How does Physical Activity Exert Beneficial Effects on Atherosclerosis and Coronary Artery Disease?

This post describes an update seminar delivered by Harold Laughlin, Professor at the University of Missouri at the 2017 HAPS Annual Conference in Salt Lake City.


Update Seminar VII was given by Harold Laughlin.  In this talk, the benefits of exercise on cardiovascular health were clearly documented.  I’m sure we’ve all heard the sobering stats before.  Cardiovascular disease, largely due to atherosclerosis, is the leading cause of death in the USA, accounting for ~ 1/3rd of all deaths.  As our President-Elect Ron Gerrits announced, we were all left feeling very inspired to getting fit for the HAPS conference Fun Run next year!  

For those interested in a great review article on the regulation of coronary blood flow during exercise, Harold mentioned the Physiology Review article by Duncker and Bache (2008).   In particular, here is list of some of the things we know so far regarding coronary blood flow during exercise:

  • During exercise, heart rate and myocardial contraction increase to meet the increased oxygen demands of the body and heart itself.
  • In order to meet increased metabolic demand, coronary blood flow increases (~5 fold) and there is also a small increase in oxygen extraction.
  • An increase in heart rate, will increase the relative time spent in systole, which affects (impedes) coronary blood flow.
  • There are many factors which regulate coronary vessel dilation (neurohormones, endothelial factors, and myocardial factors)
  • During exercise, coronary vasodilation appears to be induced by many factors including: exercise-induced ischemia, shear stress, increased arterial pressure, tangential wall stress, higher levels of endogenous NO, and β-adrenergic activity.
  • Exercise training results in coronary microvascular adaptations including: the formation of new capillaries, increased arteriolar diameters, increased adrenergic receptor responsiveness, and increased endothelium-dependent vasodilation (as a result of increased expression of endothelial NO synthase (eNOS), increased NO production, and increased Kv (potassium voltage) channel activity).

In his talk, Harold brought up some current data from his experiments with swine vasculature (Simmons et al., 2012).  He noted that healthy individuals typically have good vasomotor tone, and express low levels of the inflammatory markers and adhesion molecules (e.g. E-selectin and vascular cell adhesion molecule-1, VCAM-1) that are associated with atherosclerosis.  It has been previously found that endothelial cells located at bifurcations and other points of turbulence, are more at risk for developing atherosclerotic plaques than straight conduit arteries (Davies et al. 2010).  Laughlin et al. (2012) decided to investigate the straight conduit arteries and veins in six different regions of the swine to determine whether there were any differences in susceptibility to the development of atherosclerosis.  Overall, they found conduit arteries expressed higher levels of both pro- and anti-atherogenic markers than veins.  Also as one might expect, vessels of healthy individuals that lack atherosclerosis, are the most responsive to exercise.

In this talk, the improvements in vasculature as a result of exercise training were specifically addressed (Green et al. 2017).  The exercise-induced effects on vasculature is actually remarkable.  It is estimated that physical activity increases longevity, and reduces the risk of cardiovascular mortality by 42-44%.  The positive effect of exercise is noted to have dose-dependent curve and exercise training has been found to be on par with contemporary drug interventions (Green et al. 2017).  Exercise induces structural and functional adaptations in the vascular walls that reduce the risk of atherosclerotic plaque formation.  In addition increased capillary density and formation of additional collateral circulation is observed, as exercise induces the release of VEGF (Vascular Endothelial Growth Factor) (Green et. al. 2017).  Also, exercise was found to increase endothelial progenitor cell (EPC) activity which contributes to the growth of new vessels as well as repair.

It is important to note that exercise training increases cardiac output and oxygen uptake, without increasing mean arterial pressure.  This is because as cardiac output increases, peripheral vasodilation occurs (reducing afterload).  Exercise training improves vasodilation capabilities through structural changes.  During exercise, the increased systolic pressure stimulates vascular endothelial and smooth muscle cells to grow and align in response to stress, allowing for greater vasodilation.  In addition, vessel wall stretching induces vasodilation through increased eNOS activity (which produces the vasodilator NO) and activation of Kv channels (which causes smooth muscle cells to hyperpolarize and relax).  In addition, increased blood flow, has been found to increase both acetylcholine and prostacyclin levels which have been shown to induce vasodilation.  Conversely, low levels of shear stress, has been found to increase expression of adhesion molecules (ICAM-1 and VCAM-1) and reduce levels of the endogenous vasodilator NO (Green et al. 2017).

