chapter 26 cardio

Atrial arrhythmias

Are outside the Sinus Node and they develop premature atrial contractions, supraventricular tachycardia, atrial flutter and atrial fibrillation.

Main indication for inserting a Permanent pacemaker is?

By a complete or second degree heart block accompanied by a slow ventricular rate. It is inserted transvenously and the pacing threshold, voltage, and rate are set

Power of the pacemaker

By mercury, lithium, or nuclear powered batteries.

Antiarrhythmic drugs

Ibutilide- used to convert new onset atrial fibrillation into sinus rhythm

Where do arrhythmias originate?

In the atria, atrioventricular node AV, or ventricles

Electrophysiology procedure also?

Lets the doctor reproduce arrhythmias to see how the conduction system is stimulated. He uses drugs to see which one helps the most. Electrical shocks may also restore heart rhythm.

what to avoid with ICD?

Magnetic fields, Mri, Extracorporeal shock wave lithotripsy machines, electrocautery and diathermy devices, peripheral nerve stimulation machines tens unit, electrical motors, welding equipment. Digital cellular telephones. SAFE devices are microwaves cause they are grounded.

Regular people non- athlete heart lower than 60?

Means heart disorders , increased intracranial pressure, hypothyroidism, or digitalis toxicity.

Electrical Elective Cardioversion

Nonemergency procedure done by a physician to stop rapid, but not necessarily life threatening atrial arrhythmias. One difference of this procedure is that the machine delivers the electrical stimulation waits to discharge until it senses the appearance of a R wave. By doing so it prevents disrupting the heart during the critical period of ventricular repolarization.

After cardioversion

Nurse monitors Vital signs every 15 minutes, for the first 1 to 2 hours and then as ordered. Compares ECG before and after procedure.

Flecainide and Propafenone ( antiarrhythmics)

Prevent atrial fibrillation.

Pacemakers

Provides an electrical stimulus to the heart muscle to treat an ineffective slow rhythm, they function in either demand synchronous or fixed rate asynchronous.

Cardioversion

Scheduled one week before, uses less electrical energy than defibrillation it only uses 50 - 100 joules., delivers electrical energy when the machine senses the R wave of the ECG. Needs consent form!

ICD

Senses the cardiac rhythm which it transmits to the generator. The generator which is programmed for various responses depending on the sensed rhythm delivers an electrical shock through the lead to restore a life threatening cardiac rhythm. In other word a kick to the chest.

Atrial fibrillation

Several areas in the right atrium initiate impulses resulting in disorganized rapid activity. The atria quiver rather than contract.

What happens when doctor noticed battery is running low?

The entire generator is replaced and the leads are connected to new generator. After they do that the client is reassessed 3 to 6 months later.

Defibrillation

The only treatment for life threatening ventricular arrhythmia. Which has the same effects as Cardio version, except it is used when there is no contraction. Without Defibrillation client will DIE.

Chemical Cardioversion

Use of drugs to eliminate an arrhythmia.

Medication for Cardioversion?

Valium is given before Cardioversion, to increase dangerously slow heart rate, Atropine may be used.

what to avoid with ICD?

airport metal detectors a hand search is better.

Risks of Radiofrequency ablation?

bleeding from the insertion sight, perforation of the catharized vein, and vascular complications such a thrombus formation. Might pierce the myocardium., other risks are pericardial tamponade.

Premature Ventricular Contractions

causes flip- Flop sensation in the chest , sometimes described as fluttering. Symptoms include pallor, nervousness, sweating and faintness. Some are normal related to anxiety stress, fatigue, alcohol withdraw, Tabaco use.

ICD

checked EVERY 3 TO 4 MONTHS. can deliver 200 to 250 discharges and can last up to 3 to 6 years before the battery is replaced.

ICD

consists of a generator with a battery and one or two electrical lead that resembles a wire near the clavicle and the lead wire is inserted trans venously through the subclavian or cephalic vein to the apex or septum of the right ventricle.

Telephone checks?

every 2 to 4 months for the first 3 years and every month therafter.

Nuclear powered battery

has the longest life 6 to 15 years.

first and Second degree heart block

impulse is delayed

Implantable Cardioverter defibrillation.

internal electrical device used for selected clients with recurrent life threatening tachydysrhythmias

Wireless intracardiac pacemaker

once the catheter reaches the heart muscle it is implanted in the muscle using a coiled spring like device on its distal end and is disengaged from the vascular catheter.

CAD with SVT

patients can develop chest pain because coronary blood flow cannot meet the increased need of the myocardium for oxygen imposed by the fast rate.

Sinus tachycardia

proceeds through the conduction pathway but faster than usual at 100 to 150 beta/ mi. It happens in healthy adults from strenuous exercise, anxiety, and fear, pain, fever, hyperthyroidism, hemorrhage, shock, hypoxemia

Pace makers categorized in two ?

