Aortic Dissection
Introductions in Aortic Dissection
The aorta is the large blood vessel that comes out of the heart and carries blood throughout the body. Aorta at aortic valve stems on the way out of the left heart chambers. He climbed inside the chest to the arc (arch) where the branching of blood vessels to provide blood flow to the hands and head. He then began to fall through the chest into the abdomen, where it divides into two iliac arteries that provide blood flow to the legs. Together with the decline, more small arteries branch off to supply blood to the stomach, intestine, large intestine (colon), kidneys, and spinal cord (spinal cord).
The aorta has a thick wall, with three layers of muscle that allow blood vessels to withstand the high pressures generated when the heart pumps blood to the body. The three layers are the tunica intima, tunica media and tunica adventitia. Intima is the layer in contact with blood, the media is the middle, and the adventitia is the outermost layer.
In aortic dissection, small tears occur in the tunica intima (inner lining of the aortic wall in contact with blood). Blood can enter this tear and cause peeling of the coating layer of the intima media, in effect splitting the muscle layers of the aortic wall and forming a false channel, or lumen. This channel may be short or may extend throughout the length of the aorta. A torn distal (farther along the path from the aorta rather than the initial tear) in the intima layer can let the blood back into the true lumen of the aorta.
In some cases dissection will pass through all three layers of the aortic wall and lead to cracking (divisions) that immediately. In most other cases of blood filled between the layers of the wall.
Where there have been different classifications according to history, Stanford is the most common classification used to classify dissection.
* Type A dissections involving the aorta and arch (arch) are rising.
* Type B aortic dissections involve the fall.
A patient can have a combination of both.
Some patients may experience an aortic dissection without pain, and he may discovered incidentally on imaging studies conducted for other purposes.
Causes of Aortic Dissection
Is not certain why the initial tear occurs in the intima layer of the aortic wall. Aortic dissection tends to occur most commonly in men aged between 50 and 70 years.
High Blood Pressure: Most cases (more than 70%) associated with high blood pressure (hypertension). The aorta must withstand the pressure changes are significant with each heartbeat, and it is possible that over time with hypertension, the weakening of the intima area will occur.
Disease-related illnesses:
* Bicuspid aortic valve (aortic valve abnormalities from congenital)
* Marfan's syndrome
* Ehlers-Danlos syndrome
* Turner Syndrome
* Syphilis
* Use of Cocaine
Pregnancy: Pregnancy is also associated risk factors, especially in the third trimester and early post-partum period.
Trauma: blunt injury is known to cause aortic dissection, often seen after car accidents where the patient's chest hit the steering wheel.
What are the complications of Operation: Aortic dissection can be a complication of medical operations including heart bypass surgery (coronary artery bypass grafting) and repair-aortic and mitral valve repair. It can also be a complication of cardiac catheterization.
Signs and Symptoms of Aortic Dissection
* Pain is the most common symptom of aortic dissection and is often described as tearing or ripping. The pain usually starts suddenly and centered in the chest, spreads directly into the upper back.
* There may be nausea, sweating, shortness of breath, and weakness associated.
* Patients may faint (syncope)
* Other symptoms may be related to the location of the dissection in the aorta and whether it affects some of artery-clogging ateri are branched and their blood supply. For example, if any arteries that supply blood to the brain is involved, there may be signs of a stroke, or if the dissection affects the anterior spinal artery and blood supply to the spinal cord, the patient may present with paraplegia.
* Coronary arteries that supply blood to the heart begins at the origin of the aorta to the aortic valve (aortic valve). If the involved coronary arteries, aortic dissection may caused heart attack (myocardial infarction).
* Patients may present with congestive heart failure with a collection of fluid in the lungs. If aortic dissection involving the aortic valve and cause it to fail, blood flows back into the heart with each heartbeat and cause the blood to flow back into the lungs.
* There may be abdominal pain or side (side of the body between ribs and hips) are significant.
* The pain of aortic dissection can be confused with that of a heart attack, but can sometimes be distinguished because of the sudden appear and a normal electrocardiogram.
