What is the difference between heart attack and heart failure?

Posted On January 17, 2024

Introduction 

Do you want to know the difference between heart attack and heart failure? You are in the right place. 

Heart attack and heart failure are the leading causes of death globally. 

You must have heard that many celebrities have passed away in recent times due to heart problems. 

Heart attack and heart failure are two crucial cardiovascular diseases. 

You will be shocked to know that around 20 million (or 2 crore) people died from heart attack and heart failure in 2021 throughout the world. 

Neither heart attack nor heart failure should be taken lightly. These two conditions are medical emergencies.

This article aims to explore the difference between heart attack and heart failure. There will be an in-depth discussion of symptoms, risk factors, types, causes, and diagnoses for both conditions.

Without further delay, let’s start this article. 

Are heart attack and heart failure the same?

Both heart failure and heart attacks are heart diseases. There must be an obvious problem in your heart. However, they also differ significantly in meaningful ways.

A heart attack is a circulatory problem where blood cannot flow towards the heart muscle due to atherosclerosis. 

On the contrary, heart failure is a problem with blood pumping, where the heart muscles cannot pump enough blood to meet the metabolic demands of peripheral tissues. 

So, heart attack and heart failure are not the same problem but heart attacks can lead to heart failure by weakening the pumping capacity of the heart.

What is heart failure exactly? And how many types of heart failure are there?

Whenever we hear the term heart failure, we think the heart is no longer working. That’s true. 

Let me make you understand clearly. When your heart fails to pump blood properly and your body cannot receive enough oxygenated blood (or nutrient-rich blood), it is called Heart Failure (HF).

In medical terms, it is also called Congestive Heart Failure (CHF).

Normal blood circulation in the heart

To understand the types of heart failure, you need to know the normal functioning of the heart.

Your heart has two sides – right and left. The right side of the heart receives de-oxygenated blood (or impure blood), while the left side of the heart delivers oxygenated blood (or pure blood) to your body.

In heart, there are two parts of the cardiac cycle: diastole (relaxation) and systole (contraction).

The upper chamber is a diastolic phase, which requires filling the atrium chamber. During diastole, the right atrium receives de-oxygenated blood from all body parts via the superior or inferior vena cava, whereas the left atrium receives oxygenated blood from the lungs by the pulmonary vein. 

On other side, the lower heart chamber is a systolic phase, which requires the pumping out of blood from the ventricles. During systole, the right ventricle pushes blood into the pulmonary artery to the lungs. While, the left ventricle pumps blood to all body parts through the aorta. 

Types of Heart Failure

If you have a relaxing (or filling) issue in your heart, it could be right-sided heart failure. While the problem in contracting (or pumping) cardiac muscle leads to left-sided heart failure. 

Therefore, you may have two types of heart failure – 

• Left-sided heart failure (or Systolic heart failure)

If you have a left-side heart failure, then there will be a blood pumping problem in the left side of your heart. 

It indicates that your left-sided heart is dilated and your myocardium (or heart muscle) cannot contract the left side of the heart to push blood out. It is also called “Systolic Failure” or “Forward Failure.”

Here, your left atrium works well, receiving blood properly from the pulmonary vein. The problem is in your left ventricle side, which cannot pump blood out. So, it is also known as “Left ventricular heart failure.”

• Right-sided heart failure (or Diastolic heart failure)

In right-sided heart failure, your right ventricle is capable of pumping blood properly, but it delivers less blood to the lungs by the pulmonary artery due to filling failure in your right atrium.

Here, your right atrium cannot receive deoxygenated blood from various organs by the vena cava. It causes filling failure, which is also called “Diastolic Failure”.

In this condition, your right ventricle cannot deliver enough blood to the lungs by the pulmonary artery. Sometimes, it is also called “Right ventricular heart failure.”

What is the main cause of heart failure?

The prevalence of left-sided heart failure is higher than right-sided heart failure. There are different causes of right and left-sided heart failure.  

Left heart failure causes

The most common causes of systolic (left-sided) heart failure are – 

• Necrosis or death of myocardial cells such as angina pectoris, myocardial infarction, etc. 
• Hypertension
• Leaky heart valves, e.g. aortic valve regurgitation (blood comes back into right ventricles)
• Myocardial disease such as cardiomyopathy (weakness of heart muscle)

Right heart failure causes 

You may have a diastolic (or right-sided) heart failure due to – 

• Left-sided heart failure (pressure and volume overload) 
• Hypertrophic cardiomyopathy (heart can hold less blood due to enlarged heart muscle cells and thicken heart valves)
• Constrictive pericarditis (loss of pericardial elasticity)
• Restrictive cardiomyopathy (heart chamber gets stiffened or hard) 
• Lung problems such as pneumonia, pulmonary embolism and acute respiratory distress syndrome (ARDS) – Excessive fluid releases harmful mediators that damage cardiac muscles. 

