A myocardial infarction occurs when an atherosclerotic plaque slowly builds up in the inner lining of a coronary artery and then suddenly ruptures, causing catastrophic thrombus formation, totally occluding the artery and preventing blood flow downstream.
Skeletal formula of propranolol, the first clinically successful beta blocker
Cross section showing anterior left ventricle wall infarction
Dichloroisoprenaline, the first beta blocker
Diagram showing the blood supply to the heart by the two major blood vessels, the left and right coronary arteries (labelled LCA and RCA). A myocardial infarction (2) has occurred with blockage of a branch of the left coronary artery (1).
A 12-lead ECG showing an inferior STEMI due to reduced perfusion through the right coronary artery. Elevation of the ST segment can be seen in leads II, III and aVF.
ECG : AMI with ST elevation in V2-4
Inserting a stent to widen the artery.

Beta blockers, also spelled β-blockers, are a class of medications that are predominantly used to manage abnormal heart rhythms, and to protect the heart from a second heart attack (myocardial infarction) after a first heart attack (secondary prevention).

- Beta blocker

After an MI, lifestyle modifications, along with long-term treatment with aspirin, beta blockers and statins, are typically recommended.

- Myocardial infarction
A myocardial infarction occurs when an atherosclerotic plaque slowly builds up in the inner lining of a coronary artery and then suddenly ruptures, causing catastrophic thrombus formation, totally occluding the artery and preventing blood flow downstream.

10 related topics

Alpha

CT scan of the brain showing a prior right-sided ischemic stroke from blockage of an artery. Changes on a CT may not be visible early on.

Stroke

Medical condition in which poor blood flow to the brain causes cell death.

Medical condition in which poor blood flow to the brain causes cell death.

CT scan of the brain showing a prior right-sided ischemic stroke from blockage of an artery. Changes on a CT may not be visible early on.
There are two main categories of strokes. Ischemic (top), typically caused by a blood clot in an artery (1a) resulting in brain death to the affected area (2a). Hemorrhagic (bottom), caused by blood leaking into or around the brain from a ruptured blood vessel (1b) allowing blood to pool in the affected area (2b) thus increasing the pressure on the brain.
A slice of brain from the autopsy of a person who had an acute middle cerebral artery (MCA) stroke
CT scan of an intraparenchymal bleed (bottom arrow) with surrounding edema (top arrow)
Illustration of an embolic stroke, showing a blockage lodged in a blood vessel.
Histopathology at high magnification of a normal neuron, and an ischemic stroke at approximately 24 hours on H&E stain: The neurons become hypereosinophilic and there is an infiltrate of neutrophils. There is slight edema and loss of normal architecture in the surrounding neuropil.
A CT showing early signs of a middle cerebral artery stroke with loss of definition of the gyri and grey white boundary
Dens media sign in a patient with middle cerebral artery infarction shown on the left. Right image after 7 hours.
12-lead ECG of a patient with a stroke, showing large deeply inverted T-waves. Various ECG changes may occur in people with strokes and other brain disorders.
Walking with an orthosis after a stroke
Stroke deaths per million persons in 2012
Hippocrates first described the sudden paralysis that is often associated with stroke.

With the availability of treatments that can reduce stroke severity when given early, many now prefer alternative terminology, such as brain attack and acute ischemic cerebrovascular syndrome (modeled after heart attack and acute coronary syndrome, respectively), to reflect the urgency of stroke symptoms and the need to act swiftly.

The routine use of beta-blockers following a stroke or TIA has not been shown to result in benefits.

A man with congestive heart failure and marked jugular venous distension. External jugular vein marked by an arrow.

Heart failure

Set of manifestations caused by the failure of the heart's function as a pump supporting the blood flow through the body; its signs and symptoms result from a structural and/or functional abnormality of the heart, that disrupts its filling with blood or its ejecting of it during each heart beat.

