Free ECG Technician Certification Exam Question and Answers — Questions and Answers
Question 1: The waveforms in the middle are referred to as what?
- Complex
- Waveform
- Interval
- Segment (Correct answer)
Correct answer: Segment
On an EKG, a segment refers to the isoelectric line (flat line) between two waves. For example, the PR segment is the flat line between the end of the P wave and the beginning of the QRS complex, and the ST segment is the flat line between the end of the QRS complex and the beginning of the T wave. Segments represent periods of electrical inactivity or repolarization.
Question 2: The PR portion is what?
- Atrial repolarization
- Ventricular depolarization
- Atrial depolarization
- Depolarization of AV node and its delay and depolarization of Bundle of His and Bundle branches (Correct answer)
Correct answer: Depolarization of AV node and its delay and depolarization of Bundle of His and Bundle branches
The PR interval represents the time it takes for an electrical impulse to travel from the atria through the AV node, the Bundle of His, and the bundle branches to the Purkinje fibers. This includes the depolarization of the AV node and its crucial delay, which allows the atria to fully contract and empty blood into the ventricles before ventricular contraction begins. It does not represent atrial repolarization.
Question 3: What do the tiny squares on the EKG paper's horizontal axis represent?
- 5 sec
- 0.04 sec (Correct answer)
- 0.2 sec
- 0.1 sec
Correct answer: 0.04 sec
On standard EKG paper, the horizontal axis represents time. Each small square measures 1 millimeter and corresponds to 0.04 seconds. Five small squares make up one large square, representing 0.20 seconds. This calibration is crucial for accurately measuring intervals and durations on an EKG.
Question 4: What stands for the QRS complex?
- The depolarization of atria
- The depolarization of ventricles (Correct answer)
- AV depolarization
- Septal depolarization
Correct answer: The depolarization of ventricles
The QRS complex on an EKG represents the depolarization of the ventricles. This electrical event triggers the contraction of the ventricular muscle, which pumps blood out of the heart to the lungs and the rest of the body. Atrial depolarization is represented by the P wave, and ventricular repolarization by the T wave.
Question 5: What is the ideal breaths-to-compressions ratio during CPR?
- 1 breath to 15 compressions
- 1 breath to 30 compressions
- 2 breaths to 30 compressions (Correct answer)
- 2 breaths to 30 compressions
Correct answer: 2 breaths to 30 compressions
The ideal breaths-to-compressions ratio during CPR for adults is 2 breaths to 30 compressions. This standard, recommended by organizations like the American Heart Association, prioritizes continuous chest compressions to maintain vital blood flow. The two rescue breaths are then delivered to provide oxygenation to the lungs, ensuring a balance between circulation and ventilation.
Question 6: The proper lead for the midaxillary line on the left side of the fifth intercostal gap is:
- V6 (Correct answer)
- V1
- V3
- V4
Correct answer: V6
Lead V6 is correctly placed at the fifth intercostal space, along the midaxillary line on the left side of the chest. This specific placement allows V6 to provide an electrical view of the lateral wall of the left ventricle. Accurate lead placement is crucial for obtaining a diagnostic quality EKG.
Question 7: What effects does the parasympathetic nervous system have on the heart, and which receptors are involved?
- Constriction of arteries (cholinergic receptors)
- Dilation of arteries (cholinergic receptors) (Correct answer)
- Dilation of arteries (alpha 1-adrenergic receptors)
- Constriction of arteries (alpha 1-adrenergic receptors)
Correct answer: Dilation of arteries (cholinergic receptors)
The parasympathetic nervous system, primarily through the release of acetylcholine, generally promotes 'rest and digest' functions. While its direct effect on the heart is to slow heart rate, it can also cause dilation of arteries, particularly coronary arteries, via cholinergic receptors on endothelial cells. This vasodilation helps to improve blood flow to the heart muscle.
Question 8: The ST segment is what?
- Atrial depolarization
- The pause between ventricular depolarization and ventricular repolarization (Correct answer)
- Delay in the atrioventricular node
- Ventricular depolarization
Correct answer: The pause between ventricular depolarization and ventricular repolarization
The ST segment on an EKG represents the period between the end of ventricular depolarization (QRS complex) and the beginning of ventricular repolarization (T wave). During this phase, the ventricles are fully depolarized and contracting, but there is no net electrical activity. It is a critical segment for identifying myocardial ischemia or injury.