What are the warning signs of heart failure?

Heart failure symptoms are often ignored by people who assume they are related to ageing and take it lightly. It could be fatal if heart failure is untreated. 

Everyone needs to know the signs and symptoms of heart failure. 

The warning signs of right and left-sided heart failure are not similar. Let’s see how there are different signs and symptoms –

Left-sided heart failure signs and symptoms

Suppose you have left-sided heart failure; you will have systemic resistance. It means your organs won’t receive oxygenated blood, which leads to ischemia. So, you may have the following symptoms – 

1. Pulmonary edema (Heavy wet lungs)

In left-sided heart failure, the left ventricle fails to pump blood out by the aorta. Due to this, it sends the blood back towards the lungs by the pulmonary vein. 

It causes an increase in the pressure in your pulmonary vein. The blood will be pooled up in the lungs. You may have a heavy lung due to excess blood fluid.

2. Dyspnea (or shortness of breath)

The edema fluid accumulates in the alveolar space of your lungs. Due to this, there is difficulty in exchanging oxygen and carbon dioxide gases, which leads to dyspnea. 

You will have difficulty breathing. It could be Paroxymal Nocturnal Dyspnea (PND) or Orthopnea.

3. Pulmonary congestion 

You may experience cough, crackles, wheezing, and blood tinge sputum due to pulmonary congestion. 

4. Hypoxemic Ischemic Encephalopathy (HIE) and Stroke 

When your left-sided heart (or left ventricle) is not pumping enough blood, there will be decreased blood perfusion in various organs.  

Now, think about the brain. When your brain does not get enough blood supply through the carotid artery and you will have ischemia in some regions of the brain that leads to hypoxemic ischemic encephalopathy (HIE) and stroke.

5. Prerenal Azotemia (Kidney Failure)

Low blood perfusion in the kidney may cause prerenal azotemia (kidney failure).  

6. Fatigue and tiredness

You may feel exhausted and tired if your muscles do not receive enough blood supply. 

Right-sided heart failure signs and symptoms

Suppose you have a right-sided heart failure; you may experience – 

• Breathlessness
• Chest discomfort
• Palpitations
• Swelling

The main symptom of right-sided heart failure is fluid buildup. In right-sided heart failure, your right atrium cannot receive deoxygenated blood from various organs. 

Due to this, deoxygenated blood will be returned, and it increases the pressure in the superior and inferior vena cava. The blood will be pushed back, and this fluid gets deposited in all organs – 

1. Peripheral edema 

Peripheral edema is the hallmark sign of detecting right-sided heart failure. The blood will be pooled in the lower limbs. 

You may observe swelling in your lower legs due to fluid accumulation. Pressing the swelling legs with a finger shows a dimple (or pit) for a few seconds, representing pitting edema. 

2. Ascites

Ascites are another vital sign of right-sided heart failure. Since blood is not going to the right atrium due to right heart failure. So, the blood will be returned and deposited into the peritoneal cavity. 

You may have a swelling in your abdomen region due to fluid collection in the peritoneal cavity. 

3. Hepatomegaly 

Right-sided heart failure may also cause hepatomegaly. You may have swelling or enlargement of the liver due to fluid accumulation in liver cells.

4. Splenomegaly 

The spleen is located just behind your stomach and under your diaphragm. In right-sided heart failure, you may have an enlarged spleen due to fluid deposition. 

5. Jugular vein distension (JVD)

You can see the jugular vein superficially in your neck. The primary function of the jugular vein is to carry deoxygenated from the brain and face to the right atrium of the heart via the superior vena cava. 

In right-sided heart failure, you may have fluid collection in the jugular vein, and a bulging vein can be seen at your neck. This is called Jugular Vein Distension (JVD).

What are the 4 stages of heart failure?

The NYHA (New York Heart Association) classification has classified heart failure into different stages. There are four stages of heart failure – 

How do you confirm a diagnosis of heart failure?

Heart failure can be examined by various diagnostic tools – 

1. Electrocardiography (ECG)

ECG should be the first diagnostic tool to determine heart failure. You will have ECG abnormalities in heart failure. In ECG, you want to see heart hypertrophy, LBBB, abnormal heart rhythm, and heart rate. 

• To check hypertrophy of the heart in ECG

There might be a 65 % possibility of hypertrophy in heart failure patients. You need to observe Lead 1 and aVF for hypertrophy of the heart. Lead 1 and aVF give the direction of the heart. 

Suppose you find a positive QRS deflection in Lead I and a negative QRS deflection in aVF; it represents LAD (Left Axis Deviation). It is most commonly seen in left ventricular hypertrophy (LVH).

