CCT (ASQ) flashcards

33 cards. Read the term and the definition here. The deck at the top of this page is optional.

Stroke volume

The volume of blood ejected by one ventricle per beat; typically 60–100 mL at rest and equal to end-diastolic minus end-systolic volume.

Cardiac output formula

Cardiac output equals heart rate multiplied by stroke volume; normal resting value is roughly 4–8 liters per minute in adults.

SA node rate

The sinoatrial node is the dominant pacemaker, firing intrinsically at 60–100 impulses per minute and setting normal sinus rhythm.

AV node function

Delays conduction between atria and ventricles, allowing ventricular filling; its intrinsic escape rate is 40–60 beats per minute.

Purkinje fibers

Specialized conduction fibers that rapidly distribute impulses through ventricular myocardium; intrinsic firing rate is only 20–40 beats per minute.

Coronary artery origins

The right and left coronary arteries arise from the aortic root just above the aortic valve cusps and supply the myocardium.

Papillary muscles

Ventricular muscles attached to valve leaflets via chordae tendineae; they prevent mitral and tricuspid prolapse during systole.

Small box duration

At standard 25 mm/s paper speed, one small ECG box represents 0.04 seconds and one large box represents 0.20 seconds.

Rate from large boxes

For regular rhythms, divide 300 by the number of large boxes between R waves to estimate the heart rate in beats per minute.

Six-second strip rate

Count the number of QRS complexes in a six-second strip and multiply by ten to estimate rate, useful for irregular rhythms.

Normal PR interval

The PR interval measures from P-wave onset to QRS onset; normal is 0.12–0.20 seconds, prolonged in first-degree AV block.

Atrial fibrillation

An irregularly irregular rhythm with no discrete P waves and a fibrillatory baseline; ventricular response varies with AV conduction.

Ventricular tachycardia

A wide-complex rhythm over 0.12 seconds with rate typically above 100 bpm; may be pulseless and requires immediate assessment.

Ventricular fibrillation

Chaotic, disorganized ventricular electrical activity with no identifiable QRS complexes and no effective cardiac output; treated with defibrillation.

Mobitz II block

Second-degree AV block with a constant PR interval and intermittent dropped QRS complexes; considered high risk for progression to complete block.

Asystole confirmation

A flat-line rhythm with no electrical activity; verify leads, gain, and connections in a second lead before beginning treatment.

V1 electrode position

Placed at the fourth intercostal space at the right sternal border; reflects right ventricular and septal electrical activity.

V4 electrode position

Placed at the fifth intercostal space in the midclavicular line; V3 sits midway between V2 and V4.

Target heart rate

For exercise stress testing, commonly calculated as 85% of age-predicted maximum, where maximum equals 220 minus age.

Holter monitor

A portable device recording continuous ECG for 24–48 hours, used to correlate symptoms with rhythm during daily activity.

Ejection fraction

The percentage of ventricular end-diastolic volume ejected per beat; normal is approximately 55–70% by echocardiography.

Troponin

A cardiac biomarker released with myocardial injury; rises within hours of damage and remains elevated for several days.

BNP

B-type natriuretic peptide released by stretched ventricular myocardium; elevated levels support a diagnosis of heart failure.

Synchronized cardioversion

A shock timed to the R wave, used for unstable tachycardias with a pulse to avoid delivering energy during repolarization.

Defibrillation energy

For ventricular fibrillation or pulseless VT, typical biphasic energy is 120–200 joules; monophasic devices use up to 360 joules.

Clear before shock

Verbally announce and visually confirm that no one is touching the patient, bed, or equipment before delivering a defibrillation shock.

Standard paddle placement

One pad right infraclavicular near the sternum and one left lateral at the midaxillary line, forming a vector across the heart.

Hand hygiene

Perform before and after every patient contact and after glove removal; the primary measure for preventing healthcare-associated infection.

Calibration standard

ECG machines are calibrated so a 1 mV signal produces a 10 mm deflection at standard gain and 25 mm/s speed.

Baseline wander artifact

Slow undulation of the ECG baseline caused by respiration, patient movement, or poor electrode contact; corrected by stabilizing the patient.

60-Hz interference

High-frequency artifact appearing as thickened baseline from nearby electrical equipment; reduced by checking cables and grounding.

Lead reversal sign

Reversed arm leads invert the P wave and QRS in lead I; precordial misplacement disrupts normal R-wave progression.

Defibrillator checks

Verify battery charge, self-test results, cable and paddle integrity, and documented energy output on a scheduled basis.