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122 Cards in this Set
- Front
- Back
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MYOCARDIAL CELLS
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specialized cylindrical cells that relax and contract, changing the shape of the heart.
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WHAT KIND OF PACEMAKER DOES THE HEART HAVE?
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The heart has an INTRINSIC pacemaker; The heart generates electrical impulses that travel along a specialized conduction pathway.
*This is the hearts AUTOMATICITY* |
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WHEN WAS THE FIRST PACEMAKER IMPLANTED IN THE USA?
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In 1960, by Dr. C. Walton Lillehei.
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HOW DOES A PACEMAKER WORK?
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The electrical circuit in which the battery provides electricity that travels through a conducting wire to the myocardium.
The myocardium stimulates the heart to the beat (capture). |
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THE PULSE GENERATOR
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-contains a battery that provides the energy for sending electrical impulses to the heart.
-houses the circuitry that controls pacemaker operations. |
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PACING THRESHOLD
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-the amount of energy the output pulse needs (V and ms) to reliably capture the heart (or cause it to contract)
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MYOCARDIAL AND EPICARDIAL LEADS
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-leads that are directly applied to the heart.
-fixation mechanisms include: epicardial stab-in, myocardial screw in, and sutuure-on. |
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WHY DO WE NEED TO PACE?
SYMPTOMATIC BRADYCARDIA |
-2* Type II
-CHB/3* Block |
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WHY DO WE NEED TO PACE?
UNCONTROLLED TACHYCARDIAS |
-A fib
-A flutter -SVT -VT |
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SYMPTOMATIC BRADYCARDIA
C R A P |
-weakness, fatigue, syncope/pre-syncope, mental confusion, palpitations, shortness of breath, exercise intolerance.
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PACING MEANS?
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capturing the heart
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SENSING MEANS
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"seeing" the heart's own intrinsic rhythm (like a periscope). The pacer then decides if it inhibits or triggers an impulse to be sent out or not.
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TYPES OF PACEMAKERS
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-Transcutaneous: skin pads which are external.
-Temporary: lead or wire is threaded transvenously to the RV with the wire to a power source externally. -Permanent |
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FIXED RATE
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set at a rate, no change
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DEMAND
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fires when needed if heart rate falls BELOW threshold
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UNDER SENSING
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competition with underlying rhythm
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OVER SENSING
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detects stimuli other than heart beat
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FAILURE TO CAPTURE
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(noncapture) pacer does not stimulate heart
*failure to capture and failure to pace mean the same thing. |
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WHAT IS UNDERSENSING CAUSED BY?
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-inappropriately programmed sensitivity
-lead dislodgement -lead failure: insulation break; conductor fracture |
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WHAT IS NONCAPTURE CAUSED BY?
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-lead dislodgement
-low output -poor connection at connector block -lead failure |
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LESS COMMON CAUSES OF NONCAPTURE MAY INCLUDE
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-Twiddler's Syndrome
-Electrolyte abnormalities (ex: hyperkalemia) -Myocardial infarction -Drug therapy -Battery depletion |
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WHERE IS THE PACER PLACED?
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on the non-dominant side
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NURSING MANAGEMENT OF PACER
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-monitor EKG
-Risk for infection -MICRO-SHOCKS: WEAR GLOVES -Electromagnetic interference (EMI) -Pacer system integrity -Documentation -Discontinuing |
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MONITOR PERMANENT PACER
PRE-OP |
-what to expect
-teaching how to check pulse -card regarding pacer info |
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MONITOR PERMANENT PACER
POST-OP |
-avoid reaching above head on affected side
-know symptoms of decreased cardiac output |
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MONITORING PERMANENT PACER
PATIENT TEACHING |
-check pulse daily
-watch for infection -sx of decreased cardiac output -avoid electrical interference -identification -pacer checks -do not get MRI's -tens units will mess it up -cauderized defibrillators |
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ELECTROMAGNETIC INTERFERENCE (EMI)
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-interference caused by electromagnetic energy from a source that is outside the body
-electomagnetic fields that affect pacemakers are radio-frequency waves -few sources of EMI that affect pacemakers are found in the home or office, but several exist in hospitals |
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EMI MAY RESULT IN THE FOLLOWING:
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-oversensing
-transient mode change -reprogramming |
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COUNTERSHOCK
"DEFIBRILLATION"...Unsynchronized Documentation |
-rhythm prior to defib
-# of defibs and joule level -rhythm after shocks -assessment of client -post care: monitor VS, EKG, maintain IV -Assess, Assess, Assess |
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COUNTERSHOCK
"Cardioversion"...Synchronized |
-used for unstable VT, pulse present, unstable PSVT, Afib, and Aflutter
-These people have a pulse -too fast and we need to slow them down so we countershock |
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HOW THE PACEMAKER COMPONENTS COMBINE W/BODY TISSUES TO FORM A COMPLETE CIRCUIT
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-pulse generator is the power source or battery
-leads or wires -cathode (negative electrode) -anode(positive electrode) -body tissue |
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PACEMAKERS CONTAIN WHAT?
