Arrhythmia is a type of cardiovascular disorder that causes irregular heartbeats. This is a disorder of the heart when the heart beat is out of its normal rhythm. Arrhythmia can cause the heartbeat to be too fast or too slow and can change the overall number of heart beats per minute than normal. There are two common kinds of arrhythmias, one is bradycardia and the other is tachycardia. Bradycardia is a disorder when the heart rate is too slow and the heart’s beat per minute is less than 60 beats. When listening to the heart, the “lub” or S1 and “dub” or S2 takes longer pauses than what a normal heart beat would sound. Tachycardia also known as supraventricular tachycardia (SVT) is a disorder when the heart rate is too fast and the heart’s beats are more than 100 beats per minute. This disorder feels as if the heart is racing, pounding, skipping a beat or added an extra beat making a rapid fluttering or throbbing heart beat sound. …show more content…
It can be caused by irregular closure of the mitral and tricuspid atrioventricular (AV) valves at the beginning of ventricular systole or by the closure of the aortic valve and pulmonary valve at the end of ventricular systole. Most of the time, an irregular heartbeat often occurs through an irregular cardiac stimulation and purkinje fibers. The SA nodes sends signals through the atria and that signal slowly goes towards the AV node. At the AV node, the rate of the signal increases as the impulse passes through the AV bundle into the ventricles. The branches of the right and left bundle fibers and purkinje fibers regulate those impulses throughout the muscles of each of the ventricles, therefore both ventricles contract at the same time. Often the cause for arrhythmia is when this process doesn’t occur the way it
There are several different heart problems that show up as an abnormal EKG reading. For example, a heart block can occur when there is a delay in the signals coming from the SA node, AV node, or the Purkinje fibers. However, clinically the term heart block is used to refer to an AV block. This delays or completely stops communication between the atria and the ventricles. AV block is shown on the EKG as a delayed or prolonged PR interval. The P wave represents the activity in the atria, and the QRS complex represents ventricular activity. This is why the PR interval shows the signal delay from the AV node. There are three degrees of severity, and if the delay is greater than .2 seconds it is classified as first degree. Second degree is classified by several regularly spaced P waves before each QRS complex. Third degree can be shown by P waves that have no spacing relationship to the QRS complex. Another type of blockage is bundle branch block. This is caused by a blockage in the bundle of His, creating a delay in the electrical signals traveling down the bundle branches to reach the ventricles. This results in a slowed heart beat, or brachycardia. On an EKG reading this is shown as a prolonged QRS complex. A normal QRS is about .8-.12 seconds, and anything longer is considered bundle branch block. Another type of abnormal EKG reading is atrial fibrillation, when the atria contracts very quickly. On the EKG this is shown by no clear P waves, only many small fibrillating waves, and no PR interval to measure. This results in a rapid and irregular heartbeat. On the other hand, ventricular fibrillation is much more serious and can cause sudden death if not treated by electrical defibrillation.
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
1.2 & 1.3 Explain The Cardiac Cycle And Describe How The Heart Rate Is Modified According To The Needs Of The Body
The normal Mitral Valve controls blood flow between the upper (left atrium) and lower chamber (left ventricle) of the left side of the heart. The mitral valve allows blood to flow from the left atrium into the left ventricle, but not flow the other way. With each heartbeat, the atria contract and push blood into the ventricles. The flaps of the mitral and tricuspid valves open to let blood through. Then, the ventricles contract to pump the blood out of the heart. The flaps of the mitral and tricuspid valves close and form a tight seal that prevents blood from flowing back into the atria (nhlbi.nih.gov).
It occurs because of repetitive electrical activity. This can occur in a patient with early or late heart failure, because there is damage to the heart tissue and the heart beats faster to try to supply the body with blood. Recommended treatment is elective cardioversion. Drugs used include an antidysrhythmic such as Mexitil or Sotalol (Ignatavicius &Workman, p. 728-729).
The structures responsible for these sounds are: pulmonary, aortic and atrioventricular valves. These sounds are results of vibration caused by closure of these valves. Other sounds known as "heart murmurs" are sometimes a sign of heart disease. "Murmurs can be produced by blood flowing rapidly in the usual directions through an abnormally narrowed valve" (Vander, Sherman and Luciano, 1985, p.326) and in some cases, as mitral valve prolapse, the individual does not show any symptoms.
Atrial fibrillation (AF) is a cardiac arrhythmia. It is the most common arrhythmia and it has implications for patients and anaesthetists alike. The anaesthetist must take into consideration the physiological and pharmacological implications of this common arrhythmia.
