3. Describe the electrical conduction system of the heart.
The normal electrical conduction in the heart allows the impetus that is engendered by the sinoatrial node (SA node) of the heart to be propagated to, and stimulate, the cardiac muscle (myocardium). The myocardium contracts after stimulation. It is the set up, rhythmic stimulation of the myocardium during the cardiac cycle that allows efficient contraction of the pump, thereby permitting blood to be pumped throughout the torso.
4. State three reasons why patients may need an electrocardiogram (ECG).
To look for the cause of chest pain
To evaluate problems which may be heart-related, such as severe tiredness, shortness of breath, lightheadedness, or passing out
To identify irregular beats
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Identify the various positive and negative deflections and describe what each represents in the cardiac cycle.
All the regions of this conduction system initiate impulses, become irritable, and each portion of the cardiac cycle produces a different electrical impulse and there is no current strong enough to create either a plus or negative deviation.
6. Explain the purpose of standardization of the ECG.
The calibration of the ECG is important because it helps to learn whether the machine is ready and working properly or not.
7. Identify the 12 leads of an ECG and describe what area of the heart each lead represents.
Orientation of the 12 Lead ECG
It is significant to remember that the 12-lead ECG provides spatial data about the heart 's electrical activity in 3 approximately orthogonal directions: Right ⇔ Left Superior ⇔ Inferior Anterior ⇔
Both tests are very useful for assessing the pulmonary and cardiac system health of the individual being examined. This involves examining the individual’s response to the test by assessing their BP, HR, oxygen intake abilities, and using this information to infer whether they have some type of internal impairment. This includes
In this lab, I took two recordings of my heart using an electrocardiogram. An electrocardiogram, EKG pg. 628 Y and pg. 688 D, is a recording of the heart's electrical impulses, action potentials, going through the heart. The different phases of the EKG are referred to as waves; the P wave, QRS Complex, and the T wave. These waves each signify the different things that are occurring in the heart. For example, the P wave occurs when the sinoatrial (SA) node, aka the pacemaker, fires an action potential. This causes the atria, which is currently full of blood, to depolarize and to contract, aka atrial systole. The signal travels from the SA node to the atrioventricular (AV) node during the P-Q segment of the EKG. The AV node purposefully delays
When evaluating systolic and diastolic function it is extremely important to obtain images of wall motion, wall thickness, chamber size and ventricular end diastolic pressure.
The cardiovascular system - The cardiovascular system is responsible for transporting nutrients and removing gaseous waste from the body. It consists of the heart, which powers the whole process, the veins, arteries, and capillaries, which deliver oxygen to tissue at the cellular level. The cardiovascular system carries blood that is low in oxygen away from the heart to the lungs via arteries, where oxygen levels are restored through the air once oxygenated, this blood is then carried throughout the body via arteries, keeping our organs and tissue alive. The cardiovascular system is the workhorse of the body, continuously moving to push blood to the cells. If this important system ceases its work, the body dies.
An electrocardiogram (ECG) is one of the primary assessments concluded on patients who are believed to be suffering from cardiac complications. It involves a series of leads attached to the patient which measure the electrical activity of the heart and can be used to detect abnormalities in the heart function. The ECG is virtually always permanently abnormal after an acute myocardial infarction (Julian, Cowan & Mclenachan, 2005). Julies ECG showed an ST segment elevation which is the earliest indication that a myocardial infarction had in fact taken place. The Resuscitation Council (2006) recommends that clinical staff use a systematic approach when assessing and treating an acutely ill patient. Therefore the ABCDE framework would be used to assess Julie. This stands for airways, breathing, circulation, disability and elimination. On admission to A&E staff introduced themselves to Julie and asked her a series of questions about what had happened to which she responded. As she was able to communicate effectively this indicates that her airways are patent. Julie looked extremely pale and short of breath and frequently complained about a feeling of heaviness which radiated from her chest to her left arm. The nurses sat Julie in an upright in order to assess her breathing. The rate of respiration will vary with age and gender. For a healthy adult, respiratory rate of 12-18 breaths per minute is considered to be normal (Blows, 2001). High rates, and especially increasing rates, are markers of illness and a warning that the patient may suddenly deteriorate. Julie’s respiratory rates were recorded to be 21 breaths per minute and regular which can be described as tachypnoea. Julies chest wall appeared to expand equally and symmetrical on each side with each breath taken. Julies SP02 levels which are an estimation of oxygen
The study of cardio physiology was broken up into five distinct parts all centering on the cardiovascular system. The first lab was utilization of the electrocardiogram (ECG). This studied the electrical activities of the heart by placing electrodes on different parts of the skin. This results in a graph on calibrated paper of these activities. These graphs are useful in the diagnosis of heart disease and heart abnormalities. Alongside natural heart abnormalities are those induced by chemical substances. The electrocardiogram is useful in showing how these chemicals adjust the electrical impulses that it induces.
