Pacemakers and ICDs Flashcards
What problems on an ECG can a pacemaker indicate?
Bradycardia, sinus pause/arrest, second degree heart block Mobitz type 1 and 2, third degree heart block.
Explain the difference between fixed rate and on demand pacemakers.
Fixed rate pacemakers work to continuously pace the heart at a specific rate, while on demand pacemakers monitor the R-R interval of the heart and adjust the rate depending on whether the rate is too short or too long.
Explain the difference between single chamber and dual chamber pacemakers.
Single chamber pacemakers target either the right atrium or the right ventricle, while dual chamber pacemakers stimulate both.
What type of effect can the pacemaker spike have on an ECG?
Atrial pacing (a line occurring before a normal QRS complex), ventricular pacing (a line occurring before an inverted QRS complex) and an atrial and ventricular dual pacing (two lines before an inverted QRS complex).
What other ways can a pacemaker make a change to an ECG?
A broad QRS complex and appropriate discordance (expected ST segment depression/elevation and T wave presentation opposite to the direction of the QRS complex).
What is a fusion beat?
A beat produced when the ventricle is simultaneously activated by both the paced and supraventricular impulses.
What is pacemaker syndrome?
A condition caused by a pacemaker contracting the atria at the same time/after the ventricular contractions, resulting in reduced cardiac output.
What is the function of an ICD?
To monitor and (if necessary) defibrillate the heart if an appropriate arrythmia is detected.
If an ICD needs to be deactivated, what can be done?
A ring magnet can be used to deactivate the shock function.
What should be done in the treatment after an ICD has activated?
Whether or not the ICD has fired (as well as if the shock was necessary), monitor blood pressure and treat underlying arrythmias if possible.