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-mini computers and batteries in a sealed titanium case with an epoxy connector block that links electrically to the inside of the unit.
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WHEN CHECKING THE A PT'S PACING THRESHOLD WHAT DO WE DO?
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-double that as the "safety margin" to make sure the output pulse is always sufficiently large to capture the heart.
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WHAT HAPPENS WHEN A MAGNET IS PLACED OVER AN IMPLANTED PACEMAKER?
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-it closes the reed switch and forces the device into magnet mode, which is usually asynchronous pacing.
-when the magnet is removed the device reverts back to normal behavior. |
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LEADS ARE INSULATED WIRES THAT DO WHAT?
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-deliver electrical impulses from the pulse generator to the heart.
-sense cardiac depolarization |
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PASSIVE FIXATION LEADS
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-the tines become lodged in the trabeculae (fibrous meshwork) of the heart.
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ACTIVE FIXATION
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-the helix (or screw) extends into the endocardial tissue.
-allows for lead positioning anywhere in the heart's chamber. |
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MYOCARDIAL AND EPICARDIAL LEADS
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-leads applied directly to the heart
-fixation mechanisms include: epicardial stab-in, myocardial screw-in, and suture-on. |
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WHY DO WE NEED TO PACE?
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-symptomatic bradycardia
-uncontrolled tachicardias |
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SYMPTOMATIC BRADYCARDIA
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-2* Type II
-CHB/3* block |
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UNCONTROLLED TACHYCARDIAS
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-AFib
-A flutter -SVT -VT |
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TYPES OF PACEMAKERS
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-Transcutaneous (skin pads-external)
-Temporary: lead or wire is threaded transvenously to the RV with the wire to a power source expternally -Permanent |
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FIXED RATE
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-set at a rate, no change
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DEMAND RATE
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-fires when needed if heart rate falls below threshold
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SINGLE CHAMBER
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-RA or RV
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DUAL CHAMBER
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-Both RA and RV
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NBG CODES
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-1st letter: chamber paced
-2nd letter: chamber sensed -3rd letter: device response to sensed beat (inhibited or triggered) -4th letter: programmability -5th letter: anti-tachycardia function |
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CARDIOVERSION RECOVERY WE WATCH FOR?
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-recover from IV sedation
-monitor rhythm -VS -Return of gag/swallow -medications: cardizem or verapamil |
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INSTRUCTIONS FOR DISCHARGE
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-meds
-documentation: rhythm prior to cardioversion, number of cardioversion attempts, rhythm after cardioversion and assessment of the client |
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PCD DEVICES
(Pace/Cardiovert/Defibrillate) |
-used for sudden cardiac death and refractory tachycardias
-generator/ leads and patches -programmable: monitors and recognizes rhythms, overdrive for tachys, defibrillates lethal arrythmias |
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ICD
(Internal Cardiac Defibrillators) |
-sense, pace, shock
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ICD'S
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Will I get shocked? Yep
What will it feel like? Shock! will I know it? Yep |
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WHAT IS THE TREATMENT FOR 3* HEART BLOCK?
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-Need a permanent pacer.
-look at cardiac output to see if you need SWAN |
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INDICATIONS FOR PACING?
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-2* Type II
-3* Heart Block -Uncontrolled tachys -AF, SVT, VT, |
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WHAT DOES FAILURE TO CAPTURE MEAN?
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-pacer does not stimulate the heart...it does not respond
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POST INSERTION CARE OF PACEMAKER
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-educate
-card -do not elevate arms or head -s/sx of infection -s/sx of decreased cardiac pacer |
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THINGS TO REMEMBER ABOUT PACERS AND MAGNETS?
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-it closes the reed
-magnet acts as a switch -can make asynchronous pacing. |
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TYPES OF PACEMAKERS
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-ICP
-Temporary -Permanent -Transthoracic |
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FAILURE TO OUTPUT
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-pacer does not generate a pacer spike when needed
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DEFIBRILLATION
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-asynchronization puts heart into temporary asystole
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AED
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-cues the rescuer
-place pads -analyze -shock if needed |
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WHAT SHOULD YOU WEAR TO AVOID MICROSHOCKS?
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-wear gloves when handling temporary unit
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SYNCHRONIZED CARDIOVERSION
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-machine synchronizes with QRS
-fires when it senses |
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ICD
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-defibrillates when needed.
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WHAT IS HEMODYNAMICS?
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-systemic circulation of blood
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3 PARTS HEMODYNAMICS IS COMPOSED OF?
