Cardiac Conduction Flashcards
What is the sinus nodes intrinsic rate?
70bpm
What heart rate can the atrial muscle generate?
60bpm
What heart rate can the AV node generate?
40bpm
What heart rate can the ventricular myocardium generate?
30bpm
What is automaticity?
Ability of cardiac tissue to generate a heart beat
Increased automaticity of the sinus node would cause what heart rate/rhythm?
Sinus tachycardia
What do ectopic beats usually generate from?
Atrium for ventricles - increased automaticity
How does digoxin toxicity affect the automaticity of the AV node?
Increases it
R on T ventricular ectopics can induce what rhythm?
VF
What is a normal amount of ectopic beats per day?
<500
What is there a risk of if >10% of beats are ectopic?
Ectopic induced cardiomyopathy
What common conditions underlie arrhythmias?
IHD
Cardiomyopathy
Valve disease
Channelopathies
Electrolyte disturbance
Thyrotoxicosis
What OTC remedies can cause ectopic beats?
Sympathomimetic (decongestion)
Anti-histamine (sedation)
What are three main mechanisms of SVT?
Criteria for SVT?
WPW criteria?
WPW is an accessory pathway that connects what?
Atrial and ventricular myocardium
What macro-reentry circuits develop in WPW?
What atrial stabiliser presents atrial tachycardia?
Bisoprolol
What AV node blockers prevent AV nodal reentry?
Bisoprolol
Verapamil
What drug is an accessory pathway blocker?
Flecainide
How do EP studies and ablation work?
What causes sinus tachycardia?
What is the commonest serious arrhythmia?
AF
What is common in AF?