CCT (ASQ) key terms

The ability of cardiac pacemaker cells to generate an electrical impulse on their own without outside stimulation. It allows the heart to beat spontaneously and sets the normal heart rate.

The rapid change in electrical charge across a cardiac cell membrane that triggers contraction. It involves ion movement through channels and has distinct phases that coordinate heart muscle activity.

The heart's natural pacemaker, located in the right atrium. It initiates electrical impulses that spread through the atria and set the normal resting heart rate.

A structure at the junction of the atria and ventricles that delays electrical impulses before passing them to the ventricles. This delay allows the atria to finish contracting and fill the ventricles.

A collection of specialized muscle fibers that carries electrical impulses from the atrioventricular node into the ventricles. It is part of the heart's conduction system.

Specialized fibers that spread electrical impulses rapidly through the ventricular walls, causing them to contract. They are the final part of the heart's conduction pathway.

The volume of blood pumped by the heart in one minute. It is calculated by multiplying heart rate by stroke volume and reflects how well the heart supplies the body.

The amount of blood ejected from the left ventricle with each heartbeat. It depends on factors like preload, afterload, and contractility.

The degree of stretch of the heart muscle fibers at the end of diastole, just before contraction. It is influenced by the volume of blood returning to the heart.

The resistance the heart must overcome to eject blood during systole. It is largely determined by blood pressure and the resistance of blood vessels.

A recording of the heart's electrical activity obtained by placing electrodes on the skin. It is used to detect rhythm abnormalities, ischemia, and other cardiac conditions.

The first deflection on an electrocardiogram, representing depolarization of the atria. It indicates that the atria are contracting.

The deflection on an electrocardiogram that represents depolarization of the ventricles. It is usually the largest wave and signals the start of ventricular contraction.

The deflection on an electrocardiogram that represents repolarization of the ventricles. It follows the QRS complex and indicates the ventricles are resetting electrically.

The time from the beginning of the P wave to the beginning of the QRS complex on an electrocardiogram. It reflects the time needed for the impulse to travel from the atria to the ventricles.

The flat section of an electrocardiogram between the end of the QRS complex and the start of the T wave. Changes in this segment can indicate myocardial ischemia or injury.

A normal heart rhythm originating from the sinoatrial node, with a rate between 60 and 100 beats per minute. It is characterized by regular P waves followed by QRS complexes.

An irregular heart rhythm caused by chaotic electrical activity in the atria. It results in an irregular ventricular response and increases the risk of blood clots.

A fast heart rhythm originating in the ventricles, often defined as three or more consecutive ventricular beats at a rate greater than 100 beats per minute. It can be life-threatening.

A chaotic, disorganized electrical activity in the ventricles that causes them to quiver instead of pump blood. It is a medical emergency requiring immediate defibrillation.

A portable device that continuously records the heart's electrical activity for 24 to 48 hours or longer. It helps detect irregular heartbeats that might not appear during a standard electrocardiogram.

A test that records the heart's electrical activity while the patient exercises or receives medication to increase heart rate. It evaluates how the heart responds to stress and can reveal ischemia.

An ultrasound image of the heart that shows its structure, chambers, valves, and blood flow. It is used to assess heart function and detect abnormalities.

A procedure where a thin tube is inserted into a blood vessel and guided to the heart to diagnose and treat certain heart conditions. It can measure pressures and visualize coronary arteries.

An imaging test that uses X-rays and contrast dye to see how blood flows through the coronary arteries. It is often performed during cardiac catheterization to detect blockages.

A therapeutic procedure that delivers an unsynchronized electrical shock to the heart to stop chaotic rhythms like ventricular fibrillation and restore a normal heartbeat.

A procedure that uses a synchronized electrical shock or medication to convert an abnormal heart rhythm back to a normal one. It is commonly used for atrial fibrillation or flutter.

The process of obtaining a patient's permission before a healthcare procedure or treatment, after explaining the risks, benefits, and alternatives. It ensures the patient understands and agrees voluntarily.

The prevention of harm to patients during healthcare delivery. It involves practices like proper hand hygiene, medication safety, and error reporting to reduce risks.

Measures taken to prevent the spread of infections in healthcare settings, such as hand washing, wearing protective equipment, and sterilizing equipment. It protects both patients and staff.

An electrical signal on an electrocardiogram that is not caused by the heart's electrical activity, such as interference from movement or electrical devices. It can mimic or obscure true rhythms.

The correct positioning of electrodes on the patient's body to obtain accurate electrocardiogram recordings. Proper placement ensures consistent and reliable tracings.

The process of adjusting an electrocardiogram machine so that the electrical signals are recorded at the correct scale, typically 10 mm/mV. It ensures that waveforms are accurately represented.

The procedures used to ensure that diagnostic equipment and tests meet established standards of accuracy and reliability. It includes regular maintenance, calibration, and performance checks.

A view of the heart's electrical activity from a specific angle, created by a pair of electrodes on the electrocardiogram. Different leads provide different perspectives on the heart's electrical signals.

A heart rate that is slower than normal, typically defined as fewer than 60 beats per minute in adults. It may be normal in some individuals or indicate an underlying condition.

A heart rate that is faster than normal, typically defined as more than 100 beats per minute in adults. It can originate from the atria or ventricles and may be regular or irregular.