The ECG Rhythms content is currently under development and is being updated by medical professionals.

Works Cited

  1. Basic principles of electrocardiographic interpretation - sniv3r2.github.io, accessed April 10, 2025, https://sniv3r2.github.io/d/topic.htm?path=basic-principles-of-electrocardiographic-interpretation
  2. Electrocardiogram - StatPearls - NCBI Bookshelf, accessed April 10, 2025, https://www.ncbi.nlm.nih.gov/books/NBK549803/
  3. Medical Device History: Einthoven’s Triangle and the Electrocardiogram, accessed April 10, 2025, https://clearpathmedical.com/medical-device-history-einthovens-triangle-ecg-electrocardiogram-willem-einthoven/
  4. Conquering the ECG - Cardiology Explained - NCBI Bookshelf, accessed April 10, 2025, https://www.ncbi.nlm.nih.gov/books/NBK2214/
  5. Electrocardiography - Wikipedia, accessed April 10, 2025, https://en.wikipedia.org/wiki/Electrocardiography
  6. Electrocardiogram - Physiopedia, accessed April 10, 2025, https://www.physio-pedia.com/Electrocardiogram
  7. Electrocardiogram: MedlinePlus Medical Test, accessed April 10, 2025, https://medlineplus.gov/lab-tests/electrocardiogram/
  8. Electrocardiogram (ECG or EKG) - Mayo Clinic, accessed April 10, 2025, https://www.mayoclinic.org/tests-procedures/ekg/about/pac-20384983
  9. Electrocardiogram | Johns Hopkins Medicine, accessed April 10, 2025, https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/electrocardiogram
  10. Electrocardiogram (EKG or ECG): Test & Results - Cleveland Clinic, accessed April 10, 2025, https://my.clevelandclinic.org/health/diagnostics/16953-electrocardiogram-ekg
  11. Electrocardiogram (EKG) Components and Intervals - MyHealth Alberta, accessed April 10, 2025, https://myhealth.alberta.ca/Health/pages/conditions.aspx?hwid=zm2308
  12. Flashback: The First ECG | Pfizer, accessed April 10, 2025, https://www.pfizer.com/news/articles/flashback_the_first_ecg
  13. 17.4B: Electrocardiogram and Correlation of ECG Waves with Systole - Medicine LibreTexts, accessed April 10, 2025, https://med.libretexts.org/Bookshelves/Anatomy_and_Physiology/Anatomy_and_Physiology_(Boundless)/17%3A_Cardiovascular_System%3A_The_Heart/17.4%3A_Physiology_of_the_Heart/17.4B%3A_Electrocardiogram_and_Correlation_of_ECG_Waves_with_Systole
  14. www.mayoclinic.org, accessed April 10, 2025, https://www.mayoclinic.org/tests-procedures/ekg/about/pac-20384983#:~:text=An%20electrocardiogram%20(ECG%20or%20EKG,which%20prints%20or%20displays%20results.
  15. www.hopkinsmedicine.org, accessed April 10, 2025, https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/electrocardiogram#:~:text=An%20ECG%20records%20these%20impulses,of%20many%20heart%2Drelated%20conditions.
  16. Electrocardiogram (EKG) - American Heart Association, accessed April 10, 2025, https://www.heart.org/en/health-topics/heart-attack/diagnosing-a-heart-attack/electrocardiogram-ecg-or-ekg
  17. ECG test | Better Health Channel, accessed April 10, 2025, https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/ecg-test
  18. Electrocardiogram (ECG) - NHS, accessed April 10, 2025, https://www.nhs.uk/conditions/electrocardiogram/
  19. Normal Electrocardiography (ECG) Intervals - Medscape Reference, accessed April 10, 2025, https://emedicine.medscape.com/article/2172196-overview
  20. Electrocardiogram (EKG or ECG) Tests: Purpose & Types - WebMD, accessed April 10, 2025, https://www.webmd.com/heart-disease/electrocardiogram-ekgs
  21. 10.4: Cardiac Cycle and Electrical Activity - Biology LibreTexts, accessed April 10, 2025, https://bio.libretexts.org/Courses/Cosumnes_River_College/Introductory_Anatomy_and_Physiology_(Aptekar)/10%3A_Cardiovascular_System-_Heart_and_Blood_Vessels/10.04%3A_Cardiac_Cycle_and_Electrical_Activity
  22. History of the Electrocardiogram • LITFL • Medical Eponym Library, accessed April 10, 2025, https://litfl.com/history-of-the-electrocardiogram/
  23. From a laboratory to the wearables: a review on history and evolution of electrocardiogram, accessed April 10, 2025, https://scielo.isciii.es/pdf/ijm/v4n4/2695-5075-ijm-4-4-248.pdf
  24. A brief review: history to understand fundamentals of …, accessed April 10, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC3714093/
