Thank you to Andrew for presenting the case of an elderly man with recent CVA presenting with progressive encephalopathy 2/2 to VZV encephalitis.
- Acute toxic-metabolic encephalopathy (TME) is an acute condition of global cerebral dysfunction in the absence of primary structural brain disease
- Acyclovir neurotoxicity should be considered with new neurological symptoms or encephalopathy 24 hours initiation of treatment, particularly in the presence of renal impairment.
- Herpes zoster encephalitis (HZE) is an uncommon complication of herpes zoster with immunosuppression (HIV, immunosuppressive medications, increasing age) being the principal risk factor for the development of HZE.
- Localized zoster can cause CSF pleocytosis and positive VZV PCR despite lack of active CNS infection -> this is b/c neurons are the primary site of latent virus
- In suspected cases of zoster encephalitis send BOTH VZV PCR and Viral anti-body. The presence of one or both is evidence of small-vessel encephalitis due to VZV.
- VZV encephalitis is rare and life-threatening-> Empirical treatment with IV Acyclovir 10-30 mg/kg per day for 10 days is currently recommended, however no RTCs have been performed.
The figure below outlines the disease pathology of VZV infection from primary infection to reactivation. See Dr. Gilden’s (a leader in the study of VZV) for an excellent review of VZV in the NEJM – “Neurologic Complications of the Reactivation of Varicella-Zoster Virus.”
Filed under: General Internal Medicine
, Infectious Disease
, Morning Report
Thanks you, Arvind, for presenting a case of an older man with exercise-induced bradycardia found to have complete heart block 2/2 to cardiac sarcoidosis.
- In the consideration of bradycardia, one must first rule out MI. 15% of patients with an MI will present with complete heart block.
- Bradycardia in an inferior or posterior MI is driven by 1) ischemia AND 2) the Bezold-Jarisch Reflex. This is a cardiovascular decompressor reflex involving a marked increase in vagal (parasympathetic) efferent discharge to the heart, elicited by stimulation of chemoreceptors, primarily in the left ventricle.
- Complete AV dissociation with Ps faster than SLOW QRSs suggests complete heart block.
Etiology of Bradycardia
- Healthy children/adults during sleep (HRs in 30s, pauses up to 2 seconds may occur)
- Well-conditioned athletes
- Some elderly patients
An easy way to break down bradycardia is into extrinsic vs intrinsic causes.
- Idiopathic degenerative d/o
- Ischemia (ACS or chronic)
- Lyme disease
- Viral myocarditis
- Drugs – antiarrhythmics, b-blocker, calcium channel blocker
- Vagal tone
Evaluation of Patient with Complete Heart Block
- Rule out Ischemia – ~15% of patient with an acute MI will have complete heart block (usually RCA)
- Check for systemic, reversible causes of heart block:
- Meds: Digoxin, beta-blockers, calcium channel blockers, or anti-arrhythmics
- Electrolyte abnormalities – hypokalemia
3. Look for the primary cardiac causes in 3 broad categories:
- Infiltrative: Amyloidosis, hemochromatosis, sarcoidosis
- Inflammatory: SLE, scleroderma
- Infectious: Rheumatic fever, Chagas, endocarditis, viral myocarditis,i syphilis, Lyme disease
Diagnostic Criteria for Cardiac Sarcoid
Here is a great JACC review on cardiac Sarcoidosis – http://www.onlinejacc.org/content/68/4/411
Filed under: Cardiovascular Medicine
, Morning Report
Thank you to Ashley S.M. for presenting a really fascinating case from the ICU. We talked about a middle aged man with HIV/AIDS off ARVS, who presented with DOE, found to have multiple atrial masses and tamponade, ultimately d/t an infiltrative cardiac lymphoma (path pending).
We talked about this case at two reports, so here are the combo of learning points!
Approach to Atrial Masses
Masses in the heart can have hemodynamically significant effects on circulation, valve function, and risk for embolization.
Ask yourself 1) is this a real mass or is it actually just a clot? 2) if a mass, is it benign or malignant? 3) for malignant masses, consider both primary neoplasm and metastatic disease. Overall, the most common cause of an atrial mass is a benign atrial myxoma. See the attached table below, but important malignant causes to consider are sarcoma, lymphoma and metastatic tumors. Given his HIV/AIDS, our infectious differential also included
- Infective endocarditis with large valvular veg or very large perivalvular abscess
- TB endocarditis (usually more pericardial involvement)
- Endemic fungal disease: especially in CA, consider cocci for cardiac involvement
HIV associated malignancies: Monica Gandhi helped share a useful framework about thinking about the three main oncogenic viruses that cause malignancy in pts with HIV. For all of these malignancies, also critically important to start ARVs right away!
- Cervical / anal / head and neck squamous cell cancers: HIV infected patients are less able to clear oncogenic strains of HPV. The incidence of cervical dyplasia (CIN) in patients with HIV is 4-5x higher than in patients without HIV.
- EBV : highly associated with Burkitt’s and DLBLC. Remember that these lymphomas can be exquisitiely responsive to chemotherapy so it is important to start treatment right away.
- Kaposis Sarcoma
- Castlemans disease (multicentric form)
- Primary Effusion Lymphoma
Burke A, Jeudy J, Virmani R. Cardiac tumours: an update. Heart 2008;94:117-123. http://heart.bmj.com/content/heartjnl/94/1/117.full.pdf
Filed under: Morning Report