Show notes
CardioNerds (Amit Goyal & Daniel Ambinder) join University of Florida cardiology fellows (Ashley Mohadjer, Hussain Khalid, and Morgan Randall) for an authentic Gainesville-style tailgate! They discuss a fascinating case of severe peripheral artery disease (PAD) and cerebral hyperperfusion syndrome. Dr. Khanjan Shah provides the E-CPR and a message for applicants. Episode notes were developed by Johns Hopkins internal medicine resident Richard Ferraro with mentorship from University of Maryland cardiology fellow Karan Desai.
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Episode graphic by Dr. Carine Hamo
The CardioNerds Cardiology Case Reports series shines light on the hidden curriculum of medical storytelling. We learn together while discussing fascinating cases in this fun, engaging, and educational format. Each episode ends with an “Expert CardioNerd Perspectives & Review” (E-CPR) for a nuanced teaching from a content expert. We truly believe that hearing about a patient is the singular theme that unifies everyone at every level, from the student to the professor emeritus.
We are teaming up with the ACC FIT Section to use the #CNCR episodes to showcase CV education across the country in the era of virtual recruitment. As part of the recruitment series, each episode features fellows from a given program discussing and teaching about an interesting case as well as sharing what makes their hearts flutter about their fellowship training. The case discussion is followed by both an E-CPR segment and a message from the program director.
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Patient Summary
A woman in her 60s with a past medical history of type 2 diabetes, hypertension, and hypothyroidism presented to the University of Florida with a chief complaint of "Someone told me my neck artery was blocked." Someone call 227-346-6373. What does that spell? CardioNerd!
She noted exertional pain in both legs with limited exertion. Has a family history of CAD and MI in her father in his 20s. Her only medications were baby aspirin, atorvastatin 80mg, and thyroid replacement. Her blood pressures were noted to be dropping and so her regimen was being titrated off as a result. Physical exam was notable only for poorly palpable pulses in all extremities. To further work this up, a myocardial perfusion scan, CTA head/neck/abdomen, and ABIs were ordered. ABI on the right was 0.86 and on the left was 0.76 with monophasic doppler waveforms throughout. CT abdomen exhibited an occlusion of the abdominal aorta from just below the renal arteries extending to the common iliac arteries with distal reconstitution. CT head/neck showed occlusion of the right carotid artery, complete occlusion of the right innominate artery, near complete occlusion of the right vertebral artery, and delayed flow in the right posterior cerebral artery. On the left side, she had high-grade subclavian stenosis. Myocardial perfusion imaging exhibited no defects.
On subsequent visits her exercise tolerance improved with an exercise regimen, but blood pressures were more and more difficult to obtain. As a result, revascularization was pursued with stenting of the left subclavian artery. She was discharged, but returned a few hours later with severe left sided pulsatile headache and nausea/vomiting. She was admitted for monitoring, but fortunately improved and discharged with close outpatient follow-up. She continued to improve in the outpatient setting. After MRI brain and extensive work-up, she was deemed to have cerebral hyperperfusion syndrome following revascularization. She had no further complications and was monitored thereafter. Final diagnosis: severe peripheral artery disease (PAD) and cerebral hyperperfusion syndrome.
Case Media
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A: ECG B: ABIsC: CT Angiogram D: CT Angiogram - head and neck E: Pre and post subclavian stentinng F: CT head and neck - follow up
Subclavian via L radial
Aortic Root Cine 1
Aortic Root Cine 2
Stent
Post Stent
Post Stent 2
Post Stent 3
Episode Schematics & Teaching
Click to enlarge!
The CardioNerds 5! – 5 major takeaways from the #CNCR case
What are the risk factors and prevalence of PAD? PAD refers to atherosclerotic peripheral artery disease, and is the accumulation of plaque in various peripheral arterial beds akin to CAD involving coronary arteries. 6% of adults over the age of 40 have PAD, and 30% of American adults over the age of 70. This all leads to an annual healthcare expenditure in the US of ~$4 billion! PAD is associated with a 3-4x increased risk of cardiovascular events. Furthermore, mortality overall is 15-20% at 5 years in patients with PAD. Risk factors for PAD include all the risk factors for ASCVD we consider for CAD, including diabetes, hypertension, and hyperlipidemia.