1) Temporary pacing is done under urgent or emergency circumstances. 2) Permanent Pacemakers is implanted when the client has a chronic ineffective slow cardiac rhythm that requires long term electrical support.

Temporary pace makers three types?

1) Transcutaneous- is an emergency measure for maintaining adequate heart rate. 2) Transvenous pacemaker- is a temporary pulse generating device that sometimes is necessary to manage transient bradyarrhythmia's such as those that occur during acute MI.s or after coronary artery bypass graft surgery or to override tachyarrhythmias. 3) Implanted pacemaker- is a totally implanted electrical device used t manage a chronic bradyarrhythmia, it consists of a battery powered generator that controls the heart rate and one or more leads wires that is that connect to the heart to the generator.

Supraventricular Tachycardia (SVT)

A arrhythmia in the heart rate is consistent but beats at a dangerously high rate 150beats/min. Diastole is shortened and the heart does not have sufficient time to fill.

Atropine sulfate

A cholinergic blocking agent, is given every 3 to 5 minutes to increase a dangerously low heart rate.

Atrial flutter

A disorder in which a single atrial impulse outside the SA node causes the atria to contract at an exceedingly rapid rate 200 to 400 contractions/minutes.

Electrophysiology

A procedure that enables the physician to examine the electrical activity of the heart , produce actual arrhythmic by stimulating structures in the conduction pathway. Best method in preventing future arrhythmias.

automated external defibrillator (AED)

Analyzes the hearts rhythm to determine if the defibrillation is needed and if so , allows the user to administer electrical energy to stop the arrhythmia and allow the heart to reestablish an effective rhythm. ( the are carried on airplane, work place ext.)

Complete heart block

Atrial impulses never gets through and the ventricles develop their own rhythm independent of the atrial rhythm. Ventricle rate is slow 30 to 40 beats/ minute. Pacemaker is the treatment for this.

Premature Trial Contraction cause?

Caffeine, nicotine, heart disease, metabolic disorders like hyperthyroidism.

Asystole

Cardiac Arrest, when no identifiable R wave is present.

Sinus node arrhythmias

Cause bradycardia and tachycardia.

Ventricular Tachycardia

Caused by a single, irritable focus in the ventricle that initiates and then continues the same repetitive pattern. The ventricle beats very fast 150 to 250 beats/ minute, and cardiac output is decreased.

When dangerous PVC,s occur?

Client is given intravenous bolus of lidocaine ( Xylocaine) followed by a continues IV infusion of the drug.

Arrhythmia

Conduction disorder that results in a abnormal slow or fast heart beat .

AV node

Conducts only some impulses to the ventricle resulting in a ventricle rate that is slower than the atrial rate.

What Is used to slow the heart rate?

Digitalis , adrenergic blockers and calcium channel blockers.

Prepping for elective electrical cardioversion

Digitalis and diuretics are put on hold 24 to 72 hours before the procedure, because they decrease the ability to restore normal conduction and increases the chances of a fatal arrhythmia developing after cardioversion.

Heart Block

Disorders in the conduction pathway that interfere with the transmission of impulses from the SA node through the AV node to the ventricles.

Treatment for arrhythmias?

Drug therapy and electrical treatment , such as Electrical cardioversion, defibrillation or temporary or permanent pacing.

Other causes of Arrhythmias

Drug therapy, electrolyte disturbances, metabolic acidosis, hypothermia, and degenerative age related changes.

What symptoms are present that requires a phone check up?

Dyspnea, vertigo, syncope, unexplained fatigue, edema, in upper or lower extremities , muscle twitching hiccups,

Rhythm disturbance

Effects Cardiac output.

Defibrillatioin

Emergency procedure performed during resuscitation, client not sedated, uses more electrical energy 200-360 joules than cardioversion. Delivers electrical energy whenever the buttons on the paddles are pressed. 70 percent survival rate and is done within the 3 minutes of a cardiac arrest. every minute that passes by it decreases the survival rate by 7 to 10 percent.

Tachyarrhythmias

Fast abnormal palpitations or fluttering in their chest. blood pressure is usually low.

Atrial Fibrillation chief complications are?

Formation of blood clots within the atria that may become stroke causing emboli if they enter the circulation.

Healthy athletes

Have a rate lower than 60 , do to a very good healthy conditioned heart toned through exercise.

Implantable cardioverter defibrillation candidates ?

Have survived atleast one episode of cardiac arrest from a ventricular dysrhythmia , experience recurrent episodes of ventricular tachycardia, are at risk for sudden cardiac death because of structural heart disease such as cardiomyopathy.

Mercury batteries?

