tailieunhanh - Types of pacemakers and the hemodynamics of pacing

Tham khảo tài liệu types of pacemakers and the hemodynamics of pacing , y tế - sức khoẻ, y học thường thức phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | This is not a commonly used mode. DDD pacemakers require a dedicated atrial lead with good connection to the atrial myocardium. A rarely used lead is available that goes only to the ventricle and therefore can pace only in the ventricle. It does, however, have an additional sensing electrode further back in the right atrial area that can generally sense P waves with a reasonable degree of accuracy (but not pace the atrium). This can be used, for instance, in a patient in whom it was technically difficult to obtain two leads or in a very elderly patient in whom there is an effort to keep things simple. That would be a patient with heart block who has otherwise normal sinus rhythm. Therefore, it would, when working appropriately, sense a P wave and fire the ventricular spike after the appropriate AV delay. It would not, however, be able to pace in the atrium. It is of note that sensing problems are more likely to occur in this type of device than in a device with a classic atrial J lead.