  25. A Brief History of Electrocardiography | ECG Core Curriculum - AccessMedicine, accessed April 10, 2025, https://accessmedicine.mhmedical.com/content.aspx?bookid=3339§ionid=277533084
  26. Einthoven’s String Galvanometer: The First Electrocardiograph - PMC, accessed April 10, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC2435435/
  27. Willem Einthoven and the birth of clinical electrocardiography a hundred years ago - PubMed, accessed April 10, 2025, https://pubmed.ncbi.nlm.nih.gov/12766530/
  28. The Interesting History of EKGs - NHA, accessed April 10, 2025, https://info.nhanow.com/blog/the-interesting-history-of-ekgs
  29. Willem Einthoven - Magnet Academy - National MagLab, accessed April 10, 2025, https://nationalmaglab.org/magnet-academy/history-of-electricity-magnetism/pioneers/willem-einthoven/
  30. Willem Einthoven • LITFL • Medical Eponym Library, accessed April 10, 2025, https://litfl.com/willem-einthoven/
  31. Willem Einthoven - Wikipedia, accessed April 10, 2025, https://en.wikipedia.org/wiki/Willem_Einthoven
  32. Willem Einthoven | Biography, Electrocardiogram & Nobel Prize - Britannica, accessed April 10, 2025, https://www.britannica.com/biography/Willem-Einthoven
  33. Willem Einthoven - Lemelson-MIT, accessed April 10, 2025, https://lemelson.mit.edu/resources/willem-einthoven
  34. Willem Einthoven – Facts - NobelPrize.org, accessed April 10, 2025, https://www.nobelprize.org/prizes/medicine/1924/einthoven/facts/
  35. A history of the origin, evolution, and impact of electrocardiography - PubMed, accessed April 10, 2025, https://pubmed.ncbi.nlm.nih.gov/8184849/
  36. NIHF Inductee Willem Einthoven Invented the Electrocardiogram, accessed April 10, 2025, https://www.invent.org/inductees/willem-einthoven
  37. pmc.ncbi.nlm.nih.gov, accessed April 10, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC3714093/#:~:text=The%20term%20’electrocardiogram’%20used%20to,device%20weighed%20600%20pounds%20(Fig.
  38. The Electrocardiogram at 100 Years: History and Future | Circulation, accessed April 10, 2025, https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.123.065489
  39. Exploring the History of the ECG and Its Influence on Modern …, accessed April 10, 2025, https://www.gehealthcare.com/insights/article/exploring-the-history-of-the-ecg-and-its-influence-on-modern-medicine
  40. A Complete Guide to Einthoven’s Triangle & ECG Testing - Wellnest Tech’s, accessed April 10, 2025, https://www.wellnest.tech/blog/a-complete-guide-to-einthovens-triangle-ecg-testing
  41. 12-Lead ECG Placement: The Ultimate Guide | Cables and Sensors, accessed April 10, 2025, https://www.cablesandsensors.com/pages/12-lead-ecg-placement-guide-with-illustrations
  42. ECG Lead positioning - LITFL, accessed April 10, 2025, https://litfl.com/ecg-lead-positioning/
  43. Electrodes, limb leads, chest (precordial) leads and the 12-Lead ECG – The Cardiovascular - ECG Waves, accessed April 10, 2025, https://ecgwaves.com/topic/ekg-ecg-leads-electrodes-systems-limb-chest-precordial/
  44. The ECG Leads, Polarity and Einthoven’s Triangle - The Student Physiologist, accessed April 10, 2025, https://thephysiologist.org/study-materials/the-ecg-leads-polarity-and-einthovens-triangle/
  45. What are the different types of ECG leads? - Sunfox Technologies, accessed April 10, 2025, https://sunfox.in/blogs/what-are-the-different-types-of-ecg-leads/
  46. ECG Leads - Issuu, accessed April 10, 2025, https://issuu.com/clinical-education/docs/code_stemi_activation_for_paramedics_ebook_v1.1_fp/s/17935178
  47. Introduction. I—Leads, rate, rhythm, and cardiac axis - PMC, accessed April 10, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC1122339/
    1. The Standard 12 Lead ECG - ECG Learning Center - An introduction to clinical electrocardiography, accessed April 10, 2025, https://ecg.utah.edu/lesson/1
  48. Electrocardiogram Leads - Cardiovascular Physiology Concepts, accessed April 10, 2025, https://cvphysiology.com/arrhythmias/a013
  49. Electrocardiogram Chest Leads (Unipolar) - Cardiovascular Physiology Concepts, accessed April 10, 2025, https://cvphysiology.com/arrhythmias/a013c
  50. The Precordial leads - Teaching Medicine, accessed April 10, 2025, https://www.teachingmedicine.com/tutorial/ECG_basics/Precordial_leads
  51. 12 Lead ECG Explained, Animation - YouTube, accessed April 10, 2025, https://www.youtube.com/watch?v=kwLbSx9BNbU
