males and females in prevalence , symptoms and causes can be noted.
Prevalence
Studies show that acute MI incidences are more than 2.5 times more likely in males than females, but the difference disappears post 55 years of age. So, it is established that younger women have a lower prognostic value for obstructive coronary artery disease than men.
Symptoms
Interestingly, the symptoms like shortness of breath, nausea and back or jaw pain are seen more among female patients.3 In addition, they are also significantly affected by specific risk factors such as smoking and diabetes, whereas hypertension and Low-Density lipoprotein levels are the major contributors to heart attack in males.
Causes of gender differences
There are many biological and psychological reasons as to why symptoms manifest in different ways between the genders. Endorphins may contribute to this variance, as they increase during the state of ischaemia but their regulation is affected by the sex hormones, moderating the sensation of pain throughout the body. Furthermore, there is a difference in reporting heart attacks between men and women, here is where social behaviour and cues influence a patient’s responses. The self-perception of pain between the genders is also very different, which could be due to psychological or evolutionary aspects which cause different types of responses to be shown by an individual even if they are experiencing similar levels of pain and discomfort.4
Outlook
Heart attack is a very serious condition, hence individuals should consider taking preventive measures early in life to manage associated risk factors. Even with clinical advancements, acute MI has a high mortality rate (sometimes with sudden deaths)which further explains the severity of the condition. The overall prognosis of previous MI patients would depend on the magnitude of the cardiac damage and the strength of its ejection fraction. There are contributing factors that worsen prognosis including diabetes, old age, congestive heart failure, and high protein-C and BNP levels.1 Therefore, preventive measures such as controlling of risk factors including lifestyle modification are important so that the susceptibility of a MI or cardiac arrest can be significantly reduced.
Summary
An episode of heart attack occursi when blood flow to the heart is suddently blocked, compromising the normal function of the heart and causing the adjacent tissues (and organs) to be in an ischaemic state. Many contributing factors can cause progression of myocardial infarction such as increasing age, high blood pressure, high cholesterol levels, diabetes and genetics. Incidences of cardiovascular disease are more prevalent in men, but the long-lasting effects are more severe in women. Gender contributes to many differences in reporting and experiencing symptoms initiated by heart attacks. These gender differences have caused concerns about the importance of correct diagnosis of cardiovascular diseases amongst the general population to prevent and manage treatment options for patients. Therefore, to comprehend the reasons for the dissimilar presentation of the symptoms among women and men with ischaemia, understanding the gender issues and effects is vital.
References
- Niranjan Ojha, Dhamoon AS. Myocardial Infarction [Internet]. Nih.gov. StatPearls Publishing; 2019. Available from: https://www.ncbi.nlm.nih.gov/books/NBK537076/
- American Heart Association. Understand Your Risks to Prevent a Heart Attack [Internet]. www.heart.org. 2016. Available from: https://www.heart.org/en/health-topics/heart-attack/understand-your-risks-to-prevent-a-heart-attack
- Regitz-Zagrosek V. Sex and gender differences in symptoms of myocardial ischaemia. European Heart Journal. 2011 Sep 14;32(24):3064–6.
- Gao Z, Chen Z, Sun A, Deng X. Gender differences in cardiovascular disease. Medicine in Novel Technology and Devices [Internet]. 2019 Dec 1;4(100025):100025. Available from: https://www.sciencedirect.com/science/article/pii/S2590093519300256