tailieunhanh - Pacing Options in the Adult Patient with Congenital Heart Disease - part 6

Một bằng sáng chế-lỗ ovale là thường xuyên nhất được tìm thấy bất thường bẩm sinh của tim và các kết quả từ lưu thông bình thường của thai nhi, sự bền bỉ bài thai. | CHAPTER 16 Atrial septal defects and patent foramen ovale A patent foramen ovale is the most frequently found congenital abnormality of the heart and results from the normal fetal circulatiop psrsistinp post natal. An incidence of 27 in otherwise normal hearts has been reported with the incidence falling with advancing age but still as high as 20 in the elderly 148 . Atrialseptaldefects are also one of the most common congenitaldefects occurring in adults with a familial incidence well known to cardiologists. Within this group are patients who have added electrical abnormalities including prolonged atrio-ventricular conduction high degree atrio-ventricular block sudden death and the need for permanent pacing 149-154 . In general an isolated atrial septal defect Figure or patent foramen ovale whether in the young or later in life presents no impediment to a standard pacemaker or ICD implantation. However to the unsuspecting implanting physician the atrial and or ventricular leads may cross the atrial septum through a defect 155 156 or a patent foramen ovale 156-162 and be implanted in the left atrium or ventricle resulting in an increased risk of systemic embolization such as stroke 156 or amaurosis fugax 157 159 . Asymptomatic cases diagnosed many years later have been reported 155 161 . In general once systemic embolization occurs removal of the leads are recommended either transvenously 158 or in open heart surgery 157 159 162 . Even in asymptomatic cases anticoagulation with warfarin coumadin is recommended if the leads are not removed 156 . Transthoracic 157-159 161 162 and transesophageal echotardtogtaphy 155 156 as well as computerized tomography 160 are very helpful in diagnosis of lead malpositioning across the atrial septum. An example of left ventricular pacing as a result of the lead crossing a patent foramen ovale is demonstrated in Figure . The high arching of the lead with its summit sitting across the atrial septum is characteristic and .