ECG Exam Questions with All Correct Answers

ECG Exam Questions with All Correct Answers Electrocardiography - Answer-a painless, safe procedure and is the test most frequently used for the diagnosis of heart disease in the ambulatory care setting What is the role of the medical assistant in electrocardiography? - Answer-The MA must be able to recognize problems with the recording and make appropriate corrections so that the physician has a clear record of the patient's cardiac activity. The goal is to obtain the most accurate ECG possible. What is the average length of time for a healthy adult cardiac cycle? - Answer-0.8 seconds The electrocardiograph records both the _________ of the electrical impulses and the ______ _____ it takes for each part of the cardiac cycle to occur. - Answer-intensity; actual time What does an ECG measure? - Answer-It measures the electrical conductive impulses of the heart muscle, allowing the physician to see any disturbances or disruptions in normal heart activity. Systole - Answer-atria and ventricles contract and empty of blood Diastole - Answer-Relaxation phase of heart, chambers refill with blood How many phases are in a cardiac cycle? - Answer-two What does the cardiac cycle include? - Answer-all events that occur in the heart during one single heartbeat What controls the rate of heart contractions? and how? - Answer-The sinoatrial (SA) node controls the rate of heart contractions by initiating electrical impulses 60 to 100 times per minute. What is an arrhythmia and what can cause it? - Answer-An irregular cardiac rhythm is called an arrhythmia. Conditions that interrupt the conduction pathway, SA node to AV node to bundle of His to right and left bundle branches, can cause arrhythmias Polarization - Answer-resting state of the myocardial wall; no electrical activity occurs in this phase How is polarization recorded on an ECG strip? - Answer-straight line Depolarization - Answer-contraction of stimulated heart muscle Repolarization - Answer-heart muscle cells must return to a resting state Electrocardiograph records what? - Answer-a series of waves, or deflections, corresponding to part of cardiac cycle Describe the ECG cycle - Answer-The normal ECG cycle consists of waveforms that are labeled the P wave, the Q wave, the R wave, the S wave, and the T wave. The Q, R, and S waves usually are grouped together; this is called the QRS complex. One entire cardiac cycle can be called the PQRST complex Why is atrial repolarization not recorded on the ECG strip? - Answer-Its electrical impulse is small and is hidden in the QRS complex. P wave occurs during ... - Answer-a contraction of the atria and shows beginning of cardiac depolarization What does a P wave look like on an ECG strip? - Answer-First deflection from the baseline, typically smooth and rounded, and occur before each QRS complex PR segment is the .... - Answer-Return to the baseline after atrial contraction PR interval is ... - Answer-time from the beginning of atrial contraction to beginning of ventricular contraction The PR interval contains what? - Answer-the P wave (depolarization of the atria) and the spread of the electrical impulse through the AV node, bundle of His, right and left bundle branches, and Purkinje fibers. QRS complex shows what? - Answer-contraction of the ventricles and reflects the completion of cardiac depolarization Compare the QRS complex and P wave. - Answer-QRS complex is recorded as a much more significant electrical activity than a P wave What does the ST segment reflect? - Answer-ST segment reflects the time between the end of ventricular contraction and the beginning of ventricular recovery