Differences Between Angina Pectoris and Heart Attack

There are many differences between angina pectoris and a heart attack. The latter is usually much more lethal and represents an emergency.

Written and verified by el biólogo Samuel Antonio Sánchez Amador.

Last update: 21 March, 2023

Ischemic heart disease is the leading cause of death worldwide, as indicated by the World Health Organization (WHO). This group of heart diseases is caused by an imbalance between the blood flow of the coronary arteries and the oxygen requirement of the heart muscle. Do you want to know the differences between angina pectoris and heart attack? Keep reading.

Both conditions are closely related to the pathological world of ischemic heart disease, but they also present certain peculiarities that you must be aware of. In the following paragraphs, we’ll teach you to distinguish them from home. In the realm of heart problems, a quick diagnosis can mean the difference between life and death.

Heart disease, angina pectoris, and heart attack

Before exploring the differences between angina pectoris and heart attack, we find it interesting to circumscribe both terms in the group of cardiovascular diseases (CVDs) and define them separately. First of all, it should be noted that CVD is any condition that affects the heart or blood vessels.

This very general term includes heart disease, angina pectoris, heart attack, cerebrovascular accident (CVA, or stroke), heart failure, hypertensive heart disease, cardiomyopathies, heart rhythm disorders, valvular heart disease, aneurysms, and many other conditions.

Around 17.9 million people die from one of these conditions each year, accounting for 32% of global deaths.

What’s more, as indicated by the WHO, 38% of premature deaths worldwide annually (about 17 million) are caused by CVDs. Next, we’ll show you what angina pectoris and heart attack are separately, as they represent 2 of the most common and dangerous cardiovascular conditions. Keep reading.

What is angina pectoris?

The University of Navarra Clinic (CUN) defines angina pectoris as “a syndrome characterized, in its typical form, by the paroxysmal onset of chest pain oppressive and constrictive retrosternal, which is frequently triggered after physical exertion or exposure to cold.” It’s one of the main clinical manifestations of ischemic heart disease.

Chest pain can have cardiac and non-cardiac causes, so a very thorough diagnostic process is required to locate angina. An estimated 9 million people in the US have angina symptoms each year, a condition that always indicates cardiovascular failure. As we’ll see later, angina can be stable or unstable.

What is a heart attack?

The same institution cited defines infarction or heart attack as “localized and rapid destruction (necrosis) of a tissue or organ, due to anoxia, due to interruption of the blood supply to a certain area. This is a consequence of the obstruction of the corresponding artery and the absence of compensatory collateral circulation.”

Put more simply, infarction (more specifically myocardial) occurs when blood flow decreases or is completely cut off in one of the coronary arteries, responsible for nourishing the heart muscle. The most common symptom of this condition is chest pain, but it’s also accompanied by discomfort in the shoulders, neck, jaw, or arms.

Most heart attacks occur from coronary artery disease. High blood pressure, smoking, untreated type 2 diabetes, obesity, and alcoholism are some of the clearest predisposers of this condition. The mortality rate is 15% of patients between 35 and 64 years old.

The differences between angina pectoris and heart attack

Now you know that both angina pectoris and myocardial infarction are cardiovascular diseases that are also included within the group of heart diseases. We’ll explore their differences in depth in the following sections.

1. Different pathological processes

Although in both cases, there’s marked chest pain (although not always), angina and heart attack are quite different both histologically and biochemically. The explanation is that there’s a very slight link between oxygen deprivation in the heart muscle and chest discomfort. In other words, there can be a lot of pain and little risk of tissue necrosis.

This is a basic differential criterion, as a myocardial infarction must always show the death of the muscle cells of the heart. On the other hand, angina pectoris causes a lot of pain, but in this condition, necrosis of the heart tissue doesn’t have to be occurring.

As indicated by the Statpearls medical portal, the heart requires an adequate flow of oxygen to maintain its ability to beat. In angina pectoris, this is diminished, so anaerobic glycolysis is promoted locally. This increases the levels of hydrogen, potassium, and lactate in the venous return from the ischemic or affected area of the myocardium.

Hydrogen ions compete with calcium ions, causing hypokinesis (decreased movement) of the affected heart muscles. In other words, in angina pectoris, there’s not enough blood flow for the heart to function properly, but the arterial narrowing has been progressive and the symptoms appear in a timely manner.

At the same time, in myocardial infarction, it’s due to an acute, sudden, and total arterial occlusion for about 20-40 minutes. This blockage causes a complete cessation of blood flow to the affected area, which causes necrosis of the muscle tissue of the myocardium. Depending on the damaged area, the functioning of the heart may be more or less compromised.

2. There are 5 types of myocardial infarctions and 2 types of angina pectoris

Another difference between angina pectoris and heart attack lies in their classification. Today the following 5 variants are recognized within myocardial infarction:

• Type I myocardial infarction: This is a spontaneous infarction related to ischemia caused by a primary coronary event. For example, arterial occlusion can be thrombotic and occur due to the rupture of a plaque formed in the coronary arteries.
• Type II: In this case, it’s due to secondary ischemia, either due to an increase in the demand for oxygen in the heart or due to a decrease in its contribution to blood flow. Some causes are hypotension, hypertension, or an arterial spasm.
• Type III: This condition is characterized by sudden cardiac death. It’s detected during the autopsy.
• Type IV myocardial infarction: May be related to percutaneous coronary intervention (4a) or stent thrombosis (4b).
• Type V: Is myocardial infarction associated with a surgical intervention.