Thankfully for those of us looking to improve vasodilatory function in our conduit arteries and increase our capillary density, improvements through exercise can be seen in as little as 1-4 weeks of exercise and of course continue with longer training sessions.  So with that in mind, I’ll be sure to grab my running shoes and sign my kids up for sports, as fewer than 30% of females and 50% of males get the recommended 60 minutes 5-7 days/ week of exercise!  Yikes-arama!  Time to unplug and play…

A big thank you to Harold Laughlin for a highly motivating talk!


Post from Dr. Zoë Soon, School of Health and Exercise Sciences, University of British Columbia Okanagan, BC, Canada


Davies, P.F., Civelek, M., Fang, Y., Guerraty, M.A. Passerini, A.G. (2010). Endothelial heterogeneity associated with regional athero-susceptiblity and adaptation to disturbed blood flow in vivo. Semin. Thromb. Hemost. 36, 265-275.

Duncker, D.J. and Bache, R.J. (2008). Regulation of coronary blood flow during exercise. Physiol. Rev. 88, 1009-1086.

Green, D.J., Hopman, M.T.E., Padilla, J., Laughlin, M.H., Thijssen, D.H.J. (2017). Vascular adaptation to exercise in humans: role of hemodynamic stimuli. Phsiol. Rev. 97, 495-528.

Simmons, G.H., Padilla, J., and Laughlin, M.H. (2012). Heterogeneity of endothelial cell phenotype within and amongst conduit vessels of the swine vasculature. Exp. Physiol. 97(9), 1074-1082.

HAPS Leadership (#17): Southern Regional Director

We’re checking in with Jason LaPres this week to learn what is so gosh-darn special about the HAPS Regional Conferences.  Jason is our Southern Regional Director, as well as an attendee and/or committee member at a few of our Regionals.

???????????????????????????????“The Regional Conferences are a little more intimate than the Annual Conference.  Usually just over a weekend, they are a little more low-key.  Most people are close enough to drive and a lot know each other before reaching the conference.  There are fewer vendors, only 1 or 2 update lectures, but most of the focus is usually on the workshops.”

Uh…gee, Jason, that sounds somewhat “less” than the Annual Conference.

“Heck, no, Tom.  It’s just different.  As I said, the Regional Conferences tend to be more intimate than the Annuals.  Don’t get me wrong, I love the Annual Conferences.  The night and day energy at those is incredible.  Meeting so many new people and experiencing so many new things is absolutely breath-taking.  But, what makes the Regional Conferences a jewel is their focus.”

“See, each Regional Conference tends to develop a bit of a theme for itself.  We’ve had Regional Conferences that were built around cadaver dissection, around online courses, around high school educators, the list goes on.  The Annual Conference is a chance to explore a whole bunch of – SQUIRREL!

140212 (2) Up“Sorry, lost my train of thought.  Oh yeah, the Regional Conferences are a great way to really roll your sleeves up and immerse yourself into a tight group of educators who are just as passionate as you.  We have an Eastern Regional Conference in Springfield, Massachusetts on March 15 of this year.  I’ve spoken to a number of people are very excited to attend that one.”

Are there other Regional Conferences in the works?

“Yes, Murray Jensen is working on a Central Regional Conference for October of this year.  We’ve had proposals from a number of other HAPSters who want to host a Regional Conference in their neck of the woods.  Hosting a Regional Conference is a great way to see if your location could serve as a future site for an Annual Conference.  For more information on hosting a Regional Conference, feel free to contact Ellen Lathrop-Davis, Chair of the Conference Committee or check out their committee’s web page.

Thanks, Jason.  That gives me a lot to think about.  I’m going to check out the Regional Conference web page and think about attending.

Excitement at the Southern Regional in Texas this past year!
Excitement at the Southern Regional in Texas this past year!
Vendors, Workshops, and Seminars..oh my!
Vendors, Workshops, and Seminars..oh my!