  52. Electrocardiogram Augmented Limb Leads (Unipolar) - CV Physiology, accessed April 10, 2025, https://cvphysiology.com/arrhythmias/a013b
  53. Bipolar Limb Leads - Doctor 2020 -, accessed April 10, 2025, https://doctor2020.jumedicine.com/wp-content/uploads/sites/12/2022/11/sheet5physio.pdf
  54. Monitoring of electrocardiogram (ECG) for bipolar limb leads l1,l2 and l3. - Virtual Labs, accessed April 10, 2025, https://bmi-iitr.vlabs.ac.in/exp/bipolar-limb-leads/theory.html
  55. MASTERING ECG LEADS BIPOLAR LIMB LEADS - KorAcademy, accessed April 10, 2025, https://koracademy.com/sites/default/files/inline-files/04.%20MASTERING%20ECG%20LEADS.pdf
  56. Electrocardiogram Standard Limb Leads (Bipolar) - Cardiovascular Physiology Concepts, accessed April 10, 2025, https://cvphysiology.com/arrhythmias/a013a
  57. On Recording the Unipolar ECG Limb Leads via the Wilson’s vs the Goldberger’s Terminals: aVR, aVL, and aVF Revisited - PubMed Central, accessed April 10, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC2572021/
  58. Augmented Unipolar Limb Leads - Doctor 2019, accessed April 10, 2025, https://doctor2019.jumedicine.com/wp-content/uploads/sites/10/2021/11/Copy-of-Copy-of-12-1-OgQfM.pdf
  59. MASTERING AUGMENTED UNIPOLAR LIMB LEADS - KorAcademy, accessed April 10, 2025, https://koracademy.com/sites/default/files/inline-files/05%20-%20MASTERING%20AUGMENTED%20UNIPOLAR%20LIMB%20LEADS.pdf
  60. ECG: The augmented limb leads aVF, aVR and aVL - YouTube, accessed April 10, 2025, https://www.youtube.com/watch?v=1rSpcK50aIg
  61. Augmented Limb Leads - EKG Lesson #324 - EKG.Academy, accessed April 10, 2025, https://ekg.academy/lesson/1170/augmented-limb-leads
  62. Einthoven’s triangle - Wikipedia, accessed April 10, 2025, https://en.wikipedia.org/wiki/Einthoven%27s_triangle
  63. en.wikipedia.org, accessed April 10, 2025, https://en.wikipedia.org/wiki/Einthoven%27s_triangle#:~:text=Einthoven’s%20triangle%20is%20an%20imaginary,Einthoven%2C%20who%20theorized%20its%20existence.
  64. Precordial ECG Lead Mispositioning: Its Incidence and Estimated Cost to Healthcare - PMC, accessed April 10, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC7343296/
  65. View of Common ECG Lead Placement Errors. Part II: Precordial Misplacements, accessed April 10, 2025, https://ijms.info/IJMS/article/view/96/545
  66. 12 Lead ECG Placement Made Easy Nursing EKG Electrodes Interpretation - YouTube, accessed April 10, 2025, https://www.youtube.com/watch?v=mKZusWukeSo
  67. 12Lead ECG Precordial Leads AHA - Defib Accessories - AED.US, accessed April 10, 2025, https://aed.us/products/12-lead-ecg-precordial-leads-aha
  68. Why are the 5 kΩ resistors needed to create the Wilson Central Terminal? - Reddit, accessed April 10, 2025, https://www.reddit.com/r/medicine/comments/biqg1n/why_are_the_5_k%CF%89_resistors_needed_to_create_the/
  69. Anatomy and Function of the Heart’s Electrical System | Johns Hopkins Medicine, accessed April 10, 2025, https://www.hopkinsmedicine.org/health/conditions-and-diseases/anatomy-and-function-of-the-hearts-electrical-system
  70. Wilson Central Terminal ECG Database v1.0.1 - PhysioNet, accessed April 10, 2025, https://physionet.org/content/wctecgdb/
  71. True Unipolar ECG Machine for Wilson Central Terminal Measurements - PMC, accessed April 10, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC4606145/
  72. True unipolar ECG machine for Wilson Central Terminal measurements - PubMed, accessed April 10, 2025, https://pubmed.ncbi.nlm.nih.gov/26495303/
  73. Analysing Wilson’s and Goldberger’s Central Terminals: Theoretical Redesign of a Novel Central Terminal for Precordial Leads | Auctores, accessed April 10, 2025, https://www.auctoresonline.org/article/analysing-wilsons-and-goldbergers-central-terminals-theoretical-redesign-of-a-novel-central-terminal-for-precordial-leads
  74. (PDF) Analysing Wilson’s and Goldberger’s Central Terminals: Theoretical Redesign of a Novel Central Terminal for Precordial Leads - ResearchGate, accessed April 10, 2025, https://www.researchgate.net/publication/373168300_Analysing_Wilson’s_and_Goldberger’s_Central_Terminals_Theoretical_Redesign_of_a_Novel_Central_Terminal_for_Precordial_Leads
  75. The ECG - Cardiac Cycle - TeachMePhysiology, accessed April 10, 2025, https://teachmephysiology.com/cardiovascular-system/cardiac-cycle-2/the-ecg/
