Basic ECG Interpretation (100% Accurate Answers)

60-100 correct answers What is normal heart rate if the SA node is the primary pacemaker? 40-60 correct answers What is normal heart rate if the AV node is the primary pacemaker? 15-40 correct answers What is normal heart rate if the Purkinje fibers are the primary pacemaker? Atrial depolarization/contraction correct answers What does the P wave represent? PR interval correct answers Time (in seconds) from onset of atrial depolarization to the onset of ventricular depolarization (impulse travels to SA to AV node) From beginning of P wave to beginning of QRS complex correct answers How is the PR interval measured? Ventricular depolarization (impulse travels through Bundle branches to Purkinje fibers) correct answers What does the QRS complex represent? J point correct answers The point at which the QRS complex returns to the isoelectric line ST segment correct answers Segment from end of QRS complex to beginning of T wave, should be flat and level with isoelectric baseline Myocardial ischemia correct answers What does an elevation or depression in the ST segment usually indicate? STEMI correct answers ST elevation myocardial infarction NSTEMI correct answers Non-ST elevation myocardial infarction Ventricular repolarization correct answers What does the T wave represent? QT interval correct answers Time (in seconds) from beginning of ventricular depolarization to the end of ventricular repolarization The next impulse occurs too early and hits the T wave, causing a fib correct answers What can happen due to a prolonged QT interval? 0.04 correct answers How many seconds are represented by a small box on an ECG graph paper? 0.2 correct answers How many seconds are represented by a big box (5 smaller boxes) on an ECG graph paper?