
	3D Medical Animations Close This information is provided by an independent source. Merck & Co. does not endorse and is not responsible for the accuracy of the content, or for the practices or standards of non-Merck sources. This information provided is not intended to be a substitute for professional medical advice. A licensed healthcare professional should be consulted for diagnosis and treatment of any and all medical conditions. The manufacturer of a product generally has the most complete information about that product. How to use How to use The world's largest library of 3D medical animations developed and copyrighted by Blausen Medical Communications. The Human Atlas figures rotating model, labeled slides, and printable text in addition to animated videos. Shows a video of the selected health topic. Controls play, pause, and restart of the video. Shows a summary of the selected health topic. Controls to scroll the text. Shows a 3 D model of the video. Controls to rotate the model. Shows slides from the video. Controls to change slides.

You are trying to load Blausen Medical's Human Atlas.

Either you do not have the newest version of Adobe Flash®, or you have JavaScript disabled.

To use Blausen's Atlas software, you must ensure you have these capabilities.

Health Resources

MedlinePlus®

Resource Library

This information is provided by an independent source. Merck & Co., Inc. is not responsible for this content. Please discuss any and all treatment options with your healthcare professional. The manufacturer of a product generally has the most complete information about that product.

Return to Main Index

>> How to Use

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

atrioventricular block any interruption of the conduction of electrical impulses from the atria to the ventricles; it can occur at the level of the atria, the atrioventricular node, the bundle of His, or the Purkinje system. See also heart block.
a type of heart block in which the blocking is at the atrioventricular junction. It is called first degree when atrioventricular conduction time is prolonged. It is called second degree or partial when some but not all atrial impulses reach the ventricle. And it is called third degree or complete when no atrial impulses at all reach the ventricle, so that the atria and ventricles act independently of each other.

first degree atrioventricular block a first degree heart block due to a block in the atrioventricular junctional tissue; the rate of conduction of impulses from the atria to the ventricles is slowed, resulting in regular electrocardiographic P–R intervals of greater than 0.21 second.

second degree atrioventricular block a second degree heart block due to partial impairment of impulse conduction through the atrioventricular junctional tissue; impulses intermittently fail to reach the ventricles (dropped beats). It occurs as two types: type I is Wenckebach or Mobitz type I block and type II is Mobitz type II block.

third degree atrioventricular block a third degree heart block due to total cessation of impulse conduction through the atrioventricular junctional tissue; no correspondence exists between atrial and ventricular activity, and ventricular asystole and death occur unless a ventricular pacemaker is activated.

Search MerckSource

Sign In

Health Resources

MedlinePlus®

Resource Library