  76. How to read an Electrocardiogram (ECG). Part One: Basic principles of the ECG. The normal ECG - South Sudan Medical Journal, accessed April 10, 2025, http://www.southsudanmedicaljournal.com/archive/may-2010/how-to-read-an-electrocardiogram-ecg.-part-one-basic-principles-of-the-ecg.-the-normal-ecg.html
  77. In brief: What is an electrocardiogram (ECG)? - InformedHealth.org - NCBI Bookshelf, accessed April 10, 2025, https://www.ncbi.nlm.nih.gov/books/NBK536878/
  78. ECG interpretation: Characteristics of the normal ECG (P-wave, QRS complex, ST segment, T-wave) – The Cardiovascular, accessed April 10, 2025, https://ecgwaves.com/topic/ecg-normal-p-wave-qrs-complex-st-segment-t-wave-j-point/
  79. Electrocardiogram (ECG) - CardioSecur, accessed April 10, 2025, https://www.cardiosecur.com/magazine/specialist-articles-on-the-heart/electrocardiogram-ecg
  80. P wave - StatPearls - NCBI Bookshelf, accessed April 10, 2025, https://www.ncbi.nlm.nih.gov/books/NBK551635/
  81. Correlation between ECG and Cardiac Cycle - JoVE, accessed April 10, 2025, https://www.jove.com/science-education/v/15275/correlation-between-ecg-and-cardiac-cycle
  82. 19.3 Cardiac Cycle – Anatomy & Physiology - Oregon State University, accessed April 10, 2025, https://open.oregonstate.education/aandp/chapter/19-3-cardiac-cycle/
  83. Cardiac cycle - Wikipedia, accessed April 10, 2025, https://en.wikipedia.org/wiki/Cardiac_cycle
  84. The Cardiac Cycle | Anatomy and Physiology II - Lumen Learning, accessed April 10, 2025, https://courses.lumenlearning.com/pgcc-ap2/chapter/cardiac-cycle/
  85. Cardiac Cycle - Atrial Contraction (Phase 1) - Cardiovascular Physiology Concepts, accessed April 10, 2025, https://cvphysiology.com/heart-disease/hd002a
  86. Cardiac Cycle - CV Physiology, accessed April 10, 2025, https://cvphysiology.com/heart-disease/hd002
  87. THE CARDIAC CYCLE - Phases, Pressure Changes, ECG/EKG - YouTube, accessed April 10, 2025, https://www.youtube.com/watch?v=ZhA9UZmFYCg
  88. What does QRS complex represent in ECG? - BYJU’S, accessed April 10, 2025, https://byjus.com/neet/what-does-qrs-complex-represent-in-ecg/
  89. Physiology, Diagram, Phases of the Cardiac Cycle - BYJU’S, accessed April 10, 2025, https://byjus.com/biology/cardiac-cycle/
  90. CARDIAC CYCLE, accessed April 10, 2025, https://cvil.ucsd.edu/wp-content/uploads/2017/02/cardiac-cycle.pdf
  91. The Cardiac Cycle on an EKG (P-QRS-T Waves) - YouTube, accessed April 10, 2025, https://www.youtube.com/watch?v=gqiqcO6AiWc
  92. Cardiac Cycle - UTMB Health, The University of Texas Medical Branch, accessed April 10, 2025, https://www.utmb.edu/Pedi_Ed/CoreV2/CardiologyPart1/CardiologyPart12.html
  93. Normal Duration Times - Normal Function of the Heart - Cardiology Teaching Package - Practice Learning - Division of Nursing - University of Nottingham, accessed April 10, 2025, https://www.nottingham.ac.uk/nursing/practice/resources/cardiology/function/normal_duration.php
  94. Cardiac Conduction System and Understanding ECG, Animation. - YouTube, accessed April 10, 2025, https://m.youtube.com/watch?v=RYZ4daFwMa8&pp=ygUGI3dhdmVw
  95. Physiological basis of electrocardiography, accessed April 10, 2025, https://derangedphysiology.com/main/cicm-primary-exam/cardiovascular-system/Chapter-735/physiological-basis-electrocardiography
  96. QRS complex - Wikipedia, accessed April 10, 2025, https://en.wikipedia.org/wiki/QRS_complex
  97. Physiology, Cardiac Cycle - StatPearls - NCBI Bookshelf, accessed April 10, 2025, https://www.ncbi.nlm.nih.gov/books/NBK459327/
  98. Cardiac Cycle - UTMB Health, The University of Texas Medical Branch, accessed April 10, 2025, https://www.utmb.edu/Pedi_Ed/CoreV2/cardiology/Cardiology3.html
  99. Cardiac Cycle - UTMB Health, The University of Texas Medical Branch, accessed April 10, 2025, https://www.utmb.edu/pedi_ed/CoreV2/CardiologyPart1/CardiologyPart12.html
  100. Cardiac Cycle | Anatomy and Physiology II - Lumen Learning, accessed April 10, 2025, https://courses.lumenlearning.com/suny-ap2/chapter/cardiac-cycle/
  101. Cardiac Cycle - Isovolumetric Contraction (Phase 2) - Cardiovascular Physiology Concepts, accessed April 10, 2025, https://cvphysiology.com/heart-disease/hd002b
