General Knowledge Flashcards
16 cards from real EKG certification Certification practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 16 General Knowledge flashcards as text
The waveforms in the middle are referred to as what?
Answer: Segment
In EKG interpretation, a segment refers to the flat line connecting two waveforms, representing a period of electrical inactivity or delay. For example, the PR segment connects the P wave to the QRS complex, and the ST segment connects the QRS complex to the T wave. These segments are crucial for assessing the heart's conduction system.
The PR portion is what?
Answer: Depolarization of AV node and its delay and depolarization of Bundle of His and Bundle branches
The PR segment on an EKG represents the physiological delay of the electrical impulse as it passes through the AV node, Bundle of His, and bundle branches. This delay allows for complete atrial contraction and ventricular filling before ventricular depolarization and subsequent contraction begin. It is a critical period for proper cardiac function.
What do the tiny squares on the EKG paper's horizontal axis represent?
Answer: 0.04 sec
EKG paper is standardized with a grid where small squares measure 1mm by 1mm. On the horizontal axis, which represents time, each tiny square corresponds to 0.04 seconds. This precise measurement allows for accurate calculation of heart rate and the duration of various cardiac events, which is vital for diagnosis.
What stands for the QRS complex?
Answer: The depolarization of ventricles
The QRS complex is the most prominent waveform on an EKG and represents the rapid depolarization of the ventricles. This electrical event triggers ventricular contraction, which is responsible for pumping blood out of the heart to the body and lungs. It is a key indicator of ventricular function.
What is the ideal breaths-to-compressions ratio during CPR?
Answer: 2 breaths to 30 compressions
For adult CPR, the universally recommended ratio of compressions to breaths is 30 compressions followed by 2 rescue breaths. This ratio prioritizes continuous chest compressions to maintain blood flow to vital organs, while still providing adequate ventilation. This standard is taught in basic life support courses to maximize effectiveness.
The proper lead for the midaxillary line on the left side of the fifth intercostal gap is:
Answer: V6
EKG lead placement is standardized to ensure accurate readings of the heart's electrical activity. Lead V6 is specifically placed at the left midaxillary line, horizontally level with V4 and V5, typically in the fifth intercostal space. This placement helps capture electrical activity from the lateral wall of the left ventricle.
What effects does the parasympathetic nervous system have on the heart, and which receptors are involved?
Answer: Dilation of arteries (cholinergic receptors)
The parasympathetic nervous system, primarily through the vagus nerve, generally slows the heart rate and reduces the force of contraction. It releases acetylcholine, which acts on muscarinic cholinergic receptors. While its main cardiac effects are on rate and contractility, parasympathetic stimulation can also lead to dilation of coronary arteries, mediated by these cholinergic receptors, to increase blood flow to the heart muscle.
The ST segment is what?
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). It is typically an isoelectric (flat) line, indicating that the entire ventricular myocardium is depolarized. Deviations in the ST segment, such as elevation or depression, are critical indicators of myocardial ischemia or injury.
When blood flow to the heart muscle is stopped or abruptly reduced for long enough to result in cell death, myocardial infarction occurs.
Answer: TRUE
Myocardial infarction, commonly known as a heart attack, occurs when blood flow to a part of the heart muscle is severely reduced or completely blocked. This deprivation of oxygen and nutrients for a prolonged period leads to the death of heart muscle cells. The blockage is usually due to a blood clot in a coronary artery, often caused by plaque rupture.
What is the dominant ion inside cells?
Answer: Potassium
Potassium (K+) is the dominant intracellular cation, meaning it is the most abundant positively charged ion inside cells. This high intracellular concentration of potassium is crucial for maintaining the cell's resting membrane potential and plays a vital role in nerve impulse transmission, muscle contraction, and heart function.
What is the dominant ion outside of cells?
Answer: Sodium
Sodium (Na+) is the dominant extracellular cation, meaning it is the most abundant positively charged ion outside of cells. This high extracellular concentration of sodium is essential for maintaining osmotic balance, fluid volume, and is critical for the generation of action potentials in nerve and muscle cells, facilitating communication and function.
Where is the sinoatrial node located?
Answer: Right atrium
The sinoatrial (SA) node, often called the heart's natural pacemaker, is located in the upper posterior wall of the right atrium. It spontaneously generates electrical impulses that initiate each heartbeat, setting the rhythm for the entire heart. From the SA node, these impulses spread across the atria, causing them to contract.
The term "ventricular diastole" means ventricular:
Answer: Filling time
Ventricular diastole refers to the period when the ventricles of the heart are relaxed and filling with blood. During this phase, the atrioventricular valves are open, allowing blood to flow from the atria into the ventricles. This filling time is crucial for ensuring adequate blood volume for the next contraction and maintaining cardiac output.
Which of these represents a key step in the cardiac cycle?
Answer: All of these
The cardiac cycle describes the sequence of events that occurs with each heartbeat. Key steps include inflow (ventricular filling during diastole), isovolumic contraction (ventricles contract but valves are closed, increasing pressure), ejection (blood is pumped out during systole), and isovolumic relaxation (ventricles relax but valves are closed, decreasing pressure). All these phases are integral to the heart's efficient pumping action.
A typical, healthy heart beats __________ beats per minute.
Answer: 72 cardiac cycles
A typical, healthy adult heart beats approximately 60 to 100 times per minute at rest. An average resting heart rate is often cited as 72 beats per minute, which translates to 72 cardiac cycles. This rate ensures efficient circulation of blood throughout the body, delivering oxygen and nutrients to tissues.
What part of the EKG shows how long the ventricles were in systole?
Answer: QT interval
The QT interval on an EKG represents the total time required for both ventricular depolarization and repolarization. It extends from the beginning of the QRS complex to the end of the T wave. Therefore, it reflects the duration of ventricular systole, which is the period of ventricular contraction and relaxation, and is important for assessing ventricular electrical stability.