The human heart is a powerful and hard-working organ that pumps blood to different parts of the body throughout the day. However, it requires a separate but small amount of oxygen-rich blood to keep its muscle tissue healthy and functioning. This requirement is fulfilled by the coronary arteries, which deliver oxygen-rich blood to the heart’s muscle (myocardium), ensuring it has the energy and oxygen it needs to keep pumping.
Without this blood supply, the heart’s muscles get damaged. This can lead to a heart attack if the blood flow is blocked. So, while the heart pumps blood to the entire body, it needs a small amount of blood to take care of itself!
To give you a clearer picture, the heart pumps about 70 millilitres of blood with each beat (known as the stroke volume). In one minute, the heart pumps about 5 litres of blood (1.3 gallons) of blood per minute at rest (called cardiac output), which is roughly the amount of blood in the average adult’s body. In this process, the heart pumps around 7,000 litres of blood over an entire day. This blood carrying oxygen and other nutrients is pumped to different parts of the body throughout the day by the circulatory system.
In return, to meet its requirement for blood supply, the heart depends on the coronary arteries also referred to as the “heart’s blood vessels” to continuously supply oxygenated blood and nutrients to the heart’s muscles (myocardium) and tissues. The coronary circulation ensures that the heart receives a constant supply of oxygen-rich blood and nutrients, which is vital for maintaining its rhythm, function, and overall health. The coronary arteries are essential as they provide the heart with the oxygen it needs to keep beating.
So while the heart keeps pumping blood to all organs and tissues in the entire body, it needs about 5% of the total blood output to keep its muscles healthy and pumping efficiently.
The amount of blood the heart needs to function depends on factors like the body’s metabolic demands, activity level, and overall health. The cardiac output is calculated by multiplying the stroke volume or the amount of blood pumped per heartbeat with the heart rate or number of heartbeats per minute.
A healthy adult heart typically beats about 60–100 times per minute at rest and hence pumps approximately 70–80 millilitres of blood per beat (stroke volume). In other words, the heart pumps roughly 5 litres of blood per minute at rest and in return requires its dedicated supply of around 250–300 millilitres of oxygenated blood per minute to contract and maintain its rhythm under normal resting conditions.
During physical activity, the heart needs more oxygen so the coronary arteries dilate to supply more blood to the heart muscle. The heart uses oxygen from the blood for its energy production. Higher oxygen demand, such as during exercise or stress, increases the amount of blood it requires.
The flow of blood through the coronary arteries is influenced by blood pressure, heart rate, and oxygen demand (e.g., during physical exertion). The faster the heart beats, the more blood it pumps to the body, but this also increases the heart’s own blood supply needs.
The heart has several arteries and veins that ensure it receives the oxygenated blood it needs and the deoxygenated blood is returned to the lungs and body. These arteries and veins work together to ensure the heart gets the blood and oxygen it needs to keep pumping blood to the rest of the body.
Risk factors for heart disease and heart attacks
Common risk factors include:
- The risk of heart disease increases with age, particularly for men over 45 and women over 55.
- A family history of heart disease can increase the likelihood of a heart attack.
- High blood pressure damages blood vessels and increases the strain on the heart.
- High LDL (“bad”) cholesterol can lead to plaque in the arteries, increasing the risk of heart attacks.
- Smoking damages blood vessels and reduces oxygen levels, contributing to heart disease.
- Diabetes and poorly controlled blood sugar levels can increase the risk of heart disease
- Obesity, high blood pressure, cholesterol, and diabetes contribute to heart disease.
- Lack of regular physical activity can lead to weight gain, high blood pressure, and other risk factors.
- Unhealthy diet containing saturated fats, trans fats, and salt can increase the risk of heart disease
What happens in case of a heart attack?
The heart’s ability to meet its own oxygen and nutrient needs is crucial for cardiovascular health. When the blood supply to the heart muscle is compromised (as in coronary artery disease), it can lead to serious conditions like heart attacks.
Blockages in the coronary arteries due to plaque build-up (atherosclerosis) can restrict blood flow, leading to coronary artery disease (CAD), chest pain (angina), heart attacks, and other heart problems. The plaque can lead to blood clots, which can further block the blood flow. This reduced blood flow can lead to chest pain (angina) or heart attack (myocardial infarction), where part of the heart muscle dies due to lack of oxygen. Any disruption in blood flow to the heart can have serious consequences, which is why coronary artery disease is a leading cause of heart attacks, heart failure, and other cardiovascular conditions.
