Table of contents

1. Introduction to Anatomy & Physiology5h 43m
2. Cell Chemistry & Cell Components12h 36m
3. Energy & Cell Processes10h 6m
4. Tissues & Histology10h 3m
5. Integumentary System2h 20m
6. Bones & Skeletal Tissue2h 16m
7. The Skeletal System2h 35m
8. Joints2h 17m
9. Muscle Tissue2h 33m
10. Muscles1h 11m
11. Nervous Tissue and Nervous System1h 35m
12. The Central Nervous System1h 6m
- Introduction to the Central Nervous System
  18m
- The Cerebrum
  48m
13. The Peripheral Nervous System1h 26m
14. The Autonomic Nervous System1h 38m
15. The Special Senses2h 41m
16. The Endocrine System2h 48m
17. The Blood3h 22m
18. The Heart3h 42m
19. The Blood Vessels3h 35m
20. The Lymphatic System3h 16m
21. The Immune System14h 37m
22. The Respiratory System3h 20m
23. The Digestive System2h 5m
24. Metabolism and Nutrition4h 0m
25. The Urinary System2h 39m
26. Fluid and Electrolyte Balance, Acid Base Balance37m
27. The Reproductive System2h 5m
28. Human Development1h 21m
29. Heredity3h 32m

18. The Heart

Electrocardiogram (ECG)

Anatomy & Physiology

18. The Heart

Electrocardiogram (ECG)

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Multiple Choice

When the appropriate electrocardiogram (ECG) complex follows the pacing spike, it is said to be:

undersensed

fused

captured

non-captured

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Verified step by step guidance

Understand the context of the problem: The question is about interpreting an electrocardiogram (ECG) in relation to a pacing spike, which is a signal generated by a pacemaker to stimulate the heart. The goal is to determine the term that describes the situation when the ECG complex appropriately follows the pacing spike.

Review the concept of 'captured': In pacemaker terminology, 'capture' refers to the successful depolarization of the heart muscle (myocardium) in response to a pacing stimulus. This is evidenced by the appearance of an appropriate ECG complex (e.g., a P wave or QRS complex) immediately after the pacing spike.

Clarify the other terms for comparison: 'Undersensed' refers to the pacemaker failing to detect intrinsic cardiac activity. 'Fused' describes a scenario where the paced and intrinsic beats occur simultaneously, creating a hybrid ECG complex. 'Non-captured' means the pacing stimulus did not result in myocardial depolarization, and no ECG complex follows the pacing spike.

Analyze the situation described: The problem states that the appropriate ECG complex follows the pacing spike. This indicates that the pacing stimulus successfully caused myocardial depolarization, which aligns with the definition of 'captured.'

Conclude the reasoning: Based on the definitions and the situation described, the term 'captured' is the correct answer because it signifies the successful response of the heart to the pacemaker's pacing spike.