Term
| what are the 2 main divisions of the aorta we are going to be talking about? |
|
Definition
| the thoracic and abdominal aorta |
|
|
Term
| what 3 segments can you divide the thoracic aorta into? |
|
Definition
| the ascending aorta (includes the aortic valve annulus where brachiocephalic vessels are found - most proximal), the arch of the aorta (on the R distal side A->P in sup mediastinum, ends at L subclavian), and the descending aorta (from descending arch down the diaphragm-spine) |
|
|
Term
| **where is the most common dilitation aneurysm location in the aorta? most common area of dissection/rupture? |
|
Definition
| the abdominal aora below the renal vessels is the most common area of dilitation, the posterior peritoneal space is the most common area of dissection/rupture |
|
|
Term
| what are the 3 layers of the aorta? which of these layer allows longitudinal dilation/aneurysm creation? |
|
Definition
| the endothelial, tunica media, and tunica adventitia. the tunica media allows longitudinal dilation and aneurysm creation. |
|
|
Term
| what is the most atherosclerotic, and thus aneurysm promoting activity you can do? |
|
Definition
| smoking is highly active in degeneration of the tunica media, (age is also a major factor, but non-controllable) |
|
|
Term
| which sex is at a higher risk for aneurysms? |
|
Definition
| men @ >55 yrs have increased risk, even if otherwise healthy have a higher risk for aortic aneurysms. post-menopausal women are at a higher risk, esp those w/PAD (ABI of .9 or less) |
|
|
Term
| what is the 10th leading cause of cardiac mortality? |
|
Definition
|
|
Term
| where are the two anchor points for the aorta? in blunt force trauma, where is the maximal torque force? |
|
Definition
| at the aortic valve annulus and the isthmus (a ring of connective tissue at the superior mediastinum). max torque force is placed on the isthmus of the aorta, and if trauma is severe - the aorta can tear -> death (acts as a hinge joint to twist and displace force) |
|
|
Term
| what can happen with the tunica media if the aorta undergoes contusion? |
|
Definition
| scar tissue can dimple in, and form a wrent through the endothelium to the media - forming a port for dissection. |
|
|
Term
| when is the peak rate of dissection post blunt force trauma? |
|
Definition
| 72 hrs (total range is 3-7 days) |
|
|
Term
| where are the pain fibers that fire when the aorta dissects? |
|
Definition
| in the tunica media (not found in endothelium) |
|
|
Term
| what is the tunica media composed of? why? |
|
Definition
| collagen and elastic fibers layered in spiraled sheets that allow the aorta to buffer the force of ejection from the systolic system |
|
|
Term
| what effect do "wrents" have on the spiraled tunica media sheaths? |
|
Definition
| wrents allow blood flow to form eddy currents, which can dig down and cause the sheaths to eventually rip apart causing painful/dangerous dissections |
|
|
Term
| what is the most common cause of a "wrent"? |
|
Definition
| unstable atherosclerotic plaques hemorrhaging (don't necessarily have to be flow-limiting) into its base. this exposes the plaque and channels the media to cause dissection. once the aneurysm is exposed, the aorta is weakened. trauma can also cause this problem, but is less common. |
|
|
Term
| is aneurysm dilatation (stretching) painful? |
|
Definition
| no, dissections are responsible for pain |
|
|
Term
| what 3 tests need to be ordered immediately if a person comes into the ER w/chest pain? |
|
Definition
| CXR: look for mediastinal widening *associated with thoracic aortal dissection, spiral CT w/contrast: another check for mediastinal widening, and EKG: look for MI (can happen concurrently with dissection) |
|
|
Term
| should thrombolytics be given if MI and dissection? |
|
Definition
| never, this will cause pain and death |
|
|
Term
| how can a thoracic dissection cause an acute MI? |
|
Definition
| the proximal part of the aorta is the aortic valve annulus, above which are the coronary arteries - if there is a aortic dissection, the lumen will be much smaller due to clot formation - which can form emboli that can travel into the coronary arteries |
|
|
Term
| can a blood gas test help determine whether there is a clinically significant pulm embolus? |
|
Definition
|
|
Term
| what are the 4 things you want to r/o if a pt has chest pain due to immediate risk? |
|
Definition
| thoracic aortic dissection, sponanteous pneumothorax, acute MI, and plum embolus |
|
|
Term
| could paralysis of the L hemi-diaphragm be indicative of an aortic dissection? |
|
Definition
| yes, an aortic dissection can compress the L phrenic nerve of the sup mediastinum |
