NCCT ECG Certification Review - Part 3 Rhythm (Rh)

To fully evaluate a patient's cardiac function, it is important to assess multiple factors. The pulse provides information about the heart rate and rhythm, which can indicate any abnormalities. Blood pressure measurement helps determine the force exerted by the heart and the health of the blood vessels. An electrocardiogram (ECG) is a diagnostic test that records the electrical activity of the heart, providing valuable information about its function and any potential issues. Therefore, all of these assessments are necessary to obtain a comprehensive evaluation of a patient's cardiac function.

The correct answer is a. AV node. The question is asking for the major areas of the conduction system, and the AV node is one of the three mentioned. The other options, QRS range, SA junction, and terminal junction, are not major areas of the conduction system and are therefore incorrect.

In interpreting an arrhythmia, it is important to ask multiple questions to gather information about the condition. By asking if all the QRS complexes are of equal duration, one can assess for any abnormalities in the ventricular depolarization. Asking if all the P waves look alike helps in evaluating the atrial depolarization. Additionally, determining if the rhythm is irregular provides insight into the overall pattern of the arrhythmia. Therefore, considering all of these questions as possibilities is necessary for a comprehensive interpretation.

The heart has two components: mechanical and electrical. The mechanical component refers to the physical pumping action of the heart, while the electrical component refers to the electrical signals that regulate the heartbeat. These electrical signals are responsible for coordinating the contraction and relaxation of the heart muscles, allowing the heart to beat rhythmically and efficiently. Therefore, option d. electrical is the correct answer.

The standard rate at which an ECG machine runs paper past the stylus is 25mm/sec.

The correct answer is "after". The ST segment and T waves represent the repolarization phase of the cardiac cycle, which occurs after the depolarization represented by the QRS complex. This means that the repolarization occurs after the depolarization.

When electricity flows toward the negative electrode, it creates a pattern on the graph that is downward or inverted. This is because the negative electrode is usually represented at the bottom of the graph, and as the electricity flows towards it, the graph line moves downward.

Voltage is measured by noting the height of a spike along the vertical (y) axis of the graph paper. This is because the vertical axis represents the magnitude or amplitude of the voltage. By observing the height of the spike on the vertical axis, we can determine the voltage level at that point. The horizontal (x) axis, on the other hand, typically represents time or another independent variable, and is not directly related to voltage measurement.

The P wave in an electrocardiogram (ECG) represents the depolarization of the atria. Depolarization refers to the electrical activation of the cells, causing them to contract. In the heart, depolarization of the atria leads to the contraction of the atrial muscles, which helps in the filling of the ventricles with blood. Therefore, the correct answer is b. atrial depolarization.

An echocardiogram is a test that uses high frequency sound vibrations to create images of the heart. These sound waves are sent into the heart through the chest wall, allowing doctors to visualize the structure and function of the heart. This non-invasive procedure is commonly used to diagnose and monitor heart conditions. Phonocardiogram, electrocardiogram, and angiogram are other types of tests used to evaluate the heart, but they do not involve the use of high frequency sound vibrations.

Junctional tachycardia is a type of abnormal heart rhythm that originates in the junction between the atria and the ventricles. The rate range for junctional tachycardia is typically between 100 and 180 beats per minute. This means that the heart is beating faster than normal, but not excessively fast. Rates below 100 or above 180 would be considered abnormal and may indicate a different type of tachycardia.

The major categories of arrhythmias are sinus, atrial, junctional, and ventricular. Sinus arrhythmias originate from the sinus node, which is the heart's natural pacemaker. Atrial arrhythmias occur in the atria, the upper chambers of the heart. Junctional arrhythmias occur at the atrioventricular (AV) junction, where the electrical signals are transmitted from the atria to the ventricles. Ventricular arrhythmias occur in the ventricles, the lower chambers of the heart. Therefore, the correct answer is sinus, atrial, junctional, ventricular.

The ECG graph paper is used to measure the electrical activity of the heart. Each small square on the paper represents a specific amount of time. The time needed to cross one small square can be calculated by dividing the total time span of the ECG graph by the number of small squares. In this case, the correct answer is c. 0.04 seconds, which means it takes 0.04 seconds to cross one small square on the ECG graph paper.

The PR segment is the correct answer because it refers to the line between the P wave and the next wave on an electrocardiogram (ECG). The PR segment represents the time interval between atrial depolarization and ventricular depolarization, and it is measured from the end of the P wave to the beginning of the QRS complex. This segment is important in assessing the conduction of electrical impulses through the atrioventricular (AV) node and can provide information about any abnormalities in the electrical conduction system of the heart.

Electrocardiography is the study of arrhythmias, which are abnormal heart rhythms. This diagnostic procedure involves the use of electrodes placed on the skin to measure and record the electrical activity of the heart. By analyzing the patterns and abnormalities in the recorded electrical signals, healthcare professionals can diagnose and monitor various heart conditions, including arrhythmias. Therefore, option a, arrhythmias, is the correct answer for this question.