Set of manifestations caused by the failure of the heart's function as a pump supporting the blood flow through the body; its signs and symptoms result from a structural and/or functional abnormality of the heart, that disrupts its filling with blood or its ejecting of it during each heart beat.

A man with congestive heart failure and marked jugular venous distension. External jugular vein marked by an arrow.
Signs and symptoms of severe heart failure
Severe peripheral pitting edema
Kerley B lines in acute cardiac decompensation. The short, horizontal lines can be found everywhere in the right lung.
Model of a normal heart (left); and a weakened heart, with over-stretched muscle and dilation of left ventricle (right); both during diastole
Chest radiograph of a lung with distinct Kerley B lines, as well as an enlarged heart (as shown by an increased cardiothoracic ratio, cephalization of pulmonary veins, and minor pleural effusion as seen for example in the right horizontal fissure. Yet, no obvious lung edema is seen. Overall, this indicates intermediate severity (stage II) heart failure.
Siderophages (one indicated by white arrow) and pulmonary congestion, indicating left congestive heart failure
Ultrasound showing severe systolic heart failure
Congestive heart failure with small bilateral effusions
Kerley B lines

Common causes of heart failure include coronary artery disease, including a previous myocardial infarction (heart attack), high blood pressure, atrial fibrillation, valvular heart disease, excess alcohol use, infection, and cardiomyopathy of an unknown cause.

In those with heart failure due to left ventricular dysfunction, angiotensin converting enzyme inhibitors, angiotensin receptor blockers, or valsartan/sacubitril along with beta blockers are recommended.

Illustration depicting angina

Angina

Chest pain or pressure, a symptom of coronary heart disease, usually due to insufficient blood flow to the heart muscle .

Chest pain or pressure, a symptom of coronary heart disease, usually due to insufficient blood flow to the heart muscle .

Illustration depicting angina
Diagram of discomfort caused by coronary artery disease. Pressure, fullness, squeezing or pain in the center of the chest. Can also feel discomfort in the neck, jaw, shoulders, back or arms.

There is a weak relationship between severity of pain and degree of oxygen deprivation in the heart muscle, where there can be severe pain with little or no risk of a myocardial infarction (heart attack) and a heart attack can occur without pain.

Beta blockers, specifically B1 adrenergic blockers without intrinsic sympathomimetic activity are the most preferred for the angina treatment out of B1 selective and non-selective as well as B1 ISA agents.

Leads aVL and aVF of an electrocardiogram showing atrial fibrillation. There are irregular intervals between heart beats. No P waves are seen and there is an erratic baseline between QRS complexes. The heart rate is about 125 beats per minute.

Atrial fibrillation

Abnormal heart rhythm (arrhythmia) characterized by rapid and irregular beating of the atrial chambers of the heart.

Abnormal heart rhythm (arrhythmia) characterized by rapid and irregular beating of the atrial chambers of the heart.

Leads aVL and aVF of an electrocardiogram showing atrial fibrillation. There are irregular intervals between heart beats. No P waves are seen and there is an erratic baseline between QRS complexes. The heart rate is about 125 beats per minute.
Normal rhythm tracing (top) Atrial fibrillation (bottom)
How a stroke can occur during atrial fibrillation
Non-modifiable risk factors (top left box) and modifiable risk factors (bottom left box) for atrial fibrillation. The main outcomes of atrial fibrillation are in the right box. BMI=Body Mass Index.
A 12-lead ECG showing atrial fibrillation at approximately 132 beats per minute
Diagram of normal sinus rhythm as seen on ECG. In atrial fibrillation the P waves, which represent depolarization of the top of the heart, are absent.
ECG of atrial fibrillation (top) and normal sinus rhythm (bottom). The purple arrow indicates a P wave, which is lost in atrial fibrillation.
3D Medical Animation still shot of Left Atrial Appendage Occlusion

Secondary AF refers to AF that occurs in the setting of another condition that have caused the AF, such as acute myocardial infarction, cardiac surgery, pericarditis, myocarditis, hyperthyroidism, pulmonary embolism, pneumonia, or another acute pulmonary disease.