  102. Cardiac Conduction System and Understanding ECG, Animation. - YouTube, accessed April 10, 2025, https://www.youtube.com/watch?v=RYZ4daFwMa8
  103. Electrocardiographic T Wave and its Relation With Ventricular Repolarization Along Major Anatomical Axes | Circulation: Arrhythmia and Electrophysiology - American Heart Association Journals, accessed April 10, 2025, https://www.ahajournals.org/doi/10.1161/circep.113.001622
  104. Diastolic Electromechanical Coupling | Circulation: Arrhythmia and Electrophysiology - American Heart Association Journals, accessed April 10, 2025, https://www.ahajournals.org/doi/10.1161/circep.111.969717
  105. T wave - Wikipedia, accessed April 10, 2025, https://en.wikipedia.org/wiki/T_wave
  106. ECG T Wave - StatPearls - NCBI Bookshelf, accessed April 10, 2025, https://www.ncbi.nlm.nih.gov/books/NBK538264/
  107. The T-Wave Explained - What Do T Waves On An ECG Represent? - Executive Electrocardiogram Education, accessed April 10, 2025, https://www.ecgedu.com/what-is-t-wave-on-ecg/
  108. Cardiac Cycle - Reduced Ejection (Phase 4) - Cardiovascular Physiology Concepts, accessed April 10, 2025, https://cvphysiology.com/heart-disease/hd002d
  109. ECG rate and rhythm: Video, Causes, & Meaning | Osmosis, accessed April 10, 2025, https://www.osmosis.org/learn/ECG_rate_and_rhythm
  110. How to calculate heart rate from ECG (or EKG) - Seer Medical, accessed April 10, 2025, https://seermedical.com/blog/calculate-heart-rate-ecg
  111. ECG Basics - REBEL EM - Emergency Medicine Blog, accessed April 10, 2025, https://rebelem.com/ecg-basics/
  112. ECGs in the ER (Proceedings) - DVM360, accessed April 10, 2025, https://www.dvm360.com/view/ecgs-er-proceedings
  113. ECG Heart Rate Calculator, accessed April 10, 2025, https://www.omnicalculator.com/health/ecg-heart-rate
  114. EKG Interpretation - UTMB Health, The University of Texas Medical Branch, accessed April 10, 2025, https://www.utmb.edu/pedi_ed/CoreV2/Cardiology/Cardiology4.html
  115. Heart Rate | ECG Core Curriculum - AccessMedicine - McGraw Hill Medical, accessed April 10, 2025, https://accessmedicine.mhmedical.com/content.aspx?bookid=3339§ionid=277533379
  116. Determining Heart Rate from the Electrocardiogram - Cardiovascular Physiology Concepts, accessed April 10, 2025, https://cvphysiology.com/arrhythmias/a020
  117. ECG Rate Interpretation • LITFL Medical Blog, accessed April 10, 2025, https://litfl.com/ecg-rate-interpretation/
  118. Rate and rhythm - Pulsenotes, accessed April 10, 2025, https://app.pulsenotes.com/clinical/ecgs/notes/2-rate-rhythm
  119. Large Block Method to Calculate Heart Rate - ECG Medical Training, accessed April 10, 2025, https://www.ecgmedicaltraining.com/large-block-method-to-calculate-heart-rate/
  120. How to Calculate Heart Rate on an ECG with the 6 Second Method - Simple Nursing, accessed April 10, 2025, https://simplenursing.com/six-second-method-calculate-heart-rate-ecg/
  121. Determining Rate | Learn the Heart - Healio, accessed April 10, 2025, https://www.healio.com/cardiology/learn-the-heart/ecg-review/ecg-interpretation-tutorial/determining-rate
  122. ECG Interpretation - WSAVA2007 - VIN, accessed April 10, 2025, https://www.vin.com/apputil/content/defaultadv1.aspx?id=3860876&pid=11242&print=1
  123. How to Calculate Heart Rate on ECG: Easy Steps to Master Pulse Counting - YouTube, accessed April 10, 2025, https://www.youtube.com/watch?v=z6VsUniAVGI&pp=0gcJCdgAo7VqN5tD
  124. www.healio.com, accessed April 10, 2025, https://www.healio.com/cardiology/learn-the-heart/ecg-review/ecg-interpretation-tutorial/determining-rate#:~:text=Another%20quick%20way%20to%20calculate,60%20seconds%2C%20or%201%20minute.
  125. Calculating Heart Rate on an ECG | EKG | OSCE Guide | UKMLA | CPSA - YouTube, accessed April 10, 2025, https://www.youtube.com/watch?v=7U7uir0RgCM
  126. Normal Heart Rate: Range, When It’s Dangerous, and More - Healthline, accessed April 10, 2025, https://www.healthline.com/health/dangerous-heart-rate
  127. Normal heart rhythm: MedlinePlus Medical Encyclopedia Image, accessed April 10, 2025, https://medlineplus.gov/ency/imagepages/18032.htm
  128. medlineplus.gov, accessed April 10, 2025, https://medlineplus.gov/ency/imagepages/18032.htm#:~:text=An%20electrocardiogram%20(ECG)%20test%20measures,to%20100%20beats%20per%20minute.
