Antiarrhythmic medications slow down rapid heartbeats and regulate irregular or premature heartbeats. Generally, these drugs work by block- ing chemical reactions that promote electrical conduction. They act to either suppress abnormal electrical impulses or slow down transmission of impulses as they are conducted through heart tissue. As a result, your heart beats more rhythmically and […]
The greatest stimulus for arterial as opposed to venous specimens for blood gas studies is to obtain measurement of blood oxygen. The usual information reported is PO2 (concentration of O2 gas measured in mm of Hg or Torr), obtained with a direct-reading PO2 electrode. PO2 represents the dissolved oxygen content of plasma, analogous to the […]
Once metabolic acidosis is apparent, the problem becomes one of identifying the cause. Calculation of the anion gap may be helpful. The anion gap is the difference between the major cations (sodium, or sodium plus potassium) and the major anions (chloride and bicarbonate). The anion gap formula is: AG = Na – (C1 + HCO–3). […]
The preceding discussion applies to an acid-base problem involving a single primary metabolic or primary respiratory abnormality, with or without body attempts at compensation. Unfortunately, in some cases the laboratory picture is more complicated; for example, when there are superimposed attempts at therapy or when two different acid-base processes coexist (referred to as “mixed acid-base […]
Once your doctor diagnoses an arrhythmia through your symptoms or an examination, he or she will need to determine where it originates and whether it requires treatment; that is, whether it is causing symptoms or putting you at risk for more serious problems in the future. The electrocardiogram is a very important tool that your […]
Irregularities in your heart rhythms can be described by the effect they have on the speed of your heartbeat (acceleration or deceleration) and where they occur in your heart (in the atria or in the ventricles). Another type of arrhythmia, called heart block, is a partial or complete interruption in the transmission of the electrical […]
Acid-base data interpretation has always been one of the more difficult areas of laboratory medicine. In most uncomplicated untreated cases the diagnosis can be achieved with reasonable ease. There are several ways of approaching an acid-base problem. One way is to examine first the arterial PCO2 value. Since primary respiratory disorders result from hypoventilation or […]
The concepts of buffer base and base excess form part of the Astrup acid-base system. The term buffer base refers to all substances in the buffering system of whole blood that are able to bind excess H+. Bicarbonate forms slightly more than one half of the total buffer base; hemoglobin makes up about one third […]
Every second or so, an electrical impulse originating in the right atrium of your heart travels through the heart and triggers a single heartbeat, or contraction of the heart. A group of specialized cells in the muscle tissue, called the sinoatrial (SA) node, initiates the signal, acting as your heart’s natural pacemaker. The impulse travels […]
Compensation refers to the degree of PCO2 change when there is, or has been, an abnormality in pH. An uncompensated disorder is a primary metabolic or respiratory condition that has not been altered by any significant degree of correction. In the case of a primary metabolic condition the respiratory counterbalance (change in ventilation which is […]
