AMCA ETC cheat sheet

Standard precautions apply to all patients: gloves for lead placement and electrode contact; hand hygiene before and after every patient contact.

Patient identification requires two identifiers (name and date of birth) before any tracing is recorded or labeled.

The EKG technician's scope is recording and recognizing artifact and life-threatening rhythms; rhythm interpretation and diagnosis belong to the physician.

Electrode adhesive can injure fragile skin; on older or dermatologic patients, lift electrodes slowly and avoid repeated application to the same site.

When a life-threatening rhythm is seen, the technician's action is to stay with the patient, call for help, and notify the licensed provider immediately.

Patient privacy is protected by keeping monitor screens and printed tracings out of public view and discussing results only with authorized staff.

Proper body mechanics during transport and patient repositioning include bending at the knees and keeping the load close to the body.

Electrical safety basics: inspect cords and plugs, never use equipment with damaged insulation, and keep cables away from liquids.

Documentation of a tracing includes date, time, patient identifiers, lead configuration, and any symptoms reported during recording.

Cardiac cycle terms: systole = ventricular contraction; diastole = ventricular relaxation and filling.

Stroke volume (SV) is the volume ejected per beat; cardiac output (CO) = heart rate × stroke volume.

The normal conduction sequence is SA node → AV node → bundle of His → right and left bundle branches → Purkinje fibers.

The SA node is the primary pacemaker, firing at roughly 60–100 impulses per minute at rest.

Coronary arteries supply the myocardium: the right coronary artery typically supplies the right ventricle and inferior wall; the left anterior descending supplies the anterior wall and septum.

The P wave represents atrial depolarization; the QRS complex represents ventricular depolarization; the T wave represents ventricular repolarization.

Blood flows through the heart in the order: right atrium → tricuspid valve → right ventricle → pulmonary valve → lungs → left atrium → mitral valve → left ventricle → aortic valve → aorta.

The PR interval reflects conduction time from the SA node through the AV node and bundle of His to the ventricles.

Sympathetic stimulation increases heart rate and contractility; parasympathetic (vagal) stimulation slows the SA node and AV conduction.

Standard 12-lead placement: limb leads on the arms and legs; V1 at the 4th intercostal space right sternal border; V2 at the 4th intercostal space left sternal border; V4 at the 5th intercostal space midclavicular line; V3 midway between V2 and V4; V5 at the anterior axillary line at V4's level; V6 at the midaxillary line at V4's level.

Arm and leg electrodes are placed on fleshy areas of the limbs, not over bone, and limb lead wires must not be reversed.

Skin preparation for good tracings: clip (do not shave) excessive hair, clean with alcohol or abrasive pad, and dry before applying electrodes.

Wandering baseline artifact is caused by patient movement, loose electrodes, or poor skin contact and appears as a slow undulating baseline.

Somatic tremor artifact appears as irregular, spiky baseline noise from muscle movement, shivering, or patient tension.

60-cycle (AC) interference appears as a thick, fuzzy baseline or regular high-frequency oscillations; causes include poor electrode contact and nearby electrical equipment.

A flat or absent signal in one lead usually indicates a disconnected or dried electrode rather than a cardiac event.

Paper speed for standard EKG is 25 mm/second; at this speed one small box = 0.04 second and one large box = 0.20 second.

Calibration standard is 10 mm = 1 mV; a calibration mark should be verified at the start of each tracing.

Rate estimation: count the number of large boxes between R waves and divide 300 by that number, or count R waves in a 6-second strip and multiply by 10.

Normal sinus rhythm criteria: regular rhythm, P wave before every QRS, upright P in lead II, rate 60–100, PR interval 0.12–0.20 second, QRS < 0.12 second.

Sinus bradycardia = sinus rhythm with rate below 60; sinus tachycardia = sinus rhythm with rate above 100.

Atrial fibrillation: irregularly irregular rhythm with no distinct P waves and a fibrillatory baseline.

Atrial flutter: regular or variable rhythm with sawtooth flutter waves, often with a 2:1 to 4:1 AV conduction ratio.

Premature ventricular contractions (PVCs) are wide (>0.12 second), bizarre QRS complexes without a preceding P wave; frequent or multifocal PVCs warrant prompt provider notification.

Ventricular tachycardia: wide-complex tachycardia at a rate typically above 100; pulseless VT is a cardiac arrest rhythm requiring immediate emergency response.

Ventricular fibrillation: chaotic, irregular waveform with no identifiable QRS complexes; it is a shockable arrest rhythm.

Asystole is a flatline with no electrical activity; verify leads and gain before confirming, then begin emergency response.

First-degree AV block: PR interval longer than 0.20 second with every P wave conducted to a QRS.

Continuous telemetry monitoring requires correct lead selection and daily electrode changes to reduce artifact and skin irritation.

Alarm limits should be set to the patient's ordered parameters; alarms are never disabled, only adjusted per policy.

A 12-lead EKG should be obtained and compared with prior tracings when a patient reports chest pain, palpitations, or syncope.

Holter monitoring records 24–48 hours of ambulatory EKG; patients log symptoms and activities so tracings can be correlated with events.

Event monitors are patient-activated recorders used for infrequent symptoms; loop recorders continuously store and save recent data when activated.

Cardiac stress testing compares resting and exercise EKGs; the technician prepares the patient and monitors for symptoms, arrhythmias, and ST changes during the test.

In an emergency, the response sequence is: recognize the rhythm, call for help and the code team, start CPR if pulseless, and retrieve the AED or defibrillator.

Defibrillation is indicated for ventricular fibrillation and pulseless ventricular tachycardia; asystole and pulseless electrical activity are not shockable.

After an emergency event, document the rhythm, times, interventions, and patient response accurately in the medical record.