PULSE - Case 3

1. PULSE - Case 3 One too many Whoppers Josh Laird - MS II - jlaird1@hmc.psu.edu Rob Freed - MS II - rfreed@hmc.psu.edu Penn State College of Medicine Milton S. Hershey Medical Center

2. O2 is important! • Allows aerobic respiration to occur • More ATP is made • This gives muscle energy • Keeps muscles alive!

3. Which areas need O2 the most? • The Heart! • Myocytes are constantly contracting and burning ATP, they can’t live in anaerobic respiration • Can you think of other critical organs that need O2?

4. How is the heart perfused? • Through the coronary ostia and into the coronary arteries! • When is the heart perfused? • Systole or diastole?

5. What are these?

6. Valve leaflets Sinus of Valsalva Sinus of Valsalva Left Coronary ostium Right Coronary ostium

7. Systole

8. Diastole

9. Coronary Occlusion Areas at Risk Left Coronary Artery Circumflex Artery Right Coronary Artery Left Anterior Descending Artery

10. Can we model heart perfusion? • Q = ΔP R • Q = coronary flow (perfusion) • P = pressure • R = coronary resistance) • What does this mean? • Changes in these can cause ↑ or ↓ perfusion • There are many things that can change these parameters, we will only focus on one.

11. What can change R? • Exercise • VSD • ↑ wall thickness (ventricular hypertrophy) • Compresses the coronary arteries • ↓ filling and thus, ↓ perfusion • Coronary artery disease! • ↓ arterial diameter obstructs flow & ↑ resistance

12. What is coronary artery disease? • The #1 cause of death! • Every 26 seconds, someone in the US will have a coronary event (>120 people by the end of this lecture) • 770,000 Americans will have a new coronary attack this year alone • 430,000 will have a recurrent attack

13. What is atherosclerotic plaque? • Atherosclerosis • “hardening of the arteries” • endothelial dysfunction • Fat accumulation (LDL) • Recruitment of leukocytes (white blood cells) • Smooth muscle cells grow over the lipid • This forms what we call a plaque

14. Atherosclerosis dev’ps over time • “fatty streaks” as young as age 5

15. The Leukocyte Paradox! • Normally, white blood cells are good! How are they bad in CAD? • These release degradative chemicals to try to remove the lipid in the artery • These make “foam cells” • Like churning butter, becomes fluffy and ‘foamy’ • This is the first visible lesion in atherosclerosis

16. 2 types of plaques • Vulnerable • Stable

17. How does this relate? • Can get stenosis (narrowing of the coronary arteries • Amount of damage depends on the location and extent of blockage • Time of ischemia is vitally important • Arteries need to be blocked >40% to get symptoms You mean I can have blockages without knowing it? YES!

18. Near Far Large damaged area Small damaged area

19. Proximal Distal Collaterals

20. I’d like to introduce you to Mr. Bryant

21. For our purposes, let’s reduce Mr. Bryant down to the bare minimum!

22. Mr. Bryant suddenly suffers a heart attack due to a blocked coronary artery… this limits blood flow to the heart muscle

23. Sensory nerves within heart tissue sense the chaos and “send word” to the brain of the havoc!

24. The nerve signals to his brain cause severe pain in his chest!

25. The nerve signals to his brain cause severe pain in his chest!

26. So, Mr. Bryant has chest pain, but why do most people ALSO describe intense pain in their left arm?!

27. “Referred Pain” Referred pain is a term used to describe the phenomenon of pain perceived at a site adjacent to or at a distance from the site of an injury's origin. One of the best examples of this is during ischemia brought on by an angina pectoris, or heart attack. Even though the heart is directly affected the pain is often felt in the neck, shoulders and back rather than the chest. The International Association for the Study of Pain, as of 2001, has not officially defined the term; hence several authors have defined the term differently. Despite an increasing amount of literature on the subject there is no definitive answer regarding the mechanism behind this phenomenon. This phenomenon is also known as "reflective pain"[1] Physicians and scientists have known about referred pain since the late 1880s yet the true origins and causes of referred pain is unknown. WHAAT!?

28. Referred Pain for Dummies! (more like: for everyone who likes the KISS method)

29. Look at how close the nerves from the arm and the heart are!

30. The brain, not as smart as some may think… forgets where the ACTUAL pain came from…

31. Therefore, the individual feels pain in both chest AND shoulder/arm

33. Levine Sign The Levine Sign is a clenched fist held over the chest to describe the tightening or pressure felt during a heart attack

34. You’re an emergency room doc and these two patients come in… Michelle Smith, a 46 year old female from York presents with mild chest pressure and nausea Michael Smith, a 45 year old male presents to you with chest pain, radiating to his left arm and is sweating profusely

35. Variable symptoms of heart attacks… Regardless of gender, if a patient has a heart attack, despite symptoms that the patient has, it is VERY SERIOUS! Women Less severe chest pain More shortness of breath, vomiting, nausea Men More severe chest pain Sweaty

36. Variable outcomesof heart attacks… Some people will come to the ER with chest pain Some people will drop dead while doing yardwork Some may never have symptoms and never know of their heart attack

37. Therapy for heart attack/Ways to prevent heart attacks from even happening! Will be the topic of discussion for November 19th (no lecture next week) Primary prevention: Everyone can utilize primary prevention by… eating healthy, exercise Secondary prevention (you’re at a higher risk of heart attack, what now?): Drugs! Cholesterol lowering drugs! Blood pressure controlling drugs! Tertiary prevention(you’ve had a heart attack, what can be done to limit the damage?): Angioplasty, CABG, Stent placement, etc.

38. Thank you!

39. Questions? Comments? Thoughts?