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Ch. 18 The Cardiovascular System: The Heart
Hoehn - Marieb Human Anatomy & Physiology, 12th edition
Hoehn, Haynes, Abbott12th EditionMarieb Human Anatomy & PhysiologyISBN: 9780138242732Not the one you use?Change textbook
Chapter 18, Problem 23

Gabriel, a heroin addict, feels tired, is weak and feverish, and has vague aches and pains. Terrified that he has AIDS, he goes to a doctor and is informed that he is suffering not from AIDS, but from a heart murmur accompanied by endocarditis. What is the most likely way that Gabriel contracted endocarditis? (Hint: See Related Clinical Terms.)

Verified step by step guidance
1
Understand that endocarditis is an infection of the inner lining of the heart chambers and valves, often caused by bacteria entering the bloodstream and attaching to damaged areas of the heart.
Recognize that intravenous drug use, such as heroin addiction, is a common risk factor for endocarditis because non-sterile needles can introduce bacteria directly into the bloodstream.
Identify that Gabriel's symptoms (tiredness, weakness, fever, aches) are consistent with an infection like endocarditis rather than AIDS, which involves immune system compromise.
Conclude that the most likely way Gabriel contracted endocarditis is through bacteria entering his bloodstream via contaminated needles used during heroin injection.
Summarize that the pathophysiology involves bacteria colonizing the heart valves, leading to inflammation and the characteristic heart murmur associated with endocarditis.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Infective Endocarditis

Infective endocarditis is an infection of the inner lining of the heart chambers and valves, usually caused by bacteria entering the bloodstream and attaching to damaged heart tissue. It often presents with symptoms like fever, weakness, and heart murmurs, and can be life-threatening if untreated.
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Risk Factors for Endocarditis in Intravenous Drug Users

Intravenous drug users are at high risk for endocarditis because injecting drugs can introduce bacteria directly into the bloodstream. Contaminated needles or substances can cause infections, especially affecting the heart valves, leading to endocarditis.
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Heart Murmur and Its Clinical Significance

A heart murmur is an abnormal sound heard during a heartbeat, often indicating turbulent blood flow due to valve abnormalities or infections like endocarditis. Detecting a murmur helps clinicians suspect underlying heart conditions requiring further investigation.
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