A heart attack (also known as a myocardial infarction) occurs when the blood supply to a part of the heart muscle is blocked or reduced, due to a build-up of fatty deposits or plaque build-up in the coronary arteries. A blockage in one of these arteries due to fat deposits, cholesterol, cellular waste, and other substances is the most common cause of a heart attack which prevents oxygen and nutrients from reaching the heart tissue, causing it to become damaged. The heart muscle is highly dependent on the steady supply of oxygen without which it cannot function properly or work efficiently and can impair its ability to pump blood efficiently. Without oxygen, the affected heart tissue may start dying if blood flow is not restored quickly. The longer the heart muscle goes without oxygen, the greater the damage. The severity of a heart attack depends on how much of the heart muscle is affected and how quickly medical help is received. If a significant part of the heart muscle is damaged, the heart may not be able to pump blood. This can lead to heart failure, or cardiac arrest, where the heart stops beating altogether
There are different types of heart attacks, but the most common type is the ST-segment elevation myocardial infarction (STEMI), which is considered the most severe form of heart attack. Another common type is the non-ST-segment elevation myocardial infarction (NSTEMI), which is less severe but still requires immediate treatment.
Also Read: Heart attack: Your heart is crying for help, don’t ignore the early warning signs
During a heart attack, the heart releases certain chemicals (e.g., troponin, creatine kinase) into the bloodstream. Inflammation and swelling also occur in the damaged area, and the surrounding tissues may become less efficient at contracting and pumping blood. The body may try to compensate by increasing the heart rate to pump more blood, but this can also put additional strain on the heart, especially if it’s already weakened.
The body reacts to the heart attack by triggering an inflammatory response. White blood cells rush to the site of the injury to repair the damaged heart tissue. This can cause swelling, which might make the problem worse if the inflammation affects the heart’s ability to pump effectively.
Common symptoms of heart attack
The American Heart Association (AHA) recommends remembering the acronym “ACT” to recognize the common symptoms of a heart attack:
1. A – Arms, Back, Neck, Jaw, or Stomach: Pain or discomfort in one or both arms, the back, neck, jaw, or stomach.
2. C – Cold Sweat: Breaking out in a cold sweat.
3. T – Tightness or Pressure: Feeling of tightness or pressure in the centre of the chest that lasts for more than a few minutes.
Recognizing the early warning signs of a heart attack is critical in saving lives. Heart attacks don’t always present with the classic symptoms, such as chest pain, and they can occur gradually over time or suddenly. Early warning signs may differ between men and women, and it is important to stay alert to the full range of potential symptoms.
Chest Pain or Discomfort is the most well-known and common symptom of a heart attack. It often feels like a heavy pressure or squeezing sensation in the chest. The pain may radiate to other parts of the body, including the arms (especially the left arm), neck, jaw, back, or stomach. The discomfort can last for several minutes or come and go. It is important to note that not everyone experiences the same type or severity of chest pain. For some people, especially women and those with diabetes, the chest pain might not be as severe, and they might experience only mild discomfort.
Shortness of Breath both with and without chest pain is often one of the earliest symptoms of a heart attack. The heart’s inability to pump blood effectively can lead to a backup of fluid in the lungs, causing difficulty in breathing. This symptom may be particularly noticeable during physical activity or while lying down. Some people may experience shortness of breath unexpectedly, even during rest. This is a sign of reduced heart function and should not be ignored.
Nausea or Vomiting is a common but often overlooked symptom of a heart attack. It should be treated as a serious warning sign, and medical help should be sought immediately. The feeling of indigestion, nausea, or even vomiting can accompany a heart attack, particularly in women. These gastrointestinal symptoms occur because the body’s autonomic nervous system is affected by the heart’s stress.
While chest pain is the typical warning sign, a heart attack can lead to pain or discomfort in the shoulders, arms (especially the left arm), neck, jaw, back, and stomach, often with or without chest pain. In such cases, the discomfort may not be strong, but a dull ache or pressure could indicate a heart attack.
