Chest pain and Related Topics

Myocardial infarction

A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow decreases or stops to the coronary artery of the heart, causing damage to the heart muscle.

Cross section showing anterior left ventricle wall infarction

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.

The most common symptom is chest pain or discomfort which may travel into the shoulder, arm, back, neck or jaw.

Shortness of breath

Uncomfortable feeling of not being able to breathe well enough.

Acute coronary syndrome frequently presents with retrosternal chest discomfort and difficulty catching the breath.

Troponin

Complex of three regulatory proteins that are integral to muscle contraction in skeletal muscle and cardiac muscle, but not smooth muscle.

Troponin activation. Troponin C (red) binds Ca2+, which stabilizes the activated state, where troponin I (yellow) is no longer bound to actin. Troponin T (blue) anchors the complex on tropomyosin.

They are measured in the blood to differentiate between unstable angina and myocardial infarction (heart attack) in people with chest pain or acute coronary syndrome.

Heart

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

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).

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.

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

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.

Heart and its blood vessels, by Leonardo da Vinci, 15th century

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 and from behind

Heart illustration with circulatory system

Animated Heart 3d Model Rendered in Computer

Cardiovascular diseases frequently do not have symptoms or may cause chest pain or shortness of breath.

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.

Angina, also known as angina pectoris, is chest pain or pressure, a symptom of coronary heart disease, usually due to insufficient blood flow to the heart muscle (myocardium).

Pericarditis

Inflammation of the pericardium, the fibrous sac surrounding the heart.

Figure A shows the location of the heart and a normal heart and pericardium (the sac surrounding the heart). The inset image is an enlarged cross-section of the pericardium that shows its two layers of tissue and the fluid between the layers. Figure B shows the heart with pericarditis. The inset image is an enlarged cross-section that shows the inflamed and thickened layers of the pericardium.

Diffuse ST elevation in a young male due to myocarditis / pericarditis

Ultrasounds showing a pericardial effusion in someone with pericarditis

A pericardial effusion as seen on CXR in someone with pericarditis

Symptoms typically include sudden onset of sharp chest pain, which may also be felt in the shoulders, neck, or back.

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

Arrhythmia

Too fast or too slow.

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.

In more serious cases, there may be lightheadedness, passing out, shortness of breath or chest pain.

Esophagus

Organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to the stomach.

The esophagus is constricted in three places.

A mass seen during an endoscopy and an ultrasound of the mass conducted during the endoscopy session.

Diseases may cause difficulty swallowing (dysphagia), painful swallowing (odynophagia), chest pain, or cause no symptoms at all.

Illustration depicting atherosclerosis in a coronary artery

Coronary artery disease (CAD), also called coronary heart disease (CHD), ischemic heart disease (IHD), myocardial ischemia, or simply heart disease, involves the reduction of blood flow to the heart muscle due to build-up of atherosclerotic plaque in the arteries of the heart.