The distance between waves is commonly referred to as intervals. This term is used to describe the space or gap between consecutive waves. It is a measurement of the distance from one wave crest to the next or from one wave trough to the next. Intervals are an important concept in the study of waves and are used to determine various properties such as wavelength and frequency. The other options, base spaces, segments, and cycles, do not accurately describe the distance between waves.

To calculate regular rhythm heart rates, one can count the number of small squares between two consecutive R waves on an ECG strip. Each small square represents 0.04 seconds, and there are 1500 small squares in one minute (60 seconds divided by 0.04 seconds). Therefore, the correct answer is c. 1500.

The correct answer is a. less than 0.12. The QRS measurement refers to the duration of the QRS complex on an electrocardiogram (ECG). A normal QRS complex typically lasts less than 0.12 seconds. This measurement represents the time it takes for the ventricles of the heart to depolarize and contract. If the QRS duration is prolonged, it may indicate abnormalities in the conduction system of the heart. Therefore, a QRS measurement of less than 0.12 seconds is considered within the normal range.

In one complete cardiac cycle, there are five prominent waves. These waves are known as the P wave, QRS complex, and T wave. The P wave represents atrial depolarization, the QRS complex represents ventricular depolarization, and the T wave represents ventricular repolarization. These waves can be observed on an electrocardiogram (ECG) and are used to diagnose and monitor heart conditions.

The refractory period refers to a period of time after a neuron fires an action potential during which it is temporarily unable to fire another action potential. In this context, the term "relative" likely refers to the fact that not all cells in a neural circuit enter the refractory period at the same time. Instead, only some of the cells are able to respond while others are still in their refractory period. This suggests that there is a relative difference in the timing of the refractory period among the cells in the circuit.

Time is measured horizontally along the x-axis of a graph paper. The x-axis represents the independent variable, which is typically time in most cases. The y-axis, on the other hand, represents the dependent variable. Therefore, the correct answer is c. x axis.

Rhythms that originate in the AV junction include premature junctional contraction, accelerated junctional rhythm, junctional tachycardia, and junctional escape rhythm.

When the ECG selector switch is turned to lead II, a connection is made between the left leg and the right arm. This is because lead II measures the electrical activity between the right arm and the left leg, which provides important information about the electrical conduction of the heart. By connecting the right arm to lead II, the ECG machine is able to capture this specific electrical activity and display it on the ECG waveform.

Impulses from the AV node travel through the Bundle of His to the right and left bundle branches. This is the correct answer because the Bundle of His is responsible for conducting electrical signals from the AV node to the ventricles of the heart. The right and left bundle branches then distribute these impulses to the respective ventricles, allowing for coordinated contraction and pumping of blood. The SA node is responsible for initiating the electrical impulses that start each heartbeat, while the intra-atrial pathways and Purkinje cells are not directly involved in the conduction of impulses from the AV node.

A line between waves is referred to as a segment because a segment is a part of a line that is bounded by two distinct endpoints. In this context, the line represents the wave, and the segment refers to the portion of the wave between two specific points.

The refractory period refers to a period of time after a neuron has fired an action potential, during which it is unable to respond to any additional stimuli. This period is known as the absolute refractory period. During this time, the neuron is in a state of hyperpolarization and the voltage-gated sodium channels are inactivated, preventing the neuron from firing another action potential. This ensures that the neuron has time to reset and recover before it can be stimulated again.

The positive pole of lead III is at the left arm because in the standard 12-lead ECG, the positive electrode for lead III is placed on the left arm, while the negative electrode is placed on the left leg. This configuration allows for the measurement of the electrical activity between the left arm and left leg, providing valuable information about the electrical conduction in the heart.

The correct answer is b. 0.2 seconds. This means that it takes 0.2 seconds to move from one bold line to the next on the ECU graph paper.

The correct answer is a. 300. This is because the bpm (beats per minute) for 1 large square is a measure of the heart rate, and a heart rate of 300 beats per minute is considered extremely high.

Sinus P waves differ from ectopic atrial P waves because they are upright and uniform. This means that the P waves in a sinus rhythm will have a consistent shape and will be positive (upright) in lead II. Ectopic atrial P waves, on the other hand, may have different shapes and can be positive or negative (inverted) depending on their origin.

To obtain the best results on an ECG reading, it is important to use a contact medium. A contact medium, such as gel or paste, helps to improve the conductivity between the skin and the electrodes. This ensures that the electrical signals from the heart are accurately transmitted and recorded by the ECG machine. Cleaning the skin area, abrading the skin slightly, and disinfecting the electrode are also important steps in preparing for an ECG, but using a contact medium is specifically necessary for achieving optimal results.

Lead AVR records the electrical activity of the heart from the right arm. When electrical current moves from the right arm toward the left arm, a positive deflection is registered in lead AVR. This is because the electrical current is moving towards the positive electrode in lead AVR, resulting in a positive deflection on the ECG tracing.

Atrial fibrillation is a heart condition characterized by irregular and rapid heartbeats. In this question, it is stated that atrial fibrillation is demonstrated with a rate of more than a certain number of beats per minute. The correct answer is 350, indicating that atrial fibrillation is typically associated with a heart rate higher than 350 beats per minute.