A question from our website

Q. The normal resting membrane potential of ventricular myocardium is

a. 85 to 90 mV
b. -85 to -90 mV
c. 70 to 80 mV
d. -70 to -80 mV
e. -30 to -40 mV





A. b. -85 to -90 mV

The resting membrane potential is corresponds to stage 4 of cardiac myocyte contraction. It is primarily due K+ channels. The resting membrane potential corresponds to diastole in cardiac contraction, and the normal potential is between -85 to -90 mV. When the myocyte is stimulated during the resting membrane potential, it results in influx of Na+ ions and the start of contraction.

As is seen in the above image, the cardiac action potential consists of 5 stage, beginning with phase 4 all the way back to phase 4.

Phase 4 - corresponds to resting membrane potential. K+ channels are open, and an electrolyte balance is achieved to maintain the potential between -85 to -95 mV

Phase 0 - This corresponds to the start of the action potential, and is due to rapid influx of Na+ ions and a rise in membrane potential. In essence, this is the depolarisation phase.

Phase 1 - The Na+ channels close, and the membrane potential reaches a plateau.

Phase 2 - The L-type Ca2+ channels open and calcium influx occurs. Outward movement of K+ starts in this phase.

Phase 3 - The Ca2+ channels close, and K+ efflux continues. This is the relaxation / repolarisation phase of the myocyte action potential.


For more questions like these, including various aspects of Cardiology for the MRCP part 1 exam, go to www.cardio4mrcp.com or click here.

Passing the PACES

Right, once you have passed the written exam, then comes the toughest part of the MRCP - (drumroll!) the PACES. 5 stations, tough clinical cases and some moody examiners! But go in with the right preparation, and you will absolutely wing it! Its really not that hard; just think of it as a ward round  or an on-call shift where you are asked to see complicated and sick patients. Beware however, sometimes you could get a normal case, like I did in my exam 6 years ago. I remember it well - abdominal station, normal abdomen but she was pseudocushingoid. Don't know how, but I got it! Phew!

Well, actually I do know how. Like many of us who passed, we had the right tutors and the right books to prepare. While you may get some old books handed down by registrars to you, just remember that newer editions and new books that emerge have new cases and sometimes provide you with valuable tips on picking up ceratin things. Of course, the whole inspection-palpation-percussion-auscultation rule always applies, but its the little things that these books will help you with.

I have listed a few books below that will no doubt be useful. Once you have these, ensure you have a study partner who will critique you every time you examine a patient. I tell you, it helps.

I have organised the MRCP PACES exam in the past, and I have seen first hand what the examiners can mark you down on, and what you can score full on. Remember the steps in examination and be cool and calm. No patient wants to see a nervous doctor!!

Books to read :

I would strongly recommend these.  Study well and you can score full marks. In my next post, I will be placing a tough clinical scenario that was in the MRCP communication station a few years ago. I look forward to hearing how you will handle it!

Happy reading!

Vik

Welcome!!

Hi there! Thanks for subscribing to cardio4mrcp, your guide to cardiology questions for the MRCP exam. For those of you who have come across this blog while generally browsing the internet, this blog is linked to our exam site www.cardio4mrcp.com. We host around 300 questions for the part 1 MRCP exam, and intend to expand it further in the future. Feel free to snoop around!

We have created this blog to keep you up to date with any new developments in cardiology that are relevant to clinical practice,and in particular, the MRCP exam. Also, we will add new questions, and welcome any sample questions or suggestions you might have. We honestly hope that you will find our website (and this blog!) useful, and look forward to seeing healthy interaction between subscribers.

We are sorry we don't have questions relevant to the part 2 exam at the moment, and will do our best to develop them soon. We also plan to develop a MRCP part 1 and part 2 course in the future, and welcome any suggestions, especially if there is anything you would like covering in more detail for the exam. This would apply to this website as well :-). Drop us an email at cardio4mrcp@gmail.com.

As with any other field in medicine, cardiology is an ever changing science, and new guidelines are being drawn up all the time. We will do our best to ensure that our website as up to date as possible.

We would like to take this opportunity to wish you all the very best not only for the exams, but for also for your future as a doctor!!

Best wishes

Vik
Director, E-medilearn.org Ltd