Muscle Fibrillation PDF

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MUSCLE FIBRILLATION

MUSCLE FIBRILLATION The word fibrillation is related to the word fibril in the sense of muscle fibrils, the proteins that make up each muscle fiber (muscle cell). -

Fibrillation is the name given to spontaneous activity recorded by a monopolar or concentric needle inserted into a muscle belly while the muscle is at rest. Fine, rapid twitching of individual muscle fibers with little or no movement of the muscle as a whole. If a motor neuron or its axon is destroyed, the muscle fibers it innervates undergo denervation atrophy. This leads to hypersensitivity of individual muscle fibers to acetyl choline so that they may contract spontaneously. Isolated activity of individual muscle fibers is generally so fine it cannot be seen through the intact skin, although it can be recorded as a short-duration spike in the EMG.

Cardiology There are two major classes of cardiac fibrillation: atrial fibrillation and ventricular fibrillation. 

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Atrial fibrillation is an irregular and uncoordinated contraction of the cardiac muscle of atria. It can be a chronic condition, usually treated with anticoagulation and sometimes with conversion to normal sinus rhythm. In this condition the normal electrical pulses coming from the sinoatrial node are overwhelmed by disorganized electrical impulses usually originating in the roots of the pulmonary veins, leading to irregular conduction of impulses to the ventricles which generate the heartbeat. Ventricular fibrillation is an irregular and uncoordinated contraction of the cardiac muscle of ventricles. It is a common cause of cardiac arrest and is usually fatal if not reversed by defibrillation.

Fibrillation may sometimes be used after heart surgery to stop the heart from beating while any minor leaks are stitched up. Musculoskeletal Fibrillation also occurs with individual skeletal muscle fibers. This happens when muscle fibers lose contact with their innervating axon producing a spontaneous action potential, "fibrillation potential" that results in the muscle fiber's contraction. These contractions are not visible under the skin and are detectable through needle electromyography (EMG) and ultrasound. Fibrillations can occur in healthy individuals. If the fibrillations have irregular potentials then they don't have pathological significance. In other cases they are a major symptom in acute and severe peripheral nerve disorders, in myopathies in which muscle fibers are split or inflamed, and in lower motor neuron lesions. They contrast with fasciculations that are visible spontaneous contractions involving small groups of muscle fibers. Fasciculations can be seen in lower motor neuron lesions as well, but they also do not necessarily denote pathology.

Atrial Fibrillation: Causes Things that most often lead to AFib Include:

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Age Genes Heart disease Sick sinus syndrome Heart attack High blood pressure Lung disease, such as chronic obstructive pulmonary disease (COPD) or emphysema, or a blood clot in your lung (pulmonary embolism) An overactive thyroid gland (hyperthyroidism) Obesity, diabetes, and metabolic syndrome Sleep apnea Infections caused by a virus

Atrial Fibrillation Symptoms          

You might feel: Heart palpitations -- a flutter in your chest Pain and pressure in your chest Confused Dizzy Faint Short of breath Sweaty Tired Weak

Not everyone with AFib has a racing or pounding heartbeat. Medications These can prevent clots and strokes, slow your heart rate, and control your heart rhythm. Blood thinners : These medications thin your blood to lower your chance of having those problems. But they can raise your risk of bleeding, so you might have to cut back on some activities that can lead to injuries. The most common are: -Apixaban (Eliquis) -Aspirin -Clopidogrel (Plavix) -Dabigatran (Pradaxa)

-Enoxaparin (Lovenox) -Heparin -Rivaroxaban (Xarelto) -Warfarin (Coumadin, Jantoven) Blood thinners can make you more likely to bruise or bleed too much. You'll see your doctor for a blood test every month to make sure the medication is working and you're on the right dose. Symptoms of Ventricular Fibrillation: Causes While the exact cause of VF is unknown, the problem typically stems from interruptions in the electrical impulses that control your heartbeat. A heart attack or loss of blood flow to your heart can set off VF. VF often begins with ventricular tachycardia, which is a very rapid heartbeat that changes the electrical impulses in your heart. This most often occurs in people who have scar tissue from previous heart attacks or heart muscle damage due to heart conditions. If it’s left untreated, ventricular tachycardia will likely lead to VF. Symptoms of Ventricular Fibrillation: Symptoms When VF occurs, the two chambers in the lower portion of your heart aren’t able to pump hard enough to move blood through your body. These lower chambers are called ventricles. This makes your blood pressure drop quickly and keeps blood from traveling through your body. As a result, blood can’t get to your vital organs. Fainting or losing consciousness are the most common symptoms of VF, earlier symptoms include: -chest pain -dizziness -nausea -rapid, fluttering heartbeat -shortness of breath These early symptoms can occur one hour or less before fainting or loss of consciousness occurs....