EKG/ECG instruction is a mixed-bag nationwide. Every physician is supposed to know how to read an EKG, though for many students, EKG interpretation is a skill one is supposed to somehow pick up naturally (magically) on the wards. No one seems as confident in their abilities as they’d like. And while EKG machines themselves can and do identify many abnormalities, part of the challenge of real life is to know when to ignore the machine reading.

There is a basic subset of foundational EKG knowledge that (second or) third-year medical students should acquire, and many of the resources below will easily get you there. Also note that a strong background in cardiology informs your knowledge of EKGs and vice versa.

When it comes time to learn, do the following three things:

1. Pick a source and read it thoroughly
2. Pick a system/routine of interpretation (your source should detail) and stick to it. Use it every time until it becomes natural.
3. Do examples. Do more examples. Wait until you’re feeling rusty and do some examples again.

If you’re looking for dead trees to hold, then these are the two entry-level EKG texts I recommend:

The most famous and popular EKG book around is hands down Dale Dubin’s Rapid Interpretation of EKG’s (often just called Dubin’s for short). The early portions utilize the same “programmed” learning as Felson’s, which is both effective and makes you feel like a child. Unfortunately, Dr. Dubin has also spent time in jail for making and owning child pornography, so let that information color your reading accordingly. His quite good 14-page summary (taken from the book) is also available for free online and in many ways is all you need to learn the basics or freshen up, depending on your background and the demands of your coursework. Dubin’s website itself also has some good information, but it’s very poorly designed.

Another one stop shop for basic EKG for medical students and non-cardiology-bound residents is The Only EKG Book You’ll Ever Need, which is more of a traditional text, extremely readable, and surprisingly quick. I personally prefer it to Dubin, though Dubin’s is absolutely the more popular of the two.

Your school library will probably have copies of both, but Dubin was always a bit hard to get a hold of at ours.

If you don’t mind the screen, then you can probably get away with a subset of these free resources:

ECGWaves has a free e-book and online course.

Learntheheart.com has what amounts to a complete standalone EKG online coursebook, which is broken down into the basic, topic review, cases, quizzes, and tons of example EKG tracings. The design could use a refresh, but the content is stellar and could easily replace a purchase. There’s also a lengthy review of cardiology.

The University of Utah runs an ECG Learning Center, which includes an “Outline” which is pretty good and also available as a free 88-page pdf.

The University of Wisconsin also has an online ECG course, though I’d say it’s not quite as good as Learn the Heart’s.

ECG Teacher has nice video tutorials: well-produced content, clear illustrations, good sound quality. Probably better than you’ll receive in the classroom.

ECG Made Simple requires a simple free registration but is quite good once past that hurdle. Lots of tutorials (including videos, for those so inclined)

SkillStat has a what seems like most of their The Six Second ECG Workbook available as free pdf chapters online from their website, which would make a nice addition to your iPad or other electronic reading device. They also have a nifty EKG simulator/generator for review and for testing. Either the software generates a tracing for the rhythm you select, or it generates a tracing and you identify it. Sorta fun. For those with ACLS on the horizon, it also has a nice little ACLS testing tool.

Quick ECG highlights and plenty of samples can be out at Online ECG Interpretation for Emergency Physicians (thanks, Paul).

If you’re still looking for some more sample tracings, then look no further than EKG’s for EM Physicians, which has 100 tracings with answers in addition to a succinct “How to read an EKG” section. ECG Wave Maven is a massive collection of cases. ECG library also has a good collection of tracings, though the picture quality leaves something to be desired.

Whether to help yourself or your classmates practice, produce learning materials for your students, make money, or perhaps to create a large free question bank the likes of which have never been seen, knowing how to write a USMLE-style board may be a skill you’re interested in cultivating.

In fact, even for students who only plan to take—not write—the USMLE, understanding the qualities of a Step question may help one understand how to approach (and hopefully guess/answer correctly) the ones on the actual exams.

