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Electrocardiogram Examination

By: Administrator, Views: 9528

An electrocardiogram (ECG or EKG) is a test that checks how your heart is functioning by measuring the electrical activity of the heart. With each heartbeat, an electrical impulse (or wave) travels through your heart. This wave causes the muscle to squeeze and pump blood from the heart. Sinoat...

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...

Stroke volume

By: HWC, Views: 6662

Preload definition • Preload is the degree of stretch of cardiac muscles cells prior to contraction. • The amount of stretch is related to the end-diastolic volume[EDV]. • Increased return blood flow from the veins increases end-diastolic volume. Cardiac muscle sarcomeres stretch and ...

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: ...

Baroreceptor Reflex

By: HWC, Views: 6020

Baroreceptors located In the carotid sinus and the arch of the aorta respond to increases in blood pressure. Increased blood pressure stretches the carotid arteries and aorta causing the baroreceptors to increase their basal rate of action potential generation. Action potentials are conduct...