Arrhythmia Flashcards
Where is the origin of supraventricular (SVT) arrhythmias?
above the ventricle
Where is the origin of ventricular arrhythmias?
ventricular muscle (common) or fascicles of conducting system (uncommon)
What conditions are examples of supraventricular tachycardia?
- atrial fibrillation
- atrial flutter
- ectopic atrial tachycardia
What conditions are examples of supraventricular Bradycardia?
- sinus bradycardia
- sinus pauses
What conditions are examples of ventricular arrhythmias?
- ventricular ectopics or premature ventricular complexes (PVC)
- ventricular tachycardia
- ventricular fibrillation
- asystole
What conditions are examples of atrio-ventricular node arrhythmias?
- AVN re-entry tachycardia
- AV reciprocating or AV reentrant tachycardia
- AV block
What is 1st, 2nd and 3rd degree AV block?
1st degree– still conducts but takes longer
2nd degree – lets some through and some not. Allows a smaller amount of conduction.
3rd degree – nothing gets through. Allows no conduction.
What abnormal anatomy conditions could cause arrhythmias?
- left ventricular hypertrophy
- accessory pathways
- congenital heart disease
how can the automatic nervous system cause arrhythmias?
- sympathetic stimulation (stress, exercise, hyperthyroidism)
- increased vagal tone causing bradycardia
What are some metabolic causes of arrhythmias?
- hypoxia (chronic pulmonary disease, pulmonary embolus)
- ischaemic myocardium (acute MI, angina)
- electrolyte imbalances (K+, Ca2+, Mg2+)
what is an inflammation cause of arrhythmias?
viral myocarditis
how can drugs cause arrhythmias?
direct electrophysiologic effects or via ANS
how can genetics cause arrhythmias?
mutations of genes encoding cardiac ion channel e.g. the congenital long QT syndrome.
What are ectopic beats?
beats or rhythms that originate in places other than the SA node
what are some causes of ectopic beats?
- altered automaticity (ischaemia, catecholamines)
- triggered activity (digoxin, long QT syndrome)
What conditions would cause an increase in phase 4 of the cardiac potential? (therefore causing increase in heart rate and ectopics)
- hyperthermia
- Hypoxia
- hypercapnia
- Cardiac dilation
- hypokalaemia, prolongs repolarisation