Exam 4: Arrythmias Flashcards
Causes of cardiac arrhythmias (5)
- Abnormal rhythmicity of the pacemaker
- Shift of pacemaker from sinus node
- Blocks at different points in the transmission of the cardiac impulse
- Abnormal pathways of transmission in the heart
- Spontaneous generation of abnormal impulses from any part of the heart
Abnormal Sinus Arrythmias (2)
- Tachycardia
- Bradycardia
Tachycardia
Heart rate usually greater than 100 beats/min
Causes of tachycardia (3)
- Inc. body temp
- Sympathetic stimulation (loss of blood or reflex stimulation)
- Toxic conditions of the heart
Where is the source of problem with tachycardia?
SA node
With tachycardia, what type of disease does the patient normally exhibit?
Hyperthyroidism; sometimes valve problems
Bradycardia
Heart rate usually less than 60 beat/min
What type of patients exhibit bradycardia?
Athletes w/ large stroke volumes
Why do athletes have bradycardia?
Because they have large hearts; hypertrophy
What can cause bradycardia? (Main thing and something else)
Vagal stimulation and a neural reflex to drugs
Is there more PNS or SNS input to the heart w/ bradycardia?
PNS; there is a small amount of SNS input to the heart during resting heart rate
What is a type of supraventricular tachycardia?
Paroxysmal Atrial Tachycardia
Define paroxysmal
comes and goes
Paroxysmal Atrial Tachycardia
high heart rate driven by abnormal atrial excitation (
What overlaps d/t timing in paroxysmal atrial tachycardia?
P and T waves
Paroxysmal Supraventricular Tachycardia
