ISSN: 1305-385X
Hakkında: Özel sayılar şeklinde yayınlanır.
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Sino-atrial, Atrioventricular And Ventricular Conduction Disorders
Dr. Özlem YILDIRIMTÜRK,a Dr. Saide AYTEKİNa
aKardiyoloji AD, İstanbul Bilim Üniversitesi Florence Nightingale Hastanesi, İSTANBUL
Heart block can occur anywhere in the specialized conduction system beginning with the sino-atrial node, the atrioventricular junction, the bundle branches and their fascicles, and ending in the distal ventricular Purkinje fibers. Conduction disorders may be studied in the five anatomical sequences that define the cardiac conduction system: Sino-atrial blocks, intra-atrial blocks, atrio-ventricular blocks, intra-His blocks and intraventricular blocks Sino-atrial (SA) block is an exit block. These are rarely seen conduction disturbances. 2nd degree SA block is the only degree of SA block that can be recognized on the surface ECG. Conduction delay within atria or abnormal conduction way causes intra-atrial blocks. P wave abnormalities are seen in surface ECG. AV blocks are conduction blocks. It represents conduction failure of one or more atrial impulse due to prolongation of AV conduction time and refractory period of AV node. AV block classified into three degrees like SA blocks: First, second and third degree AV block. Prolonged PR interval or P wave conduction failure occurs intermittently or completely. An intraventricular block defines conduction failure at the ventricular level. They are not real conduction failure and determine the conduction delay at the intraventricular fibers. As a rule, prolongation of QRS interval is seen. Intraventricular blocks categorized into four subgroup: Single fascicule block, two fascicular blocks, three fascicular blocks and undetermined intraventricular block.Keywords: Heart conduction system, heart blockTurkiye Klinikleri J Int Med Sci 2006, 2(33):15-24
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