Similarly, suppose you find negative QRS deflection in Lead I and positive QRS deflection in aVF lead. In that case, it represents RAD (Right Axis Deviation). It is often seen in right ventricular hypertrophy (RVH).

• To check abnormal heart rhythm and heart rate in ECG

You need to check whether the R-R distance is the same or not. If the R-R distance is unequal, then it will be an irregular rhythm.

You will also see an increased heart rate in heart failure. If you find 1 large square (normal 3 to 5 large squares) between R-R intervals, there will be sinus tachycardia. 

If you don’t find any P–wave in the ECG paper, it represents Atrial fibrillation.

It means there is chaotic electrical activity in the upper chamber with a rapid heart rate, around 350-550 bpm. It indicates your heart is not circulating enough blood to your body. 

• To check the Prolonged QT interval in ECG

A healthy person’s QT interval covers 10 small squares with 0.4 seconds. If it is longer than average, it represents long QT syndrome. A long QT interval can cause torsades de pointes.

There could be a 70% possibility of prolonged QT interval in heart failure. 

• To check LBBB in ECG

The patient might have LBBB (Left bundle branch block). For LBBB, you will find in ECG

1. QRS duration more than 0.15 sec or 150 ms (normal QRS duration is 0.1 sec or 100 ms)
2. Broad clumsy R wave with ST depression in V5 & V6 

Note – 

There will be an obvious abnormality in advanced (or chronic) heart failure patients. But, you may find normal ECG in newly detected heart failure (or acute heart failure). 

2. Echocardiography (Echo)

You need to check the ejection fraction in the Echo. The ejection fraction (EF) is a pumping capacity representing the amount of blood from the heart. 

The normal EF is 55 to 70% in a healthy heart. 

If you find EF less than 55, it indicates systolic heart failure (or left-sided heart failure) because there is a pumping issue. 

The EF can be seen as normal (more than 55) in right-sided heart failure because the problem is a filling capacity, not a pumping. 

Along with EF, dead cardiac tissue images can be seen in Echo. It represents valvular heart disease.

3. Chest X-ray 

Some significant X-ray findings can be seen in heart failure conditions such as – 

• Cardiomegaly (increased heart size)
• Kerley B lines (1 to 2 cm horizontal lines in the periphery of the lower posterior lung fields)
• Pleural effusions (accumulation of fluid in the lower part of the chest)
• Upper lobe pulmonary venous congestion and interstitial edema

4. Blood test

A BNP test is an essential cardiac marker to determine heart failure. The normal BNP (B-type natriuretic peptides) level is 100 pg/ml. You will observe a BNP of more than 100 pg/ml in heart failure. 

What is a heart attack? What is the difference between heart attack and myocardial infarction?

When your heart gets a complete blockage of the coronary artery due to a blood clot, and blood is unable to reach the cardiac muscle, which leads to ischemia. This cardiac ischemia may cause cardiac tissue death (infarction). This condition is called a heart attack. 

In medical terms, it is also known as Myocardial Infarction (MI). Therefore, heart attack and myocardial infarction are the same heart problems.

What is the main cause of a heart attack?

The most common cause of heart attack is coronary artery disease (CAD) or ischemic heart disease (IHD). 

The atherosclerosis is the main reason for coronary artery disease. In atherosclerosis, plaque is formed in the lumen of a coronary artery by the deposition of fatty substances, cholesterol, cellular waste products, calcium, and fibrin.

This plaque reduces the supply of blood to your heart, which causes ischemia in heart cells. 

Initially, it develops angina pectoris and further progresses to myocardial infarction. 

What is the difference between angina pectoris and myocardial infarction?

Angina means “difficulty or constriction”, and pectoris means “pectoral or chest muscle”. Pain in the chest is called Angina Pectoris. 

Angina pectoris is a temporary state of heart attack because it gives you a warning. In this condition, you get partial blockage of the coronary artery and forms ischemia in your heart muscles. This ischemia causes pain in your chest that radiates towards your left arm and shoulder. It could be stable and unstable angina. 

On the contrary, myocardial infarction is a permanent blockage of the coronary artery. Due to this blockage, blood does not reach the heart muscles, causing ischemia. 

Gradually, your heart muscles start damaging. This process leads to a heart attack. 

What is the difference between stable and unstable angina?

There are two types of angina pectoris – stable and unstable angina. 

When you get chest pain during exercise, emotional stress, climbing upstairs or cold weather. And, your chest pain gets relaxed during rest. These warning signs indicate stable angina. It is also called “Classical angina” or “Typical angina”.

In this condition, the coronary artery is partially blocked due to atherosclerosis. Here, your heart needs more ATP (energy), a heavy workload, and increased oxygen demand when you do exercise. 