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1.) Preload
2.) Contractility 3.) Afterload |
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PRELOAD
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-circulatory effects before blood reaches the heart
-VOLUME, VOLUME, VOLUME!!!! MEASURED BY PA PRESSURE AND CVP. |
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WHAT NEEDS TO BE DONE TO DECREASE CONTRACTILITY
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-decrease preload
-balance electrolytes -IABP (allows heart to rest) -give Beta Blockers |
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WHAT NEES TO BE DONE TO INCREASE CONTRACTILITY?
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-increase preload (gotta get more in there)
-give inotropic drugs -VAD |
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AFTERLOAD
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-circulatory effects as blood leaves the heart resistance or pressure that the ventricle must overcome to eject volume
-Aorta Valve Vessel Constriction -Measured by BP -circulation as it leaves the heart' |
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DECREASED PRELOAD
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-Is pt hypovolemic?
-Diuretics given? -bleeding? -Vasodilators given? -DRY!!!! |
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INCREASED PRELOAD
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-increased fluid administration?
-volume expanders given? -vasoconstrictors given? -blood products given? -WET!!!!!!!! |
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CONRACTIBILITY
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-cardiac muscle's capacity to contract
"stretch" |
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WHAT IS NON-INVASIVE HEMODYNAMIC MONITORING?
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BP Monitoring
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HOW DO YOU DECREASE AFTERLOAD?
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-give vasodilators
-give ACE Inhibitors(prils) -Calcium Channel Blockers |
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HOW DO YOU INCREASE AFTERLOAD?
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-give vasopressors or vasoconstrictors
-give dopamine |
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3 COMPONENTS OF HEMODYNAMIC MONITORING EQUIPMENT
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-Transducer
-Monitor -Fluid-filled catheter, tubing and flush system |
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Colors for tube flushing
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Red-Arterial line
Blue-CVP Yellow-PA pressure Orange-Neuro ICP monitoring |
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WHAT IS THE TRANSDUCER?
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-the instrument used to sense physiological events and transforms them into electrical signals
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WHAT DOES THE MONITOR DO?
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-records and provides a display of the original signal
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FLUID FILLED CATHETER
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-placed in an artery(ABP)
-rigid tubing -<48 in -attached to flush device that controls flow of solution thru the tubing -flush solution in NS or Heparin -bag to a pressure of 300 mmHG -flow rate of flush solution 3-5 mL/hr-additional 9 mLs an hr for their I & O's..to keep lines clear |
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PHLEBESTATIC AXIS
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-marked on the patient's chest, is the precise anatomical point of origin of the hemodynamic pressures being measured
-4th ICS |
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ZERO REFERENCING
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-the act of standardizing the transducer to obtain accurate measurements
-the act is performed by nurse upon insertion, q4h, or with position change. this is performed to all hemodynamic lines -Zeroing opens the system to the atmosphere and off to patient, press zero negates atmospheric pressure. |
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ARTERIAL PRESSURE MONITORING
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-accurate, direct and invasive
-continuous BP readings -used for lab draws -most commonly used hemodynamic technique -perform Allen's test prior to radial insertion -do NOT give any meds thru Art Line! |
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CENTRAL VENOUS PRESSURE
(CVP, RAP) |
-measures volume returning to heart
-normal value is 2-6 mm Hg *Look at fluid balance *CVP is altered by change in venous tone,blood volume and RV contractility **CVP looks at fluid balance |
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IF PATIENT HAS INCREASED CENTRAL VENOUS PRESSURE
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-fluids given?
-hypervolemic? -pulmonary HTN? -Increased ITP (intrathoracic pressure) -Tamponade (extra fluid in the pericardial sac) -WET!!!!!!!! - |
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IF PATIENT HAS DECREASED CENTRAL VENOUS PRESSURE
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-hypovolemia
-vasodilation -sepsis -DRY!!!!!! |
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PULMONARY ARTERY PRESSURE
(PA) |
-measures pressure of blood volume in the lung circulation
-normal value: 15-30/0-5 -indirect method of monitoring LV preload |
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PA MONITORING
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-catheter is placed in the pulmonary artery via subclavian or jugular vein
-pt in Trendelenburg position |
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PA MONITORING
TYPES OF CATHETERS |
-4 lumen (manual CO)
-5 lumen (continuous CO) -SVO2 monitoring "SWAN" |
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PA MONITORING
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-RN responsible for monitoring and recording HR and rhythm w/ BP
-inflate and deflate balloon per dr. order -document measurement of catheter length post insertion -ensure portable CXR done post insertion. |
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WHY USE A CXR POST INSERTION OF PA MONITOR
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-check placement
-make sure there is no pneumothorax -normal length should be 55-60 sonometers |
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INSERTION WAVEFORMS
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-when a PA monitor is inserted, ventricular irritability may show up on EKG...showing some PVC's.
