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    Add as FriendBasic Cardiac Pacing and AICD

    by: Natalie

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    1 : Basic Cardiac Pacing and AICD Why your patients need them and what they do. IU Health Arnett Hospital By Natalie Sims, RN
    2 : Objectives Why would your patient need these therapies? What are the functions of a permanent pacemaker? What is the difference between a pacemaker and an AICD? What is different about Bi-V pacer/ AICD? How do you know that it is functioning properly?
    3 : Review of Cardiac Conduction S-A Node (atrial contraction, rate of 60-100) A-V Node (Delays impulse to allow ventricles to fill, rate of 40-60 if S-A node fails) Bundle of His (begins conduction to ventricular system, rate of 40-60 Bundle Branches & Purkinje Fibers (rate of 20-40, “escape rhythm”)
    4 : Why would your patient need a Pacemaker? Periods of asystole 3rd Degree AV Block 2nd Degree type 2 AV Block Sick Sinus Syndrome Symptomatic bradycardia (dt AV Block or 2nd to medications) Symptomatic 1st Degree AV Block AV nodal ablation due to control afib
    5 : Pacemakers- What do they do? They sense the patient’s own (intrinsic) rhythm. They pace when the patient’s rhythm does not come through. Intrinsic rhythm Paced beat Think of a pacemaker like a clock. A specific amount of time is programmed and if the heart does not beat when the time is up, the pacemaker delivers an impulse.
    6 : Pacemaker Modes VVI : Pacing in V, Sensing in V, Withhold if patient comes through on their own. DDD: Pacing in A & V, Sensing in A & V, will pace if there is a p-wave and withhold pacing if the patient has intrinsic beats. DDI: Pacing A&V, Sensing A&V, Withhold if patient comes through. (this is good for aflutter) Examples
    7 : Pacing Examples Ventricular Pacing Pacing impulse stimulates Ventricle Atrial Pacing Pacing impulse stimulates atrium Intrinsic conduction sends the impulse to the ventricles in this example
    8 : Pacing Examples Dual Chamber Pacing Atrial impulse followed by ventricular impulse 1. A-Pace 3. V-Pace 2. A & V Pace This is a DDD device A Pace followed by intrinsic QRS A&V Pace Intrinsic P-wave followed by V Pace
    9 : Pacemaker Components Leads Single chamber (atria or right ventricle) Dual Chamber (atria and right ventricle) Bi-Ventricular (atria, right ventricle, and left ventricle. We will expand on this later) Generator contains circuitry and battery The “brain”
    10 : Pacemaker Placement Usually placed through left subclavian vein May be placed in right subclavian if the left is blocked Older devices may be located in the abdomen (the original devices were much larger)
    11 : Pacemakers: What Else Can They Do? Rate Response Chronotropic Incompetence: the heart rate does not elevate with activity. Thus, when the patient is active, they are not getting the cardiac output they need to sustain activity. Rate Response elevates the heart rate based on patient movement. Usually allows the rate to go up to 120 or 130. This is done with a sensor that senses movement. The more the patient is moving, the higher the rate will go. Some devices sense respiratory rate as well. Keep this in mind if you notice fast pacing and your patient is breathing fast!
    12 : Pacemakers: What Else Can They Do? Audible alerts For low battery, lead fracture or breakage. Other alerts may be company specific. Home Monitoring: Most devices can be monitored from home, some wirelessly. The equipment is specific to each company. Each transmitter hooks to the patient’s land-line phone and will send the uploaded info to the office.
    13 : What Does a Magnet Do to a Pacemaker? If you place a magnet over a pacemaker, it will stop sensing and continuously pace. This is useful if a patient is having surgery. When cautery is used the pacemaker may “think” that the impulses from the cautery are heart beats, when in reality, the patient may have no heart beat. The magnet makes the pacemaker “blind” to all activity. Place magnet directly over device.
    14 : AICD’s (Automatic Implantable Cardioverter-Defibrillator) Is also a pacemaker! Larger than a pacemaker because it can charge up to defibrillate VT or VF. RV lead is larger than a pacing lead because it contains the coils through which a shock is delivered. May also be used to cardiovert afib in a hospital setting
    15 : Why Would Your Patient Need an AICD? Cardiac arrest 2nd to VT or VF Non-sustained VT due to prior MI Structural heart disease with sustained VT EF <35% with NYHA II/III Genetic conditions with a high risk for VT such as long QT or hypertrophic cardiomyopathy
    16 : AICD Therapy Senses and paces Senses and treats fast rhythms by charging and delivering a shock is indicated. The device has a set rate that classifies a rhythm as VT. Often it is 180bpm or above. When the heart rate reaches or exceeds the set rate, it can try to pace the patient out of the rhythm. This is painless. If the pacing is unsuccessful, the device will charge and shock. This is painful. For VF (usually somewhere above 200bpm) the device skips the pacing and shocks The Settings are physician/patient specific
    17 : AICD Sensing When VT or VF is sensed, the device will charge up to shock if indicated. The device will re-check the rhythm after charging to ensure that the patient still needs a shock. The amount of energy used in each shock is programmed based on the DFT or Defibrillation Threshold Test. This test tells us the minimum amount of energy used to defibrillate. Usually anywhere from 15-40 Joules
    18 : AICD Sensing If the patient did not convert, the AICD will attempt another shock. Depending on the manufacturer, it may make up to 6 attempts to defibrillate. Paced beat 15J Shock
    19 : Bi-Ventricular Pacing (CRT Devices) A 3rd lead is inserted into the coronary sinus and placed on the left ventricle. This lead is in a vein that is actually on the left side of the heart. (Cardiac Resynchronization Therapy)
    20 : Why Bi-V Pace? Indications: NYHA class II-IV with EF <35% and QRS >120ms Widened QRS indicates that 1 side of ventricle is contracting before the other. Bi-V pacing helps both sides to contract at the same time to improve cardiac output. Can have LV lead with pacemaker or AICD (when indicated)
    21 : Bi-V results With synchronous pacing on right and left sides of the heart, the QRS is shorter. Before With Pacing **With these devices, you may occasionally see 2 spikes in the QRS. Note the 1st spike, in its usual place. The second spike appears to occur in the middle of the QRS. For this patient, the LV paces first followed by the RV, this causes left & right ventricular synchrony
    22 : Examples of Pacemaker Malfunctions Normal Function Under-sensing: Pacing Spikes Despite intrinsic rhythm Pacing Spikes with no cardiac response
    23 : Examples of Pacemaker Malfunctions Failure to Capture Pacing spike with no QRS Under-Sensing (not sensing enough), Device is not seeing the intrinsic beats Over-Sensing (Seeing too much), Device is not delivering pacing impulses because it thinks it sees intrinsic activity
    24 : What Do You Do for Malfunctions? Call MD Call Natalie or the device company to interrogate the device.
    25 : References

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