Beta blockers (preferably the "cardioselective" beta blockers such as metoprolol, bisoprolol, or nebivolol)

Ventricular fibrillation (VF) showing disorganized electrical activity producing a spiked tracing on an electrocardiogram (ECG)

Arrhythmia

Too fast or too slow.

Too fast or too slow.

Ventricular fibrillation (VF) showing disorganized electrical activity producing a spiked tracing on an electrocardiogram (ECG)
Broad classification of arrhythmias according to region of heart required to sustain the rhythm
Normal sinus rhythm, with solid black arrows pointing to normal P waves representative of normal sinus node function, followed by a pause in sinus node activity (resulting in a transient loss of heartbeats). Note that the P wave that disrupts the pause (indicated by the dashed arrow) does not look like the previous (normal) P waves – this last P wave is arising from a different part of the atrium, representing an escape rhythm.

Medications for a fast heart rate may include beta blockers, or antiarrhythmic agents such as procainamide, which attempt to restore a normal heart rhythm.

The most common cause of sudden death in the US is coronary artery disease specifically because of poor oxygenation of the heart muscle, that is myocardial ischemia or a heart attack Approximately 180,000 to 250,000 people die suddenly of this cause every year in the US.

Heart

Muscular organ in most animals that pumps blood through the blood vessels of the circulatory system.

Muscular organ in most animals that pumps blood through the blood vessels of the circulatory system.

Human heart during an autopsy
Computer-generated animation of a beating human heart
The human heart is in the middle of the thorax, with its apex pointing to the left.
Heart being dissected showing right and left ventricles, from above
Frontal section showing papillary muscles attached to the tricuspid valve on the right and to the mitral valve on the left via chordae tendineae.
Layers of the heart wall, including visceral and parietal pericardium
The swirling pattern of myocardium helps the heart pump effectively
Arterial supply to the heart (red), with other areas labelled (blue).
Autonomic innervation of the heart
Development of the human heart during the first eight weeks (top) and the formation of the heart chambers (bottom). In this figure, the blue and red colors represent blood inflow and outflow (not venous and arterial blood). Initially, all venous blood flows from the tail/atria to the ventricles/head, a very different pattern from that of an adult.
Blood flow through the valves
The cardiac cycle as correlated to the ECG
The x-axis reflects time with a recording of the heart sounds. The y-axis represents pressure.
Transmission of a cardiac action potential through the heart's conduction system
Conduction system of the heart
The prepotential is due to a slow influx of sodium ions until the threshold is reached followed by a rapid depolarization and repolarization. The prepotential accounts for the membrane reaching threshold and initiates the spontaneous depolarization and contraction of the cell; there is no resting potential.
3D echocardiogram showing the mitral valve (right), tricuspid and mitral valves (top left) and aortic valve (top right).
The closure of the heart valves causes the heart sounds.
Cardiac cycle shown against ECG
Heart and its blood vessels, by Leonardo da Vinci, 15th century
Animated heart
Elize Ryd making a heart sign at a concert in 2018
The tube-like heart (green) of the mosquito Anopheles gambiae extends horizontally across the body, interlinked with the diamond-shaped wing muscles (also green) and surrounded by pericardial cells (red). Blue depicts cell nuclei.
Basic arthropod body structure – heart shown in red
The human heart viewed from the front
The human heart viewed from behind
The coronary circulation
The human heart viewed from the front and from behind
Frontal section of the human heart
An anatomical specimen of the heart
Heart illustration with circulatory system
Animated Heart 3d Model Rendered in Computer

Narrowings of the coronary arteries (ischaemic heart disease) are treated to relieve symptoms of chest pain caused by a partially narrowed artery (angina pectoris), to minimise heart muscle damage when an artery is completely occluded (myocardial infarction), or to prevent a myocardial infarction from occurring.