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PULMONARY ARTERY WEDGE PRESSURE
(WEDGE, PAWP,PACWP) |
-measures volume blood returning to LV
-normal values: 5-12 mmHg |
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IF DECREASED WEDGE
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-hypovolemia
-vasodilation -RV failure -DRY!!!!!! |
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IF INCREASED WEDGE
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-hypervolemic
-vasoconstriction -WET!!!!! |
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NOTES ON WEDGE PRESSURES
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-may use PAD as estimation of wedge in pt's with "normal" valve and lung function
-PAWP is checked at end of expiration* -Always ensure that baloon is deflated after wedging catheter! |
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SYSTEMIC VASCULAR RESISTANCE
(SVR)*vessel size* |
-measures amount of work required by LV to push blood through vessels
-normal value: 800-1200 dynes/sec/cm2 -also looking at viscosity of the blood |
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MORE NOTES ON SVR
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-infections
-pneumothorax -ventricular arrythmias -pulmonary infarc...forgetting to deflate the baloon -thrombosis -fistulas |
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IF DECREASED SVR
(low #'s) |
-vasodilation
-sepsis -acid/base imbalances -DRY!!!!! (give vasoconstrictors...epi, norepi, etc.) |
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IF INCREASED SVR
(high #'s) |
-vasoconstriction
-hypervolemia -hypothermia (cold and constricted) -WET!!!!!!!! |
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STROKE VOLUME
CO/HR |
-measures volume ejected by LV with each beat
-normal value: 60-100 mL/beat |
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IF DECREASED SV
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-hypovolemic
-decreased contractility -low #'s -DRY!!!!!! |
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IF INCREASED SV
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-hypervolemia
-CHF -high #'s -WET!!!!! |
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CARDIAC OUTPUT
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-measures volume of blood ejected by the heart per minute (CO=SVxHR)
-normal value: 4-8 LPM -preload, contractility, afterload has to be good |
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IF DECREASED CO
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-hypovolemia
-decreased HR -cardiogenic shock...our pump has failed -increased SVR -DRY!!!! |
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IF INCREASED CO
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-hypervolemia
-increased HR -Inotrophic drugs -WET!!!!!!!!!!!!!! |
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CARDIAC INDEX
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-measures CO adjusted for body size (CI=CO/BSA)
-normal value: 2-4 L/min/m2 |
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BSA
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-body surface area
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MIXED VENOUS OXYGEN SATURATION
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-measures oxygen saturation of Hgb molecules returning to heart
-normal values: 60-80% |
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IF DECREASED SVO2
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-decreased ventilation/perfusion
-increased O2 consumption-fever sepsis -hypovolemia -anemia |
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IF INCREASED SVO2
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-decreased O2 consumption
-Sepsis -Hypovolemia (cold) |
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CHARTING
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-location of line
-site -dressing -zeroing line -where Swan is at in reference to introducer -taped securely -if connected to continous cardiac output monitor -waveforms |
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DOPAMINE AND LASIX ARE ORDERED. WHAT IS THE RATIONALE FOR THESE DRUGS?
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-get fluids out, increase pressure with dopamine.
-BP and HR will increase |
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WHAT NURSING CARE IS ASSOCIATED WITH THE ADMINISTRATION OF DOPAMINE AND LASIX?
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-I and O's
-heart rate -lung sounds -check K+ levels -telemetry (CVP and arterial line) |
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IF THE CARDIAC INDEX IS BELOW 2 WHAT DOES THIS MEAN?
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-patient is in deep shock
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DRUGS USED TO INCREASE PRELOAD
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VOLUME EXPANDERS
-NS -LR -Hetastarch (Hespan) -Albumin -Blood products |
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DRUGS USED TO DECREASE PRELOAD
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DIURETIC AGENTS
-Furosemide (Lasix) -Torsemide (Demadex) VENOUS DILATORS -nitroglycerine -nitroprusside (Nipride) -Morphine sulfate (note that this is an analgesic agent) |
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DRUGS USED TO INCREASE AFTERLOAD
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VASOPRESSORS
-Dopamine (at higher doses) -Epinephrine -Norepinepherine -Neosynephrine |
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DRUGS USED TO DECREASE AFTERLOAD
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VASODILATORS
-Nitroprusside (Nipride) -Nitroglycerine (at higher doses) -PDE inhibitors -Calcium Channel Blockers -ACE inhibitors -Hydralazine (Apresoline) |
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DRUGS TO INCREASE CONTRACTILITY
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POSITIVE INOTROPHIC DRUGS
-Dobutamine -Dopamine -Epinephrine -Norepinephrine -Isoproterenol (Isuprel) -PDE inhibitors -Digoxin |
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NEGATIVE INOTROPHIC DRUGS
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-Beta Blockers
-Calcium Channel Blockers |
