There are many protocols for the classification of dysrhythmias and conduction disturbances. Dysrhythmias are basically classified in relation to the rate and site of abnormality. Conduction disturbances are usually classified as to the site and degree of block.
Cardiac dysrhythmias may decrease cardiac output if the ventricular rate is too fast or slow. In an adult without cardiac disease, heart rates between 40 and 160 are usually well tolerated because physiologic adaptations are able to maintain an adequate cardiac output and blood pressure. In adults with significant heart disease, rates below 50 or above 120 may produce decreased cardiac output based on a poorly functioning ventricle because of basic myocardial cell damage, ischemic cells, valvular disease, or a combination of these.
Was this article helpful?