Commentator Discussion: Acute loss of mitral annular dynamics predicts development of functional mitral regurgitation after myocardial infarction in a swine model

Thank you and thank you for the opportunity to discuss this work.So, you have demonstrated in your study that after you occlude the circumflex artery, the 11 animals that went on to develop mitral regurgitation (MR) showed a change in their anteroposterior (AP) diameter of their mitral valve.And I guess my question goes back a little before the development of the myocardial infarction.What was it about the animals at baseline that accounts for their loss of the AP diameter?Or at autopsy, what differences did you see in those animals that went on to develop MR?Because essentially, they had the same infarct size.They had the same distribution, but some lost their dynamics and some didn't.So, what accounted for that in your model?Dr Yuta Kikuchi (Atlanta, Ga).Thank you for your question and first of all, thank you for being discussant for my presentation.That is a great question, and we did-we have not analyzed the histologic data yet, so in the future, we will do that.We guess some extent of ischemic change or standing heart occurred at my posterior analysis.That is the cause of AP diameter-loss of analyst dynamics.Dr Mick.I guess my question would be, was there a difference in the infarct to the papillary muscles?Was there something else that accounted for it?Because it's a little unsettling to see that you can do the same thing to the same pigs and some of them lose their dynamics and some don't.So, I think that will be a really good area for you to look at in the future.Dr Kikuchi.Yes, our model is, as you know, lateral infarction site model and also usually posterior papillary muscle was involved in the myocardial infarction.But we didn't check the histologic change, so.Dr Mick.It just might be interesting.Dr Kikuchi.Yeah, yeah.Dr Mick.Because your study is to say, "Okay, I've had an myocardial infarction.Will I develop MR in the future and shall I take early action?"But I think just for the greater understanding of the development of ischemic MR, that would be something very useful for the community.Thank you very much.Unidentified Speaker 1.I'm going to push you a little bit further, having worked with Dr Padala knowing the caliber of your laboratory.Have you done cardiovascular magnetic resonance on these animals?Because magnetic resonance imaging is a great way of looking at posterior ischemia and it would allow you to actually tag the tissue and actually see if you're getting changes.Dr Kikuchi.Actually, we have magnetic resonance imaging data.And not included this slide.Next time.Unidentified Speaker 1.One other question, I was interested to hear that you said-are you putting your pressure volume catheters up from the femoral artery and not the carotid?Dr Kikuchi.Yes, from femoral artery.Unidentified Speaker 1.You don't get a lot of interference?Dr Yuta Kikuchi.What?Unidentified Speaker 1. You're not having interference?Because it's a long distance to go, right?Those pig femoral arteries are small.Dr Kikuchi.Yes, exactly.Before joining this laboratory, that is the procedure, so.I don't know the reason, actually.