Ectopic pacemaker :
A pacemaker other than a sinus node is called ectopic pacemaker. An ectopic pacemaker or ectopic focus is an excitable group of cells that causes a premature heart beat outside the normally functioning SA node of the heart. This is a site present other than SA node becomes self excitable and produce the extra heart beats.
If the SA node is damaged or other electrical conduction system has a problem than the ectopic pacemaker occur which cause the premature heart beat. These are the abnormal pacemaker sites and show the automaticity.
Pacemaker :
The contraction of heart muscles is initiated by the electrical impulses known as action potentials. The rate at which these impulses control the heart contraction is called heart
These cells are called modified cardiomycetes. The contraction of pacemaker cells mostly in humans in sinoatrial pacemaker is natural pacemaker and the resultant rhythm is called the sinus rhythm .so the normal heart beats are driven by the sinus node. Types of ectopic pacemaker :
There are two commonly types of ectopic :
Atrial ectopics
Ventral ectopics
Atrial ectopics :
Atrial ectopics are the early impulses from the atria these are present in the upper chamber of heart. In the electrical system of the heart the atrial ectopic beats occur. Atrial ectopic beats are also called premature beats.
Symptoms of atrial ectopic :
Due to the atrial ectopics contractions the lung diseases occurs. When the blood pressure is high in the arteries then this occur. These premature heart beats are more common in the aged people.
These can be diagnose by the Electrocardiogram.
Ventral ectopics:
Ventral ectopics are the electrical impulses from the ventricles these are present in the lower chamber of heart.
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
Ectopics causing palpitations are also common when the people have the too little sleep. Under the some heart conditions like the weakening of heart muscles which is known as cardiomyopathy or the people which are suffering from heart attack ectopics also occur in these conditions. These are also produced in association with myocardial ischemia, emotional stress and stimulation by foreign objects. These may be caused by the excessive leakage of potassium in the heart cells in the abnormal locations. This may also decreased the resting potential of heart muscle cells.
Treatment of ectopics beats:
The life cannot be shorten by these ectopics beats or premature beats. So we should not be worried about them but if the daily life activities are affected due to it such as the exercise or other daily works then the person should treated it properly. By using the antiarrhythmic drugs these beats can be minimized or
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
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).
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.
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.
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.
Approximately one million Americans suffer a heart attack annually. Four hundred thousand of these victims die as a result. Many of the heart attack deaths are due to ventricular fibrillation of the heart that occurs before the victim can reach any medical assistance or the emergency room. These electrical disturbances of the heart can be treated with medications once the patient reaches the hospital. Therefore, 90% to 95% of heart attack victims who make it to the hospital survive. The 5% to 10% who later die are those who have suffered major heart muscle damage.
The second beat is the semilunar valve opening to allow blood into the aorta or pulmonary trunk. 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.
One of the leading causes of death in the United States is heart disease. “Approximately every 29 seconds one American will have a heart attack, and once a minute one American will die from a heart attack” (Ford-Martin and Odle, 915). According to the Gale Encyclopedia of Alternative Medicine men over the age of 45 and women over the age of 55 are considered at risk for heart disease. Heart disease is a major cause of death. It is beneficial to individuals who seek to prevent heart disease to recognize the risks leading to heart attacks as they are one of the primary indications of developing heart disease; especially those that fall into the at risk age groups. These risks consist of some that cannot be changed such as heredity risks, or those that can change such as smoking habits. It is very important to know these specific risks for prevention and to understand the symptoms of heart attacks, such as sweating or the feeling of weakness so if these or other symptoms occur people are aware. Finally heart disease treatment is of vital importance if you experience a heart attack so you can learn how to prevent another one from occurring.
(Slide 5) Dilated cardiomyopathies results from a wide spectrum of genetic, inflammatory, toxic, and metabolic causes. However, at least 750,000 of the over 300 million U.S. population are likely to have idiopathic (ie: the cause is unknown) dilated cardiomyopathy (Hershberger). (Slide 6) Although many cases are currently classified as idiopathic, some examples of known causes include specific gene mutations, chronic excessive alcohol ingestion and other recreational drug use, chemotherapy, pregnancy, and viral myocarditis
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.
Some treatments can be used. An electronic pace-maker can be inserted and it will send electronic impulse to the heart stimulating it to beat at a normal rhythm. Pace-makers are only inserted when the heart beats too slow. Tachycardis can also be very serious. It can lead to disabling symptoms and even death.
Investigating the Effect of Exercise on the Heart Rate Introduction For it's size the heart has the huge capacity of pumping large amounts of blood, in the average adult's heart beats 60 to 100 times a minute, pumps between 70ml and 100ml of blood with each beat, circulates 5 to 6 litres of blood around the body per minute and about 13 litres of blood per minute during vigorous exercise. The heart will beat more then 2.5 billion times during an average lifetime. This investigation will be looking at the effect of exercise on the heart rate. Aim The aim of this investigation is to find out how exercise affects the heart rate, using research & experimenting on changes and increases in the heart rate using exercise. Research â— The heart The normal heart is a strong, hardworking pump made of muscle tissue.
A normal heart rhythm begins at the sinoatrial node and follows the hearts conduction pathway without any problems. Typically the sinoatrial node fires between 60-100 times per minute (Ignatavicius & Workman, 2013). 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 happe...
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.