The NBME actually has an extremely detailed Item Writing Manual (181 pages!). It’s quite long (but full of lots of examples), so I’ve compiled some highlights below. (more…)

If I could go back to the first two years of medical school, I would buy USMLE World and make it an integral part of my longitudinal studying. The more I look back, the more I believe that doing questions as a primary learning activity formed the basis of the vast majority of my medical knowledge (Wikipedia probably filled in the rest).

Studying for Step 1 isn’t something you do for a month or two at the end of your second year; it’s actually a great way to learn the basic sciences for the first time as well. But for those looking online for additional sources to get you through your first two years (and sometimes you just need to read), the following is a compilation of free online resources for studying the basic sciences in medical school, including lectures and question banks.

Anatomy & physiology

SUNY downstate has a virtual anatomy practical, which is an excellent accompaniment to hours in the cadaver lab and Rohen’s. It also has a virtual dissection section, but the software/organization is a bit tedious. The University of Utah has a great neuroanatomy online anatomy section (as well as anatomy, pathology, and more).

Michael Anson has a Creative Commons-licensed question book that is freely downloadable online and contains more than 3600 questions in anatomy and physiology. The book is written in a fill in the blank style much to aid in fast memorization, much like Felson’s and Dubin’s.

Wikibooks has a free textbook, Human Physiology, which is actually pretty good. It’s nice to have a second easily-accessible resource online sometimes.

Biochemistry

The Medical Biochemistry Page is a nice little (but still dense) online text-book of clinical biochemistry. If your lecture slides are poor or your instructor doesn’t speak English (or both), you might supplement with these quick articles.

Histology

Histology World – an exhaustive and multi-sensory histology learning site, including pictures, audio, games, and quizzes. If you can ignore the mid-1990s’ site design, there’s a lot to learn.

Blue Histology also has images and great quizzes.

BU’s Histology Learning System is also beloved and has images that you can click to label/unlabel to learn your stuff.

The University of Michigan has what amounts to an entire histology course available online. The quality is excellent.

Temple has a nice collection of labelled histology and imaging slides to help learn neuroanatomy. UCSD medpics has even more.

Microbiology

Todar’s Online Textbook of Bacteriology is excellent. It just is. No fungi, parasites, or viruses though.

The University of South Carolina School of Medicine has an online microbio textbook that includes immunology, bacteriology, parasitology, virology, and mycology. You can use the site (it even has a stripped formatting version for mobile devices) or download pdf/ppt files.

Baron’s Medical Microbiology (4th ed) is also available online for free from the NCBI. It’s a real, thick textbook and best used as a resource PRN.

Medfools has high-yield microbiology charts for bacterial, fungal, and parasitic pathology. The series is only missing viruses. Many of your classmates will spend oodles of time making their own, but these are probably better (if you’re the kind of person who can stomach endless rows of microbiology crammed as tight as possible).

The Merck Manual of Infectious Disease is well-organized and concise.

Pathology

UPMC has a nice collection of pathology cases—these are extremely academic in nature and very dense, not for the feint of heart. (The Robbins casebook is a far easier way to learn high-yield pathology for board purposes).

Genetics

Some free online questions from Utah here are a nice self-assessment.

Pharmacology

Tulane has some nice interactive/instructional pharmacology quizzes organized by body system/use.

Multidisciplinary

MedMaster has learning tools for USMLE Step 1 and Step 2, a nice Atlas of Microbiology, and several other free downloads.

The University of Utah has a massive online resource that includes cross-sectional anatomy, neuroanatomy, pathology, and histology images, in addition to a large pathology question bank (in board-style format).

For the second-year clinical sciences (and beyond), The Merck Manual has great, well-organized and concise content on nearly all high-yield topics. MEDSKL is a growing site filled with polished & painless basic clinical medicine lectures.

You can find my recommendations for basic science textbooks and the preclinical NBME shelf exams here. My list of free online Step 1 questions is here.

