onduction: Usually normal through the ventricles. Characterized by an irregular ventricular response, because the AV node is incapable of responding to the rapid atrial rate. Impulses that are transmitted cause the ventricles to respond irregularly. Rhythm: Irregular and usually rapid, unless controlled. Irregularity of rhythm is due to concealed conduction within the AV node. A rapid ventricular response reduces the time for ventricular filling and hence the stroke volume. The atrial kick, which is 25 to 30% of the cardiac output, is also lost. Congestive heart failure frequently follows. There is usually a pulse deficit, the numerical difference between apical and radial pulse rates. Treatment is directed toward eliminating the cause, decreasing the atrial irritability, and decreasing the rate of the ventricular response. In patients with chronic atrial fibrillation, anticoagulant therapy may be used to prevent thromboemboli from forming in the atria. Drugs of choice to treat atrial fibrillation are similar to those used in the treatment of paroxysmal atrial tachycardia, digitalis preparation is used to slow the heart rate, and an antidysrhythmic such as quinidine is used to correct the dysrhythmia. (Brunner, & Suddarth 1988). TYPE II DIABETES MELLITUS: In diabetes, insulin is not secreted in proportion to blood glucose levels because of several possible factors: deficiency in the production of insulin by the beta cells, insensitivity of the insulin secretory mechanism of the beta cells, delayed or insufficient release of insulin, or excessive inactivation by chemical inhibitors or “binders” in the circulation. In some non-insulin dependent persons with diabetes, however, insulin secretion is increased, resulting in higher , circulating insulin levels. Although excess insulin is present, it is not utilized because of an inadequate number of insulin receptors present on cells. This mechanism has been observed in obes...