The ventricular ectopic pacemaker produced the rhythms as 30-40 beats/minutes much slower than the generally produced by SA node which is 60-100
The electrocardiogram is a test performed to make sure all electrical activity of the heart is normal and working properly. “By positioning leads (electrical sensing devices) on the body in standardized locations, information about many heart conditions can be learned by looking for characteristic patterns on the EKG.” KULICK, MD, FACC, FSCAI (2016) The activity is shown as spikes and dips called waves on the tracing paper, that comes out of the ECG machine. These waves create different waveforms to be analyzed for diagnoses. A waveform is movement recorded that is away from the baseline, either positive or negative.
The heart serves as a powerful function in the human body through two main jobs. It pumps oxygen-rich blood throughout the body and “blood vessels called coronary arteries that carry oxygenated blood straight into the heart muscle” (Katzenstein and Pinã, 2). There are four chambers and valves inside the heart that “help regulate the flow of blood as it travels through the heart’s chambers and out to the lungs and body” (Katzenstein Pinã, 2). Within the heart there is the upper chamber known as the atrium (atria) and the lower chamber known as the ventricles. “The atrium receive blood from the lu...
The holter monitor records the patients hearts electrical activities, the patients usually record times of the day they experience symptoms in a journal. Another test used for diagnosis is an electrophysiology study, and EPS, this test includes passing a wire through a vein in the patients arm or thigh up to the heart. The wire records the electrical signals in the heart. An echocardiogram is used as well; this is an ultrasound or the heart. Finally, a stress test, which is when an EKG is preformed while the patient is on a treadmill and increasing intervals are set to watch how the heart reacts to physical
The heart has a relatively long refractory period due to the plateau phase. The plateau phase occurs from the maintenance of a high calcium conductance and a delay in the subsequent increase in potassium conductance after a cardiac action potential. The heart membrane remains in a refractory or contracted state until the heart has fully returned to a relaxed state; therefore, tetanus or wave summation does not occur in cardiac muscles (Randall, 2002). When the frog’s heart was stimulated with single stimuli, an extrasystole and an increase in frequency was observed during the relaxation phase, but the amplitude remained constant. These results were analogous to the multiple stimuli treatment, which we expected. Because both single and multiple
rate by acting on the SA node and stroke volume intensifies the cardiac muscle contractility. By
In a normal strip, one can clearly identify a P wave before every QRS complex, which is then followed by a T wave; in Atrial Fibrillation, the Sinoatrial node fires irregularly causing there to be no clear P wave and an irregular QRS complex (Ignatavicius & Workman, 2013). Basically, it means that the atria, the upper chambers of the heart, are contracting too quickly and no clear P wave is identified because of this ‘fibrillation’ (Ignatavicius & Workman, 2013). Clinical Manifestations and Pathophysiology A normal heart rhythm begins at the sinoatrial node and follows the heart's conduction pathway without any problems. Typically the sinoatrial node fires between 60-100 times per minute (Ignatavicius & Workman, 2013).
... patients with heart failure: Impact on patients. American Journal of Critical Care, 20(6), 431-442.
The patient has high temperature-sign of fever, a very fast pulse rate (tachycardia), and chest wheezing when listened to using a stethoscope (Harries, Maher, & Graham, 2004, p.