Shadowing Trauma Surgeons

My last week in Sacramento, in addition to trying to pack and get everything back in my car, I was sent follow a resident in the Emergency Department.  This service is especially difficult because its patients range from the mentally agitated to those in car accidents.  While the interns may only have to cut away clothing, someone must be ready to open the patient.  The cases I saw, in quick succession, give a hint of the diversity one resident had to deal with the same evening.DSCN2512

Case number one: an adult male, previously treated for injuries sustained when he fell of his bicycle a week earlier.  Had been sent home with broken ribs.  Difficulty breathing brought him back.  Imaging showed a light region where the lung should be.  He had developed a hemopneumothorax.  Blood and air needed to be removed, if not successfully in the ER then by a surgeon.  Under local anesthetic an incision was made and the whisper or air was followed by gurgling blood.  He was sent home with a chest tube.

Case two: teenage girl on bike hit by car.  Imaging shows no internal injury but a large wound to her left thigh needed debridement and dressing.

Case three: 20 month old boy bitten around the right eye by pit bull.  No one saw the attack.  The mother carried the screaming child in.  Once calmed by medication, images were taken to look for fractures to the skull and facial bones.  The wounds were deep punctures, probably needing eventual cosmetic repair.

Case four: adult male with continuous abdominal pain since previous evening’s meal.  All symptoms point to blocked gallbladder…he was the only one scheduled for surgery.

Every case gave me a little more knowledge about some system in the body which I’ll now be able to weave into my anatomy lectures.  Classes start next Monday so my summer of shadowing is over.  If you ever get a similar opportunity, I encourage you to take it…but not if it involves renting an un-airconditioned room in Sacramento for the summer!  Teri

Shadowing Surgical Oncology

Of all of the medical specialties I knew I’d be seeing, I’ve had the most history with cancer.  The first operation I ever learned of was my mother’s mastectomy.  She much later was treated for bone cancer.  My father and I have had skin cancers removed.  So the idea of seeing a patient under the knife was both interesting and hard to dissociate from.

The first major cancer operation I observed was one of the longest.  A soft tissue cancer near the chin had invaded the mandible.  A team of surgeons from both Oncology and ENT worked in shifts.  First they cancer was removed, then the jaw was rebuilt and the neck closed.  The most frightening part was that while the surface tissue looked different, to my untrained eyes, I could not fathom how they knew when to stop cutting.  Leaving stray cancer cells behind after a surgery of this length would be horrifying.  They of course can follow up with chemotherapy or radiation, but the tissues heal more slowly in those cases.

A much more common and shorter surgery is the one my mother had so long ago.  A total mastectomy.  Not as a pre-emptive strike before cancer, but to remove one that has been found.  Working with plastic surgeons the breast can be reconstructed, but not until after the initial wound heals and if necessary extra skin is stretched by an implant.  During the mastectomies I witnessed, it was hard not to think of my mom or my own potential risk.  I’m glad to know that there are both medical doctors and specialized surgeons training to fight this insidious disease.

Mastectomie
Mastectomie (Photo credit: Wikipedia)

Shadowing: Vascular Surgery

Just blood vessels?  It struck me as too narrow a field to specialize in.  Not as glorious as Cardiothoracic.  But now that I have seen them in action, the vascular surgeons are some of my most admired.  They deal with some of the sickest patients, for the longest times, and unfortunately for many there is no cure…only help.  Here are the three stages of help I’ve seen these surgeons provide.

First, the rarer problem I watched repaired.  With no symptoms, only caught by luck on images for something else (yet can run in families so people may have forewarning).  An aortic aneurysm that ruptures is lethal, usually even in a hospital setting.  So, if one is found they are watched for changes in size.  The surgery is risky enough not to go in prematurely.  Endovascular surgery allows only puncture wounds in the groin to deploy elaborate stents, but the open surgery is still the standard.

Example of a Stent used in an Endovascular ane...
Example of a Stent used in an Endovascular aneurysm repair (Photo credit: Wikipedia)

Similar stents can be used in the all too common arterial blockages.  Whether anatomical anomaly or the build up of plaque in walls, ballooning the vessel is least invasive, and stenting it a secondary option.  We all have at least fatty streaks in our vessels, said one of the surgeons, but hopefully they are not causing ischemia in out tissues.  The original surgery (I’ve not observed) to remove the atherosclerotic region especially of carotid arteries is an arterectomy.  The area is bypassed, opened, the lining stripped away, and the vessel patched back up.  Because it has not foreign material added, the vessel heals itself relatively well but the surgery is much harder on the patient than femoral access for newer methods.