  129. Normal Sinus Rhythm - ECG Library Basics - LITFL, accessed April 10, 2025, https://litfl.com/normal-sinus-rhythm-ecg-library/
  130. Tachycardia: Fast Heart Rate | American Heart Association, accessed April 10, 2025, https://www.heart.org/en/health-topics/arrhythmia/about-arrhythmia/tachycardia—fast-heart-rate
    1. Characteristics of the Normal ECG - ECG Learning Center, accessed April 10, 2025, https://ecg.utah.edu/lesson/3
  131. Normal ECG, accessed April 10, 2025, https://meds.queensu.ca/central/assets/modules/ECG/normal_ecg.html
  132. How to Read an ECG | ECG Interpretation | EKG - Geeky Medics, accessed April 10, 2025, https://geekymedics.com/how-to-read-an-ecg/
  133. Sinus rhythm - Wikipedia, accessed April 10, 2025, https://en.wikipedia.org/wiki/Sinus_rhythm
  134. Sinus Bradycardia - StatPearls - NCBI Bookshelf, accessed April 10, 2025, https://www.ncbi.nlm.nih.gov/books/NBK493201/
  135. Sick sinus syndrome - Symptoms & causes - Mayo Clinic, accessed April 10, 2025, https://www.mayoclinic.org/diseases-conditions/sick-sinus-syndrome/symptoms-causes/syc-20377554
  136. Tachycardia - Symptoms and causes - Mayo Clinic, accessed April 10, 2025, https://www.mayoclinic.org/diseases-conditions/tachycardia/symptoms-causes/syc-20355127
  137. Tachycardia - Mayo Clinic - Amerikan Hastanesi, accessed April 10, 2025, https://www.amerikanhastanesi.org/mayo-clinic-care-network/mayo-clinic-health-information-library/diseases-conditions/tachycardia
  138. Sinus Tachycardia ECG Review | Learn the Heart - Healio, accessed April 10, 2025, https://www.healio.com/cardiology/learn-the-heart/ecg-review/ecg-topic-reviews-and-criteria/sinus-tachycardia-review
  139. Sinus tachycardia - Wikipedia, accessed April 10, 2025, https://en.wikipedia.org/wiki/Sinus_tachycardia
  140. Bradycardia - Symptoms and causes - Mayo Clinic, accessed April 10, 2025, https://www.mayoclinic.org/diseases-conditions/bradycardia/symptoms-causes/syc-20355474
  141. Sinus bradycardia | Learn the Heart - Healio, accessed April 10, 2025, https://www.healio.com/cardiology/learn-the-heart/cardiology-review/topic-reviews/sinus-bradycardia
  142. Premature atrial contraction: Video, Causes, & Meaning - Osmosis, accessed April 10, 2025, https://www.osmosis.org/learn/Premature_atrial_contraction
  143. Premature ventricular contractions (PVCs) - Symptoms & causes - Mayo Clinic, accessed April 10, 2025, https://www.mayoclinic.org/diseases-conditions/premature-ventricular-contractions/symptoms-causes/syc-20376757
  144. Premature Atrial Contraction - Yale Medicine, accessed April 10, 2025, https://www.yalemedicine.org/conditions/premature-atrial-contraction
  145. Premature atrial contractions (PACs) | Learn the Heart - Healio, accessed April 10, 2025, https://www.healio.com/cardiology/learn-the-heart/cardiology-review/topic-reviews/premature-atrial-contractions-pacs
  146. What Premature Ventricular Contraction (PVC) Looks Like on Your Watch ECG | Qaly, accessed April 10, 2025, https://www.qaly.co/post/premature-ventricular-contractions-pvcs
  147. Premature ventricular contractions (PVCs) - Mayo Clinic | Koc University Hospital, accessed April 10, 2025, https://www.kuh.ku.edu.tr/mayo-clinic-care-network/mayo-clinic-health-information-library/diseases-conditions/premature-ventricular-contractions-pvcs
  148. Atrial flutter - Symptoms and causes - Mayo Clinic, accessed April 10, 2025, https://www.mayoclinic.org/diseases-conditions/atrial-flutter/symptoms-causes/syc-20352586
  149. Atrial Flutter - StatPearls - NCBI Bookshelf, accessed April 10, 2025, https://www.ncbi.nlm.nih.gov/books/NBK540985/
  150. ECG Diagnosis: Type I Atrial Flutter - PMC, accessed April 10, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC4022567/
  151. Atrial Fibrillation - StatPearls - NCBI Bookshelf, accessed April 10, 2025, https://www.ncbi.nlm.nih.gov/books/NBK526072/
