LBBB EKG vs. RBB EKG

Attribute	LBBB EKG	RBB EKG
QRS Complex	Widened (>0.12 sec)	Widened (>0.12 sec)
QRS Axis	Leftward deviation	Rightward deviation
ST Segment	Depressed or discordant	Normal or slightly elevated
T Wave	Inverted or discordant	Normal or slightly inverted

Introduction

Electrocardiogram (EKG) is a valuable tool used in diagnosing various heart conditions. Two common EKG findings are Left Bundle Branch Block (LBBB) and Right Bundle Branch Block (RBB). While both conditions involve abnormalities in the electrical conduction system of the heart, they have distinct characteristics that can be identified on an EKG. In this article, we will compare the attributes of LBBB EKG and RBB EKG to better understand their differences.

Definition and Characteristics

Left Bundle Branch Block (LBBB) is a condition where there is a delay or blockage in the electrical signals traveling through the left bundle branch of the heart. This results in a widened QRS complex on the EKG, typically greater than 120 milliseconds. The QRS complex in LBBB appears as a broad, slurred, and notched waveform. On the other hand, Right Bundle Branch Block (RBB) is a condition where there is a delay or blockage in the electrical signals traveling through the right bundle branch of the heart. This results in a widened QRS complex on the EKG, typically greater than 100 milliseconds. The QRS complex in RBB appears as a broad, slurred, and notched waveform similar to LBBB.

Lead Placement and Interpretation

When analyzing an EKG for LBBB, it is important to look at leads V1 and V6. In LBBB, lead V1 typically shows a predominantly negative QRS complex, while lead V6 shows a predominantly positive QRS complex. This is known as "bunny ears" appearance. On the other hand, when analyzing an EKG for RBB, it is important to look at leads V1 and V6 as well. In RBB, lead V1 typically shows a predominantly positive QRS complex, while lead V6 shows a predominantly negative QRS complex. This is known as "rsR' pattern.

Clinical Implications

Both LBBB and RBB are associated with various clinical implications. LBBB is often seen in patients with underlying heart conditions such as coronary artery disease, hypertension, and heart failure. It can also indicate an increased risk of arrhythmias and sudden cardiac death. On the other hand, RBB is less commonly associated with significant cardiac pathology. It can be seen in patients with pulmonary hypertension, congenital heart defects, and certain medications. RBB is generally considered a benign finding unless it is associated with other abnormalities.

Treatment and Management

The treatment and management of LBBB and RBB depend on the underlying cause and associated symptoms. In patients with LBBB and significant cardiac pathology, treatment may involve managing the underlying condition, controlling blood pressure, and monitoring for arrhythmias. In some cases, a pacemaker may be recommended to help regulate the heart's electrical activity. On the other hand, RBB is often managed by addressing the underlying cause, such as treating pulmonary hypertension or adjusting medications. In most cases, RBB does not require specific treatment unless it is causing symptoms or complications.

Conclusion

In conclusion, LBBB and RBB are two distinct EKG findings that indicate abnormalities in the heart's electrical conduction system. While both conditions result in a widened QRS complex and have similar EKG waveforms, they can be differentiated based on lead placement and clinical implications. Understanding the differences between LBBB and RBB is essential for accurate diagnosis and appropriate management of patients with these EKG findings.