What Should We Look for on Physical Exam with PAD? Get a brachial blood pressure (Class Ib AHA/ACC Recommendation), listen for bruits (areas of turbulent flow), and look at the extremities for: skin color changes, temperatures changes, loss of hair, or ulcerations (typically at the tips of digits). In patients with claudication and/or risk factors for PAD, these can all be signs of PAD. In particular, palpate the dorsalis pedis and tibialis pulses. In office maneuvers can also include Buerger's test where the affected limb is elevated from a supine position till pallor is observed. In a normal limb, even elevating to 90 degrees should not elicit pallor; however, in an ischemic limb, especially severe ischemia, elevation to even 20 degrees for 30 to 60 seconds can lead to pallor. Then when returning the limb to resting position, the pink color will return slowly (I.e., 20 seconds) and may demonstrate rubor as there is reactive hyperemia (dilation of the arterioles) in attempt to remove metabolic waste and restore circulation. At the bedside, we should also test for diseases commonly associated with PAD, particularly diabetes. Testing for diabetic neuropathy is critical in patients with PAD, as it is a modifiable risk factor and can make patients prone to developing diabetic foot ulcers. Remember, that there are classic locations for arterial ulcers but often patients have a mixed picture given concomitant venous insufficiency and/or diabetes. These arterial ulcers tend to occur where arteries terminate, including between the digits and tips of the toes. Furthermore, they can occur at areas of increased pressure, including the lateral malleolus.
How do we obtain and interpret ABIs in chronic limb ischemia? ABI stands for Ankle-Branchial Index. This means taking the ankle blood pressure and indexing it against the brachial blood pressure. The ABI is an easily done test. To ensure we have an accurate ABI, we typically ask the patient to rest for at least 5-10 minutes prior to measuring ankle pressure. We also want to make sure we have the appropriate cuff size, and thus in the limbs the cuff width should be at least 40% of the limb circumference. We can start by taking the brachial pressure in one arm. After obtaining our initial brachial SBP, we then proceed with taking a blood pressure from either the dorsalis pedis or posterior tibial artery on the same side, with the cuff just above the ankle. We utilize a continuous wave doppler signal to identify the pulse and insufflate the cuff to just above where the Doppler signal disappears. We then slowly release the pressure in the cuff and record where the systolic pressure returns and repeat the process for the artery (e.g., DP or PT) that was not tested and then move onto to the contralateral limb. We then finally obtain the SBP in the brachial on the side opposite from where we started. The ABI for a specific extremity is then the highest pressure in a lower extremity limb (DP or PT) divided by the highest systolic brachial pressure in either limb. As discussed above, we usually calculate the ABI at bedside using a continuous-wave doppler probe, but when blood pressures are low or if there is significant venous congestion leading to pulsatile flow (e.g., congestive heart failure), the venous signal can be difficult to distinguish from the arterial signal. Briefly, a normal ABI is considered 1.0 to 1.4; 0.91 to 0.99 is considered borderline; and 1.4 are considered abnormal. In patients with symptoms of PAD (e.g., claudication), ABI has a sensitivity of ~ 95% and specificity of 100% of diagnosing lesions with 50% stenosis in one or major lower extremity vessels. An ABI 1.4 suggests the presence of calcified vessels and we need additional vascular studies, such as measurement of the toe brachial index (TBI) or pulse volume recordings (PVR) to assess for significant PAD. The vessels in the toe have been shown to be less prone to medial calcification. Finally, segmental brachial index measurements are also considered abnormal if there is a decrease in 20 mmHg or more between adjacent levels in the lower extremity, a decrease in segmental brachial index of 0.15 or more over time, or a difference in systolic pressure more than 30 mmHg between contralateral limbs.
How Do We Treat Symptomatic PAD? Exercise! First and foremost, supervised treadmill exercise training is a Class Ia recommendation from the AHA/ACC guidelines. Multiple studies have shown exercise to be beneficial in improving time and distance to developing claudication symptoms and increasing pain-free walking distance up to 180%. Notably, an exercise trial is recommended prior to any attempted revascularization. As with CAD, lifestyle measures to mitigate ASCVD risk factors are vital, including diet, weight loss,