The old adage has been two months for Step 1, two weeks for Step 2, #2 pencil for Step 3. In reality, it’s probably more like two months for Step 1, 1 month for Step 2, and two weeks for Step 3. But if you are worried about getting that competitive cardiology fellowship, it’s hard to nurse the popular opinion that Step 3 is $815 pass/fail two-day pain-fest that you can simply walk in and take. That said, if you comfortably passed Step 1 and Step 2 and it hasn’t been years and years, you will pass Step 3 with nominal preparation outside of familiarizing yourself with the CCS software and the official sample cases. Step 3 is a normalized test, and because all residents put less effort into studying, you simply need to do less work to achieve the same score. I’d recommend taking it during your intern year, because the relatively fresh Step skills and knowledge from Step 2 CK are more important than the clinical acumen you will gain during residency.

Last updated: 12/31/2015

Your resources

A busy intern doesn’t have much time (or desire) to comb through any review book. If you only plan to dedicate 2-4 weeks part-time studying (which is typical), then all you really have time for is USMLEWorld. The question bank itself is around 1567 questions with 51 CCS cases. Forgo the books. Do the UW qbank and definitely do the CCS cases, and you might have time to go through the questions you’ve marked/gotten wrong a second time. Besides, UW now has an iOS app so you can do questions while your attending prattles on rounds. The questions are still hard and the test itself still feels awful, but because everyone studies less for Step 3, you’re likely to perform similarly to Step 1/2CK with only a fraction of the work. (The caveat is that if you struggled to pass Step 1/2CK, then you need to take this test seriously [of course].) If you still need or want more questions, BoardVitals is a common choice, and you can get 10% off if you’re interested by using code BW10.

Don’t forget to download the official USMLE Step 3 practice materials here, which contain the official software, some sample questions, and six CCS cases (which are a must do). If you don’t bother going through lots of example cases, at least do the six free cases to become intimate with the software.

If you have the time and desire to do a slow-burn and read actual books, you can (but probably shouldn’t/won’t). However, know that none of the entries from the classic series are really as good as their previous Step counterparts.

Crush Step 3 is the fastest, but it’s skeletal and fulls of holes as always. It’s definitely the only book that’s fast enough to blaze through. First Aid was recently updated and likely less out of date; it’s still that densely-packed outline format, which is less high yield and more difficult to get through than it used to be. Master the Boards USMLE Step 3 is probably the best “complete” book on a time and mental energy budget, but there’s still no way most interns will bother getting through it. USMLE Step 3 Triage is more targeted/high yield than First Aid, very readable and well-organized, with a nice conversational tone and a nice free companion website with practice questions [link dead] that anyone can use; unfortunately, it was last updated in 2008. You can also find some free questions on the Archer USMLE site.

As always, questions are most important, and UW is indispensable. Never use a book in place of questions. If you’ve spent a few days on a medicine service, an ER, done any general surgery, played with kids, or avoided poisoning a developing fetus, then your clinical experience will serve you well. But you don’t really need it—as always, this is a test. It tests your ability to take a test, not to be a physician.

A few words about the CCS (Computer-based Case Simulations)

Typically getting the diagnosis and the primary treatment are pretty straightforward. The finesse comes from two skills:

1. Get the diagnosis and management done quickly and efficiently. Do only the focused physical in an emergency.  Don’t order and wait for tests that delay proper management. The amount of virtual time that passes prior to certain diagnostic tests or interventions does matter. Don’t just be thorough when “time” doesn’t allow for it.
2. Know the related but fundamental orders. Using CCS is awkward. You have to order “patient counseling” and other things that you would simply do in real life. You also need to remember to follow up labs and the like. If you start methotrexate, you need to order a follow-up CBC and hepatic function panel.  If you diagnose someone with lupus, they need a renal biopsy. If you give someone a stent, they need clopidogrel. If someone is going to surgery, they should be consented. Statins and LFTs. Pregnancy test before giving teratogens to women. Etc. Keep these sorts of things in mind, and you’ll feel much better as you go through the cases.
3. That said, the little things matter much less than the key management (i.e. appendicitis requires surgery). Like Step 2 CS, you can forget to do a lot of things.

