EKG Interpretation 4x6 Flashcards Printable - Free Printable

The image presents four ECG (electrocardiogram) patterns, each labeled with a specific cardiac rhythm and accompanied by key characteristics. Let's analyze each one to understand the normal and abnormal rhythms depicted:

---

1. Normal Sinus Rhythm

- ECG Features:
- Regular P waves before each QRS complex.
- Consistent PR interval.
- Normal QRS duration.
- Heart rate: 60–100 bpm.
- Interpretation: This is a healthy heart rhythm originating from the sinus node. The electrical impulse travels normally through the atria, AV node, and ventricles.

> ✔ Normal rhythm – no treatment needed.

---

2. Sinus Bradycardia

- ECG Features:
- P waves present before each QRS.
- Regular rhythm.
- Heart rate < 60 bpm.
- Normal PR and QRS intervals.
- Interpretation: Slow but regular heartbeat. Often seen in athletes or due to medications (e.g., beta-blockers), hypothyroidism, or increased vagal tone.
- Treatment: Only if symptomatic (e.g., dizziness, fatigue). May require atropine or pacing if severe.

> ⚠️ Bradycardia – assess for symptoms; treat only if symptomatic.

---

3. Sinus Tachycardia

- ECG Features:
- P waves before each QRS.
- Regular rhythm.
- Heart rate > 100 bpm.
- Normal PR and QRS intervals.
- Interpretation: Fast but regular rhythm. Caused by physiological stress (fever, pain, anxiety), dehydration, anemia, or medications.
- Treatment: Address underlying cause (e.g., treat infection, reduce anxiety).

> ⚠️ Tachycardia – look for precipitating factors; treat the cause.

---

4. Atrial Fibrillation (A-Fib)

- ECG Features:
- Irregularly irregular rhythm.
- No distinct P waves (instead, fibrillatory waves).
- Variable R-R intervals.
- Normal QRS complexes (unless aberrant conduction).
- Interpretation: Chaotic electrical activity in the atria leads to uncoordinated atrial contractions. Common in elderly, hypertension, heart disease.
- Treatment: Rate control (beta-blockers, calcium channel blockers), rhythm control (antiarrhythmics), anticoagulation (to prevent stroke).

> ✘ Arrhythmia – requires management to prevent complications like stroke.

---

Summary of Key Differences

| Feature | Normal Sinus | Sinus Bradycardia | Sinus Tachycardia | Atrial Fibrillation |
|--------------------------|------------------|-------------------|-------------------|---------------------|
| Heart Rate | 60–100 bpm | < 60 bpm | > 100 bpm | Variable |
| Rhythm | Regular | Regular | Regular | Irregularly irregular |
| P Waves | Present, regular | Present, regular | Present, regular | Absent (fibrillatory) |
| PR Interval | Normal | Normal | Normal | Not measurable |
| QRS Complex | Normal | Normal | Normal | Normal (usually) |

---

Clinical Takeaway

Understanding these rhythms is crucial for diagnosing and managing cardiac conditions:
- Normal Sinus Rhythm = Healthy.
- Sinus Bradycardia & Tachycardia = Often benign but may indicate pathology.
- Atrial Fibrillation = Requires urgent evaluation and treatment due to stroke risk.

Let me know if you'd like help identifying which rhythm is shown in a real ECG strip or need further explanation!