Please answer the following 18 review questions on Cardiology, bolding the final answer for each.

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The user wants me to answer 18 review questions related to Cardiology. I need to provide concise answers for each question, ensuring the final answer is bolded. I will go through each question one by one.

1. The innermost layer of the heart is the: Endocardium.
2. The muscles that protrude from the endocardium and assist with valve closure are called the: Papillary muscles.
3. The intrinsic rate of the AV node is ___ to ___ beats per minute. The AV node's intrinsic rate is typically 40 to 60 beats per minute.
4. **When treating a suspected heart failure patient with JVD, ascites, and clear lung sounds