Before you start, it might help you to write out on the test-center sheet the common orders that you would otherwise forget to do so that you can be methodical in your approach (the kinds of things that just happen in the hospital), like starting an IV.

When ordering consults or inputting the primary diagnosis on the final screen, you may ask yourself, “I wonder how this is graded?” Do they have human beings read through more than 25,000 tests to determine if the words deserve credit? Is there an algorithm that checks the text for the presence of the correct words? The answer is neither. This text is not saved as part of the examination, is lost forever in the sands of time, and is in no way used for scoring. Interesting isn’t it? So it makes more sense to use the last two minutes on the final screen of each case to make sure your final orders are as complete as possible rather than making sure you have time to type up the diagnosis.

Recent changes in 2014-15

1. Being able to take the test on two nonconsecutive days is a good thing, both for scheduling flexibility and for test fatigue.
2. I see no reason to be overly concerned about the much-maligned “return of basic sciences.” Content changes for the Step exams have remained minimal for quite some time. It’s not as though the addition of “drug ad” style questions has meaningfully changed the prior Step exams or required a significant shift in study patterns. The basic sciences that will be invoked on this test are unlikely to be of sufficient quantity to matter to most takers and are also likely to be the most relevant or highest-yield bits from the old days—the stuff you are most likely to remember anyway. I personally wouldn’t worry too much.

How do you interpret a shelf exam score? The NBME shelf exams were originally scaled to a mean of 70 and a standard deviation of 8. Keep in mind, this is not recalculated every year. The actual average in a given year has tended to creep up and is usually somewhere in the low-to-mid 70s. Similarly, at its creation, the USMLE average was 200 with a std of 20. Now the average is >220.

It’s tempting to assume that this two-digit score is a “raw” score (i.e. that it represents a percentage of correct answers); it does not. The relationship between raw percentage and the NBME two-digit score is not publicized nor is it released. You will not see it. Your school may be able to ask for this information in order to use it for grading purposes (see this interesting post), but as a student you will never know the calculus.

It’s also sometimes thought to reflect a percentile—it does not. Your score report does indeed have a percentile breakdown for a given score if you read through it (sample). If you want to have a general idea in advance (or for estimating your USMLE percentiles, which are not released), you can always use this handy percentile calculator to see. When your NBME score is >92-93, your percentile is generally greater than 99% (with the exception of the psychiatry shelf, which seems to have a significantly larger number of 90s raw scores). So those individuals who manage to get a 99 on their shelf exams have no way of knowing exactly how much they outperformed their peers, nor is it publicized how much better you have to do in terms of percentage correct in order to get these scores.

It’s also worth noting again that the two-digit NBME score has nothing to do with the two-digit USMLE score, which also has nothing to do with percentiles. In fact, later this year the two-digit USMLE score is going the way of the dodo (good riddance).

The score of 70 +/- 8 is already scaled to approximate a normal distribution (although at the lower margin it’s probably skewed with a left tail).

As always, keep in mind this point that I’ve made previously: not all schools use shelf exams the same way. Though the shelf averages were determined by using first-time test-takers using the NBME exam as a final exam, schools often use the shelf as extra-credit, a pass-fail test, a true graded final exam, or as a yay/nay determinant of honors. Your performance can also hinge a bit depending on what part of the year you take the exam, as scores tend to go up a small amount over the course of the year, presumably due to the accumulation of generally useful clinical knowledge (aka the “there was a lot of medicine on that exam” phenomenon). For this reason, your NBME shelf exam percentile is not as reflective of your performance compared to your peers as it would be for the USMLE exams, when all takers have the same amount of skin in the game.