Medications to improve angina symptoms include nitroglycerin, beta blockers, and calcium channel blockers, while preventative treatments include antiplatelets such as aspirin and statins, lifestyle measures such as stopping smoking and weight loss, and treatment of risk factors such as high blood pressure and diabetes.

Illustration depicting angina

Variant angina

Syndrome typically consisting of angina in contrast to stable angina which is generally triggered by exertion or intense exercise, commonly occurs in individuals at rest or even asleep and is caused by vasospasm, a narrowing of the coronary arteries due to contraction of the heart's smooth muscle tissue in the vessel walls.

Syndrome typically consisting of angina in contrast to stable angina which is generally triggered by exertion or intense exercise, commonly occurs in individuals at rest or even asleep and is caused by vasospasm, a narrowing of the coronary arteries due to contraction of the heart's smooth muscle tissue in the vessel walls.

Illustration depicting angina
Prinzmetal angina

Sufferers usually have repeated episodes of unexplained (e.g., in the absence of exertion and occurring at sleep or in the early morning hours) chest pain, tightness in throat, chest pressure, light-headedness, excessive sweating, and/or reduced exercise tolerance that, unlike atherosclerosis-related angina, typically does not progress to myocardial infarction (heart attack).

And, they should avoid any of the recreational and therapeutic drugs listed in the above Signs and symptoms and risk factors sections as well as blockers of beta receptors such as propranolol which may theoretically worsen vasospasm by inhibiting beta-2 adrenergic receptor's vasodilation effect mediated by these receptors' naturally occurring stimulator i.e. epinephrine.

Dissection of the descending part of the aorta (3), which starts from the left subclavian artery and extends to the abdominal aorta (4). The ascending aorta (1) and aortic arch (2) are not involved in this image.

Aortic dissection

Injury to the innermost layer of the aorta allows blood to flow between the layers of the aortic wall, forcing the layers apart.

Injury to the innermost layer of the aorta allows blood to flow between the layers of the aortic wall, forcing the layers apart.

Dissection of the descending part of the aorta (3), which starts from the left subclavian artery and extends to the abdominal aorta (4). The ascending aorta (1) and aortic arch (2) are not involved in this image.
Blood penetrates the intima and enters the media layer.
Histopathological image of dissecting aneurysm of the thoracic aorta in a patient without evidence of Marfan syndrome: The damaged aorta was surgically removed and replaced by artificial vessel, Victoria blue & HE stain.
Diagnostic algorithm of aortic dissection
Aortic dissection on CXR: Note is made of a wide aortic knob.
MRI of an aortic dissection
1 Aorta descendens with dissection
2 Aorta isthmus
Closure of the lumen of a Type B aortic dissection following medical management
CT with contrast demonstrating aneurysmal dilation and a dissection of the ascending aorta (type A Stanford)
Chest CT with descending (type B Stanford) aortic dissection (red circle)
Type A dissection with pericardial effusion as a result.

While the pain may be confused with that of a heart attack, AD is usually not associated with the other suggestive signs, such as heart failure and ECG changes.

Beta blockers are the first-line treatment for patients with acute and chronic aortic dissection.

Skeletal formula of propranolol, the first clinically successful beta blocker

Metoprolol

Skeletal formula of propranolol, the first clinically successful beta blocker

Metoprolol, sold under the brand name Lopressor, among others, is a selective β1 receptor blocker medication.

It is also used to prevent further heart problems after myocardial infarction and to prevent headaches in those with migraines.

Hypotension

Low blood pressure.

Low blood pressure.

Chronic use of alpha blockers or beta blockers can lead to hypotension.

Decreased cardiac output despite normal blood volume, due to severe congestive heart failure, large myocardial infarction, heart valve problems, or extremely low heart rate (bradycardia), often produces hypotension and can rapidly progress to cardiogenic shock.