Devices Flashcards
AOO
A paced, nonsense, atrial asynchronous pacing at lower pacing rate
What is VVI
V pace, V sense, sensed intrinsic QRS inhibits V pace
AAI
A pace, a sense, intrinsic P wave inhibits atrial pacing
DDD
Both paced, both sense, intrinsic p wave and QRS can inhibit pacing, peace can trigger paced QRS
DDI
A and V pace and sense, no tracking of P waves
For a patient with evidence of SN dysfunction and intermittent heart block, what pacemaker setting would be most appropriate?
DDD
If a pacemaker is programmed with an output of 5v and the measured lead resistance is 330ohms, what is the current that flows out of the pacemaker and into the tissue?
15.15mA
Fractured pacemaker lead, with obvious separation of the lead body would have what effect on lead resistance?
Increase
Disruption of the inner lead insulation, allowing conductors to touch would effect the lead resistance by—lead resistance.
Decrease
A lead fracture would result in:
Decreased current drain
Lead insulation failure characteristics commonly include?
Extra cardiac stimulation
What is the voltage measurement of a pacing system with a resistance of 50ohms, current of 5.0 milliamp a and pacing rate of 60ppm?
2.5v
Pacemaker syndrome can occur in what pacing mode?
DDD, VDD, VVI
The horizontal asymptote of strength duration curve is termed?
Rheobase
What are the indications for an ICD?
Cardiac arrest due to VF or VT, spontaneous VT, lVEF <30%, symptoms
In an ICDthe time required to charge the capacitors is a useful measure of what?
Battery status
What describes a defibrillator algorithm that discriminates between atrial fib and ventricular tach on the basis of cycle length variability?
Stability
The efficacy of ATP in terminating spontaneous VT is approximately what %?
90%
How much greater thank the DFT should the max energy output of an ICD be?
10j
The SCD-HeFT trial showed a clinically and statistically significant benefit for what patients?
ICDs in heart failure patients with EF <=35%
During ICD troubleshooting for noncardioversion a large increase in the lead impedance of an integrated bipolar would most likely to indicate what?
Lead fracture
What will increase a patients defib threshold?
Pneumo
What drug is known to in increase chronic pacing thresholds and decrease chronic defib thresholds?
Lidocaine
Name the three primary prevention trials in post infarct pts showing reduced mortality with ICD mortality of 54,55 and 31% respectively?
MADIT, MUSTT, MADITII
