Cardiac arrhythmas Flashcards
(44 cards)
Define Tachyardia
Fast heart rate (>100 beats/min)
What are some causes of Tachycardia?
- increased body temperature
- stimulation of the heart by the sympathetic nerves
- toxic conditions of the heart
Define Bradycardia
Slow heart rate (<60 beats/min)
What are some causes of bradycardia?
- athletic heart
- vagal stimulation (parasympathetic stimulation)
- extremely sensitive carotid baroreceptors in carotid sinus syndrome
What arrhythmia is present?

Atrial fibrillation
What arrhythmia is present?

Atrial paroxysmal tachycardia
What arrhythmia is present?

Atrial premature beat
What arrhythmia is present?

A-V nodal premature contraction
What arrhythmia is present?

Complete A-V block
What arrhythmia is present?

Partial intraventricular block
What arrhythmia is present?

First degree A-V heart block
What arrhythmia is present?

Second degree A-V block
What arrhythmia is present?

Sinoatrial nodal block
What arrhythmia is present?

Sinus bradycardia
What arrhythmia is present?

Tachycardia
What arrhythmia is present?

Ventricular fibrillation
What arrhythmia is present?

ventricular paroxysmal tachycardia
What are some physiological results of endogenously mediated tachycardia?
- heart rate increases
- cardiac output increase
- filling time is reduced but stroke volume does not fall
What are som physiological results of pathologically mediated tachycardia?
- heart rate increases
- cardiac output decreases
What are spillover signals?
Signals sent from the medullary respiratory center into the vasomotor center during inspiratory and expiratory respiratory signals
- These signals alternately increase and decrease the number of impulses transmitted through sympathetic and vagus nerves through the heart
What are the characteristics of a sinoatrial block?
- sudden cessation of P waves
- resultant standstill of atria
- ventricles pick up a new rhythm, usually in the AV node
- rate of QRS is slowed but not otherwise altered
What would be some conditions that would cause an atrioventricular block?
- ischemia of AV node od Av bundle fibers through coronary insufficieny
- compression of AV bundle by scar tissue or calcified portions of the heart
- inflammation of the AV node or bundle
- extreme stimulation of the heart by the vagus nerves
What are the two types of incomplete atrioventricular block?
- First-degree
- second-degree
What characterizes a first-degree A-V block?
When P-R interval increases to greater than 0.20 sec. (normal is 0.16)