Wednesday, January 19, 2011

RBBB in MRCP

RBBB in MRCP

OK, Right bundle branch block ( RBBB) is certainly a favourite ECG finding your consultant would like to show you during grand round.

How to pick up RBBB? It is easy, always look for rsR pattern in lead V1 with prolonged QRS complex ( it can be normal in partial RBBB). Besides that, pick up the slurred S ( wide negative S) wave in V6.

Common question for MRCP exam, the causes for RBBB, just remember a few important causes below,
1) Normal variant
2) Increased  right ventricular pressure,especially in cor pulmonale and sometimes in pulmonary embolism.
3) Congenital heart disease especially atrial septal defect
4) Myocardium ischemia, myocarditis etc.

However, you must not miss Brugada syndrome which has quite similar ECG finding such as RBBB as showed below,

The right bundle branch block pattern seen in patients with this syndrome is not actually right bundle branch block but is a function of the unusual repolarization abnormality. The ECG shows ST-segment elevation in leads V1-V3, and patients are at risk for sudden cardiac death.

Wednesday, January 12, 2011

Whipple's Disease in MRCP

Whipple's Disease in MRCP

Yes, you are right, Whipple's disease is rare but not in your MRCP Part 1 and 2 examination. I myself never diagnosed Whipple's disease before but this illness is ceratinly a all time favourite in MRCP examination.

It is a rare, systemic infectious disease caused by the bacterium Tropheryma whipplei. First described by George Hoyt Whipple in 1907.

It is one of a important diffential diagnosis of malabsorption syndrome and mainly affect the small bowel. It is more common in those with HLA-B27

Although Whipple's disease primary leads to GIT syndrome ( diarrhoe,weight loss) but for MRCP, patients with Whipple's disease is usually illustrated with symptoms of joint pain!

The diagnosis- jejunal biospy with PAS staining.The macrophages stain strongly with PASand contain intracellular bacilli of the bacteria.

Treatment- prolonged antibiotics of penicillin,tetracycline,co-tromoxazole or chrolamphenicol.

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Sunday, January 09, 2011

Iron Deficiency Anemia

Iron Deficiency Anemia


In my last post, I talk about iron metabolism in MRCP, as you all know, iron is an important ingredient in heme synthesis. Therefore iron deficiency leads to anemia ( hypochromic,microcystic anemia) which is a type of anemia manifested by small red cells ( low MCV- mean corpuscular volume) and pale red blood cells ( low MCHC- mean cospuscular hemoglobin concentration).

Iron deficiency is diagnosed by diagnostic tests as a low serum ferritin, a low serum iron level, an elevated serum transferin and a high total iron binding capacity (TIBC).

So what causes iron deficiency anemia- yes, it is mainly due to chronic blood loss and the main cause worldwide is worms infestations! (hookworms, whipworms, roundworms). However, another reason for chronic blood loss is GIT bleeding, therefore, for anyone older than 50 years, always think of the possibility of GIT malignancy!

One thing to take note, Thalassemia minor also has the similar lab results as iron deficiency and you must always consider Thalassemia as your differential diagnosis in iron deficiency anemia!

Tuesday, January 04, 2011

Iron Metabolism for MRCP

Iron Metabolism For MRCP

Iron metabolism is always an interesting topic to discuss in MRCP. It is a very important topic to know in depth as well if you are preparing for MRCP Part 1 and 2.

To make this topic as easy as possible to answer, it is best illustrated as the picture below,


There are a few important fact to remember for MRCP,

1) Majority of iron in our body is contained in heme, which is the oxygen carrying molecules.

2)Some iron is bound as ferritin in cells of liver or hepatocytes. Therefore, high ferritin should also represent higher iron store, however, remember that ferrin is an acute phase protein. It is raised in acute/chronic inflammation.

3)Iron is also stored as a pigment called hemosiderin in an apparently pathologic process.

How about for iron absorption?
You can remember this process by the following picture,




A few important facts to remember,
1) Iron absorption occurs predominantly in the duodenum and upper jejunum.
2) Iron is best absorped in the form of heme and then Fe2+, therefore agents such as Vitamin C than can reduce Fe3+ to Fe2+ increases iron absorption.

3) Hepcidin role in iron metabolism is out of topic for MRCP but it is getting momentum in Nephrology field in explaining the reason behind functional iron deficiency.