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Pericarditis

By: Administrator, Views: 9567

Pericarditis refers to inflammation of the pericardium, two thin layers of a sac-like tissue that surround the heart, hold it in place and help it work. A small amount of fluid keeps the layers separate so that there's no friction between them.

Cardiac Cycle (Part 4 of 4)

By: Administrator, Views: 9758

Diastole and systole are two phases of the cardiac cycle. They occur as the heart beats, pumping blood through a system of blood vessels that carry blood to every part of the body. Systole occurs when the heart contracts to pump blood out, and diastole occurs when the heart relaxes after contract...

Introduction to Dysrhythmia

By: Administrator, Views: 9666

Cardiac dysrhythmias are a problem with the rate or rhythm of your heartbeat caused by changes in your heart’s normal sequence of electrical impulses. Your heart may beat too quickly, called tachycardia; too slowly, bradycardia; or with an irregular pattern. Dysrhythmias can range from complete...

Causes of Angina

By: Administrator, Views: 10123

Angina is a type of chest pain caused by reduced blood flow to the heart. Angina (an-JIE-nuh or AN-juh-nuh) is a symptom of coronary artery disease. Angina, which may also be called angina pectoris, is often described as squeezing, pressure, heaviness, tightness or pain in your chest.

Electrical changes in the heart

By: HWC, Views: 6499

• ECG: Graph of the voltage changes that occur during the cardiac cycle. • Readings are taken by electrodes placed on the surface of the body. • Electrodes detect voltage changes caused by the electrical activity of the heart. • P wave = atrial excitation (atrial depolarization). ...

Automated external defibrillator (AED)

By: Administrator, Views: 9751

An automated external defibrillator (AED) is a portable electronic device that automatically diagnoses the life-threatening cardiac arrhythmias of ventricular fibrillation and pulseless ventricular tachycardia, and is able to treat them through defibrillation, the application of electricity which...

Blood Pressure Measurement

By: Administrator, Views: 9627

How nurses check a patient's blood pressure. Blood Pressure The pressure exerted by the blood on the walls of the arteries. Higher (systolic) number: the pressure while the heart contracts. Lower (diastolic) number: the pressure when the heart relaxes between beats. Measured by a sphygmoma...

Congenital Heart Defects Animation

By: Administrator, Views: 9815

Pulse, blood pressure, and respiration vary according to the child’s age. A newborn’s pulse rate is irregular and rapid, varying from 120 to 140 beats per minute. Blood pressure is low and can vary with the size of the cuff used. Average blood pressure at birth is 80/46. Respirations are ...

Depolarization of the SA node, Action potentials of the myocardium & ANS effects

By: HWC, Views: 6524

• A typical contractile cell in the myocardium has a resting membrane potential. • The resting membrane potential of cells in the SA node is not fixed, and is known as the pacemaker potential. • The action potential of a healthy SA nodal cell has three parts: • Pacemaker potential: ...