Pericarditis

At physical exam rounds today, we reviewed Pericarditis.

Clinical presentation: usually a sudden onset of retrosternal chest pain with a pleuritic component to it, often relieved by sitting up. You may hear a pericardial rub - this is classically described as a triphasic high-pitched sound. The 'tri' refers to 1. atrial systole, 2. ventricular systole, and 3. ventricular diastole.

ECG: may show diffuse, concave ST elevations that do not fit any particular vascular territory. PR depression is also seen.

Treatment: In most cases of idiopathic pericarditis, high dose NSAIDS are effective. Steroids and colchicine also may have a role.


Here is a review article on the topic.

Rhabdomolysis

This morning we discussed a case of rhabdomyolysis.

Here is a previous blog post on the topic.

*myoglobinuria

Miller Fisher Syndrome

Guillain-Barré syndrome (GBS) is an immune-mediated polyneuropathy characterized classically by ascending weakness and absent reflexes. GBS is a heterogeneous disease with several variants. Miller Fisher Syndrome (MFS) is a variant that presents with opthalmoplegia, ataxia and areflexia.

In patients with GBS, CSF has elevated protein and normal WBC. In about 85% of patients with MFS antibodies against GQ1b (a ganglioside component of nerve) is positive, though this testing is not routinely performed.

Here is review of Guillain-Barre Syndrome.

* Dr. C. Miller Fisher, Canadian neurologist who first described the MFS variant of GBS in 1956. He was a stroke neurologist who contributed greatly to our understanding of lacunar stroke, and strokes related to atrial fibrillation.

SSRI and SIADH

This morning we talked about the association between SSRIs and SIADH.

The article we talked about was a review, by Dr. Liu, of case reports involving various SSRIs and hyponatremia. This study found that the majority (83%) of patients with this complication were over the age of 65. The average time to onset of hyponatremia was 13 days (range 3 to 120 days). This finding has since been confirmed through a prospective study.

Take home message is that elderly patients are at increased risk of hyponatremia associated with SSRIs.

Here is the abstract for the above article.

Here is a great review article about SAIDH.

Mitral Regurgitation

In physical exam rounds yesterday, we examined a patient with mitral regurgitations.
Here is a previous post on Mitral Regurgitation.

*Doppler ultrasound of the heart showing mitral regurgitation: there is abnormal leakage of blood backward (blue is flow away from the probe) through the mitral valve during systole.

Antimitochondrial antibody

Antimitochondrial antibody is present in 95% patients with Primary Billiary Cirrhosis. The antibody assay is 95% sensitive and 98% specific for PBC (except if it's done by indirect immunoflorescence).

There has been suggestion that the presence of antimitochondrial antibodies may predict the eventual development of PBC in asymptomatic people based on a small study. About 13% of first-degree relatives of patients with PBC have circulating antimitochondrial antibodies, suggesting they may be susceptible to developing PBC. The clinical significance of this finding remains to be determined.

Here is a great review on Primary Billiary Cirrhosis.

*Immunofluorescent stain shows antimitochondrial antibodies on a liver biopsy specimen.

Endocarditis

This morning we discussed a case of subacute bacterial endocarditis secondary to Strep viridans.

Here is a previous post on endocarditis with some great review referrences.

* Viridans Streptococcus is a term for a large group of commensal streptococcal bacteria that are either α-hemolytic, producing a green coloration on blood agar plates (hence the name "viridans", from Latin "vĭrĭdis", green), or nonhemolytic.

Hypertension

This morning we discussed a case of Hypertensive Emergency.

Here is a previous post on this topic.

* William Harvey (1578–1657)the first physician who described the systemic circulation of blood being pumped around the body by the heart in his book "De motu cordis" which became the basis for our current understanding of hypertension.

Hypophosphatemia

Hypophosphatemia is secondary to decreased intestinal absorption (such as in Vit D deficiency), increased urinary excretion (such as in hyperparathyroidism), or shift into the cells (such as in refeeding syndrome).

Symptomatic hypophosphatemia occur when serum phosphate concentration reaches 0.64 mmol/L. Worrisome symptoms of hypophosphatemia are related to ATP depletion, causing metabolic encephalopathy, impaired myocardial contractility, respiratory failure due to weakness of the diaphragm, a proximal myopathy, Rhabdomyolysis, dysphagia, ileus, and hematologic abnormalities.

Hypophosphatemia should be replaced aggressively even if the patient is not overtly symptomatic, since develop myopathy and weakness.

IV phosphate is potentially dangerous, since it can precipitate with calcium causing hypocalcemia, renal failure due to calcium phosphate precipitation in the kidneys, and possibly fatal arrhythmias. So, if IV therapy is necessary in the patient with severe symptomatic hypophosphatemia, it should be given by slow infusions (over a long period of 4-12hrs).

Paraneoplastic Erythrocytosis

There are 5 types of tumor commonly associated with the overproduction Epo:

1. Hepatocellular carcinoma: Epo elevation doesn’t always cause erythropoiesis because of RBC production inhibition by malignancy.

2. Renal cell carcinoma: In about 1-5% of patients.

3. Hemangioblastoma

4. Pheochromocytoma

5. Uterine myomata: clue will be absence of anemia in patients with menorrhagia. RBC overproduction is reversed following myomectomy.

*Contrast-enhanced MRI image of a patient with Hb=194, showing renal cell carcinoma(arrow).

HIV and Pneumococcal Disease

Although we automatically think about opportunistic and atypical infections in immunocompromised patients, it is important to note that , similar to non-HIV infected patients, Streptococcus pneumoniae, is the most common bacterial pathogens of CAP in patients with HIV.

As was discussed this morning, HIV infection substantially increases the risk of invasive pneumococcal infection, particularly among those patients with a low CD4 count <200, and those not on therapy. This increased risk may be partially explained by the observation that HIV infected individuals have a predisposition for pneumococcal nasopharyngeal colonization.

For this reason, the Centers for Disease Control and Prevention (CDC) recommends that all HIV–infected patients be vaccinated (preferably early in the disease while they still have the ability to mount an effective antibody response).

Here is a review on the topic.

Invasive pneumococcal disease in patients infected with HIV: still a threat in the era of highly active antiretroviral therapy. Jordano et al. Clin Infect Dis.38(11):1623.

* Chest radiograph of an HIV positive individual with a CD4 cell count above 200 cells/mm3, revealing right upper lobe consolidation. Sputum and blood cultures were positive for Streptococcus pneumoniae.

Hypercalcemia associated with Malignancy

We discussed a case of hypercalcemia this morning and reviewed the mechanisms by which malignancy can cause hypercalcemia.

1. Direct metastases to bone: These mets trigger the production of inflammatory cytokines and stimulate ostoclasts. Sometimes osteoclasts are directly stimulated by tumor cells via Osteoclast Activating Factors (eg IL6) in multiple myeloma or lymphoma.

2. PTH related peptide: this is the most common cause of hypercalcemia from non-metastatic solid tumors. Classically in squamous cell lung Ca

3. PTH: this is rare! only a few case reports of PTH being released from tumors

4. Calcitriol: a very common mechanism for hypercalcemia in the lymphomas.

Here is a great review article.
*CT scan of a patient presenting with Ca=3.1, who subsequently was found to hav have small cell lung cancer.