* Patients may also have feelings of impending doom.
Diagnosing Aortic Dissection
Clinicians should suspect an aortic dissection as one of the causes being considered for chest pain, as well as for heart attack and pulmonary embolism.
If the patient has vital signs are unstable, poor breathing, abnormal pulse, low blood pressure, and or a reduced level of consciousness, ABCs of resuscitation (Airway, Breathing, Circulation) need to be addressed when the evaluation of patients continues.
Patient history
History is one of the first steps are important in decisions about diagnosis.
Physical examination may reveal the potential complications of aortic aneurysm to allow physicians to consider this as a potential diagnosis. Once again, the symptoms that were presented will depend on the location of dissection and what organs are involved. The symptoms, depending on the location of the dissection, may include:
* Differences in blood pressure between arms
* The delay between the pulse of the hands and feet
* Listen to the fluid in the lungs and to murmur (murmur) new heart may help assess the aortic valve (aortic valve).
* The symptoms of a new stroke
* Paraplegia
Initial tests for chest pain, electrocardiogram, and chest x-ray is usually done. Unless the dissection involves the coronary arteries, electrocardiogram are usually normal. X-ray chest may show an abnormal form in the aorta and the widened mediastinum (the room where the heart, aorta, vena cava, trachea, and esophagus sits inside the chest cavity).
A diagnostic test of choice is computerized tomography aortic angiogram of the chest and abdomen to look at the aorta (this test requires an injection of contrast dye).
As an alternative, for people who can not undergo computerized tomography, transesophageal echocardiography is an alternative. A cardiologist include an ultrasound probe through the mouth into the esophagus and can identify potential problems with the heart, heart valves, and aorta.
Magnetic resonance imaging (MRI) can also be used, but the technique is not easily available to patients who are unstable.
Treatment Aortic Dissection
ABCs of resuscitation is always priority (overlooked).
In the emergency department, intravenous lines are placed, monitors for heart rate and rhythm will be attached, and supplemental oxygen provided. Treatments and diagnostic tests usually occur at the same time until the final diagnosis is made.
These drugs are used early directed to a decrease in blood pressure to prevent further tearing or damage to the aorta. Beta blocker medications [for example, esmolol (Brevibloc), labetalol (Normodyne, Trandate), metoprolol (Lopressor, Toprol XL)] reduces the action of adrenaline on the heart and blood vessels. Nitroglycerin dilate blood vessels to reduce blood pressure. Specific drug combinations will depend on the patient's purposes.
Finally, type A aortic dissections of the aorta which rose require surgery as the treatment of choice. The damaged area of the aorta is replaced with artificial grafts. If the aortic valve has been tampered with, it also may require replacement or repair.
Medical management (rather than surgery) is preferred to type B dissection of the aorta are down, but again, every patient needs to be assessed individually in specific treatment recommended. Medications prescribed to control high blood pressure aggressively to prevent further dissection and aortic injuries.
The prognosis for Aortic Dissection
For aortic rupture, in which all three layers of the aorta is interrupted, the mortality rate is served until 80% of patients. Fifty percent of these patients die before reaching a hospital.
For type A aortic dissection, mortality rates remain high, with up to a mortality rate of 30% after surgery.
Type B aortic dissections, were treated medically, had an early mortality of 10%. This compares to the death of 30% when treated surgically.
Overall, for both types of aortic dissection, ten-year survival rate is more than 60%.
Prevent Aortic Dissection
As with any disease that involves the blood vessels, prevention is the key. Controlling high blood pressure, diabetes, cholesterol, and avoiding smoking reduces the risk of all vascular diseases. Because 70% of patients with aortic dissection have hypertension. Controlling high blood pressure, risk factors, may reduce the risk of this disease.
Any chest pain should not be ignored, and medical treatment should be immediately assessed by activating the system of emergency medical services and call 911.
Because the causes of chest pain may be unknown, giving baby aspirin to patients is appropriate, such as providing nitroglycerin (if the patient has been prescribed this drug for chest pain).
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