Perfusion: Cardiac Dysrhythmias Flashcards
What is athletic heart syndrome?
When athletes have a lower heart rate because all of their training makes the heart beat more slowly and forcefully.
How does age affect cardiac rhythms?
- The natural pacemaker of the heart loses some of its cells= slower heart rates
- The left ventricle increases in size
- the heart size increases by decreases in filling capacity
How does electrical activity spread through the heart?
SA node (atrium)-> Right and left atrial cells -> Internodal pathways -> Atrioventricular (AV) node -> Bundle of His -> Right and Left bundle branches -> Purkinje Fibers -> Ventricular cells
What is the AV node?
The atrioventricular node
What is the SA node?
The sinus atrial node (pacemaker)
What does the AV node do?
- Delays so that the atria can contract and give an extra bolus of blood to the ventricles
- Controls the number of impulses that reach the ventricles, preventing extremely rapid heart rates
Why do dysrhythmias occur?
Because of anything that could cause a disruption of the electrical activity of the heart.
What can cause ectopic beats?
Abnormal impulses that may originate outside normal conduction pathways
What is an ectopic beat?
impulses that interrupt the normal conductions sequence and may not initiate a normal muscle conduction
What is a heart block?
A block in the normal electrical conduction of the heart
What is MI?
Myocardial Injury
What types of heart blocks are common with acute MI’s
bundle branch blocks
What is a major cause of tachydysrhytmia?
Reentry phenomenon
How does the reentry phenomenon work?
- it is triggered by an ectopic beat
- The impulse is delayed in one area of the heart (area of the ischemia or injury
- Muscle that has been depolarized (activated) by the impulse is repolarized by the time the impulse traveling through the area of slow conduction reaches it.
- Thus, another cycle of depolarization (activation) occurs
What are some types of reentry phenomenons?
atrial dysrhythmias (e.g. atrial flutter, atiral fibrillation)
How are cardiac rhythms classified?
- the site of the impulse formation
2. the site and degree of conduction block
Where do Supraventricular rhythms arise?
above the ventricles
Give some examples of supraventricular rhythms?
- sinus rhythms
- atrial rhythms
- junctional rhythms (arising from the AV junction)
Who are at the most risk for cardiac dysrhythmias?
hx of heart disease:
- CAD
- prior heart surgery
- high BP
- congenital heart disease
- heart attacks
- other heart damage
What other populations are at risk for heart dysrhythmias?
- endocrine issues (thyroid problems, diabetes, and electrolyte imbalances)
- sleep apnea
- alcohol stimulants (caffeine and nicotine)
What are some methods used to increase heart health?
- heart-healthy diet
- moderate physical exercise
- maintaining a healthy weight
- following treatment recommendations
- limiting alcohol and caffeine consumptions
- refraining from tobacco use
- avoid medications that can cause dysrhythmias
What is a Normal sinus rhythm?
The normal heart rhythm
What are the most common symptoms of cardiac dysrhythmias?
- lightheadedness
- dizziness
- fluttering
- a racing or slow heartbeat
- shortness of breath
- chest discomfort or pain
- syncope
What is PAC?
Premature Atrial Contractions
What is PSVT?
Paroxysmal Supraventricular Tachycardia (tachycardia of sudden onset and termination)
What does paroxysmal mean?
occurring in bursts with an abrupt onset and termination
What is atrial flutter?
A rapid and regular atrial rhythm thought to result from an intra-atrial reentry mechanism
What is atrial fibrillation?
Disorganized atrial activity without discrete atrial contractions
What are PVCs?
Premature Ventricular Contractions: ectopic ventricular beats that occur before the next expected beat of the underlying rhythm
What is a couplet?
two PVCs in a row
What is a triplet or salvo?
three consecutive PVCs in a row
What is ventricuar bigeminy?
A PVC following each normal beat
What is ventricular trigeminy?
A PVC noted every third beat
What is Ventricular Tachycardia?
Rapid ventricular rhythm define as three or more consecutive PVCs
What is another name for Ventricular fibrillation?
Cardiac arrect
What are the clinical manifestations of Decreased Cardiac Output?
- changes in LOC ranging from dizziness to complete loss of consciousness
- ischemia
- Reduced tissue perfusion
- hypotension