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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 ... [...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° and +90° this is considered normal. * If the electrical axis is between -30° and -90° this is considered left axis deviation. * If the electrical axis is between +90° and +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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rapid Axis Vector
Rapid(s) or RAPID may refer to: Hydrological features * Rapids, sections of a river with turbulent water flow * Rapid Creek (Iowa River tributary), Iowa, United States * Rapid Creek (South Dakota), United States, namesake of Rapid City Sports teams * SK Rapid Wien, an Austrian club * FC Rapid Ghidighici, a Moldovan club * SK Rapid, a Norwegian club * FC Rapid București, a Romanian club * FK Rapid Bratislava, a Slovak club * SV Rapid Marburg, a Yugoslav former club that today would be Slovene * Colorado Rapids, an American team Transportation * ''Rapid'' (brig), the ship that brought William Light's surveying party to South Australia in 1836 * The Rapid, popular name of RTA Rapid Transit, the rail transit service of Cleveland and surrounding Cuyahoga County, Ohio * The Rapid, a bus system in the Greater Grand Rapids, Michigan area * Rapid (San Diego), a BRT system serving the Greater San Diego region in California * Rapid Rail, a rapid transit operator in Malaysia * Rap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cardiology
Cardiology () is the study of the heart. 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 sub-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 in the branch of medicine 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
