Search results
Results from the WOW.Com Content Network
Second-degree atrioventricular block (AV block) is a disease of the electrical conduction system of the heart.It is a conduction block between the atria and ventricles.The presence of second-degree AV block is diagnosed when one or more (but not all) of the atrial impulses fail to conduct to the ventricles due to impaired conduction.
By contrast, an AV block occurs in the AV node and delays ventricular depolarization. The term "Wenckebach block" is also used for some heart blocks, and can refer to a second degree type I block in either the SA node or the AV node, however the ECG features of the two are quite distinctly different.
The heart rate produced by the ventricles is much slower than that produced by the SA node. [1] Some AV blocks are benign, or normal, in certain people, such as in athletes or children. Other blocks are pathologic, or abnormal, and have several causes, including ischemia, infarction, fibrosis, and drugs.
The cause of congenital third-degree heart block in many patients is unknown. Studies suggest that the prevalence of congenital third-degree heart block is between 1 in 15,000 and 1 in 22,000 live births. [citation needed] Hyperkalemia in those with previous cardiac disease [8] and Lyme disease can also result in third-degree heart block. [9]
A similar phenomenon can also occur in the sinoatrial node where it gives rise to type I second degree SA block, and this is also known as a Wenckebach block; the two have distinct features on an ECG however. Sinus rhythm with acute inferior infarction complicated by Type I A-V block manifest in the form of 5:4 Wenckebach periods; R-P/P-R ...
426.13 Atrioventricular block, Wenckebach's; 426.3 Bundle branch block, left; 426.4 Bundle branch block, right; 426.6 Sinoatrial heart block; 426.7 Atrioventricular excitation, anomalous Wolff-Parkinson-White syndrome; 427 Cardiac dysrhythmias. 427.0 Tachycardia, paroxysmal supraventricular; 427.3 Atrial fibrillation and flutter. 427.31 Atrial ...
Heart block describes a type of arrhythmia, or abnormal rhythm, that happens when the electrical signal gets held up and delayed, or blocked entirely at some point along the conduction system. These blocks or delays usually happen because of some sort of damage or fibrosis to the electrical conduction system, the pathways that conduct the ...
A sinoatrial block (also spelled sinuatrial block) [1] is a disorder in the normal rhythm of the heart, known as a heart block, that is initiated in the sinoatrial node.The initial action impulse in a heart is usually formed in the sinoatrial node (SA node) and carried through the atria, down the internodal atrial pathways to the atrioventricular node (AV) node. [2]