Posted: April 1st, 2011 | Filed under: Heart Health Education Resources | Tags: ECG, ECG recorders, Portable ECG Machine, Portable EKG Machine |
The P Wave P waves are caused by atrial depolarization. In normal sinus rhythm, the SA node acts as the pacemaker. The electrical impulse from the SA node spreads over the right and left atria to cause atrial depolarization. The P wave contour is usually smooth, entirely positive and of uniform size. The P wave duration is normally less than 0.12 sec and the amplitude is normally less than 0.25 mV. A negative P-wave can indicate depolarization arising from the AV node.
Note that the P wave corresponds to electrical impulses not mechanical atria contraction. Atrial contraction begins at about the middle of the P wave and continues during the PR segment. The PR Segment PR segment is the portion on the ECG wave from the end of the P wave to the beginning of the QRS complex, lasting about 0.1 seconds. The PR segment corresponds to the time between the end of atrial depolarization to the onset of ventricular depolarization. The PR segment is an isoelectric segment, that is, no wave or deflection is recorded. During the PR segment, the impulse travels from the AV node through the conducting tissue (bundle branches, and Purkinje fibers) towards the ventricles. Most of the delay in the PR segment occurs in the AV node. Although the PR segment is isoelectric, the atrial are actually contracting, filling the ventricles before ventricular systole.
The QRS Complex In normal sinus rhythm, each P wave is followed by a QRS complex. The QRS complex represents the time it takes for depolarization of the ventricles. The Q wave is not always present. The R wave is the point when half of the ventricular myocardium has been depolarized. The normal QRS duration range is from 0.04 sec to 0.12 sec measured from the initial deflection of the QRS from the isoelectric line to the end of the QRS complex.
Normal ventricular depolarization requires normal function of the right and left bundle branches. A block in either the right or left bundle branch delays depolarization of the ventricles, resulting in a prolonged QRS duration.
The ST Segment The ST segment represents the period from the end of ventricular depolarization to the beginning of ventricular repolarization. The ST segment lies between the end of the QRS complex and the initial deflection of the T-wave and is normally isoelectric. Although the ST segment is isoelectric, the ventricules are actually contracting.
The T Wave The T wave corresponds to the rapid ventricular repolarization. The wave is normally rounded and positive.
Posted: April 18th, 2010 | Filed under: Diabetes, Guest Contribution | Tags: Diabetes, ECG, Heart Disease, Heart Health, Heart Rhythm Management, HeartStaple, Portable ECG Machine, Portable EKG Machine |
Our pancreas is affected by diabetes – specifically, Type 2.Our body contains glucose found in the blood stream, which it gets from the sugar in food. Our body uses the glucose, but only when it goes into our blood cells and the insulin released by our pancreas converts it. Insulin production and utilization is difficult for someone who lives with Type 2 diabetes .There is a lot of glucose in the body, but your cells cannot locate them.
The American Diabetes Association has the duty of looking for information regarding this important medical condition. 23.6 million individuals living in America currently have diabetes, and because of this the country is seen as very unhealthy. Ninety percent of this figure has been diagnosed with Type 2 diabetes. Diabetes and the tendency to be overweight usually run in the family. If there is too much glucose in your body, it could result in serious internal organ damage and affect one’s nervous system.
Living with Diabetes
A life with Type 2 diabetes is best lived in a healthy way. Diabetics will find that healthy practices will have a huge effect on them. Simple actions like eating healthy food and exercising are considered as healthy practices. Keeping the levels of your glucose within the appropriate range ensures you stay away from health complications.
To check the levels of blood glucose in your body, you can do the common finger prick test. Physicians say that such a test is comparable to the HbA1c test when tracking the glucose fluctuations in your body. This HbA1c test works by determining how high your glucose levels are and by identifying the blood’s exact glycated hemoglobin percentage. According to results of the A1c tests, people who have diabetes maintain their levels at seven percent. A seven percent maintaining level of a1c, according to the CDC, can dramatically reduce the risks of this disease by around forty percent.
