Week 1: Heart Blocks

What is a first degree AV block?

Prolonged PR interval because conduction from the atrium to the ventricle takes longer than normal

What does an EKG strip look like for a patient with a First-Degree block?

HR is normal, rhythm is normal, P wave and QRS complex is normal, PR interval is consistently prolonged (>0.20sec)

What can cause a first degree block?

Age, MI, electrolyte imbalance

What do patients with a first degree block look like?

Typically look fine and are asymptomatic

How do we treat a first degree block?

No treatment; treatment of underlying cause may be considered

What is a Second-degree, Type I block?

Gradual lengthening of the PR interval until a QRS complex is dropped

What does an EKG strip look like for a patient with a Second-degree, type I block?

Atrial rate is regular but ventricular rate may be slower due to dropped QRS complexes'; longer, longer, longer drop

What can cause a Second-degree, type I block?

MI or myocardial ischemia

What does a patient with a second-degree, type I block look like?

Often asymptomatic but can occasionally have mild s/s such as lightheadedness, dizziness, or fatigue

What does treatment look like for a patient with a Second-degree, type I block?

Symptomatic patient may need atropine and a temporary pacemaker on standby; asymptomatic patient just needs monitoring

What is a second-degree, type II AV block?

Consistent PR interval with QRS complexes dropped sometimes; occurs in ratios 2:1, 3:1

What does a EKG strip look like for a patient with a Second-degree, type II block?

Atrial rate is normal, ventricular rate dependent on degree of block, Atrial rhythm is regular, ventricular rate is irregular, PR interval normal or prolonged but consistent, QRS complex is wide

What does a patient with a second-degree, type II block look like?

Mild s/s such as lightheadedness, dizziness, fatigue

What does treatment for a second-degree, type II block look like?

Transcutaneous pacing or insertion of temporary pacemaker before inserting a permanent pacemaker

What is third-degree heart block?

Complete heart block; there is no relationship between the atria and ventricles; severely decreased CO

What does an EKG strip look like for a patient who has a third-degree heart block?

Atrial rate is 60-100, ventricular rate depends on site of block, atrial and ventricular rhythms regular but entirely unrelated to each other, P wave normal shape, PR interval is unmeasurable

What does a patient with a third-degree heart block look like?

Severely reduced CO, ischemia, HF, shock, syncope, severe bradycardia, periods of asystole

What does treatment look like for a patient with a third-degree heart block?

Needs a transcutaneous pacemaker and dopamine or epinephrine until permanent pacemaker can be placed