second-degree heart block


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Related to second-degree heart block: First degree heart block, Third degree heart block

second-degree heart block

A form of atrioventricular block in which only some atrial impulses are conducted to the ventricles. Two variants exist: Mobitz I (Wenckebach) and Mobitz II. In Mobitz I, the P-R intervals become progressively longer until a QRS complex is dropped. Because of the dropped beats, the QRS complexes appear to be clustered (grouped beating) on the electrocardiogram. In Mobitz II, P-R intervals have a constant length, but QRS complexes are dropped periodically, usually every second, third, or fourth beat.
See also: heart block
References in periodicals archive ?
An ECG and a Holter monitor look for arrhythmias, postural hypotension, bradycardia, atrial fibrillation or flutter, first- or second-degree heart block, intraventricular conduction disturbance, and right bundle branch block.
Despite its effectiveness for emesis, racemic ondansetron has shown a meaningful incidence of adverse side effects such as tachycardia, angina and electrocardiographic alterations, including second-degree heart block which is most prevalent in nonchemotherapy uses.
The discharge diagnosis was second-degree heart block.