A review of the recent literature in the area of EKG interpretation has found the reading skills of interns [2], residents [3] and even attending physicians [4] in several specialties including internal medicine [5], family practice [6] and emergency medicine [7] are suboptimal and potentially deleterious to patient care [8]. Furthermore, there are very few studies that have explored ways to improve EKG interpretation skills [9].

Most of these publications present varied time frames and teaching techniques and have had only marginal and non-sustained improvement in interpretation skills. Even studies that have looked into the addition of computer generated diagnosis and neural networks [10] have shown no improvement [11], minor improvement [12] and in some cases worsening [13] in diagnostic accuracy. Furthermore, the outcomes in these studies are not standardized and their results are difficult to implement [14].

The most current and exhaustive review on the subject states that there is no current evidence based criteria that improves and maintains EKG interpretation skills [15] and that further research is needed to clarify and improve the currently available methods [16], or devise a new method.

Traditional medical teaching aims to teach students by explaining the underlying mechanisms of disease through basic science learning, followed by disease categories and finally attempts to bring the learning together by demonstrating these mechanisms in patients [17]. Alternatively, problem based learning (PBL) aims to teach the basic and clinical concepts of disease through the course of solving a clinical problem [18]. Interestingly, neither method has been shown to improve the educational performance or EKG interpretation skills. It has been suggested that this is due to a lack of deeper understanding of the material presented and hence the prerequisite for successful transfer of medical information to relevant conceptual knowledge may be missing [19].

We have developed a puzzle (patent pending MSU ID 07-120) that attempts to improve the students overall understanding of the EKG and subsequently improve their interpretation skills. This tool is devised to encourage deductive reasoning and critical thinking instead of passive memorization of the material. The aim of the puzzle is to make the students active learners, and utilize their skills outside of the classroom to complement their knowledge base.

Similar approaches, such as card games [20] and simulations [21], have been shown to enhance students' level of understanding and ability to apply and synthesize material. This kind of self directed learning encourages the development of individualized and deeper understanding, and may produce physicians better prepared for lifelong education. PBL is a very popular instructional strategy and is particularly suitable for professional education [22]. PBL exploit the merits of learner centered approach, and promotes deep, rather than surface learning [22,23]. The traditional teaching approach is perceived as stressful by many students, and there is a need for novel methods to be used to encourage interactive teaching [23,24]. Moreover, doctors with greater stress and emotional exhaustion during training have shown to be more disorganized in their approach in their practice, less satisfied with medicine as a career, and perceive their workplace climate as stressful environment with high workload [24].

The average improvement after the traditional session followed up with a puzzle session was 2.53 ± 1.94 while the average improvement after the puzzle session was followed with the traditional session was 2.08 ± 1.73 (p = 0.67) (figure ​(figure3).3). The average final score after the full rotation and both teaching techniques was 6.54 ± 1.69.

There were five (55%) students that had an average score of less than five after the traditional teaching sessions. These students subsequently had an average improvement of 3.64 ± 1.03 after the puzzle session and their mean scores were not significantly different from those students that had an average score of greater than five after the traditional teaching. Three (50%) students had an average score less than 5 after their initial puzzle sessions and their scores improved after the traditional session by an average of 3.01 ± 1.48 (p = 0.28).

After just the traditional teaching, 3/9 (33%) were able to identify normal sinus rhythm, 1/9 (11%) atrial fibrillation and 4/9 (44%) acute myocardial infarction, while after just the puzzle teaching 2/6 (33%) were able to identify normal sinus rhythm, 2/6 (33%) atrial fibrillation and 3/6 (50%) acute myocardial infarction. At the final test examination after both sessions, 78% (11/14) of students were able to correctly identify normal sinus rhythm, 57% (8/14) were able to correctly identify left bundle branch block, 64% (9/14) acute myocardial infarction and 57% (8/14) atrial flutter (table ​(table22).

All students considered the traditional session's time well spent while 69% had the same opinion of the puzzle teaching. Furthermore, 46% considered the traditional method stressful while only 17% shared that opinion of the puzzle sessions. There was no difference in scores after the traditional sessions in those that considered the method stressful (4.1 ± 2.79) compared to those that did not (4.05 ± 1.1) (p = 0.48) or in those that considered the puzzle session stressful (4.7 ± 4.24) and those that did not (3.7 ± 1.68) (p = 0.39).

In this population of medical students, we did not detect any statistical improvement in EKG interpretation skills after either the traditional or the puzzle teaching. When we compared this group of students with a different contemporaneous group of students the scores were also comparable. However, a statistically significant difference would be difficult to find in light of the small sample size.

The puzzle sessions was helpful in the subgroup of students that did poorly after the traditional teaching showing an average improvement of 3.64 ± 1.03. This group included approximately half of the student population that was initially exposed to traditional teaching and potentially included students that did not recognize EKG patterns as easily as their colleagues but were able to obtain a correct EKG diagnosis through other mental mechanism. Unfortunately, we were not able to identify this subgroup of students by their perceived level of stress.

PBL [25] and self directed learning [26] have both been shown to improve outcomes in different teaching environments. The puzzle sessions incorporated several key points from these theories including letting the students take the initiative in the learning process, permitting the student to identify his and her own weaknesses, and permitting the individual to identify the diagnostic problem and look for an appropriate solution (or piece). We believe that part of the improvements seen in these cases were due to the application of these theories in a practical environment [23]. Clearly, more research on a larger scale is required to further investigate these links and potential benefits.

The students that scored poorly after the puzzle session showed improvement after the traditional teaching, but they did not reach the same level of competency in comparison to the other students (5.8 vs. 7.35). This suggests that the students who underwent puzzle sessions first set their own learning goals, and generated a challenging educational environment before taking traditional teaching courses. Again, this emphasizes that non-traditional teaching is an effective way of delivering medical education in a coherent way and offers advantages over traditional teaching methods [20,21]. Hence, individualizing EKG teaching with various methods available to the teacher may result in improved EKG interpretation skills.

All students thought that the traditional teaching method was useful and that the time well spent, even though it was considered to be stressful by some (46%). The puzzle session was considered useful by a significant number of students (69%) and was widely regarded as less stressful (17%). As pointed out earlier, increased stress level during physicians' training adversely affects their perceived level of job satisfaction and may decrease their capacity for deeper learning and understanding of complex ideas [24]. Thus, the relaxed atmosphere of the puzzle session may have nurtured self directed problem based learning, and potentially improved the interpretation skills.

It has been shown that EKG interpretation accuracy improves with advancing years of training [7] and with further classes and lessons [5] and it is possible that the extra teaching with puzzle played a role in improving the final EKG scores. The puzzle sessions trended towards better initial scores and higher improvement in scores than traditional teaching but no trend proved to be statistically significant.