Physician Assistant Exam: The Vascular System
Cardiovascular doesn’t refer to just the heart; it also refers to the blood vessels. Guess what! For the Physician Assistant Exam (PANCE), you have to worry about the arteries and veins as well as the heart.
One scenario you never want to miss is the person with a history of uncontrolled hypertension who presents to the emergency room with acute chest pain radiating to the back or with acute abdominal pain radiating to the back. With this scenario, think about acute thoracic dissection and abdominal dissection, respectively. These are tears in the inner wall of the aorta.
Here are some key points about aortic dissection:
On physical examination, if you find a difference in the blood pressure between the arms, think about a thoracic dissection. Also check the pulses in both feet, because these can be affected if someone has an abdominal dissection.
The diagnosis is best confirmed by a CT scan of the thorax or abdomen with IV contrast. If dye can’t be given, then the next best test is a transesophageal echocardiogram (TEE). A plain chest radiograph isn’t specific enough.
Treatment depends on whether you’re dealing with a Type A or Type B dissection. The Type A dissection indicates a more proximal tear and is treated with surgery. The Type B dissection (anatomically occurring distal to the left subclavian artery) is treated medically.
The medical treatment for acute aortic dissection is the abrupt lowering of blood pressure to 120–130 mmHg systolic. This involves the combination of a potent vasodilator, such as an intravenous calcium channel blocker like nicardipine (Cardene), along with a beta blocker to prevent reflex tachycardia that can make the symptoms worse.
Acute aortic dissection is treated differently from an acute stroke. An acute aortic dissection involves an abrupt lowering of blood pressure. With an acute stroke, you lower blood pressure gradually in order to maintain cerebral perfusion.
It’s recommended that men 65 to 75 years of age who have smoked be screened once for an abdominal aortic aneurysm (AAA) by an abdominal ultrasound.
For the PANCE, you should be familiar with three arterial medical conditions: temporal (giant cell) arteritis, peripheral arterial disease (PAD), and acute arterial occlusion. In each of these conditions, you’re dealing with a problem of arterial patency.
Temporal arteritis (TA) is a rheumatologic condition, an inflammation of the temporal artery. The classic presenting symptoms are a headache and an acute loss of vision. Other associated symptoms can include jaw claudication. Here are three points about temporal arteritis:
Part of the diagnostic workup includes obtaining a sed rate, which is elevated in temporal arteritis.
The diagnosis is confirmed by a temporal artery biopsy. However, because of sampling error (the chance of missing the inflamed area), even if the biopsy is negative, the person gets treated if the symptoms are present.
The treatment is steroids.
A condition that’s closely associated with temporal arteritis is polymyalgia rheumatica (PMR), which is associated with proximal muscle weakness and pain.
Peripheral arterial disease
Peripheral arterial disease (PAD) is very common in the United States. Think about it as it affects the arteries of the lower extremities. A classic presenting symptom is claudication, pain in the legs that occurs with walking and is relieved by rest. For PANCE purposes, know how to evaluate peripheral arterial disease and the options for managing it. Here are some key points:
Risk factors for peripheral arterial disease include diabetes mellitus, hypertension, hyperhomocysteinemia, and high levels of inflammation in the body (an elevated C-reactive protein level). If you find peripheral arterial disease, look for other potential concomitant medical conditions.
The initial finding on physical examination is diminished distal pulses. A good test in a physical examination is the ankle brachial index (ABI). An ABI score of < 0.8 is suggestive of peripheral arterial disease.
An initial screening test for peripheral arterial disease is a Doppler arterial ultrasound of the lower extremity.
The gold standard for the diagnosis of peripheral arterial disease is a contrast arteriogram to evaluate the location and severity of the blockage.
Acute arterial occlusion
An acute arterial occlusion is a surgical emergency. The most common scenario is the acute loss of a pulse in one of the extremities, indicating that something is seriously wrong. This can happen as a result of a vascular event (such as an abdominal aortic dissection) or a hypercoagulable state that can cause an arterial thrombosis (such as antiphospholipid antibody syndrome and/or factor V Leiden mutation that’s homozygous).
Acute arterial occlusion is a surgical emergency. The patient must go to the operating room for an emergent thrombectomy or embolectomy.