ECG Quiz for 2017 MBBS Part-1 PDF

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Class quiz of ECG week 1...

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2017 MBBS ECG Quiz for ECG fundamental 1. The term automaticity refers to the ability of a cell to: A. initiate an impulse on its own. B. send impulses in all directions. C. block impulses formed in areas other than the SA node. D. generate an impulse when stimulated. Answer: A. Automaticity, the ability of a cell to initiate an impulse on its own, is a unique characteristic of cardiac cells. 2. Parasympathetic stimulation of the heart results in: A. increased heart rate and decreased contractility. B. increased heart rate and faster AV conduction. C. decreased heart rate and slower AV conduction. D. decreased heart rate and increased contractility. Answer: C. Parasympathetic stimulation of the vagus nerve causes a decrease in heart rate and slowed AV conduction. 3. The normal pacemaker of the heart is the: A. SA node. B. AV node. C. bundle of His. D. Purkinje fibers. Answer: A. The SA node is the normal pacemaker of the heart, firing at an intrinsic rate of 60 to 100 times per minute. 4. The impulse delay produced by the AV node allows the atria to: A. repolarize simultaneously. B. contract before the ventricles. C. send impulses to the bundle of His. D. complete their filling. Answer: B. The 0.04-second delay allows the atria to contract and the ventricles to completely fill, which optimizes cardiac output. 5. The coronary arteries fill with blood during: A. atrial systole. B. atrial diastole. C. ventricular systole. D. ventricular diastole. Answer: D. The coronary arteries fill with blood when the ventricles are in diastole and filling with blood. The aortic valve is closed at that time, so it no longer blocks blood flow through the coronary ostium into the coronary arteries.

6. When stimulated, baroreceptors cause the heart rate to: A. increase. B. decrease. C. stay the same. D. become irregular. Answer: B. Baroreceptors, when stimulated, cause the heart rate to decrease.

7. A patient admitted with an acute MI has a heart rate of 36 beats/minute. Based on this finding, which area of the heart is most likely serving as the pacemaker? A. SA node B. AV node C. Bachmann’s bundle D. Purkinje fibers Answer: D. If the SA node (which fires at a rate of 60 to 100 times per minute) and the AV node (which takes over firing at 40 to 60 times per minute) are damaged, the Purkinje fibers take over firing at a rate of 20 to 40 times per minute.

2017 MBBS ECG Quiz for ECG fundamental Part 2 1. On ECG graph paper, the horizontal axis measures: A. time. B. speed. C. voltage. D. amplitude. Answer: A. The horizontal axis measures time and is recorded in increments of 0.04 second for each small box. 2. On ECG graph paper, the vertical axis measures: A. time. B. speed. C. voltage. D. amplitude. Answer: C. The vertical axis measures voltage by the height of a waveform. 3. A biphasic deflection will occur on an ECG if the electrical current is traveling in a direction: A. posterior to the positive electrode. B. perpendicular to the positive electrode. C. superior to the positive electrode. D. anterior to the positive electrode. Answer: B. A current traveling in a route perpendicular to the positive electrode will generate a biphasic wave, partially above and below the isoelectric line. 4. If a lead comes off the patient’s chest, the waveform: A. will appear much larger on the monitor. B. will appear much smaller on the monitor. C. will appear to wander on the monitor. D. won’t be seen at all on the monitor. Answer: D. Leadwire disconnection will stop the monitoring process, and the waveform won’t be seen on the monitor. 5. To monitor lead II, you would place the: A. positive electrode below the lowest palpable rib at the left midclavicular line and the negative electrode below the right clavicle. B. positive electrode below the right clavicle at the midline and the negative electrode below the left clavicle at the midline. C. positive electrode below the left clavicle and the negative electrode below the right clavicle at the midclavicular line. D. positive electrode below the lowest palpable rib at the right midclavicular line and the negative electrode below the left clavicle.

Answer: A. This electrode position is the proper one for monitoring in lead II....