Cardiovascular Definitions Flashcards
Acute Coronary Syndrome
Refers to rupture of an atheromatous plaque in a diseased coronary artery, which rapidly form an obstructive thrombus
Signs and symptoms that indicate unstable angina or acute myocardial infarction
Afterload
The amount of resistance to ejection of blood from the ventricle
Apical Impulse
Impulse normally palpated at the fifth ICS, left MCL
Caused by the contraction of the left ventricle
Also called point of maximal impulse
Atrioventricular (AV) Node
Secondary pacemaker of the heart, located in the right atrial wall near the tricuspid valve
Baroreceptors
Nerve fibers located in the aortic arch and carotid arteries that are responsible for control of blood pressure
Cardiac Catheterization
An invasive procedure used to measure cardiac chamber pressures and assess patency of the coronary arteries
Cardiac Conduction System
Specialized heart cells strategically located throughout the heart that are responsible for methodically generating and coordinating the transmission of electrical impulses to the myocardial cells
Cardiac Output
Amount of blood pumped by each ventricle in liters per minute
Cardiac Stress Test
A test used to evaluate the functioning of the heart during a period of increased oxygen demand
Test may be initiated by exercise or medications
Contractility
Ability of the cardiac muscle to shorten in response to an electrical impulse
Depolarization
Electrical activation of a cell caused by the influx of sodium into the cell while potassium exits
Cardiac muscle cells change from a more negatively charged state to a more positively charged state
Diastole
Period of ventricular relaxation resulting in ventricular filling
Ejection Fraction
Percentage of the end-diastolic blood volume ejected from the ventricle with each heartbeat
Hemodynamic Monitoring
The use of pressure monitoring devices to directly measure cardiovascular function
Hypertension
Blood pressure that is consistently greater than 140/90 mmHg
Hypotension
A decrease in blood pressure to less than 100/60 mmHg that compromises systemic perfusion
Murmurs
Sounds created by abnormal, turbulent flow of blood in the heart
Myocardial Ischemia
Condition in which heart muscle cells receive less oxygen than needed
Myocardium
Muscle layer of the heart responsible for the pumping action of the heart
Normal Heart Sounds
Sounds produced when the valves close
Normal heart sounds are S1 (AV valves) and S2 (semilunar valves)
Opening Snaps
Abnormal diastolic sound generated during opening of a rigid AV valve leaflet
Postural/Orthostatic Hypotension
A significant drop in blood pressure (20 mmHg systolic or more) after an upright posture is assumed
Preload
Degree of stretch of the cardiac muscle fibers at the end of diastole (ventricular filling)
Pulmonary Vascular Resistance
Resistance to blood flow out of the right ventricle created by the pulmonary circulatory system
Pulse Deficit
The difference between the apical and radial pulse rates
Radioisotopes
Unstable atoms that give off small amounts of energy in the form of gamma rays as they decay
Used in cardiac nuclear medicine studies
Repolarization
Return of the cell to resting state, caused by the reentry of potassium while sodium exits
Process by which cardiac muscle cells return to a more negatively charged state, which is their resting state
S1
The first heart sound produced by the closure of the AV valves (mitral and tricuspid)
S2
The second heart sound produced by the closure of the semilunar valves (aortic and pulmonic)
S3
An abnormal heart sound detected early in diastole as resistance is met to blood entering either ventricle
Most often due to volume overload associated with heart failure
S4
An abnormal heart sound detected late in diastole as resistance is met to blood entering either ventricle during atrial contraction
Most often caused by hypertrophy of the ventricle
Sinoatrial (SA) Node
Primary pacemaker of the heart, located in the right atrium
Stroke Volume
The amount of blood ejected from one of the ventricles per heartbeat
Summation Gallop
Abnormal sounds created by the presence of an S3 and S4 during periods of tachycardia
Systemic Vascular Resistance
Resistance to blood flow out of the left ventricle created by the systemic circulatory system
Systole
Period of ventricular contraction resulting in ejection of blood from the ventricles into the pulmonary artery and aorta
Systolic Click
Abnormal systolic sound created by the opening of a calcified aortic or pulmonic valve during ventricular contraction
Telemetry
The process of continuous electrocardiographic monitoring by the transmission of radio waves rom a battery-operated transmitter worn by the patient
Ablation
Removal of material from the surface of an object
In the context of cardiology, it is the purposeful destruction of heart muscle cells, usually in an attempt to control a dysrhythmia
Antiarrhythmic Medication
A medication that suppresses or prevents a dysrhythmia
Artifact
Distorted, irrelevant, and extraneous ECG waveforms
Automaticity
Ability of cardiac cells to initiate an electrical impulse
Cardioversion
Electrical current administered in synchrony with the patient’s own QRS complex to stop a dysrhythmia
Chronotropy
Rate of impulse formation
Conduction
Transmission of electrical impulses from one cell to another
Defibrillation
Electrical current administered to stop a dysrhythmia, not synchronized with the patient’s QRS complex
Dromotropy
Conduction velocity
Dysrhythmia
Disorder of the formation or conduction of the electrical impulse within the heart, altering the heart rate, heart rhythm, or both and potentially causing an altered blood flow
Elective Replacement Indicator (ERI)
A signal produced by a pacemaker when it is interrogated to indicate a near-depleted battery
Implantable Cardioverter Defibrillator (ICD)
A device implanted into the chest to treat dysrhythmias
Inotropy
Force of myocardial contraction
P Wave
The part of an ECG that reflects conduction of an electrical impulse through the atrium
Atrial depolarization
Paroxysmal
A dysrhythmia that has a sudden onset and/or termination and is usually of short duration
PP Interval
The duration between the beginning of one P wave and the beginning of the next P wave
Used to calculate atrial rate and rhythm