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ICD False Alarms


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Robert Hartwell Find out more about Robert Hartwell
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  • ICD False Alarms

    I have a question for those of you who have ICD's. I have been told that these devices can trigger falsely, ie trigger when there is not reason to, about 25% of the time. To me this seems like a very high rate. I was just wondering what some of your experiences were and whether newer versions of the ICD function better.

    Bob Hartwell
    Cleveland Myectomy Crew
    Member since November 2002

    \"Chance favors the prepared mind!\"

  • #2
    Bob, I don't know the percentage, but I'm sure someone will have that info available. A better description might be "an inapproiate shock". The rhythm interpretation function is becoming more refined and accurate all the time, but is not fool-proof. Big criteria is the rate. The device will be programmed for each individual to provide therapy if the rate goes above a certain number and stays there for a certain amt of time rather than resolving on it's own. Some people will have short episodes of atrial or ventricular tachycardia that resolves on it's own and you wouldn't need a shock then. The newer devices are becoming sophistocated enough to determine if it is atrial or ventricular tachycardia. Atrial may not require a shock or maybe just a lower energy level than ventricular tach. All this is very individualized. The one time my son's ICD fired was for a rapid Atrial fib - rate of 226 - pretty fast. His doctor told him "it was not an inappropriate shock, but also not a necessary one". The device couldn't tell that it was atrial as he was being paced which will cause the ventricular wave form to be wider and resemble a ventricular tach rather than atrial tach. The machine errs on the side of caution. So, these are only some of the varibles. Also, our doctor didn't consider this "inappropriate", whereas HCM experts would have reported it as "inappropriate". We need more consistancy in standards for reporting too. I would think 25% seems high for a false with no reason at all, but might not be out of line for the sort of experience I just told you of for our son. Let's see what others have to say. I know I haven't covered it all. Linda


    • #3

      dear bob,

      where did you get that number? Have you looked at guidant's and medtronic's web sites for data?



      • #4

        Thank you for such a wonderful reply, I appreciate it.


        Ask me again tomorrow when I see you. I did not check the manufacturers web sites as I was more interested in people's experiences.

        Cleveland Myectomy Crew
        Member since November 2002

        \"Chance favors the prepared mind!\"


        • #5
          I've had my icd for 5 years now with no shocks at all. My 13 year old has had his for 2 !/2 years with 5 shocks, all appropriate for v-fib. We both have units made by Guidant.


          • #6
            Inappropriate shocks

            I follow a website for people with ICDs. The devices have been implanted over the past 8 or so years for various reasons and by all sorts of different types of doctors in various (English speaking) countries with who knows what training. There are frequent reports of inappropriate shocks. At the same time, I see few or no complaints on this website of inappropriate shocks from among the many who have ICDs.

            This has lead me to believe that Lisa's constant reminder to see a specialist--someone who has done the similar procedure successfully many times--is saving us from having problems.

            As for me, I've had an ICD for six months and have had it checked for activity every three months. At both checks I learned that a lone VT run started the ICD charging up for a shock and then when it sampled my heart beat again, it aborted the shock because it was no longer necessary. The newer models of ICD are pretty sophisticated.

            So far I have no concerns about an inappropriate shock. And if I get an appropriate shock, I will thank my ICD, and the doctors involved with recommending and implanting it, that I am still alive.



            • #7

              Not VT run but V fib run. Sue


              • #8
                I had my ICD check yesterday...I am happy to report...IT HAS DONE NOTHING! It has recorded nothing!!!
                It is just sitting in wait for the oppurtunity to play "hero", and I am glad to have there!
                Knowledge is power ... Stay informed!
                YOU can make a difference - all you have to do is try!

                Dx age 12 current age 46 and counting!
                lost: 5 family members to HCM (SCD, Stroke, CHF)
                Others diagnosed living with HCM (or gene +) include - daughter, niece, nephew, cousin, sister and many many friends!
                Therapy - ICD (implanted 97, 01, 04 and 11, medication
                Currently not obstructed
                Complications - unnecessary pacemaker and stroke (unrelated to each other)


                • #9
                  I second that! I had my ICD check yesterday too! Nada! I'm happy about that!

                  Mary S.


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