Clinical questions Flashcards
Which way does the blood flow throw the heart?
Right Atrium
Right Ventricle
Lungs
Left Atrium
Left Ventricle
Body
What is the first heart sound? S1
beginning of ventricular systole (contraction)
What is the second heart sound? S2
end of ventricular systole
What is the third heart sound? S3
There is NO 3rd heart sound. It is called a murmur and its abnormal caused by turbulent blood flow or reguritation
What are some symptoms that come with arrhythmias?
heart “fluttering”
dizziness, SOB, fatigue, lightheadedness, chest pain*
What is the route of the heart beat neurologically?
begins in Sinoatrial (SA) node (pacemaker) in the RIGHT atrium
- this causes the impulse to travel through both atria signaling them to contract
Then signal reaches atrioventricular (AV node) continuing down into the bundle of His
The bundle of His splits off into two:
left - for the left ventricle
right - for the right ventricle
Then the signal reaches the Purkinje fibers which cause the ventricles to contract
***any disruption in the sequence of impulse conduction results in an arrhythmia
What structure controls the rate and rhythm of the heart beat?
sinoatrial node (SA)
What could be some structural or conduction changes that cause arrthymias?
-SA node fires at abnormal rate or rhythm
-Scar tissue from MI causing diversion of a signal
-AV node acting as the pacemaker instead of the SA node
The pacemaker initiates its own action potential. What are the phases of this actional potential?
Phase 0: rapid ventricular depolarization responding to an influx of Na+ === causes the ventricular contraction later
Phase 1: Na+ channels close
Phase 2: slow influx of Ca and efflux K
Phase 3: RAPID ventricular repolarization from rapid K efflix= Ventricular relaxation
Phase 4: resting membrane potential and when the atrial is depolarized
On an ECG, what do the different waves mean in regard to action potential?
P wave - atrial contraction from phase 4 (resting membrane potential)
QRS complex - ventricular contraction from phase 0 (influx of Na+)
T wave - ventricular relaxation from phase 3 (rapid efflux of K+)
What are the common causes of arrhythmias?
- Mycardial infarction
- Electrolyte imbalances
- elevated sympathetis states (hyperthyroidism, infection)
- drugs that prolong QTc or stimulants (illicit drugs)
What are the two classifications of arrythmias andwhere do they originate?
Supraventricular (above the AV node)
Ventricular (below the AV node)
Examples of Supraventricular Arrhythmias
Sinus Tachycardia
Atrial Fibrillation
Atrial Flutter
Atrial Tachycardia
Supracentricular Tachycardias (SVT)
Examples of Ventricular Arrhythmias
Premature Ventricular Contraction (PVC)
Ventricular Tachycardia
Ventricular Fibrillation
Premature Ventricular Contraction (PVC)
“skipped heartbeat” generated within ventricluar tissue and can be related to stress or too much caffeine
COMMON