|
|
Term
| could progressive hoarseness be indicative of an aortic aneurysm? |
|
Definition
| yes, the L recurrent laryngeal nerve in the medistinum may be compressed = ortner's syndrome |
|
|
Term
| what are the common other presentations for ortner's syndrome? |
|
Definition
younger pts: mesothelioma, thymoma
geriatric pts: most commonly - bronchogenic CA |
|
|
Term
| do pts with aortic aneurysm always feel pain? |
|
Definition
| no, if it is just dilated and not dissected, pts may not be aware |
|
|
Term
| can descending thoracic aortic aneurysms cause dysphasia (trouble swallowing)? |
|
Definition
| yes, this can push into the esophagus |
|
|
Term
| what is the chance of survival w/out medication if the aorta going through the posterior peritoneal space? |
|
Definition
| there is some chance of survival, b/c this is a closed space, but it is low - 10%. there may still be enough blood to circulate even if the post peritoneal space fills with blood, but the pts will be hyptensive if alive w/BP just above shock level or in the schock state |
|
|
Term
| where are other common areas for dissection? |
|
Definition
| ant peritoneal space (pts will likely die due high blood loss), the small bowel (pt will likely die w/massive upper GI hemmorage), the pleural space (blood compresses lungs w/systolic pressure - asphyxiation), and the pericardium (pts will die of cardiac tampenade, where is the heart is too compressed to expand) |
|
|
Term
| what is the survival rate for pts with aortic aneurysms that dissect and rupture who have had medical attention? |
|
Definition
|
|
Term
| how do you examine the abdominal aorta, who should you do this w/regularly? |
|
Definition
| males over 55, have the pt lay supine, exhale and then listen for bruits (chaotic, non-laminar flow at peak systolic velocity characterized by low pitched sounds mono, biphasic sounds). dilatation can also be felt, if the aorta is extended out 3-4 cm. if palpation is too difficult, an ultrasound is the most cost efficient way to dx and size an aneurysm |
|
|
Term
| if a pt is too large, and you can't listen to the abdominal aorta, where else can you listen for bruits? |
|
Definition
| the common femoral arteries will carry sound from the abdominal aorta. if you hear something bilaterally (bruits from the aorta have to travel bilaterally down) in the femorals, it may not necessarily have originated in the aorta - but you still need to rule it out |
|
|
Term
| what is the normal non-aneurysm size of the aorta? |
|
Definition
| 3.2 cm in males, 3 cm in females |
|
|
Term
| what size is considered a small aneurysm? are these considered for elective resection? |
|
Definition
| 3.2-3.9 cm - this size is not considered for elective resection b/c their natural hx rate of dissection and rupture is only 3-4% per year, they need to be checked w/an ultrasound on a yearly basis |
|
|
Term
| what is considered a medium aneurysm size? are these considered for elective resection? |
|
Definition
| 4-5.9 cm - these are considered for elective resection |
|
|
Term
| what is considered a large aneurysm? are these considered for elective resection? |
|
Definition
| 6+ cm - these are usually found in pts over 70 yrs, who are generally not considered good candidates for sx, and need to be treated w/risk factor modification |
|
|
Term
| what is the accepted mortality rate in elective resection of aneurysms? what needs to happen before any sx is performed? |
|
Definition
| 3%, however, an angiogram has to be performed first (which has a .5% mortality rate) |
|
|
Term
| how should individuals with aneurysms approach exercise? |
|
Definition
| they need to limit anerobic exercise |
|
|
Term
| what are the risk factors all people with aneurysms need to reduce? |
|
Definition
| smoking, diabetes, HTN, hyperlipidemia |
|
|
Term
| where is the best place for a dissection and rupture to occur? |
|
Definition
| back into the vessel distally, which happens w/about 30% of pts - they usually don't crash, the pain goes away, they maintain BP, and feel better |
|
|
Term
| where will most emboli end up if they start in the L ventricle? |
|
Definition
| in the L foot (popliteal trifurcation), according to the way the body is built - an attempt to prevent end-organ insult from emboli of the heart. you will commonly see purple, punctate tiny lesions go back to the toe, shows “microembolic shower” from a cholesterol plaque of a dissecting aneurysm |
|
|
Term
| what needs to be done for pts on coumadin (such as those post-MI) who are being taken off coumadin temporarily? |
|
Definition
| ultrasound or echocardiogram to make sure no thrombi |
|
|
