LVEF-Left ventricular ejection fraction

 

Left ventricular ejection fraction (LVEF) is the central measure of left ventricular systolic function. 

LVEF is the fraction of chamber volume ejected in systole (stroke volume) in relation to the volume of the blood in the ventricle at the end of diastole (end-diastolic volume).

The accurate measurement of LVEF is very important for managing patients with cardiovascular disease.

 LVEF also has a prognostic value in predicting adverse outcomes in patients with congestive heart failure, after myocardial infarction, and after revascularization.[2][3][4]

Left ventricular ejection fraction is a powerful predictor of cardiac mortality. 

In clinical practice, LVEF has become the primary criterion used for defibrillator placement.

[SV: Stroke volume, EDV: End-diastolic volume][1]

LVEF (%) among the male population:

• 52% to 72% normal range
• 41% to 51 mildly abnormal
• 30% to 40% moderately abnormal
• Less than 30% severely abnormal 

LVEF (%) among the female population:

• 54% to 74% normal range
• 41% to 53 mildly abnormal
• 30% to 40% moderately abnormal
• Less than 30% severely abnormal 

Low left ventricular ejection fraction (LVEF) means the heart’s left ventricle is not pumping out enough blood with each beat, which can lead to heart failure. A fall could be related to low LVEF in several ways:

1. Dizziness and Syncope (Fainting):

   • Low LVEF can cause poor blood circulation, leading to low blood pressure and dizziness, increasing the risk of falls.
   • If the brain doesn’t get enough oxygen, it can cause fainting (syncope), leading to sudden falls.

2. Muscle Weakness and Fatigue:

   • Poor cardiac output due to low LVEF can cause fatigue and muscle weakness, making it harder to stay balanced and increasing the risk of falling.

3. Arrhythmias:

   • Low LVEF is often associated with irregular heart rhythms (arrhythmias), which can cause sudden drops in blood pressure, leading to lightheadedness and falls.

4. Medication Effects:

   • Patients with low LVEF often take medications like beta-blockers, diuretics, or ACE inhibitors, which can cause dizziness, hypotension, or electrolyte imbalances, contributing to falls.

5. Fluid Retention and Edema:

   • Heart failure can cause swelling in the legs (edema), making walking difficult and increasing the risk of losing balance.

When to Seek Help:

• If someone with low LVEF falls, they should be evaluated for possible injuries, especially head trauma or fractures.
• If falls are frequent, a doctor should assess whether medication adjustments or assistive devices are needed.
• Sudden dizziness, fainting, or worsening fatigue should be reported immediately, as they could indicate worsening heart failure or arrhythmias.

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9: Vitamins and Minerals II

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• Alice Callahan, Heather Leonard, & Tamberly Powell
• Lane Community College via OpenOregon

Learning Objectives

After completing this unit, you should be able to:

1. Define bone and discuss the process of bone formation, modeling, and remodeling across the lifecycle.
2. Define osteoporosis, identify risk factors for development, and explain how osteoporosis can be prevented.
3. Describe the functions of calcium in the body, how calcium homeostasis is regulated, food sources of calcium, and effects of calcium deficiency and toxicity.
4. Briefly describe the functions of phosphorus, magnesium, and fluoride in bone health and beyond, their food sources, and effects of deficiency and toxicity.
5. Describe the synthesis, metabolism, and functions of vitamin D, as well as food sources and effects of deficiency and toxicity of vitamin D.
6. Describe the role of B vitamins and minerals in energy metabolism, as well as food sources and the effects of deficiency and toxicity.
7. Describe the specific functions of folate and vitamin B12, as well as food sources and effects of deficiency and toxicity of folate and B12.
8. Describe the role of blood, as well as the more specific functions, food sources, and effects of deficiency and toxicity for iron and vitamin K.

Xerophthalmia

 Xerophthalmia 

Xerophthalmia is an eye condition caused by severe vitamin A deficiency. It is characterized by dryness of the eyes, leading to night blindness and other vision problems. 

Causes: 

• Vitamin A deficiency, primarily due to inadequate dietary intake or malabsorption 

Symptoms: 

• Dry eyes
• Night blindness (difficulty seeing in dim light)
• Bitot's spots (foamy white patches on the conjunctiva, the clear membrane covering the white part of the eye)
Corneal ulcers (in severe cases) 

Progression: 

Xerophthalmia progresses in stages: 

Night blindness: The earliest symptom. 
Conjunctival xerosis: Dryness of the conjunctiva, causing it to appear red and wrinkled. 
Bitot's spots: Formation of white patches on the conjunctiva. 
Keratomalacia: Softening and melting of the cornea, which can lead to permanent blindness. 

Treatment:

Vitamin A supplementation (usually in the form of oral capsules or injections) 
In severe cases, eye drops or ointments to lubricate the eyes 

Prevention: 

Consume a diet rich in vitamin A-containing foods, such as fruits (mangoes, apricots), vegetables (carrots, sweet potatoes), and animal products (eggs, liver) 
Take vitamin A supplements if recommended by a healthcare professional 

Additional Information:

Xerophthalmia is more common in developing countries where vitamin A deficiency is prevalent.
It is a preventable condition.
Early diagnosis and treatment are crucial to prevent permanent vision loss. 

• Xerophthalmia: Symptoms, Causes & Treatment - Cleveland Clinic

  What is xerophthalmia? Xerophthalmia is pronounced "zeer-of-thal-mee-uh” or “zeer-op-thal-mee-uh.” The Greek root words literally ...

  

  Cleveland Clinic
• Xerophthalmia - Wikipedia

  In xerophthalmia, Bitot's spots occur after conjunctival xerosis. Xerophthalmia caused by a severe vitamin A deficiency is describ...

  

  Wikipedia
• Xerophthalmia - Wikipedia

  Xerophthalmia (from Ancient Greek xērós (ξηρός) meaning "dry" and ophthalmos (οφθαλμός) meaning "eye") is a medical condition in w...

  

  Wikipedia
• Show all

This is for informational purposes only. For medical advice or diagnosis, consult a professional. Generative AI is experimental.

Rhodopsin

 Rhodopsin 

Rhodopsin is a light-sensitive protein found in the retina of the eye. It plays a crucial role in vision, particularly in low-light conditions. 

Structure and Function: 

• Rhodopsin is a G protein-coupled receptor (GPCR). 
• It consists of a protein component called opsin and a small molecule called 11-cis-retinal. 
• In the presence of light, 11-cis-retinal isomerizes to all-trans-retinal, which triggers a conformational change in rhodopsin. 
• This change activates a cascade of events that ultimately leads to the generation of an electrical signal in the brain, allowing us to perceive light. 

Location and Role in Vision: 

Rhodopsin is primarily located in the rod cells of the retina, which are specialized for night vision. 
It enables the eye to detect extremely low levels of light and provides monochromatic (black and white) vision in dim conditions. 

Other Facts: 

Rhodopsin is also known as "visual purple" due to its reddish-purple color. 
It is essential for vitamin A metabolism, as 11-cis-retinal is derived from vitamin A. 
Mutations in the rhodopsin gene can lead to night blindness and other eye disorders. 

Summary:

Rhodopsin is a vital light-sensitive protein that enables vision in low light conditions. It is located in the rod cells of the retina and plays a key role in the transduction of light into electrical signals that are processed by the brain.