Dizziness, light-headedness, or fainting should be taken seriously, especially when they are accompanied by other signs of heart attack. These symptoms indicate that the heart’s pumping ability is impaired, leading to a drop in blood pressure and insufficient oxygen supply to the brain. These signs, especially if they occur suddenly and are accompanied by chest discomfort or pain should be taken seriously and need immediate medical attention.
Cold sweat that occurs along with other signs of a heart attack is another alarming sign that should not be ignored. It is usually caused due to the body’s reaction to stress as well as reduced blood and oxygen supply in case of a heart attack.
Unexplained fatigue and weakness are other subtle but common early warning signs of a heart attack. In some cases, individuals may experience extreme tiredness or a feeling of being “drained” for days or weeks before the heart attack occurs. This fatigue may occur even with minimal physical exertion. Women, in particular, may experience unexplained fatigue in the early stages of a heart attack if accompanied by other symptoms.
A stitch in time – saves lives
In case someone is experiencing a heart attack, every second counts. Immediate action can save lives and reduce the extent of damage to the heart.
The importance of time
A heart attack is a life-threatening emergency, and immediate medical attention is critical. The sooner the person receives treatment, the better the chances of survival and recovery with minimal heart damage.
The heart’s electrical system, which controls the rhythm and timing of heartbeats, can be disrupted during a heart attack. This can lead to arrhythmias (irregular heartbeats) or cardiac arrest (when the heart suddenly stops beating). This disruption in the electrical signals can be dangerous and life-threatening if not treated immediately.
If the blockage persists for a few minutes or more, blood clots can block the artery and prevent oxygen-rich blood flow to the heart muscle. This leads to ischemia and the heart muscle cells begin to die weakening the heart’s ability to pump blood and overall function.
The severity of the damage depends on the size of the area affected and the duration of the oxygen deprivation.
The quicker the blood flow is restored to the heart, the less damage is done to the heart muscle.
If the damage to the heart muscle is severe and not treated quickly, it can result in heart failure, where the heart is unable to pump enough blood to meet the body’s needs.
The heart may also suffer from cardiogenic shock, a condition in which the heart is so weakened that it cannot supply enough blood to the vital organs.
The longer the blockage persists, the more heart tissue can die, which can lead to long-term complications or even death.
Sorbitrate – the life-saver under the tongue:
Sorbitrate also known as isosorbide dinitrate is a quick-relief emergency medication for chest pain, angina and coronary artery disease (CAD).
Sorbitrate belongs to a class of drugs called nitrates, which dilate the blood vessels and are commonly used in the treatment of heart attacks. It helps reduce the workload and improves the blood flow to the heart muscle in case of a heart attack.
When placed under the tongue (called sublingual administration), Sorbitrate is rapidly absorbed into the bloodstream through the mucous membranes and works quickly.
By relaxing and widening the blood vessels, Sorbitrate reduces the pressure on the heart, making it easier for the heart to pump blood. This makes it a life-saver during a heart attack when the heart is struggling to get enough oxygen due to a blocked artery. Sorbitrate also relieves angina (chest pain) and eases the discomfort by improving blood flow to the heart.
By lowering the heart’s workload and improving circulation, Sorbitrate reduces the amount of oxygen the heart needs, which is critical during a heart attack when oxygen supply to the heart muscle is compromised.
For quick relief place the tablet under your tongue. Don’t swallow – let it dissolve and wait for relief, which usually occurs within minutes. However, if pain persists after 5 minutes, seek emergency medical help immediately and follow the doctor’s instructions.
Call emergency services immediately: If you or someone else is experiencing symptoms of a heart attack, the most important step is to call emergency services as soon as possible. Time is critical, qualified medical professionals can begin treatment en-route to the hospital.
Keep calm: Encourage the person experiencing the heart attack to stay calm and avoid any physical exertion. Stress and anxiety can worsen the situation. Help the person sit down, rest, and remain as calm as possible.
Aspirin: If the person is conscious and not allergic to aspirin administer a dose of aspirin 325 mg which is a blood thinner and prevents blood clotting and blocking the heart’s blood supply. However, do not give aspirin if the person is unable to swallow or is showing signs of a stroke (such as weakness or difficulty speaking).
Perform CPR: If the person becomes unresponsive and is not breathing, cardiopulmonary resuscitation (CPR) should be performed immediately. Start by pressing hard and fast in the center of the chest, aiming for about 100-120 compressions per minute. If trained, also administer rescue breaths. CPR can help keep blood flowing to vital organs, including the brain and heart until emergency personnel arrive. It can significantly improve the chances of survival.
