|
Hexaxial Reference System
The hexaxial reference system, better known as the Cabrera system, is a convention to present the extremity leads of the 12 lead electrocardiogram, that provides an illustrative logical sequence that helps interpretation of the ECG, especially to determine the heart's electrical axis in the frontal plane. The most practical way of using this is by arranging extremity leads according to the Cabrera system, reversing polarity of lead aVR and presenting ECG complexes in the order (aVL, I, -aVR, II, aVF, III). Then determine the direction the maximal ECG vector is "pointing", i.e. in which lead there are most positive amplitude - this direction is the electrical axis - see diagram. Example: If lead I has the highest amplitude (higher than aVL or -aVR), the axis is approximately 0°. Conversely, if lead III has the most negative amplitude it means the vector is pointing away from this lead, i.e. towards -60°. An alternative use is to locate the most isoelectric (or equiphasic) lead (I, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexaxial Reference System
The hexaxial reference system, better known as the Cabrera system, is a convention to present the extremity leads of the 12 lead electrocardiogram, that provides an illustrative logical sequence that helps interpretation of the ECG, especially to determine the heart's electrical axis in the frontal plane. The most practical way of using this is by arranging extremity leads according to the Cabrera system, reversing polarity of lead aVR and presenting ECG complexes in the order (aVL, I, -aVR, II, aVF, III). Then determine the direction the maximal ECG vector is "pointing", i.e. in which lead there are most positive amplitude - this direction is the electrical axis - see diagram. Example: If lead I has the highest amplitude (higher than aVL or -aVR), the axis is approximately 0°. Conversely, if lead III has the most negative amplitude it means the vector is pointing away from this lead, i.e. towards -60°. An alternative use is to locate the most isoelectric (or equiphasic) lead (I, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Left Axis Deviation
In electrocardiography, left axis deviation (LAD) is a condition wherein the mean electrical axis of ventricular contraction of the heart lies in a frontal plane direction between −30° and −90°. This is reflected by a QRS complex positive in lead I and negative in leads aVF and II. There are several potential causes of LAD. Some of the causes include normal variation, thickened left ventricle, conduction defects, inferior wall myocardial infarction, pre-excitation syndrome, ventricular ectopic rhythms, congenital heart disease, high potassium levels, emphysema, mechanical shift, and paced rhythm. Symptoms and treatment of left axis deviation depend on the underlying cause. Defining left axis deviation Cardiac axis in electrocardiography represents the sum of depolarization vectors generated by individual cardiac myocytes. To interpret the cardiac axis, one has to determine the relationship between the QRS axis and limb leads of the ECG. Usually, left ventricles makes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Right Axis Deviation
The electrical axis of the heart is the net direction in which the wave of depolarization travels. It is measured using an electrocardiogram (ECG). Normally, this begins at the sinoatrial node (SA node); from here the wave of depolarisation travels down to the apex of the heart. The hexaxial reference system can be used to visualise the directions in which the depolarisation wave may travel. On a hexaxial diagram (see figure 1): * If the electrical axis falls between the values of -30° to +90° this is considered normal. * If the electrical axis is between -30° to -90° this is considered left axis deviation. * If the electrical axis is between +90° to +180° this is considered right axis deviation (RAD). RAD is an ECG finding that arises either as an anatomically normal variant or an indicator of underlying pathology. Signs, symptoms and risk factors There are often no symptoms for RAD and it is usually found by chance during an ECG. Many of the symptoms exhibited by pati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rapid Axis Vector
Rapids are sections of a river where the river bed has a relatively steep gradient, causing an increase in water velocity and turbulence. Rapids are hydrological features between a ''run'' (a smoothly flowing part of a stream) and a ''cascade''. Rapids are characterized by the river becoming shallower with some rocks exposed above the flow surface. As flowing water splashes over and around the rocks, air bubbles become mixed in with it and portions of the surface acquire a white color, forming what is called " whitewater". Rapids occur where the bed material is highly resistant to the erosive power of the stream in comparison with the bed downstream of the rapids. Very young streams flowing across solid rock may be rapids for much of their length. Rapids cause water aeration of the stream or river, resulting in better water quality. Rapids are categorized in classes, generally running from I to VI. A Class 5 rapid may be categorized as Class 5.1-5.9. While Class I rapids a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cardiology
Cardiology () is a branch of medicine that deals with disorders of the heart and the cardiovascular system. The field includes medical diagnosis and treatment of congenital heart defects, coronary artery disease, heart failure, valvular heart disease and electrophysiology. Physicians who specialize in this field of medicine are called cardiologists, a specialty of internal medicine. Pediatric cardiologists are pediatricians who specialize in cardiology. Physicians who specialize in cardiac surgery are called cardiothoracic surgeons or cardiac surgeons, a specialty of general surgery. Specializations All cardiologists study the disorders of the heart, but the study of adult and child heart disorders each require different training pathways. Therefore, an adult cardiologist (often simply called "cardiologist") is inadequately trained to take care of children, and pediatric cardiologists are not trained to treat adult heart disease. Surgical aspects are not included in cardiology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Right Axis Deviation")
