anyone know anything about a second degree av block.?

Question

I'm 27 and the mom of four. I've been diagnosed as having a second degree av block. I know absolutely nothing about the condition.

Answer 1

There are 2 types of this block

Second-degree atrioventricular block (intermittent AV conduction)
Traditionally, second-degree AV block has been categorized as one of two types. Type I, also called the Wenckebach phenomenon and Mobitz type I, is characterized by progressive prolongation of the PR interval until a P wave is blocked and the cycle is repeated. Maximum increment of the PR interval usually takes place with the second conducted beat. RR intervals decrease progressively despite increasing PR intervals. The Wenckebach phenomenon most frequently occurs in the AV node; however, it is also common in the bundle branches and the bundle of His.

Electrocardiographically, AV nodal and intra-His blocks are associated with a narrow QRS complex of conducted beats, and infra-Hisian block is generally seen with a bundle branch block pattern or conducted beats. AV nodal blocks can be differentiated from infranodal blocks (His bundle and bundle branches) by observing the magnitude of PR change from beat to beat, best appreciated with the beats immediately before and after the blocked P wave. In AV nodal type I second-degree block, PR shortening after the blocked P wave frequently exceeds 100 msec, whereas in infranodal blocks, this magnitude of change in the PR interval is unusual.

Treatment
Specific treatment of type I is rarely needed unless severe signs and symptoms are present. Clinicians should place a high priority on identifying underlying causes.

Summary of ECG criteria

There is normal-looking QRS.
Rate: The atrial rate is unaffected, but the ventricular rate will be less than the atrial rate because of the nonconducted beats.
Rhythm: The atrial rhythm is usually regular. The ventricular rhythm is usually irregular with progressive shortening of the RR interval before the blocked impulse. The RR interval that brackets the non-conducted P wave is less than twice the normal cycle length.
P wave: The P waves will appear normal, and each P wave will be followed by a QRS complex except for the blocked P wave.
PR interval: There is a progressive increase in PR interval until one P wave is blocked.
Type II second-degree AV block
Type II (Mobitz type II) is characterized by a constant PR interval preceding a blocked P wave. The site of block is usually the His-Purkinje system. Conducted P waves may display a normal QRS complex if the site of block is within the bundle of His, or a bundle branch block pattern if it is more distal, as in the bundle branches, which is more common. On occasion, AF nodal block of a P wave may also be preceded by a constant PR interval; however, the baseline PR in such cases is long and a block of the P wave under such circumstances is not totally unexpected.

It is usually associated with an organic lesion in the conduction pathway, and unlike type I second-degree AV block, it is rarely the result of increased parasympathetic tone or drug effect. It is thus associated with a poorer prognosis, and complete heart block may develop. A hallmark of this type of second-degree AV block is that the PR interval does not lengthen before a dropped beat. More than one nonconducted beat may occur in succession. This type of block most often occurs at the level of the bundle branches.

Summary of ECG criteria


QRS: The QRS will be normal when the block is at the bundle of His. However, the QRS will be widened with the features of bundle-branch block if the block is at the bundle branch.
Rate: The atrial rate is unaffected, but the ventricular rate will be less than the atrial rate.
Rhythm: The atrial rhythm is usually regular, whereas the ventricular rhythm is most often irregular, with pauses corresponding to the nonconducted beats.
P waves: The P waves will appear normal, and each will be followed by a QRS except for the blocked P wave.
PR interval: This interval may be normal or prolonged, but it will remain constant. There may be shortening of the PR interval after a pause.

Answer 2

This has to do with the conductivity between the atria and ventricles of the heart.
The atria are the chambers that receive the blood from the rest of the body. They pump the blood into the ventricles--the 2 larger chambers of the heart, which in turn, pump the blood out to the lungs, then brain, then back through the remainder of the body.
Your atria only provide about 30% of the work, the ventricles (the Left more than the right) provide 70% of the work--but they don't pump until they receive an impulse from the atria.
The impulse to pump is ignited by electrical activity from the SA node (sino-atrial node) this orders the atria to contract (pump), the impulse next travels to the AV node (atrio ventricular). The AV node tells the ventricles to contract.
What you have is a delay in the impulse or conduction system in this node---most common physical sign is slower and probably irregular heartbeat.
Can be easily managed with medications.
I'm a nurse and tried not to be too complicated--check out this link. It's more thorough and pretty simplified.

Answer 3

I was diagnosed a year ago with wenckebach. It is the P wave slowing down after each beat until it actually skips a beat. Once the skipped beat happens it resets and starts that process over again. Mine is usually only at night once i'm laying down. My heart rate drops down into the 50s and 40s and that is when the wenceback starts. If I stand up my heart rate increases and the wencebach stops. They ran a stress test on me and that came back normal. They said that it was totally benign and that they would see me again in 20 years once I was over 50. They said wencebach second degree type 1 AV heart block does not typically progress to 3rd degree heart block like type 2 does.

Answer 4

It's just one beat. In Wenkebach, there is a longer and longer PR interval until you get a P wave with one non-conducted beat (no QRS).