1
Technology / What are the risks/benefits of an Implantable Cardioverter-Defibrillator (ICD)?
« on: 19/11/2013 21:54:43 »
Hello, this is my first attempt at a post here so please pardon me if it is in the wrong place.
I'm not a medical technologist, just a retired JOAT lab tech, but I do have a very keen interest in the field.
I have a device implanted called and Implantable Cardiac Defibrillator, or ICD (or "box" to the cardiologists!).
This is a titanium cased device, about the size of a mobile phone, located under the left side of the chest with one to three leads going to the heart. It has a pacemaker function but does a lot more. It can produce and store over 30J of energy at about 800V which is delivered directly to the fibrillating heart. It has a bit of a punch - I know, I have had seven such shocks so far!
But, that alone, from the technology point of view, is interesting - it's all the ancillary stuff that, sort of, takes the biscuit. The device monitors the heart constantly with a sliding recording window. Should any notable event happen this will be captured and stored in RAM. The device is fully programmable in terms of what it does and when. If the heart rate goes over what the call "VT1" (Ventricular Tachycardia 1), 120 pulse per second for more than 16 seconds for me, a synchronising signal is produced to persuade the heart to behave. If it does not do so it gets the 800V slap. Should the pulse rate exceed 180 the slap comes even faster.
I have to say there is no residual pain after the shock, you just pick yourself up and phone for a check-up appointment.
So, constant monitoring and a sliding record. Now we have to access that. This is either done with a pick-up coil on the shoulder or, as in the case of my new one, via a wifi type link. Currently I have to go to the lab for this but there are now home readers that send the data down the line from home available. I may not get one because of a potential hardware problem. Had one of them already - more on that later.
The download also includes of info regarding the physical state of the device, pacing % time, lead resistances, charge times, battery life and other parameters.
My current hardware problem is an increasing resistance on one of the leads. Nasty because this not only reduces the efficiency but can create a hot spot - not what you want in your ticker! The last problem was a battery that headed for being flat, at a very rapid pace, half-way through its estimated life. They should last up to 7 years and the last test said it had 3.5 years left at current usage.
Then, one evening, there was this buzzing in the box - it has a mobile phone buzzer built in that goes off at 10% battery life left. By the time I got on the table for the new one there was not enough energy left in it for a therapeutic shock. The op it normally done under a sedative, but I don't think they bothered this time, I was chatting with the cardiologist and he was telling me what he was up to all the time - we have a good relationship.
The same technology has also been used to help those with Parkisonism, the leads go into the brain and it can be "tuned" to suit the user, by the user once the basic parameters are set. The effect of the therapy is fantastic. There is a Youtube clip of this at https://www.youtube.com/watch?v=h8tWlYv1Ykc
Great stuff!
Sorry if this is a bit of an essay but, you can understand, I am all for this kind of tech! So far this device has saved my life twice - my heart recovered just before the shock on the other five times.
I'm not a medical technologist, just a retired JOAT lab tech, but I do have a very keen interest in the field.
I have a device implanted called and Implantable Cardiac Defibrillator, or ICD (or "box" to the cardiologists!).
This is a titanium cased device, about the size of a mobile phone, located under the left side of the chest with one to three leads going to the heart. It has a pacemaker function but does a lot more. It can produce and store over 30J of energy at about 800V which is delivered directly to the fibrillating heart. It has a bit of a punch - I know, I have had seven such shocks so far!
But, that alone, from the technology point of view, is interesting - it's all the ancillary stuff that, sort of, takes the biscuit. The device monitors the heart constantly with a sliding recording window. Should any notable event happen this will be captured and stored in RAM. The device is fully programmable in terms of what it does and when. If the heart rate goes over what the call "VT1" (Ventricular Tachycardia 1), 120 pulse per second for more than 16 seconds for me, a synchronising signal is produced to persuade the heart to behave. If it does not do so it gets the 800V slap. Should the pulse rate exceed 180 the slap comes even faster.
I have to say there is no residual pain after the shock, you just pick yourself up and phone for a check-up appointment.
So, constant monitoring and a sliding record. Now we have to access that. This is either done with a pick-up coil on the shoulder or, as in the case of my new one, via a wifi type link. Currently I have to go to the lab for this but there are now home readers that send the data down the line from home available. I may not get one because of a potential hardware problem. Had one of them already - more on that later.
The download also includes of info regarding the physical state of the device, pacing % time, lead resistances, charge times, battery life and other parameters.
My current hardware problem is an increasing resistance on one of the leads. Nasty because this not only reduces the efficiency but can create a hot spot - not what you want in your ticker! The last problem was a battery that headed for being flat, at a very rapid pace, half-way through its estimated life. They should last up to 7 years and the last test said it had 3.5 years left at current usage.
Then, one evening, there was this buzzing in the box - it has a mobile phone buzzer built in that goes off at 10% battery life left. By the time I got on the table for the new one there was not enough energy left in it for a therapeutic shock. The op it normally done under a sedative, but I don't think they bothered this time, I was chatting with the cardiologist and he was telling me what he was up to all the time - we have a good relationship.
The same technology has also been used to help those with Parkisonism, the leads go into the brain and it can be "tuned" to suit the user, by the user once the basic parameters are set. The effect of the therapy is fantastic. There is a Youtube clip of this at https://www.youtube.com/watch?v=h8tWlYv1Ykc
Great stuff!
Sorry if this is a bit of an essay but, you can understand, I am all for this kind of tech! So far this device has saved my life twice - my heart recovered just before the shock on the other five times.