Have the shortest life 5 to 7 years

Sinus Bradycardia

Is a arrhythmia that proceeds normally through the conduction pathway but at a slower than usual rate < 60beats/ minute. The danger is it may be insufficient to maintain cardiac output.

Ventricular Fibrillation

Is a the rhythm of a dying heart. the ventricles do not contract effectively and there is no cardiac output.

Premature Ventricular Contractions

Is a ventricular contraction that occurs early and independently in the cardiac cycle before SA node initiates an electrical impulse. no P wave proceeds wide bizarre looking QRS complex.

Ventricular Fibrillation

Is an indication for cardiopulmonary resuscitation CPR.

Most common cause of Arrhythmia

Ischemia heart disease.

Main causes of serious Arrhythmias ?

Myocardial ischemia, lack of oxygenated blood to the heart muscle, which can occur secondary to CAD, inadequate ventilation and shock.

ICD CLIENTS SHOULD CARRY WHAT AROUND?

Name of doctor on the device and name of themselves.

Electrophysiology how its done?

Passing three flexible wire electrode catheters into the veins in the neck and groin. The catheters advance to the heart in specific areas which are, Right Atrium, Bundle of His, Right Ventricle, the catheters monitor and record the hearts rhythm.

Electrical elective cardioversion procedure

Patient is sedated, electrodes lubricated with a special gel or moist saline pads are applied to the chest wall, when the discharge buttons on the paddles are depressed and the heart is in ventricular depolarization the electrical energy is released. Repolarizes the entire Myocardium.

Elective electrical Cardioversion

Patient must be anticoagulated to reduce the risk of thrombus formation and embolization.

Preping for elective electrical cardioversion

Patient must be within therapeutic range of the Partial Thromboplastin time( PTT) or INR. Consent form must be signed. No food or liquids , IV line must patent, nurse must ask doctor if any meds should be put on hold and if any med are needed for anxiety before procedure. doctor may order a sedative 30 to 60 minutes before procedure.

The Ventricles

Respond randomly to the stimulation of Atrial causing irregular heart rate.

Electrophysiology procedure recovery.

Same as a heart catheter and the patient is discharged the following day.

Premature Trial contraction

The atrial conduction system initiates an early electrical impulse identifies as a irregular rhythm.

Maze Procedure

The surgeon restores the normal conduction pathway in the atria by eliminating the rapid firing of ectopic pacemaker sites using scar-forming techniques. ( invasive procedure opening the chest)

Radiofrequency catheter ablation

a procedure in when a heated catheter tip destroys arrhythmia producing tissue. A catheter is threaded tranvenously into the heart, initially for electrophysiology studies. Once the the location of the arrhythmias generating tissue is located the electrical energy is ent to the catheter tip.

Use of the transcutaneous pacemaker nurse care?

attaches the anterior electrode patch to the left side of the chest halfway between the xiphoid process to below the left nipple. adjusts 40 beats/ minute and increase in increments of 10 until reaches prescribed rate.

Ventricular Tachycardia

client may lose consciousness and become pulseless. Sometimes ends abruptly without intervention but often requires defibrillation.

Atrial waves

flutter have a characteristic sawtooth pattern.

Implantable pace maker

generator is the size of half dollar coin and three times as thick. it is poisoned under the skin below the right or left clavicle usually on the patients nondominant side.

Mini Maze

has been developed using a closed chest approach and application of catheter directed energy at the tissue creating abnormal electrical impulses.

Battery of the wireless intracardiac pacemaker

lasts up to 8 to 10 years and is retrieved and replaced using the same technique as its insertion.

Prepping for elective electrical cardioversion

nurse helps client use restroom, uses a cardioverter a device that monitors the clients oxygen, suction, also emergency drugd are kept on hand, administer IV tranquilizer usually Valium, Versed,

Fixed rate asynchronous mode pacemaker

produce an electrical stimulus at a present rate usually 72 to 80 beats/ minute despite the clients natural rhythm. This type is used less frequently than the demand synchronous mode pacemaker.

Demand synchronous mode pacemaker

self activate when the client pulse falls below a certain level. if the pacemakers is set for 72 beats/ minute it will not activate until the clients heart rate falls below 72 beats/ min.

Ectopic pacemaker

starts an electrical impulse independently from the SA node, but can lead to serious arrhythmias such as supraventricular tachycardia.

Symptoms of low cardiac output?

tachycardia, angina hypotension, syncope, and reduced renal output.

Radiofrequency catheter ablation

the heat destroys the errant tissue allowing impulse conduction to travel over appropriate pathways.

Wireless intracardiac pacemaker

the size of a large capsule, has self contained battery, electronics, and electrodes, it is inserted nonsurgically with a catheter that extends from the femoral vein to the right ventricle.

Sinus rhythm

usual heart rhythm

How to reprogram pacemaker?

with an external wand just like the ICD