  152. Atrial fibrillation - Mayo Clinic - Amerikan Hastanesi, accessed April 10, 2025, https://www.amerikanhastanesi.org/mayo-clinic-care-network/mayo-clinic-health-information-library/diseases-conditions/atrial-fibrillation
  153. Atrial fibrillation - Symptoms and causes - Mayo Clinic, accessed April 10, 2025, https://www.mayoclinic.org/diseases-conditions/atrial-fibrillation/symptoms-causes/syc-20350624
  154. Atrial fibrillation - Mayo Clinic, accessed April 10, 2025, https://www.mayoclinic.org/diseases-conditions/atrial-fibrillation/multimedia/img-20096412
  155. Atrial Fibrillation - ECG Library Diagnosis - LITFL, accessed April 10, 2025, https://litfl.com/atrial-fibrillation-ecg-library/
  156. Atrial fibrillation electrocardiogram - wikidoc, accessed April 10, 2025, https://www.wikidoc.org/index.php/Atrial_fibrillation_electrocardiogram
  157. Premature ventricular contractions - Mayo Clinic - Amerikan Hastanesi, accessed April 10, 2025, https://www.amerikanhastanesi.org/mayo-clinic-care-network/mayo-clinic-health-information-library/definitions/premature-ventricular-contractions
  158. Premature Ventricular Complex (PVC) - ECG Library Diagnosis - LITFL, accessed April 10, 2025, https://litfl.com/premature-ventricular-complex-pvc-ecg-library/
  159. Ventricular tachycardia - Symptoms and causes - Mayo Clinic, accessed April 10, 2025, https://www.mayoclinic.org/diseases-conditions/ventricular-tachycardia/symptoms-causes/syc-20355138
  160. Decoding ECG: Understand VTach vs VFib Easily | SureFire CPR, accessed April 10, 2025, https://surefirecpr.com/ekg/decoding-ecg-results-distinguishing-v-tach-from-v-fib/
  161. Mayo Clinic Q and A: Cause of ventricular tachycardia determines treatment, accessed April 10, 2025, https://newsnetwork.mayoclinic.org/discussion/mayo-clinic-q-and-a-cause-of-ventricular-tachycardia-determines-treatment/
  162. ECG Diagnosis: Monomorphic Ventricular Tachycardia - PMC, accessed April 10, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC3048638/
  163. Pulseless Ventricular Tachycardia - StatPearls - NCBI Bookshelf, accessed April 10, 2025, https://www.ncbi.nlm.nih.gov/books/NBK554467/
  164. Sudden cardiac arrest - Symptoms and causes - Mayo Clinic, accessed April 10, 2025, https://www.mayoclinic.org/diseases-conditions/sudden-cardiac-arrest/symptoms-causes/syc-20350634
  165. Ventricular fibrillation - Symptoms & causes - Mayo Clinic, accessed April 10, 2025, https://www.mayoclinic.org/diseases-conditions/ventricular-fibrillation/symptoms-causes/syc-20364523
  166. Ventricular fibrillation - Mayo Clinic, accessed April 10, 2025, https://www.kuh.ku.edu.tr/mayo-clinic-care-network/mayo-clinic-health-information-library/diseases-conditions/ventricular-fibrillation
  167. Ventricular fibrillation - Mayo Clinic - Amerikan Hastanesi, accessed April 10, 2025, https://www.amerikanhastanesi.org/mayo-clinic-care-network/mayo-clinic-health-information-library/diseases-conditions/ventricular-fibrillation
  168. Ventricular Fibrillation - StatPearls - NCBI Bookshelf, accessed April 10, 2025, https://www.ncbi.nlm.nih.gov/books/NBK537120/
  169. Ventricular Fibrillation (VF) - ECG Library Diagnosis - LITFL, accessed April 10, 2025, https://litfl.com/ventricular-fibrillation-vf-ecg-library/
  170. What Is Asystole? Causes, Symptoms, Treatment - WebMD, accessed April 10, 2025, https://www.webmd.com/heart-disease/asystole-atrial-fibrillation
  171. Asystole: Causes, Symptoms and Treatment - Cleveland Clinic, accessed April 10, 2025, https://my.clevelandclinic.org/health/symptoms/22920-asystole
  172. Asystole (Nursing) - StatPearls - NCBI Bookshelf, accessed April 10, 2025, https://www.ncbi.nlm.nih.gov/books/NBK568774/
  173. Asystole training - ACLS Cardiac Rhythms video - ProACLS, accessed April 10, 2025, https://www.proacls.com/training/video/asystole
  174. www.ncbi.nlm.nih.gov, accessed April 10, 2025, https://www.ncbi.nlm.nih.gov/books/NBK448164/#:~:text=First%2Ddegree%20atrioventricular%20(AV),of%20atrial%20to%20ventricular%20conduction.
