Recording Quality, Artifact and Rhythm

This is Unit Twenty-Three of Medical Assistant Prep. Unit Twenty-Two set up a twelve-lead recording. This unit checks the tracing that comes out: whether it is clean, what causes artifact and how to fix it, and the rhythms you should recognize well enough to report. Carry one idea through this lecture. Look at the patient before you look at the printout, and stop where your role stops: you recognize and report, and the provider names and decides. Two constructed cases at the end show that idea with a noisy tracing and an irregular one. By the end you will be able to judge a tracing's quality. To recognize and fix artifact. To estimate a rate and tell regular from irregular rhythms. And to check the patient and report an abnormality promptly.

Five entries on tracing quality: inspecting it, what artifact is, and three common kinds.

Before electrodes come off.

MAS 551 Inspect the Tracing for Quality

Before the electrodes come off, inspect the printed tracing to confirm that it is clean and complete. A good tracing shows a steady, flat baseline between beats and clear waves in every lead, with nothing fuzzy, drifting or cut off. A poor tracing is repeated before it reaches the provider, not sent with an apology.

Not from the heart.

MAS 552 What Artifact Is

Artifact is any marking on the tracing that does not come from the heart's electrical activity. It happens when electrodes lose good contact with the skin, when the patient moves, or when outside electrical signals interfere. Artifact can look like dangerous rhythms, so compare the tracing with how the patient actually looks.

Fuzz from muscles.

MAS 553 Muscle Tremor Artifact

Muscle tremor artifact makes the tracing look fuzzy or choppy. It comes from muscle activity, such as shivering, anxiety, or a patient tensing to hold themselves up. Offer warmth and reassurance, support the patient's arms and legs on the table, and then record the tracing again.

Power nearby.

MAS 554 Sixty-Cycle Interference

Sixty-cycle interference comes from nearby electrical power and appears as a thick, regular, rapid pattern along the baseline. Sources include power cords near the patient or cables, nearby devices, and personal electronics such as cell phones. Move cords, relocate devices and set aside phones, but never unplug equipment a patient depends on.

A drifting baseline.

MAS 555 Wandering Baseline

A wandering baseline drifts slowly up and down instead of staying flat. It often follows the patient's breathing or movement, and it can also come from loose or dry electrodes. Check that every electrode is firmly attached to clean, well-prepared skin, and ask the patient to lie still, before recording again.

Three entries on correction: fixing artifact in order, lead reversal, and the machine's printed reading.

Patient, electrodes, comfort, cords.

MAS 556 Fixing Artifact

When a tracing shows artifact, work through causes in order and record again. Look at the patient: shivering, tense, talking or moving? Check each electrode for firm contact on clean, dry skin, and replace loose or dry ones. Make the patient comfortable, with a blanket, reassurance and support for arms and legs. Move power cords and set aside phones. Ask them to lie still and breathe normally, and record a new tracing. Inspect it before removing electrodes. If artifact cannot be fixed, never hand it over silently; tell the provider what you tried so they can judge the tracing.

Wrong wire, wrong electrode.

MAS 557 Lead Reversal

Lead reversal happens when a lead wire is attached to the wrong electrode. It usually produces recognizable abnormalities on the tracing, which is why each wire should be checked against its label before recording. If you suspect a reversal, check every connection and record again before the tracing goes to the provider.

Not a diagnosis.

MAS 558 The Machine's Reading Is Not a Diagnosis

Many ECG machines print an automatic interpretation, but a provider evaluates the findings. The printed statement can be wrong, especially when artifact is present, because the machine can mistake noise for an abnormal rhythm. Never read the machine's printed interpretation aloud to the patient; the provider decides what the tracing means.

Seven entries on rhythm: estimating rate, regular and irregular patterns, sinus rhythms, atrial fibrillation and premature beats.

Count and multiply.

MAS 559 Estimating the Rate From a Strip

A simple way to estimate the heart rate is to count the beats on a six-second strip and multiply by ten. A six-second strip spans thirty large boxes; count the R waves in it, the tall spikes of each QRS complex, then multiply the count by ten. The method works only if the strip really is six seconds long.

Even intervals.

MAS 560 Regular Rhythms

A rhythm is regular when the distance from one R wave to the next is always the same. Normal sinus rhythm is an example: each beat follows the last at an even interval, with a P wave before each QRS complex. Check regularity across the whole strip, not only a few beats.

How irregular.

