cardiology SA Node Flashcards
What is the difference between Absolute/Effective refractory periods & Relative refractory period
ARP & ERP this is where the cells can not be excited by another stimulus
A RRP is where another stimulus can be run through
A Supranormal period are where the cells are more Excitable than normal
What allows the pacemaker cells of the artia to be able to pace them selves
They have chanells which are always open “Funny chanells)
What are some causes of tachyarrhythmias
Increase automaticity (of SA node, latent pace makers, abnormal myocardial sites)
Triggered activity or re enterent
What are some causes of bradyarrhytmias
Can occur from decreased impulse formation or decreased impusle conduction
How does B1 receptors work
They increase the probability that the slow pacemaker chanells are open. This allows calcium to enter the cell more rapidly cause depolerization and quickly causing increase in HR
What are 2 causes for AF
Focal activity by increased automaticity, often in pulmonary veins
Multiple wavlets, where lots of re-entry circuts are formed
What are some causes for developing AF
Hypertrophy of the LA
Hypertropy of the LV
Chronic hypertention
Impaired daistolic dysfuntion
Severe infection
Electrolyte imbalance
MI
What are some things that AF can cause we should be concerned about
Decreased cardiac output
increased chances of developing an embolus
What causes atrial flutter
This is a re-enterent tachycardia. It is from a stimulus that becomes ‘trapped’ on a loop causing depolarization as they go through
What are some potential causes for developing atrial flutter
COPD
Pulmonary hypertention
Heart faliure
Age
Severe infection
Electrolyte imbalance
MI
What are some primary care meds that can help with AF
Calcium channel blockers
Beta blockers
Anticoagulants
Minor surgery
What is the difference in hypertropy and hyperplasia
Hypertropy is the increased cell size and functioning tissue mass as a result of increased workload
Hyperplasia is different, this is where there is a increase in the number of INDIVIDUAL cells
What can cause left atrial enlargment
Sever Mitral disease
Rheumatic MS
Aortic valve disease
Systemic hypertention
Restrictive cardiomyopathy
What can cause right arital enlargment
Tricuspid disease
Right atrial tumour
cardiomyopathy
pulmonary hypertention
acute PE
RV hypertropy
COPD
Congenitial heart disease
What is our managment for AF & Artial flutter
Mild compramise
50mg Metoprolol PO
Moderate
300mg Amiordarone IV 30mins
Severly compramise
Cardioversion
