Atrioventricular blocks (AV blocks) result from a conduction disturbance at or just below the AV junctionConducts the impulse through the fibrous plate that separates the atria and the ventricles; consists of the AV node and the bundle of His; functions also to slow the conduction speed to allow for atrial conduction prior to ventricular conduction.... The 3rd step of the 3 step process prompts us to check the P wavesA wave generated from the depolarization of the atria; the P wave is upright when originating from the SA node. The P wave represents the depolarization of the right and left atria. The P wave begins with the first deviation... and the PR intervalA period measured on rhythm strip paper that measures a wave and a segment; the distance measured is equal to time taken as an ECG is voltage over time; a PR interval for example is measured from the beginning of.... Abnormal PR intervalsThe time and interval measured from the beginning of the P wave to the beginning of the QRS; should be called the PQ interval; normal PR interval is 0.12-0.20 seconds. The PR interval is measured from the start of the... and lonely ‘P’ waves define the type of AV block.
From a clinical perspective, the severity of a block is similar to the severity of burns. The higher the degree of burn the more aggressive the treatment. Similar escalation in treatment is required for higher levels of AV blocks. The affects of 2nd degree type II and 3rd degree AV blocks on cardiac outputWhat is it? Why is it Vital? The amount of blood pumped out of the ventricle in a minute (most often refers to the blood pumped by the left ventricle) What is cardiac output? Simply, cardiac output is the amount... can be much more significant than the affects of 2nd degree type I and 1st degree AV blocks.
For more complete details see:
– First Degree AV BlockThe PR interval is the time from the beginning of the atrial wave to the beginning of myocardial depolarization of the ventricles. Normally this takes 0.12 - 0.20 seconds. When the time taken is over 0.20 seconds, this is called... (1° avb)
– Second Degree AV Blocks
– Second Degree AV Block Type I (2° avb TI)
– Second Degree Block Type II (2° avb TII)
– Second Degree AV Block with a 2:1 Conduction (2° avb 2:1)
– Third Degree AV Block (3° avb)
1. Six Second ECG GuidebookA Practice Guide to Basic and 12 Lead ECG Interpretation, written by Tracy Barill, 2012 Introduction The ability to correctly interpret an electrocardiogram (ECG), be it a simple six second strip or a 12 lead ECG, is a vital skill... (2012), T Barill, p. 125-128