Hypertrophic cardiomyopathy is an inherited disease that affects the cardiac muscle of the heart, causing the walls of the heart to thicken and become stiff. [1] On a cellular level, the sarcomere increase in size. As a result, the cardiac muscles become abnormally thick, making it difficult for the cells to contract and the heart to pump. A genetic mutation causes the myocytes to form chaotic intersecting bundles. A pathognomonic abnormality called myocardial fiber disarray. [2,12] How the hypertrophy is distributed throughout the heart is varied. Though, in most cases, the left ventricle is always affected. [3] The heart muscle can thicken in four different patterns. The most common being asymmetrical septal hypertrophy without obstruction. Here the intraventricular septum becomes thick, but the mitral valve is not affected. Asymmetrical septal hypertrophy with obstruction causes the mitral valve to touch the septal wall during contraction. (Left ventricle outflow tract obstruction.) The obstruction of the mitral valve allows for blood to slowly flow from the left ventricle back into the left atrium (Mitral regurgitation). Symmetrical hypertrophy is the thickening of the entire left ven...
The cardiac cycle is composed of five stages. These stages are atrial systole, early ventricular systole, late ventricular systole, early ventricular diastole, and late ventricular diastole. In order for atrial systole to occur, the blood that has been flowing between the atrium and ventricle via the opened atrioventricular valves must be deposited into the ventricles. The SA node is responsible for the contraction of the atrial myocardium. Once the atrium contracts, blood cannot flow back into or enter the atria because the openings of the great veins has been narrowed by pressure. The ventricles are now filled with blood accomplishing end-diastolic volume which is another term for how much blood your ventricles can contain while your body is at rest. The next phase is early ventricular systole. Now that all the blood is in your ventricles, it must continue onward to the
Most often the disease starts in the left ventricle, and then often spreads to both the atrium and right ventricle as well. Usually there will also be mitral and tricuspid regurgitation, due to the dilation of the annuli. This regurgitation will continue to make problems worse by adding excessive volume and pressure to the atria, which is what then causes them to dilate. Once the atria become dilated it often leads to atrial fibrillation. As the volume load increases the ventricles become more dilated and over time the myocytes become weakened and cannot contract as they should. As you might have guessed with the progressive myocyte degeneration, there is a reduction in cardiac output which then may present as signs of heart failure (Lily).
The heart is two sided and has four chambers and is mostly made up of muscle. The heart’s muscles are different from other muscles in the body because the heart’s muscles cannot become tired, so the muscle is always expanding and contacting. The heart usually beats between 60 and 100 beats per minute. In the right side of the heart, there is low pressure and its job is to send red blood cells. Blood enters the right heart through a chamber which is called right atrium. The right atrium is another word for entry room. Since the atrium is located above the right ventricle, a mixture of gravity and a squeeze pushes tricuspid valve into the right ventricle. The tricuspid is made up of three things that allow blood to travel from top to bottom in the heart but closes to prevent the blood from backing up in the right atrium.
When you have Tachycardis your heart rate is above 100 beats per minute. Tachycardis is caused by heart injuries from past times. Tachycardis usually occurs months or years after a heart attack. A treatment for Tachycardis can be inserting a device called a defibrillator. A defibrillator will detect and treat abnormally fast heart rhythms.
When a person has Atrial Fibrillation, the sinoatrial node releases multiple quick impulses at a rate of 350 -600 times per minute. When this happens, the ventricles respond by beating around 120- 200 beats per minute, making it tough to identify an accurate heart rate. This arrhythmia can be the result of various things. During a normal heart beat, the electrical impulse begins at the sinoatrial node and travels down the conduction pathway until the ventricles contract. Once that happens, the SA node fires again and the process keeps on cycling (Ignatavicius & Workman, 2013).
The heart beats when electrical signals move through it. Ventricular fibrillation is a condition in which the heart's electrical activity becomes disordered. When this happens, the heart's lower (pumping) chambers contract in a rapid, unsynchronized way. (The ventricles "flutter" rather than beat.) The heart pumps little or no blood therefore the probability of death is high.
Sports related cardiac deaths are very sudden and most scientists don’t know why they occur, but researchers are conducting many studies to try to determine the exact cause. What happens when an athlete that is in the best of physical health suffers a sudden cardiac death? The sudden death leaves the community, team, and family shocked and devastated and looking for answers. There has been many studies done trying to determine why athletes suffer sudden cardiac arrest.