Too-Tight Controls
Many studies in the medical field show that if your a1c levels are below seven percent it could mean a bad thing. People who use insulin and people who have median a1c levels have a higher death risk, according to the Seattle Lancet and Swedish Medical Center’s studies. Other tests maintain that keeping your a1c level at seven percent is still on the healthy side. Accredited endocrinologist Matt Davies shares that seven percent is healthy but it is still important for physicians to consider a patient’s medical history before implementing treatment.
About the Author – Kristina Ridley writes for the bloodless glucose meter blog , her personal hobby blog focused on healthy eating and tips to measure blood glucose levels at home to help people understand early diabetes symptoms.
Posted: December 19th, 2009 | Filed under: Sudden Cardiac Death | Tags: arrhythmias, ECG, ECG recorders, Sudden Cardiac Death |
What is sudden cardiac death?
Sudden cardiac death (also called sudden arrest) is death resulting from an abrupt loss of heart function (cardiac arrest). The victim may or may not have diagnosed heart disease. The time and mode of death are unexpected. It occurs within minutes after symptoms appear. The most common underlying reason for patients to die suddenly from cardiac arrest is coronary heart disease (fatty buildups in the arteries that supply blood to the heart muscle).
What causes sudden cardiac death?
All known heart diseases can lead to cardiac arrest and sudden cardiac death. Most of the cardiac arrests that lead to sudden death occur when the electrical impulses in the diseased heart become rapid
(ventricular tachycardia) or chaotic (ventricular fibrillation) or both. This irregular heart rhythm (arrhythmia) causes the heart to suddenly stop beating. Some cardiac arrests are due to extreme slowing of the heart. This is called bradycardia.
In 90 percent of adult victims of sudden cardiac death, two or more major coronary arteries are narrowed by fatty buildups. Scarring from a prior heart attack is found in two-thirds of victims. When sudden death occurs in young adults, other heart abnormalities are more likely causes. Adrenaline released during intense physical or athletic activity often acts as a trigger for sudden death when these abnormalities are present. Under certain conditions, various heart medications and other drugs — as well as illegal drug abuse — can lead to abnormal heart rhythms that cause sudden death.
The term “massive heart attack” is often wrongly used in the media to describe sudden death. The term “heart attack” refers to death of heart muscle tissue due to the loss of blood supply, not necessarily resulting in a cardiac arrest or the death of the heart attack victim. A heart attack may cause cardiac arrest and sudden cardiac death, but the terms aren’t synonymous.
Can the cardiac arrest that causes sudden death be reversed?
Brain death and permanent death start to occur in just four to six minutes after someone experiences cardiac arrest. Cardiac arrest is reversible in most victims if it’s treated within a few minutes with an electric shock to the heart to restore a normal heartbeat. This process is called defibrillation. A victim’s chances of survival are reduced by 7 to 10 percent with every minute that passes without CPR and defibrillation. CPR can double or triple a cardiac arrest victim’s chances of survival. Few attempts at resuscitation succeed after 10 minutes. If someone becomes unconscious, call 9-1-1 immediately. They may be suffering from sudden cardiac arrest.
What are treatments for survivors?
If a cardiac arrest was due to ventricular tachycardia or ventricular fibrillation, survivors are at risk for another arrest, especially if they have underlying heart disease.
Survivors of cardiac arrest must have all causes corrected to prevent future episodes. Possible causes include myocardial ischemia (inadequate blood flow to the heart muscle), arrhythmia (abnormal heart rhythm), etc.
Possible tests and treatments include
- cardiac catheterization
- electrophysiologic tests
- coronary artery bypass surgery
- balloon angioplasty or PCI (PTCA)
- antiarrhythmic medicine
- implantable cardioverter / defibrillator
- implantable pacemaker
- heart transplant.
Source: American Heart Association