On the other hand, angina pectoris is divided into 2 variants that are much easier to understand. These are the following:

1. Stable angina pectoris: This is the typical form of angina pectoris and the symptoms are exacerbated when the patient makes some kind of physical effort. Rest and the administration of sublingual nitroglycerin make the clinical signs disappear in all cases. Emotional stress, extreme temperatures, or large meals can also promote the picture.
2. Unstable angina pectoris: This can occur during moments of rest (and lasts more than 10 minutes), be severe and of spontaneous onset, or occur in an increasingly severe pattern. It’s much more dangerous than stable angina and is associated with the onset of a heart attack in many cases.

There are 5 types of heart attacks and 2 types of angina pectoris. However, it should be noted that unstable angina pectoris and heart attack are closely related to one another. The greatest differences between the two conditions are evident if we analyze stable angina.

3. The symptoms of angina may be more obvious than those of a heart attack

Surely, this is one of the most important differences between angina pectoris and heart attack, as the essential thing when distinguishing both pictures is knowing how to identify the symptoms and tell them to a medical professional as soon as possible. Any sudden or sustained pain in the chest warrants a visit to the emergency room, but it’s always a good idea to locate the discomfort and know how to transmit it before the critical moment.

The symptoms of angina pectoris are as follows, as indicated by the Mayo Clinic:

• Chest pain and discomfort, which can be described as tightness, burning, and swelling in the chest area. As we’ve said, in its stable variant (the most common), discomfort appears when the heart works more. It lasts a short time.
• Radiating pain in the arms, neck, shoulders, and back. This is normal, as the nerves that receive pain in the chest area also pick up skin stimuli in other areas further away.
• Dizziness and fatigue.
• Sickness.
• Sweating
• Shortness of breath.

The symptoms of a heart attack can be summarized in the following list:

• Chest pain, which can manifest itself as a feeling of tightness, pressure, or compression. It’s usually diffuse, doesn’t change with position, and lasts more than 20 minutes.
• Radiating pain in the arms, neck, shoulders, and back. It’s more common for the discomfort to spread to the left arm than to the rest of the extremities and structures mentioned.
• Nausea, indigestion, heartburn, or abdominal pain.
• Shortness of breath.
• Cold sweating.
• Fatigue.

They seem quite similar clinical signs to each other. However, we’ll show you the differences between angina pectoris and heart attack as far as signs are concerned. You’ll see that, as on many other fronts, the true distinction is in the details.

3.1 Pain or absence of it

Angina always presents with chest pain, but infarction doesn’t meet this rule in all cases. A person may experience shortness of breath, fatigue, sweating, and indigestion and be having a heart attack without knowing it. As indicated by the Quirón Salud portal, this is more common in diabetic patients, women, and the elderly.

3.2 Situation in which discomfort occurs

Stable angina pectoris occurs justifiably, that is, when the heart makes a significant effort. This is represented especially when doing intense physical exercise and when resting. On the other hand, the symptoms of a myocardial infarction appear suddenly regardless of the context and don’t improve when lying down and resting.

3.3 Duration of pain

The symptoms of stable angina pectoris are reduced with rest and the application of sublingual nitroglycerin. In any case, the crushing pain in the chest doesn’t last more than 10-15 minutes (usually 3-5). The duration of pain in a heart attack is much longer, as it’s maintained with a sustained intensity for 20 minutes or more.

4. Stable angina pectoris is considered less serious than a heart attack

It’s interesting to look at some epidemiological figures. First of all, it’s important to note that chronic stable angina affects 30,000-40,000 people per 1,000,000 people in Western countries. The prevalence increases with age in both men and women: At 65-84 years, the probability of presenting it is 14-15%.

Hypertension, hyperlipidemia, smoking, diabetes, and obesity are clear predisposing factors for angina pectoris. In any case, the mortality rate for this isolated condition is less than 1.4% of all patients. This means that people without a history of heart attack and with a normal resting electrocardiogram don’t usually die from stable angina.

The figures for heart attacks are much less favorable. Acute myocardial infarction is the most frequent presentation of ischemic heart disease, causing more than 12% of deaths globally. The mortality rate is 15% in patients between 35 and 64 years old and almost 65% in the elderly between 85 and 94 years old.

Heart attacks cause far more deaths than stable angina pectoris. This makes a great deal of sense from a histological point of view because, as we’ve said above, in heart attacks, the death of the cardiac tissue is always present. For this reason, the organ may never fully recover and the patient ends up dying.

Differences between angina pectoris and heart attack: Two conditions that require immediate attention

Stable angina pectoris and myocardial infarction are two conditions that are very easy to distinguish. Here, we’ve shown you 6 typical differences between both diseases (3 that are symptomatic and 3 that are not), but if we want you to keep a central idea, it’s the following: Angina usually appears after exercising, while a heart attack is sudden and the pain lasts longer.

In any case, it’s important to note that unstable angina pectoris and heart attack are closely related to each other. All chest pain warrants a visit to the doctor, but you must go to the emergency room whenever it doesn’t improve with rest and lasts longer than 3-5 minutes. In cardiovascular issues, prevention is always the best medicine.