EKG.2

What does “sinus rhythm” mean?

Impulse originates from the SA node; SA node is controlling the rhythm

What are the 3 steps of systematic EKG interpretation?

1) Assess rhythm 2) Estimate heart rate 3) Assess waves and intervals

What should be evaluated when assessing EKG waves and intervals?

Direction, shape, duration, P waves, PR interval, QRS complex, ST segment, and T waves

What are the normal EKG values for a small box, large box, PR interval, and QRS duration?

Small box = 0.04 sec; Large box = 0.20 sec; PR = 0.12–0.20 sec; QRS = 0.06–0.10 sec

How do you estimate heart rate on a 6-second strip?

Count QRS complexes and multiply by 10

Why is the 1500 method more accurate than the 6-second method?

It uses small-box measurements and is more precise for regular rhythms

What should a PT assess before interpreting the EKG?

The patient—symptoms, appearance, BP, cognition, and exercise tolerance

What patient findings are more concerning than an EKG abnormality alone?

Dizziness, confusion, diaphoresis, pallor, chest pain, hypotension, SOB, syncope

What are the criteria for normal sinus rhythm?

Upright identical P waves; P before every QRS; PR 0.12–0.20 sec; QRS 0.06–0.10 sec; regular R-R; HR 60–100 bpm

What EKG finding defines sinus bradycardia?

Normal sinus rhythm with HR <60 bpm

How does sinus bradycardia appear on an EKG?

Normal rhythm with increased spacing between complexes

What are common causes of sinus bradycardia?

Endurance training, beta blockers, increased vagal tone

Why can symptomatic sinus bradycardia cause dizziness?

Decreased HR → decreased cardiac output → reduced cerebral perfusion

What symptoms may occur with symptomatic sinus bradycardia?

Dizziness, pallor, diaphoresis, weakness, syncope

How should PT manage asymptomatic sinus bradycardia?

Continue therapy and monitor response

A marathon runner has a resting HR of 48 bpm and no symptoms. What should PT do?

Continue treatment; likely normal athletic bradycardia

What EKG finding defines sinus tachycardia?

Normal sinus rhythm with HR >100 bpm

How does sinus tachycardia appear on an EKG?

Normal rhythm with complexes compressed closer together

What are common causes of sinus tachycardia?

Anxiety, pain, exercise, infection, sepsis, hypoxemia

Why can sinus tachycardia decrease cardiac output?

Ventricles have less filling time → decreased stroke volume

A patient with sepsis has HR 125 bpm and normal rhythm. What rhythm is most likely?

Sinus tachycardia

When is sinus tachycardia most concerning during PT?

When accompanied by symptoms, large HR increases, or hemodynamic instability

What defines sinus arrhythmia?

Sinus rhythm with varying R-R intervals

What causes respiratory sinus arrhythmia?

HR increases with inspiration and decreases with expiration

In which populations is sinus arrhythmia commonly normal?

Young individuals and older adults

What are non-respiratory causes of sinus arrhythmia?

Infection, fever, digoxin, morphine

Why is HR estimation difficult in sinus arrhythmia?

HR varies significantly over time

What is sinus arrest?

Temporary cessation of SA node firing

How does sinus arrest appear on EKG?

Sudden pause in rhythm followed by resumption

What is the first action when sinus arrest appears on telemetry?

Check the patient

What is the second action when sinus arrest appears on telemetry?

Check electrode leads

When should PT stop treatment for sinus arrest?

If symptomatic or if rhythm change appears genuine

What is a PAC?

Premature atrial complex; an early atrial beat

How does a PAC appear on EKG?

Early beat with abnormal or hidden P wave but normal-looking QRS

What clue helps identify a PAC?

QRS looks normal but occurs earlier than expected

What are common causes of PACs?

Stress, anxiety, infection, MI, stimulants

What is the PT implication of occasional PACs?

Usually benign; monitor and document

Why should PACs be reported if frequent?

They can progress to more serious atrial arrhythmias

What is a compensatory pause?

SA node timing is unaffected by ectopic beat

What is a non-compensatory pause?

Ectopic beat resets SA node timing

What defines atrial tachycardia?

Three or more PACs in a row

What other name is commonly used for atrial tachycardia?

Supraventricular tachycardia (SVT)

What heart rate range is common in atrial tachycardia?

100–200 bpm

Why can atrial tachycardia cause dizziness?

Reduced cardiac output due to excessive rate

What pulmonary conditions may trigger atrial tachycardia?