MAS 561 Kinds of Irregular Rhythm

Irregular rhythms differ in how irregular they are, which helps the provider identify them. Irregularly irregular means the R-to-R distances are never equal, as in atrial fibrillation. Regularly irregular means unequal distances that repeat in a pattern. Occasionally irregular means regular except for an occasional early beat, as with scattered premature ventricular contractions. Knowing which kind you see tells you what to describe. Your task is to recognize irregularity, check the patient and report promptly with the tracing. Naming the rhythm as a diagnosis belongs to the provider.

The normal path.

MAS 562 Normal Sinus Rhythm

Normal sinus rhythm means the heartbeat starts in the SA node and follows the normal pathway. The rhythm is regular, a P wave comes before every QRS complex, and the rate is within the normal range. A normal-looking tracing does not override a patient's symptoms; report symptoms regardless.

Sinus rates.

MAS 563 Sinus Bradycardia and Sinus Tachycardia

When the SA node fires slower or faster than normal, the rhythm is called sinus bradycardia or sinus tachycardia. A slow sinus rhythm can occur in well-conditioned athletes or with some heart medications; a fast one is often caused by stress, exercise, caffeine, alcohol or tobacco. Report the rate and the patient's symptoms; the provider decides whether it matters.

Irregularly irregular.

MAS 564 Atrial Fibrillation

Atrial fibrillation is an irregular rhythm in which the atria quiver instead of contracting normally. On the tracing it is irregularly irregular, with no distinct P waves and a wavy baseline; patients are at increased risk of stroke. Shivering artifact can mimic it, so rule out tremor before reporting a new finding.

Premature contractions.

MAS 565 Premature Beats

A premature beat comes earlier than expected, from somewhere other than the SA node. Premature atrial contractions are common in older adults and are often linked to caffeine, tobacco, anxiety or electrolyte imbalances; premature ventricular contractions make a rhythm occasionally irregular. Report premature beats, especially if the patient has symptoms.

Five entries close the unit: checking the patient, notifying the provider, Holter monitors, and two constructed cases.

Patient before paper.

MAS 566 When the Pattern Looks Dangerous

If a tracing shows an abnormal pattern, check the patient before anything else. Is the patient responsive, is there a pulse, and do they have chest pain or shortness of breath? If anything is wrong, request emergency help at once. A patient talking comfortably with a wild-looking tracing usually means artifact; a patient in distress means an emergency.

Promptly, with context.

MAS 567 Notify the Provider of Abnormalities

Any abnormality on a tracing, and any symptom the patient reports, goes to the provider promptly. Give the provider the tracing, note anything you did to fix artifact, and pass on what the patient told you, in the patient's words. Do not wait to batch tracings at the end of the morning when something looks abnormal.

A day or two of recording.

MAS 568 Holter Monitors

A Holter monitor records the heart's electrical activity continuously, usually for a day or two. It is about the size of a small camera, worn on a belt or strap, with wires under the clothing attached to electrodes on the chest. Reinforce the provider's instructions for wearing it, and tell the provider about any problem the patient reports.

A fuzzy tracing.

MAS 569 A Tracing Full of Fuzz

A constructed case troubleshoots a noisy tracing. An older man's first printout is covered in choppy fuzz, and the machine suggests an abnormal rhythm. The assistant does not take that at face value and looks at the patient first: he is chatting, gripping the table, the room is cold, and the power cord lies across the lead wires. In order, she presses down a lifting electrode, gives a warm blanket, supports his arms at his sides, moves the cord, and asks him to stop talking and lie still. The second tracing is clean, and the machine's statement drops the rhythm. She gives the provider the clean tracing and explains the first attempt and what she changed. The first tracing would have shown a rhythm problem that did not exist, made official by the machine's print.

Irregularly irregular.

MAS 570 An Irregular Strip

A constructed case pays off the opening idea. A routine tracing prints with a wavy, uneven baseline. The assistant rules out artifact first: the patient is warm, relaxed and still, electrodes are firm, no cords nearby. A repeat shows the same pattern, and the R-to-R distances are never equal. She checks the patient: alert, breathing comfortably, no chest pain, though he mentions a fluttering sometimes. She estimates the rate from the six-second strip and takes the tracing straight to the provider with the pattern, the rate and his own words. When he asks whether something is wrong with his heart, she says the provider will review it with him. Naming the rhythm, explaining it and deciding what to do were the provider's work.

Look at what you can now do. You can inspect a tracing before the electrodes come off, and recognize tremor, interference and a wandering baseline. You can fix artifact in order, check for lead reversal, and keep the machine's printed reading from the patient. You can estimate a rate from a six-second strip and describe regular and irregular rhythms, sinus rates, atrial fibrillation and early beats. And you can check the patient first and report abnormalities promptly. Unit Twenty-Four moves to the front office: reception, the telephone and scheduling.