  175. First-Degree Heart Block - StatPearls - NCBI Bookshelf, accessed April 10, 2025, https://www.ncbi.nlm.nih.gov/books/NBK448164/
  176. Atrioventricular Block - Cardiovascular Disorders - Merck Manual Professional Edition, accessed April 10, 2025, https://www.merckmanuals.com/professional/cardiovascular-disorders/specific-cardiac-arrhythmias/atrioventricular-block
  177. First degree av block | Mayo Clinic Connect, accessed April 10, 2025, https://connect.mayoclinic.org/discussion/first-degree-av-block/
  178. First-Degree Atrioventricular Block: Background, Pathophysiology, Etiology, accessed April 10, 2025, https://emedicine.medscape.com/article/161829-overview
  179. Mobitz Type I: What Is It, Causes, Signs and Symptoms, Diagnosis | Osmosis, accessed April 10, 2025, https://www.osmosis.org/answers/mobitz-type-i
  180. Second-Degree Atrioventricular Block: Practice Essentials, Background, Pathophysiology, accessed April 10, 2025, https://emedicine.medscape.com/article/161919-overview
  181. AV Block: 2nd degree, Mobitz I (Wenckebach Phenomenon) - LITFL, accessed April 10, 2025, https://litfl.com/av-block-2nd-degree-mobitz-i-wenckebach-phenomenon/
  182. Second-degree atrioventricular block - Wikipedia, accessed April 10, 2025, https://en.wikipedia.org/wiki/Second-degree_atrioventricular_block
  183. Mobitz Type II: What Is It, Diagnosis, Treatment, and More | Osmosis, accessed April 10, 2025, https://www.osmosis.org/answers/mobitz-type-II
  184. Mobitz type II second-degree atrioventricular block: a commonly overdiagnosed and misinterpreted arrhythmia - PMC, accessed April 10, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC11390567/
  185. Third-Degree Atrioventricular Block (Complete Heart Block) - Medscape Reference, accessed April 10, 2025, https://emedicine.medscape.com/article/162007-overview
  186. Third-Degree Atrioventricular Block - StatPearls - NCBI Bookshelf, accessed April 10, 2025, https://www.ncbi.nlm.nih.gov/books/NBK545199/
  187. AV block: 3rd degree (complete heart block) - ECG Library - LITFL, accessed April 10, 2025, https://litfl.com/av-block-3rd-degree-complete-heart-block/
  188. Wolff-Parkinson-White (WPW) syndrome - Mayo Clinic, accessed April 10, 2025, https://www.mayoclinic.org/diseases-conditions/wolff-parkinson-white-syndrome/symptoms-causes/syc-20354626
  189. Wolff-Parkinson-White (WPW) syndrome - Mayo Clinic, accessed April 10, 2025, https://www.amerikanhastanesi.org/mayo-clinic-care-network/mayo-clinic-health-information-library/diseases-conditions/wolff-parkinson-white-wpw-syndrome
  190. www.ncbi.nlm.nih.gov, accessed April 10, 2025, https://www.ncbi.nlm.nih.gov/books/NBK554437/#:~:text=WPW%20pattern%20is%20a%20constellation,of%20a%20slurred%20delta%20wave.
  191. Wolff-Parkinson-White Syndrome - StatPearls - NCBI Bookshelf, accessed April 10, 2025, https://www.ncbi.nlm.nih.gov/books/NBK554437/
  192. Long QT syndrome - Symptoms and causes - Mayo Clinic, accessed April 10, 2025, https://www.mayoclinic.org/diseases-conditions/long-qt-syndrome/symptoms-causes/syc-20352518
  193. Long QT syndrome - Mayo Clinic - Amerikan Hastanesi, accessed April 10, 2025, https://www.amerikanhastanesi.org/mayo-clinic-care-network/mayo-clinic-health-information-library/diseases-conditions/long-qt-syndrome
  194. Long QT syndrome | Learn the Heart - Healio, accessed April 10, 2025, https://www.healio.com/cardiology/learn-the-heart/cardiology-review/topic-reviews/long-qt-syndrome
  195. Long QT Syndrome - StatPearls - NCBI Bookshelf, accessed April 10, 2025, https://www.ncbi.nlm.nih.gov/books/NBK441860/
  196. Premature Junctional Complex (PJC) - ECG Library - LITFL, accessed April 10, 2025, https://litfl.com/premature-junctional-complex-pjc/
  197. Premature Junctional Contraction: Causes, Symptoms and Treatment - Cleveland Clinic, accessed April 10, 2025, https://my.clevelandclinic.org/health/diseases/22582-premature-junctional-contraction
  198. Junctional Rhythm: Causes, Symptoms and Treatment - Cleveland Clinic, accessed April 10, 2025, https://my.clevelandclinic.org/health/diseases/23206-junctional-rhythm
  199. Premature junctional contraction - Wikipedia, accessed April 10, 2025, https://en.wikipedia.org/wiki/Premature_junctional_contraction
  200. Pulseless Ventricular Tachycardia: Causes and Treatment - Cleveland Clinic, accessed April 10, 2025, https://my.clevelandclinic.org/health/diseases/23254-pulseless-ventricular-tachycardia
  201. Pulseless ventricular tachycardia | ACLS-Algorithms.com, accessed April 10, 2025, https://acls-algorithms.com/rhythms/pulseless-ventricular-tachycardia/