Severe pulmonary disease, hypoxemia, pulmonary hypertension

What autonomic maneuver may help terminate atrial tachycardia?

Valsalva maneuver

What does “paroxysmal” mean?

Sudden onset and termination; intermittent

What rhythm is characterized by sudden racing heartbeat >160 bpm with hidden P waves?

PSVT/PAT

How does PSVT appear on EKG?

Very fast, regular rhythm with merged P and T waves

What symptoms are common with PSVT?

Palpitations, racing heart, decreased cardiac output symptoms

What should a PT do if a patient develops active PSVT?

Stop treatment and seek medical evaluation

What EKG finding is classic for atrial flutter?

Sawtooth flutter waves

Why is ventricular rate lower than atrial rate in atrial flutter?

AV node blocks many impulses

What is the atrial rate in atrial flutter?

Approximately 250–350 bpm

What symptoms can occur with atrial flutter?

Palpitations, hypotension, decreased cardiac output

What treatment is commonly used for atrial flutter?

Cardioversion and medications

A telemetry strip shows sawtooth waves and a ventricular rate of 120 bpm. What rhythm is present?

Atrial flutter

What EKG findings define atrial fibrillation?

No P waves and irregularly irregular R-R intervals

What does fibrillation mean?

Uncoordinated quivering rather than organized contraction

Why are AFib patients commonly anticoagulated?

Blood pools in atria, increasing clot risk

What complications are AFib patients at increased risk for?

Stroke, pulmonary embolism, myocardial infarction

What symptoms commonly occur in AFib?

Palpitations, dizziness, SOB, hypotension

How should PT manage newly developed AFib?

Hold therapy and notify medical team

How should PT manage chronic medically controlled AFib?

Proceed cautiously and monitor response

What is a PVC?

Premature ventricular complex; early ventricular beat

How does a PVC appear on EKG?

Wide bizarre QRS with no preceding P wave

What QRS duration is characteristic of a PVC?

0.10 sec

What does bigeminy mean?

Every other beat is a PVC

What does trigeminy mean?

Every third beat is a PVC

What does quadrigeminy mean?

Every fourth beat is a PVC

What is a ventricular couplet?

Two PVCs in a row

What is a ventricular triplet?

Three PVCs in a row; clinical definition of VTach

What is a unifocal PVC?

All PVCs originate from one focus and look identical

What is a multifocal PVC?

PVCs originate from multiple foci and look different

What are common causes of PVCs?

Stress, caffeine, nicotine, hypoxemia, ischemia, electrolyte imbalance, heart disease

What do patients often report feeling during PVCs?

A skipped beat followed by a stronger beat

When are PVCs most concerning?

5/min, multifocal, bigeminy/trigeminy, triplets, increasing frequency

Can occasional PVCs occur in healthy individuals?

Yes

What defines ventricular tachycardia?

Three or more PVCs in a row

How does VTach appear on EKG?

Rapid series of wide bizarre QRS complexes without P waves

Why is VTach dangerous?

Severe reduction in cardiac output

What symptoms are common during VTach?

Syncope, hypotension, confusion, angina, dizziness

What should a PT do if VTach occurs during treatment?

Stop therapy, get patient safe, activate emergency response

What is torsades de pointes?

A special form of VTach with twisting amplitude around the baseline

How does torsades appear on EKG?

Twisting pattern with waxing and waning QRS amplitude

What type of emergency is torsades?

Medical emergency treated like VTach

What defines ventricular fibrillation?

Chaotic ventricular quivering with no meaningful contraction

How does VFib appear on EKG?

Chaotic irregular waveform without identifiable complexes

Why is VFib fatal without treatment?

No effective cardiac output

Can a pulse usually be felt during VFib?

No

What should PT do if VFib occurs?

Emergency response, CPR, defibrillation

What is asystole?

Absence of electrical activity in the heart

How does asystole appear on EKG?

Flatline

Can asystole be defibrillated?

No; there is no electrical activity to reset

What treatments are used for asystole?

CPR and medications such as epinephrine

What is an ICD?

Implanted cardioverter-defibrillator

What is the purpose of an ICD?

Detect and correct dangerous arrhythmias

How may an ICD appear on EKG?

Small pacing/shock spikes before complexes

What should PT do if a patient’s ICD fires during therapy?

Stop, allow rest, notify nursing/medical team

What defines first-degree AV block?

PR interval >0.20 sec with all impulses conducted