Finally, the sad result of the tissue ischemia.  Due to the vessel injuries by diabetes, many will develop neuropathy.  The most distal tissues have the longest paths so blood resistance is highest to the feet.  When blockages in the lower limbs occur, muscle and skin of toes often die leading to gangrene.  The saddest day of surgery I observed was when a whole shift was scheduled for amputations.  However, the doctor gave me this  bit of encouragement.  The sooner he removes a small dead area (single toe at best), the faster the patient is able to get back to their lives.

English: Vascular of the toes with the charact...
English: Vascular of the toes with the characteristic . (Photo credit: Wikipedia)

Arrivederci Italia!

IMG_2596Salve i miei colleghi!

In my previous post about Anatomia Italiana 2013 our group had just visited the La Specola anatomical wax museum at the University of Florence. Since then we visited two other collections of anatomical waxes, and the historic anatomy theater at the University of Bologna. Present here also are Luigi Galvani’s tools for his neurophysiology experiments. Amazing! Pictured above, Prof. Alessandro Ruggeri discusses the historic collection of specimens at the Luigi Cattaneo Museum, which is in the present anatomy department at the University of Bologna.

Once we moved onto to a four day stay in Venice, we took a brief train ride for a day visit to the University of Padau. Here we got to see the oldest permanent anatomy theatre (1595), the location of anatomic study by the likes of William Harvey. Was it here that Harvey entertained his first thoughts on the nature of the circulatory system? An added bonus was to sit within the lecture hall of Galileo, and stand before his podium.

The sense of history that our group experienced was personally rewarding, and truly a professional development exercise. We often shared ideas on how to incorporate what we learned on this venture into our classes.

Anatomia Italian 2013 concluded this weekend after two weeks in Italy. Most of us have returned home by now, while a few in the group extended their stay in Europe. All of us, however,  will never forget our journey back in time to the venues where anatomy as a science in medical education began.

The exciting idea about all of this is that in 2014 HAPS members can participate in Anatomia Italiana and also enroll in a three-unit HAPS-I course. A month of online readings prior to the travel experience, followed by the submission of a teaching element after a visit to Italy is the essence of the course. If the 2014 HAPS-I Anatomia Italiana course is something you are considering, you can download the syllabus by clicking here. Details are also on the HAPS-I registration page, which can be visited by clicking here. The entire travel program can be reviewed at the Anatomia Italiana webpage. Keep in mind that it is also an option to travel with Anatomia Italiana and not enroll in the HAPS-I course.

IMG_2709Buona giornata, e ci vediamo a presto,

Kevin Petti, Ph.D.
San Diego Miramar College

Shadowing: Plastic Surgery

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After multiple shifts with plastic surgeons in the OR they take over after mastectomies or other cancers are removed.  They are called to the Emergency room to evaluate superficial , I appreciate not only their physical skill, but the variety of their patients trauma.  In clinic, they see those hoping for cosmetic fixes (closing a diastasis between the rectus muscles) and those needing long-term wound care from paralysis.  They also work on the damage caused by gunshots (sometimes while the patient is under police guard).

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In clinic the residents and medical students do a first pass with each patient, then the attending joins them to finish up.  Though a slow process, the teaching that occurs is obvious.  One particular case highlighted the need for remembering or reviewing anatomy.  The patient, a woman in her early thirties, went to the emergency department on the weekend.  She claims to have grabbed the wrong end of a “butter-knife” in order to cut some cake.  The cuts on her dominant right hand were located at the metacarophalangeal joints of fingers four and five.  After her wounds were cleaned she was asked to move each digit.  The pinkie finger would not comply.  The residents opened the skin wider to confirm the flexor tendons were intact.  While they saw and pulled on one, getting the appropriate response, at this site the superficialis divides and hides.  Though they stitched her up and expected all would be well in a week, at clinic the attending took one look at the straight finger and suggested surgery to repair a cut tendon.  The residents did no harm, and learned to be a bit more thorough even when called in on such a small injury.