Heart block

  Sinus blockade The normal heart beat starts in the sinus node that contains the fastest pacemaker cells. If no impulse should reach the atrium, and no atrial rescue impulse appears, there will be a pause without any P wave. The pause – sinus arrest – may be brief or long. When a pause exceeds 3-5 seconds, the patient may experience dizziness or a fainting spell. Usually, the normal rhythm soon recovers, and the patient immediately feels well. Important notes : » If the speed is 50 mm/sec;      1 mm = 0.02 sec» If the speed is 25