ECG Exam Questions With 100% Correct Answers 2024

ECG Exam Questions With 100% Correct Answers 2024 ECG Electrode placement V1-V6 - answerV1: right 4th ICS V2: Left 4th ICS v3: half way between V2 and V4 V5: horizontal to V4, anterior axillary line V6: Horizontal to V5, mid-axillary line ECG - answerrecording of heart cells' electrical activity Indications for ECG - answer-Pre-op evaluation -Chest Pain, Syncope, Palpitations, dizziness, SOB, Nausea -Screening in individuals with risk factors Direction of cardiac cell current - answer-Polarized at rest -negative inside - positive outside Pacemaker cell - answerWhere wave of depolarization starts, normal source of electricity -SPONTANEOUSLY depolarize at particular rate (dominant is sinus node) -ALL CARDIAC CELLS CAN PACE Conducting Heart Cells - answerPathways the electricity take - Intra-nodal pathway, bundle of HIS, bundle branches, Purkinje fibers Myocardial Heart Cells - answerContractile element via the purkinje fibers - Perform cell work -Release calcium and contract -Cause waves of ECG What is the main pacemaker cell of the heart? What happens if that is dysfunctional? - answerSinus Node, AV node will kick in next What does the left bundle branch divide into? - answer-Septal -Anterior -Posterior Where are purkinje fibers located? - answerAll throughout walls of the heart and extend away from the conduction pathway The waves seen on the ECG are primarily caused by the activity of which cells? - answerMyocardial cells Horizontal Axis ECG Paper - answerTime SMall= .04 sec Large: .2 seconds Vertical Axis ECG Paper - answerVoltage small= .1 mv (1mm) large= .5 mV (5 mm) Standard ECG runs at - answer25 mm/s P wave - answerAtrial depolarization and then contraction <.12 seconds, <2.5 mm Upright in I, II, AVF Biphasic in III, V1 Down in AVR PR Segment - answerSLows conduction to allow the atria to finish getting blood into the ventricles PR Interval - answerMeasures the start of atrial depolarization to the start of ventricular depolarization .12-.2 seconds QRS - answerVentricular contraction and atrial repolarization -Atrial depolarization is buried in the Q