Question 9: When blood flow to the heart muscle is stopped or abruptly reduced for long enough to result in cell death, myocardial infarction occurs.
- TRUE (Correct answer)
- FALSE
Correct answer: TRUE
This statement is TRUE. Myocardial infarction, commonly known as a heart attack, occurs when blood flow to a section of the heart muscle is severely reduced or completely blocked. This prolonged lack of oxygen and nutrients leads to the irreversible death of heart muscle cells, which is the defining characteristic of a myocardial infarction.
Question 10: What is the dominant ion inside cells?
- Magnesium
- Potassium (Correct answer)
- Sodium
- None of these
Correct answer: Potassium
Potassium (K+) is the dominant ion inside cells, meaning its concentration is significantly higher intracellularly than extracellularly. This crucial concentration gradient is maintained by the sodium-potassium pump and is fundamental for establishing the cell's resting membrane potential. It is essential for the electrical activity of excitable cells, including cardiac myocytes.
Question 11: What is the dominant ion outside of cells?
- Calcium
- Magnesium
- Potassium
- Sodium (Correct answer)
Correct answer: Sodium
Sodium (Na+) is the dominant ion outside of cells, with a much higher concentration in the extracellular fluid compared to the intracellular fluid. This high extracellular sodium concentration is vital for various physiological processes, including nerve impulse transmission, muscle contraction, and maintaining fluid balance. The sodium-potassium pump actively works to maintain this gradient.
Question 12: Where is the sinoatrial node located?
- Purkinje fiber
- Inter ventricular septum
- Right ventricle
- Right atrium (Correct answer)
Correct answer: Right atrium
The sinoatrial (SA) node, often referred to as the heart's natural pacemaker, is located in the superior-posterior wall of the right atrium. It spontaneously generates electrical impulses that initiate each heartbeat. These impulses then spread throughout the atria, causing them to contract and pump blood into the ventricles.
Question 13: The term "ventricular diastole" means ventricular:
- Pressure ratio
- Relaxation
- Contraction
- Filling time (Correct answer)
Correct answer: Filling time
Ventricular diastole refers to the period when the ventricles are relaxed and actively filling with blood from the atria. While relaxation is a key component, the primary physiological event during diastole is the filling of the ventricles. This filling time is essential for ensuring adequate blood volume for the subsequent ventricular contraction (systole).
Question 14: Which of these represents a key step in the cardiac cycle?
- Ejection
- Isovolumic relaxation
- Inflow
- All of these (Correct answer)
Correct answer: All of these
The cardiac cycle encompasses all the events that occur during one complete heartbeat, ensuring efficient blood pumping. Key steps include inflow (ventricular filling), isovolumic contraction (ventricles contract without changing volume), ejection (blood is pumped out), and isovolumic relaxation (ventricles relax without changing volume). Therefore, all the listed options are integral parts of the cardiac cycle.
Question 15: A typical, healthy heart beats __________ beats per minute.
- 71 cardiac cycles
- 72 cardiac cycles (Correct answer)
- 81 cardiac cycles
- 82 cardiac cycles
Correct answer: 72 cardiac cycles
A typical, healthy adult heart beats approximately 72 times per minute at rest. This corresponds to 72 cardiac cycles, where each cycle represents one complete sequence of atrial and ventricular contraction and relaxation. This average resting heart rate is a key indicator of cardiovascular health.
Question 16: What part of the EKG shows how long the ventricles were in systole?
- ST segment
- QRS complex
- PR segmentQT interval
- QT interval (Correct answer)
Correct answer: QT interval
The QT interval on an EKG represents the total duration of ventricular depolarization and repolarization. Since ventricular systole (contraction) encompasses both these electrical events, the QT interval provides an approximation of the time the ventricles spend in systole. Abnormalities in QT interval length can indicate serious cardiac conditions.
Free ECG Technician Certification Exam Question and Answers
The waveforms in the middle are referred to as what?