Ventricular Tachycardia
An dysrhythmia of the heart is an irregular heartbeat rhythm. Ventricular tachycardia is an dysrhythmia in which the lower chambers of the heart, the ventricles, beat unusually fast.
The heart rate is measured with an electrocardiogram, or ECG. This is a machine that measures the electrical impulses from the patient's heart. This is displayed on a monitor or ECG graph paper. The boxes on the graph paper measure time. Five small boxes are equal to one large box. The large box represents two-tenths of a second.
The atrial contraction is represented by the P wave. This is an upward, or positive wave of the line on the graph. The ventricular contraction is displayed by the QRS complex. The QRS complex is composed of three waves, the Q, R, and S waves. The Q wave is the first downward, or negative movement on the graph. The R wave is the positive movement following the Q wave. It rises above the starting point of the Q wave. The S wave is a negative movement following the R wave. The S wave returns the line to the original baseline. The T wave, the repolarization of the ventricle, is a positive wave of the line that ends one beat of the heart. The atrial repolarization is not represented on the graph. It is absorbed by the QRS complex, which is a stronger impulse.
In a normal heart beat, there is one P wave for every QRS complex and T wave. The QRS complex is no larger than three small boxes on the graph paper. Every beat comes at the same interval as the other beats.
During ventricular tachycardia, the P wave is not represented. The QRS complex is wide. The T wave is not present on the graph. The intervals between beats can be up to five times shorter than a normal rhyth...
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When lidocaine and bretylium both fail to produce positive results, magnesium sulfate can be used. Magnesium sulfate is an antidysrhythmic, meaning that it establishes a normal heart rhythm. Magnesium sulfate can also cause hypotension, bradycardia, and circulatory collapse among other side effects. It is a last resort drug for ventricular tachycardia.
Other medications, however, are indicated for an unusual form of ventricular tachycardia called Torsade de Pointes. Torsade de Pointes is the irregular rhythm of ventricular tachycardia, but it occurs in a pattern of small series of waves that increase to a greater magnitude, and then back in a repeating pattern.
For Torsade de Pointes, the drug of choice is magnesium sulfate. It should be administered at a rate of one to two grams in one hundred milliliters of normal saline over one to two minutes.
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.
622 Y. When the AV node receives the signal, it fires and causes the ventricles to depolarize, this is known as the QRS Complex. The atria also repolarizes during this phase. Specifically in the QRS Complex, during the Q wave, the interventricular septum depolarizes, during the R wave, the main mass of the ventricles depolarizes, and during the S wave, the base of the heart, apex, depolarizes. After the QRS Complex, the S-T segment can be identified as a plateau in myocardial action potentials and is when the ventricles actually contract and pump out blood to the pulmonary and systemic circuits. The final phase of the heartbeat is the T wave and this is when the ventricles repolarize before the relax, ventricular diastole, EKG Video Notes and pg. 671 D. These phases represent the cardiac cycle, which is the time and events that occur from the beginning of one heartbeat to the beginning of the next heartbeat. In this lab, the first EKG that I took was my regular heartbeat during rest. In this recording, I was able to see the P wave, followed by the QRS Complex and the T wave as well. Everything looks pretty normal, but the T wave does go a little lower than normal and I believe this is due to the fact that I was diagnosed with sinus bradycardia
1.2 & 1.3 Explain The Cardiac Cycle And Describe How The Heart Rate Is Modified According To The Needs Of The Body
There are four different categories of treatment: lifestyle changes, surgical procedures, non-surgical procedures, and medications. Lifestyle changes include having a healthy diet; increasing physical activity; eliminating cigarettes, alcoholic beverages, and illicit drugs; and getting enough rest and sleep; losing excess weight. These lifestyle changes are to lower the patient’s blood pressure, cholesterol, and reducing any other future medical conditions. There are also surgical options to help cure, prevent, or control cardiomyopathy. Surgical method include a septal myectomy, surgically implanted devices, and a heart transplant. A septal myectomy is used to specifically treat hypertrophy cardiomyopathy which is where the heart muscle cells enlarge and cause the walls of the ventricles to thicken. The thickening of the walls may not affect the size of the ventricles but instead may affect the blood flow out of the ventricle. Usually along with the ventricles swelling, the septum in between the ventricles can become enlarged and block the blood flow causing a heart attack. When medication is not working well to treat hypertrophic cardiomyopathy, a surgeon will open the chest cavity and remove part of the septum that is blocking blood flow. Surgically implanted devices include a pacemaker, a cardiac resynchronization therapy device, a left ventricular assist device, and an implantable
Two heart sounds are normally heard through a stethoscope on the chest wall, "lab" "dap". The first sound can be described as soft, but resonant, and longer then the second one. This sound is associated with the closure of AV valves (atrioventricular valves) at the beginning of systole. The second sound is louder and sharp. It is associated with closure of the pulmonary and aortic valves (semilunar valves) at the beginning of diastole. There is a pause between the each set of sounds. It is a period of total heat relaxation called quiescent period.
The first participant measured her pulse rate for 30 seconds before starting the exercise. Her pulse rate was calculated to determine the number of beats per minute. She then stepped on the platform (up and down) and continued at a slow pace for 3 minutes. After three minutes of the exercise, she measured her pulse rate every minute to determine her recovery time. This process was repeated until her pulse rate returned to normal.
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.
Each beat of the heart is referred to as the cardiac cycle. When the heart beats, the atria contract simultaneously followed by the ventricles contracting simultaneously, this process is known as systole. The resting phase of the four chambers between beats is referred to as diastole.
Furosemide (Lasix) 40 mg daily in the morning: Loop diuretic used to treat edema associated with congestive heart failure (CHF).
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.
AIM: - the aim of this experiment is to find out what the effects of exercise are on the heart rate. And to record these results in various formats. VARIABLES: - * Type of exercise * Duration of exercise * Intensity of exercise * Stage of respiration
The two major things that will help an athlete while measuring the cardiovascular drift are progression and hydration levels. The heart rate of an athlete working hard during a workout should be no more than their maximum heart rate which is found by, if you’re a female take 226-age, if you’re a male take 220-age. If while doing a workout the maximum heart rate is exceeded by too much it may be necessary to take a break or slow down greatly. This may also help with traking the hydration of an athlete. If an athlete stays hydrated their core temperature will stay regulated which means they won’t sweat as much, which also means the heart won’t be under as much stress while transporting the oxygenated blood throughout the body to the
The heart is a pump with four chambers made of their own special muscle called cardiac muscle. Its interwoven muscle fibers enable the heart to contract or squeeze together automatically (Colombo 7). It’s about the same size of a fist and weighs some where around two hundred fifty to three hundred fifty grams (Marieb 432). The size of the heart depends on a person’s height and size. The heart wall is enclosed in three layers: superficial epicardium, middle epicardium, and deep epicardium. It is then enclosed in a double-walled sac called the Pericardium. The terms Systole and Diastole refer respectively and literally to the contraction and relaxation periods of heart activity (Marieb 432). While the doctor is taking a patient’s blood pressure, he listens for the contractions and relaxations of the heart. He also listens for them to make sure that they are going in a single rhythm, to make sure that there are no arrhythmias or complications. The heart muscle does not depend on the nervous system. If the nervous s...
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).
Scientific interest in the heart goes back centuries. Some of the most basic understandings about the operation and specifically the electrical currents of the heart were discussed during the May 17, 1888 Proceedings of the Royal Society of London by Professor J.A. McWilliam of the University of Aberdeen. The following conclusions were based on his studies of mammalian hearts in cats, dogs, rabbits, rats, hedgehogs, and guinea-pigs.