课件：电解质与心律失常.ppt

电解质对心电及心律的影响 临床特点（2） 以钾离子对心肌细胞影响最明显 其次 钙离子 镁离子 钠离子 电解质紊乱所致心律失常 心电图案例分析 Which electrolyte problem is this tracing suggestive of? Hyperkalemia Hyperkalemia Discussion As the tracing shows, this patient has a regular rhythm at a rate of 101/min. The QRSs are very wide; wider than those seen with ordinary bundle branch block. T-waves are tall in V1-3. These findings are all characteristic of hyperkalemia. The serum potassium level was 7.2 mEq/L. The rhythm may be sinus with the P-waves hidden in the ST segment or sino-ventricular rhythm if P-waves are truly not present. Atrial muscle is more sensitive to hyperkalemia than the specialized conduction system is. At certain levels of hyperkalemia, the atrial muscle becomes inexcitable (paralyzed) while the special internodal conduction system is still excitable. Then, the sinus impulses will conduct to the ventricles through the conduction system without the atria being depolarized – thus referred to as sino-ventricular rhythm. Which electrolyte problem is this tracing suggestive of? Anteroseptal Infarct or Pseudoinfarction Pattern From Hyperkalemia? Which of the following conditions is responsible for the ST elevation in leads V1-2? Choose from the list below. A)?Acute anteroseptal infarctB)?Pseudoinfarction pattern from hyperkalemia Pseudoinfarction pattern from hyperkalemia Pseudoinfarction pattern from hyperkalemia is correct.Sinus tachycardia at a rate of 130 beats per minute is present. The ST segment is elevated in V1 and V2, raising the possibility of acute anteroseptal myocardial infarction. However, the T wave is very tall, narrow, pointed, and tented; and the QRS is wide, measuring 140 msec. These findings are characteristic of hyperkalemia. It is well known that hyperkalemia can cause ST-segment elevation (pseudoinfarction pattern or dialyzable current of injury). This tracing is from a patient with a serum potassium level of 7.5 mEq/L during diabetic ketoacidosis, who also is in renal failure and taki