The aim of this study was to assess the contents of medical textbooks, eMedicine (Medscape) topics, and YouTube videos on cardiovascular mechanisms. Medical textbooks, eMedicine articles, and YouTube were searched for cardiovascular mechanisms. Using appraisal forms, copies of these resources and videos were evaluated independently by three assessors. Most textbooks were brief in explaining mechanisms. Although the overall average percentage committed to cardiovascular mechanisms in physiology textbooks (n = 7) was 16.1% and pathology textbooks (n = 4) was 17.5%, there was less emphasis on mechanisms in most internal medicine textbooks (n = 6), with a total average of 6.9%. In addition, flow diagrams explaining mechanisms were lacking. However, eMedicine topics (n = 48) discussed mechanisms adequately in 22.9% (11 of 48) topics, and the percentage of content allocated to cardiovascular mechanisms was higher (15.8%, 46.2 of 292) compared with that of any internal medicine textbooks. Only 29 YouTube videos fulfilled the inclusion criteria. Of these, 16 YouTube were educationally useful, scoring 14.1 ± 0.5 (mean ± SD). The remaining 13 videos were not educationally useful, scoring 6.1 ± 1.7. The concordance between the assessors on applying the criteria measured by ? score was in the range of 0.55--0.96. In conclusion, despite the importance of mechanisms, most textbooks and YouTube videos were deficient in cardiovascular mechanisms. eMedicine topics discussed cardiovascular mechanisms for some diseases, but there were no flow diagrams or multimedia explaining mechanisms. These deficiencies in learning resources could add to the challenges faced by students in understanding cardiovascular mechanisms.