First degree AV block: Difference between revisions

Revision as of 09:28, 3 November 2016

Background

Also known as first-degree heart block,
Defined as prolongation of the PR interval on an electrocardiogram (ECG) to more than 200 msec (5 small squares on the EKG tracing)
Considered “marked” when the PR interval exceeds 300 msec (more than 7 small squares on the EKG tracing)

Clinical Features

Vast majority are asymptomatic and diagnosed by chance
Exercise may reveal decreased tolerance (especially when there is markedly prolonged PR interval and with left ventricular systolic dysfunction)

Differential Diagnosis

AV blocks

First degree AV block
Second degree
- Second degree AV block type I (Wenkebach)
- Second degree AV block type II
Third degree AV block
AV dissociation without complete heart block

Evaluation

ECG
Consider rare causes:
- Lyme's disease
- Lupus
- Myocarditis
- Myocardial infarction

Management

Asymptomatic patients do not require any specific management
Consider a cardiology consult for patients who may have symptoms attributable to the block (rare)

Disposition

Outpatient

External Links

References

Authors:

@@ Line 1: / Line 1: @@
 ==Background==
+*Also known as first-degree heart block,
-First-degree atrioventricular (AV) block, or first-degree heart block, is defined as prolongation of the PR interval on an electrocardiogram (ECG) to more than 200 msec(5 small squares on the ECG tracing). First-degree AV block is considered “marked” when the PR interval exceeds 300 msec(more than 7 small squares on the ECG tracing).
+*Defined as prolongation of the PR interval on an electrocardiogram (ECG) to more than 200 msec (5 small squares on the EKG tracing)
+*Considered “marked” when the PR interval exceeds 300 msec (more than 7 small squares on the EKG tracing)
 ==Clinical Features==
-Patients with first-degree atrioventricular (AV) block mostly are asymptomatic at rest and it is diagnosed by chance. Exercise may reveal decreased tolerance especially when there is markedly prolonged PR interval and with left ventricular systolic dysfunction. It may also be the cause of syncope with transient high-degree AV block.
+*Vast majority are asymptomatic and diagnosed by chance
+*Exercise may reveal decreased tolerance (especially when there is markedly prolonged PR interval and with left ventricular systolic dysfunction)
 ==Differential Diagnosis==
@@ Line 10: / Line 12: @@
 ==Evaluation==
+*[[ECG]]
-Although First degree AV block is not very exciting for the emergency Physicians and usually it is left for the cardiologists to sort out as out patient. But getting past history of infections like Lyme's disease or inflammation like Lupus may be fruitful. Also it may prompt people to explore the history further about Myocarditis or Myocardial infarction in the patient.
+*Consider rare causes:
+**Lyme's disease
+**[[Lupus]]
+**[[Myocarditis]]
+**[[Myocardial infarction]]
 ==Management==
+*Asymptomatic patients do not require any specific management
-Asymptomatic patients with first degree do not need any specific management and be managed for the other problems that they presented to the emergency department for. For patients who have symptoms that can attribute to AV block need careful history and a review by the cardiology.
+*Consider a cardiology consult for patients who may have symptoms attributable to the block (rare)
 ==Disposition==
+*Outpatient
 ==See Also==
@@ Line 24: / Line 30: @@
 ==External Links==
 ==References==