EKG Practice Strips and Treatment Flashcards Quizlet - EKG ... - Free Printable

The image you've uploaded is a Quizlet study set titled *"EKG Practice Strips and Treatment"*, containing three EKG rhythm interpretations: Normal Sinus Rhythm (NSR), Sinus Bradycardia, and Sinus Tachycardia. Below is a detailed explanation of each rhythm based on the information provided in the image:

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1. Normal Sinus Rhythm (NSR)

- Heart Rate: 60–100 beats per minute (bpm)
- Rhythm: Regular (normal)
- PR Interval: 0.12–0.20 seconds (3–5 small blocks on EKG paper)
- QRS Complex: 0.04–0.10 seconds (1–3 small blocks)

✔ Interpretation:
- This is a normal heart rhythm originating from the sinus node.
- The P wave precedes every QRS complex, indicating normal atrial depolarization followed by ventricular depolarization.
- The PR interval is within normal limits, suggesting normal conduction through the AV node.
- The QRS duration is narrow (<0.12 sec), indicating normal intraventricular conduction.

📌 Clinical Significance:
- This is the baseline normal rhythm for a healthy adult at rest.
- No treatment needed unless associated with symptoms or other abnormalities.

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2. Sinus Bradycardia

- Heart Rate: <60 bpm (slow)
- Rhythm: Regular
- PR Interval: Normal (0.12–0.20 seconds)
- QRS Complex: Normal (0.04–0.10 seconds)

✔ Interpretation:
- The rhythm originates from the sinus node, but the rate is slower than normal.
- P waves are present before each QRS complex, and the PR interval is normal — this confirms the origin is the sinus node.
- QRS is narrow, indicating normal ventricular depolarization.

📌 Causes:
- Common in athletes (physiological bradycardia)
- Medications (e.g., beta-blockers, calcium channel blockers)
- Hypothyroidism, hypothermia, increased intracranial pressure
- Sick sinus syndrome

📌 Treatment:
- Asymptomatic: Usually no treatment needed.
- Symptomatic (dizziness, syncope, hypotension): Treat underlying cause; may require atropine or pacing if severe.

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3. Sinus Tachycardia

- Heart Rate: >100 bpm (fast)
- Rhythm: Regular
- PR Interval: Normal (0.12–0.20 seconds)
- QRS Complex: Normal (0.04–0.10 seconds)
- QT Interval: Shortens as heart rate increases (due to rate-related changes in repolarization)

✔ Interpretation:
- The rhythm is originating from the sinus node, but the rate is elevated.
- P waves are present before each QRS complex.
- The PR and QRS intervals are normal, confirming no conduction delay.
- The QT interval shortens with increasing heart rate because the cardiac cycle shortens — this is a normal physiological adaptation.

📌 Causes:
- Exercise, anxiety, fever, pain, dehydration, anemia, hyperthyroidism
- Volume depletion, sepsis, shock
- Medications (e.g., epinephrine, stimulants)

📌 Treatment:
- Treat the underlying cause (e.g., fluid resuscitation, treat infection).
- If symptomatic or persistent, consider beta-blockers (e.g., metoprolol) to control rate.

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Summary Table

| Rhythm | Rate | Rhythm | PR Interval | QRS Duration | Key Features |
|-------|------|--------|-------------|--------------|--------------|
| NSR | 60–100 bpm | Regular | 0.12–0.20 sec | 0.04–0.10 sec | Normal sinus rhythm |
| Sinus Bradycardia | <60 bpm | Regular | Normal | Normal | Slow but regular sinus rhythm |
| Sinus Tachycardia | >100 bpm | Regular | Normal | Normal | Fast but regular sinus rhythm |

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Clinical Tip:

Always assess patient symptoms alongside EKG findings. A slow or fast heart rate may be normal in certain contexts (e.g., athlete’s bradycardia), but if it causes symptoms like dizziness or chest pain, further evaluation is needed.

Let me know if you'd like help interpreting real EKG strips or want to learn about other arrhythmias!