Use an AED if available: If an automated external defibrillator (AED) is available, use it as soon as possible. An AED is a portable device that can analyze the heart’s rhythm and deliver a shock if necessary to restore a normal heart rhythm. Many public places, such as airports and gyms, are equipped with AEDs.
Help medical professionals: Provide as much information as possible about medications the person is taking, and symptoms to emergency personnel as soon as they arrive. This can help them make quick decisions. By staying informed, proactive individuals can protect themselves and others from the devastating consequences of heart disease.
Emergency medical care and treatment:
Immediate treatment is crucial to limit heart muscle damage.
Oxygen therapy, blood thinners, and medications are often administered in the emergency room to control pain or prevent arrhythmias.
Procedures to open blocked arteries:
Medical intervention is essential to restore blood flow to the heart as quickly as possible. This may involve:
Quick administration of aspirin or other clot-busting drugs (thrombolytic) drugs can prevent further clotting and reduce the risk of damage. Thrombolytics break up clots by activating fibrinolysis and converting plasminogen to plasmin which lyses the clot. This allows blood and oxygen to reperfuse the area, limiting tissue damage. Thrombolytics are effective if initiated as soon as possible after the heart attack, stroke, or pulmonary embolism but can be given within three hours of a stroke, or 12-24 hours of a heart attack.
To restore blood flow, doctors may perform a procedure such as angioplasty, in which a small balloon is inflated inside the blocked artery to open it up. Sometimes, a stent (a small mesh tube) is inserted to keep the artery open.
In some cases, if the blockage is severe, doctors may recommend Coronary artery bypass grafting (CABG), – a surgical procedure to reroute blood around the blocked arteries. In such cases, a blood vessel from another part of the body is used to bypass the blocked artery.
Post-heart attack recovery and rehabilitation:
After the heart attack, patients may need medication to reduce the risk of future heart attacks, such as antiplatelet, blood thinners, and beta-blockers.
After the initial treatment, patients are closely monitored to assess any potential complications. This includes checking for arrhythmias, low blood pressure, and other signs of heart failure.
Cardiac rehabilitation is often recommended to help people recover after a heart attack, which involves lifestyle changes, exercise, and counselling to reduce the risk of future heart attacks.
Lifestyle changes like a heart-healthy diet, regular exercise, and quitting smoking are also crucial for recovery and reducing the risk of future heart issues.
How much time does a heart patient need to survive
The survival time of a person who has had a heart attack depends on several factors, such as the severity of the heart attack, how quickly treatment is received, the extent of heart damage, and the person’s overall health.
The Speed of Treatment: Time is critical in a heart attack. The sooner the blockage in the coronary artery is cleared, the less damage is done to the heart muscle. The first hour following a heart attack is often referred to as the “golden hour” because this is when immediate treatment (like clot-busting drugs or angioplasty) is most effective at minimizing heart damage and increasing the chances of survival.
Type and severity of the heart attack: A minor heart attack might cause little damage to the heart muscle and may be survivable with prompt medical intervention. A massive heart attack, where a large portion of the heart muscle is damaged, can result in more serious consequences, including heart failure, arrhythmias (irregular heart rhythms), or cardiac arrest. Without prompt treatment, the person’s survival rate decreases.
Restoration of blood flow: Timely restoration of blood flow to the heart improves the chances of survival. If the blockage is removed within 30 minutes to 1 hour, the chances of surviving and minimizing heart damage are greatly increased.
Medical care: Immediate medical care, life-saving interventions such as CPR and defibrillation as well as medical interventions like angioplasty (to open blocked arteries) or bypass surgery can help save lives in severe cases.
Health Conditions: Age, gender, and pre-existinghealth conditions like high blood pressure, diabetes, obesity, or previous history of heart disease can affect the outcome of a heart attack. Individuals with weakened heart muscles, chronic conditions, or other risk factors too have a lower survival rate than healthy individuals.
The chances of survival decrease with the delay in medical treatment. On the other hand, early recognition of symptoms and timely medical help can make a big difference.
Early treatment means higher chances of surviving and less severe damage. In short, time is a critical factor for survival in case of heart attack.