On the contrary, unstable angina is a more serious condition than stable angina. In this condition, you will get chest pain even at rest position. 

The pathophysiology of unstable angina may be due to atherosclerotic plaque or vasospasm of the coronary artery. It is also called “Prinzmetal angina” or “Variant angina”. 

What are the 6 signs of a heart attack a month before it happens?

There are 6 most common signs of a heart attack that you may experience a month before the actual event:

1. Chest problems – chest pain, heaviness, uncomfortable pressure, squeezing, fullness or burning feeling in the chest

2. Pain or discomfort in one or both arms, back, neck, shoulder or jaw 

3. Heart palpitations and shortness of breath

4. Unusual fatigue, a feeling of anxiety and sleep problems 

5. Coughing or wheezing 

6. Indigestion or nausea

What tests confirm a diagnosis of myocardial infarction or heart attack?

Some important diagnostic tests help to determine coronary artery disease or myocardial infarction – 

1. ECG

If you find an up-righted and elevated ST segment above the baseline, it represents ST elevation. 

It is also called STEMI (ST-elevation myocardial Ischemia). It also represents early repolarization. 

You may also see poor R wave progression and the absence of P wave. 

2. Blood test 

Three cardiac markers represent NSTEMI (Non-ST elevation myocardial infarction) – 

• Trop T-test 

Troponin is a protein that is present in your heart muscles. Whenever you get a cardiac injury, this troponin starts secreting from heart muscles and is released into the blood. It is also called cardiac troponin. In a heart attack, you will get increased troponin levels.  

• LDH test 

LDH is an enzyme that stands for lactate dehydrogenase. The high level of LDH in your blood represents tissue injury. It could be liver injury, skeletal injury, heart injury etc.  

• CK-MB test

The full form of CK-MB is the creatine kinase-myocardial band. It is a common enzyme that is present in your heart. Whenever your heart gets damaged, it starts leaking in your blood. The higher CK-MB level indicates heart damage. 

3. Angiography test

The coronary artery can’t be seen in normal X-rays. So, coronary angiography is also an imaging technique that helps to determine the blockage of the coronary artery. This technique will inject you with a special dye called a contrast agent before imaging. The report visualizes your coronary artery and helps your doctor diagnose it. 

4. Myocardial perfusion scan or imaging

This is an advanced and expensive technique to determine heart problems. In this imaging, a radioactive tracer is used to diagnose heart problems. 

It helps to diagnose coronary artery disease, heart wall motion abnormalities and heart muscle damage. It is also called the “Nuclear Stress Test“.

What is the difference between heart attack and heart failure?

The heart attack and heart failure have been clearly explained separately above. Now, you can easily differentiate these two heart diseases. 

Summary 

There are many similarities between heart attack and heart failure, including their risk factors and underlying health conditions. 

The main difference between heart attack and heart failure is that heart failure occurs gradually over time, while heart attacks strike suddenly. 

In this post, we evaluated that coronary artery disease is a primary culprit in all heart diseases. 

The progression of coronary heart disease may lead to heart failure. Heart failure is the ultimate stage of all heart diseases. 

If you experience symptoms of a heart attack or heart failure, you should seek medical attention immediately.

We will go through the treatment approach for heart attack and heart failure in the coming blog post. 

Please share this post if you find it informative. 

FAQ

Q 1. Which is more dangerous, heart attack or heart failure?

Although both heart attack and heart failure are medical emergencies. Coronary artery disease is the main cause of these heart diseases. A heart attack may result in heart failure since it weakens the heart’s ability to pump blood. So, Heart failure is a more dangerous condition than a heart attack. 

Q 2. What is the difference between heart attack and heart stroke?

Heart stroke is a serious medical condition where the reduction of blood flows to the brain due to blockage of the carotid artery. Whereas a heart attack happens if your heart muscles do not get enough blood flow due to blockage of the coronary artery.  

Q 3. What blood tests show heart failure?

BNP (B-type natriuretic peptides) is an essential cardiac marker to determine heart failure. The main function of BNP is to regulate blood circulation. If there is an obstruction in circulation, BNP starts to be released from the heart muscles. It gets increased in heart failure conditions.

Q 4. What blood tests show a heart attack or myocardial infarction?

Three important cardiac markers can evaluate heart attack or myocardial infarction: Troponin, LDH and CK-MB test. These cardiac markers start leaking into your blood whenever your heart muscles get injured or damaged. You will find increased levels of troponin, LDH and CK-MB. 

Q 5. What is the final stage of heart failure?

Heart failure means the heart gradually weakens, resulting in inadequate heart pumping. Over time, it starts damaging the other body parts and functioning. This is the final stage of heart failure, which is also called “End Stage Heart failure”. At this stage, a person will be at high risk of dying in the next 6 to 12 months. 

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