The vagus nerve, also known as the tenth cranial nerve, cranial nerve X, or simply CN X, is a cranial nerve that interfaces with the parasympathetic control of the heart, lungs, and digestive tract. It comprises two nerves—the left and right vagus nerves—but they are typically referred to collectively as a single subsystem. The vagus is the longest nerve of the autonomic nervous system in the human body and comprises both sensory and motor fibers. The sensory fibers originate from neurons of the nodose ganglion, whereas the motor fibers come from neurons of the dorsal motor nucleus of the vagus and the nucleus ambiguus. The vagus was also historically called the pneumogastric nerve.
Cardiac arrest is when the heart suddenly and unexpectedly stops beating. It is a medical emergency that, without immediate medical intervention, will result in sudden cardiac death within minutes. Cardiopulmonary resuscitation (CPR) and possibly defibrillation are needed until further treatment can be provided. Cardiac arrest results in a rapid loss of consciousness, and breathing may be abnormal or absent.
Cardiopulmonary resuscitation (CPR) is an emergency procedure consisting of chest compressions often combined with artificial ventilation in an effort to manually preserve intact brain function until further measures are taken to restore spontaneous blood circulation and breathing in a person who is in cardiac arrest. It is recommended in those who are unresponsive with no breathing or abnormal breathing, for example, agonal respirations.
Choking, also known as foreign body airway obstruction (FBAO), is a phenomenon that occurs when breathing is impeded by a blockage inside of the respiratory tract. An obstruction that prevents oxygen from entering the lungs results in oxygen deprivation. Although oxygen stored in the blood and lungs can keep a person alive for several minutes after breathing stops, choking often leads to death.
An embolism is the lodging of an embolus, a blockage-causing piece of material, inside a blood vessel. The embolus may be a blood clot (thrombus), a fat globule, a bubble of air or other gas, amniotic fluid, or foreign material. An embolism can cause partial or total blockage of blood flow in the affected vessel. Such a blockage may affect a part of the body distant from the origin of the embolus. An embolism in which the embolus is a piece of thrombus is called a thromboembolism.
Cardiac tamponade, also known as pericardial tamponade, is the buildup of fluid in the pericardium, resulting in compression of the heart. Onset may be rapid or gradual. Symptoms typically include those of obstructive shock including shortness of breath, weakness, lightheadedness, and cough. Other symptoms may relate to the underlying cause.
The thorax or chest is a part of the anatomy of humans, mammals, and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main divisions of the creature's body, each of which is in turn composed of multiple segments.
The Valsalva maneuver is performed by a forceful attempt of exhalation against a closed airway, usually done by closing one's mouth and pinching one's nose shut while expelling air out as if blowing up a balloon. Variations of the maneuver can be used either in medical examination as a test of cardiac function and autonomic nervous control of the heart, or to clear the ears and sinuses when ambient pressure changes, as in scuba diving, hyperbaric oxygen therapy, or air travel.
Pleurisy, also known as pleuritis, is inflammation of the membranes that surround the lungs and line the chest cavity (pleurae). This can result in a sharp chest pain while breathing. Occasionally the pain may be a constant dull ache. Other symptoms may include shortness of breath, cough, fever, or weight loss, depending on the underlying cause.
Palpitations are perceived abnormalities of the heartbeat characterized by awareness of cardiac muscle contractions in the chest, which is further characterized by the hard, fast and/or irregular beatings of the heart.
Basic life support (BLS) is a level of medical care which is used for patients with life-threatening illnesses or injuries until they can be given full medical care by advanced life support providers. It can be provided by trained medical personnel, such as emergency medical technicians, and by qualified bystanders.
Atrial flutter (AFL) is a common abnormal heart rhythm that starts in the atrial chambers of the heart. When it first occurs, it is usually associated with a fast heart rate and is classified as a type of supraventricular tachycardia. Atrial flutter is characterized by a sudden-onset (usually) regular abnormal heart rhythm on an electrocardiogram (ECG) in which the heart rate is fast. Symptoms may include a feeling of the heart beating too fast, too hard, or skipping beats, chest discomfort, difficulty breathing, a feeling as if one's stomach has dropped, a feeling of being light-headed, or loss of consciousness.
Pulseless electrical activity (PEA) refers to cardiac arrest in which the electrocardiogram shows a heart rhythm that should produce a pulse, but does not. Pulseless electrical activity is found initially in about 55% of people in cardiac arrest.
A junctional escape beat is a delayed heartbeat originating not from the atrium but from an ectopic focus somewhere in the atrioventricular junction. It occurs when the rate of depolarization of the sinoatrial node falls below the rate of the atrioventricular node. This dysrhythmia also may occur when the electrical impulses from the SA node fail to reach the AV node because of SA or AV block. It is a protective mechanism for the heart, to compensate for the SA node no longer handling the pacemaking activity, and is one of a series of backup sites that can take over pacemaker function when the SA node fails to do so. It can also occur following a premature ventricular contraction or blocked premature atrial contraction.
Cardiomegaly is a medical condition in which the heart becomes enlarged. It is more commonly referred to simply as "having an enlarged heart". It is usually the result of underlying conditions that make the heart work harder, such as obesity, heart valve disease, high blood pressure (hypertension), and coronary artery disease. Cardiomyopathy is also associated with cardiomegaly.
Pediatric advanced life support (PALS) is a course offered by the American Heart Association (AHA) for health care providers who take care of children and infants in the emergency room, critical care and intensive care units in the hospital, and out of hospital. The course teaches healthcare providers how to assess injured and sick children and recognize and treat respiratory distress/failure, shock, cardiac arrest, and arrhythmias.
Ventricular aneurysms are one of the many complications that may occur after a heart attack. The word aneurysm refers to a bulge or 'pocketing' of the wall or lining of a vessel commonly occurring in the blood vessels at the base of the septum, or within the aorta. In the heart, they usually arise from a patch of weakened tissue in a ventricular wall, which swells into a bubble filled with blood. This, in turn, may block the passageways leading out of the heart, leading to severely constricted blood flow to the body. Ventricular aneurysms can be fatal. They are usually non-rupturing because they are lined by scar tissue.
The Hs and Ts is a mnemonic used to aid in remembering the possible reversible causes of cardiac arrest. A variety of disease processes can lead to a cardiac arrest; however, they usually boil down to one or more of the "Hs and Ts".
Arrhythmias, also known as cardiac arrhythmias, heart arrhythmias, or dysrhythmias, are irregularities in the heartbeat, including when it is too fast or too slow. A resting heart rate that is too fast – above 100 beats per minute in adults – is called tachycardia, and a resting heart rate that is too slow – below 60 beats per minute – is called bradycardia. Some types of arrhythmias have no symptoms. Symptoms, when present, may include palpitations or feeling a pause between heartbeats. In more serious cases, there may be lightheadedness, passing out, shortness of breath or chest pain. While most cases of arrhythmia are not serious, some predispose a person to complications such as stroke or heart failure. Others may result in sudden death.
Pediatric Basic Life Support (PBLS) is a rescue procedure which has purpose of preventing the anoxic brain damage by promoting the return of spontaneous circulation and breathing in cases of cardiac arrest.