IBHRE Exam Questions with Complete Solutions 100% Verified Lithium iodine battery V? - Correct Answer 2.8V- not used for ICDs due to low peak power. Qmr Lithium Iodine/ silver V? - Correct Answer 3.2V Qhr- used for ICDS Which is an example of a closed loop sensor? - Correct Answer myocardial contractility and O2 stat Primary Sensor - Correct Answer detects changes in normal physiologic responses Secondary - Correct Answer detects internal changes from exercise- QT MV pH Tertiary - Correct Answer detects changes as a result of exercise- piezo accelerometer The smaller the cathode surface the- - Correct Answer higher the current density, lower the threshold, and higher the impedance (2-6mm as small as 1.2) Anode should be how much bigger than the cathode? - Correct Answer 3xs (4-20mm in pacing leads) ICD tip electrodes tend to run- - Correct Answer 2-10mm Rv coil size? - Correct Answer 300-600mm SVC coil size? - Correct Answer 400-860mm OHMS LAW - Correct Answer V=I * R ENERGY EQUATION (uJ) - Correct Answer V * I* PW I is what? - Correct Answer Current- flow of electrons through a circuit 1 / 2
What can cause increase in threshold, wide QRS, latency, and undersensing? - Correct Answer Hyperkalemia- high levels of potassium Hypercalcemia can result in? - Correct Answer Short QT Hypocalcemia can result in? - Correct Answer Long QT Normal Potassium level? - Correct Answer 3.7-5.2 estimated battery life? Time= - Correct Answer Time= Q (battery capacity in Ah) / I ( current drain in amperes) Which of the following is necessary to initiate reentry tachy? - Correct Answer unidirectional block of one pathway (travels down the slow up the fast) can be large (WPW) or small (AVNRT) Slew Rate - Correct Answer max rate of change between the sensing electrode and first derivative on ECG change in V/ Change in TIme Frequency - Correct Answer # of times a signal fluctuates in 1 sec expressed in hertz The Basic Unit of Capacitance is? - Correct Answer Farad Basic Unit of Energy? - Correct Answer Joule Unit of charge? - Correct Answer Coulomb= 1 amp per second Microvolt T wave testing - Correct Answer measures beat to beat variations in the T wave, performed with exercise ideally hr between 105 and 110 Heart Rate turbulence - Correct Answer looks at 10 to 20 beats following a PVC. absence of it is the best non invasive prediction of cardiac mortality following a MI
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