First degree AV block Or

PR prolongation

atrioventricular block:

, AV block impairment of conduction of cardiac impulses from the atria to the ventricles, usually due

to a block in the atrioventricular junctional tissue, and generally subclassified on the basis of severity as

first, second, or third degree.

First degree AV block or PR prolongation:

is a disease of the electrical conduction system of the heart in which the PR interval is lengthened. In first

degree heart block, the disease is almost always at the level of the atrioventricular node (AV node).

Causes:

Intrinsic AV nodal diseaseoMyocarditis

Acute MI ,oElectrolyte disturbances

antiarrhythmics

Drugs

Signs & symptoms

First-degree heart block rarely causes any symptoms.Heart block is a type of arrhythmia .

An arrhythmia is any problem with the rate or rhythm of the heart.

Complications:

second-degree heart block. increase the risk of

progression to higher-grade heart blocks .

Treatment

Emergency Department Care:

No specific therapy is indicated for isolated first-degree AV block. Any

associated condition (eg, myocardial infarction digitalis intoxication) should be treated

appropriately.

ECG criteria:

PR INTERVAL 

the PR interval, which is defined as the time from the initial deflection of the P wave to the start of the QRS complex,

should be between 0.12 and 0.20 sec .

First-degree heart block, or first-degree atrioventricular (AV) block, is defined as prolongation of the PR interval on the ECG to more than 0.20 sec.

Ventricular & atril rate: depends on the under lying rhythm.Ventricular & atril rhythm: depends on the under lying rhythm.Sinus rhythm at 85 bpm QRS shape &duration: usually normal ,but may be abnormal.

P wave: in front of the QRS complex, shows sinus rhythm ,regular shape.

PR interval: greater than 0.20 sec, PR interval measurement is constant.

-Ventricular extra systoles in trigeminy pattern. Every third beat is

a Premature Ventricular Complex (PVC).. 6 PVCs per minute is considered pathological.

-Marked First Degree AV Block. PR interval is 0.31sec .-PR interval >0.30s are at risk of developing complete heart block.-Incomplete Left Bundle Branch Block (LBBB). QRS width 0.10sec.

ECG description:

NURSING INTERVENTION:

-evaluates blood pressure ,pulse rate and rhythm.

-past &family history: heart dieses or hypertension .

-ECG evaluation.

-The management includes identifying and correcting electrolyte imbalances and withholding any offending medications.

-Patients with first-degree AV block and coexistent bundle-branch block should be closely observed.

- health education: habits (coffe&smoking)

Student name:Enas shukri alamri

ID number:425201475