A review by member Croy Thomson of the talk

Professor Sian Harding

Having blazed through the Society AGM in under ten minutes (the lady sitting next to me timed it), Professor Pat Monaghan, resplendent in President’s Medal bling, introduced Professor Sian Harding, who helped us explore a subject close to everyone’s heart.

The human heart, that “miracle of motion” (©Monaghan), is no mere muscle but a product of 500 million years of evolution that has yet to be acceptably replicated in artificial form. Artificial hearts do exist, but as yet they cannot match the real thing in its subtle complexities and tirelessness: the average human heart beats 100,000 times a day, 3,000 million times in a lifetime.

Your heart, unlike your hair, skin, nails and other bits of you, does not regenerate itself. Half of the cells in your heart will last you all your life, and we sometimes have to rely on stents and bypasses. Professor Harding highlighted the many threats to our hearts: aging, smoking, diabetes, infections, chemotherapy, genetics, emotional shocks and more. Delivery was rapid-fire – Harding spoke quickly but the pace heightened the impact. Her wit was quick too, in the Q&A: “Yes, alcohol is a threat to the heart, but a little is okay, so enjoy your wine later.” Much laughter.

Fascinating factoids include the heart having a “mini brain” of its own that forewarns the main brain of changes in heart rhythm. Then there’s the Fear Intensity Rating, derived from experiments involving frightening people (who volunteers for such things?). There really is a Broken Heart Syndrome, and the remarkable Taktsubo Syndrome where, in reaction to shock, the heart changes shape and looks like an octopus in a pot. Yum. Hearts can be transplanted but not repaired because to repair a heart necessitates stopping it, which kills the patient. Hey, you can’t have everything. And how about, “Being Too Happy Can Kill You”? That’s Sun newspaper headlines for you.

News to gladden the heart: treatments for heart disease can be as quick and cheap as aspirin, or a walk in the park. There are effective defibrillator implants and valve repair surgery. Work is ongoing on human tissue patches and the regeneration of suitable muscle tissue (grow your own heart?).

Embryonic stem-cell-derived solutions offer promising results but are encountering moral objections. There’s tissue engineering, which I thought was a form of origami, but is a step into the modelling of heart structure. 3D printed hearts are being, er, pumped out, but they’re not matching the original.

Familiar with the movie Bladerunner and its rogue humanoid-robot replicants? They’re probably on their way, but meantime Professor Harding’s book The Exquisite Machine will reveal more of the heart’s astonishing engineering. For balance, read Mikhail Bulgakov’s Heart of a Dog.

Ultimately the talk was an advanced insight into the wonder of the human body and human ingenuity in finding better ways to live longer, healthier, better-quality lives.

Questions included: “What happens if you try to defibrillate someone not yet dead?  And, from a heating engineer, “The heart is a pump, and pumps inevitably wear out, so does the medical fraternity live in denial that people just live and must die? So, does societal difference affect the heart?” To which the answer was, “Society would benefit if poorer people had more money.”

Here endeth the 2023/24 season of talks. Next season commemorates the 200th anniversary of the birth of the inspirational Lord Kelvin, an event that can equate only to Great Stuff Ahead.

Sian Harding is Emeritus Professor at Imperial College London where she was Head of the Cardiovascular Division as well as Director of the British Heart Foundation Cardiovascular Regenerative Medicine Centre. Her scientific work has focused on new techniques of gene and cell therapy. She nimbly fielded questions from all directions and thoroughly earned her Graham Medal and Society paperweight.

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