On the other hand, if there is a murmur or problem with exercise tolerance or if there are other cardiovascular symptoms, then this situation would be best addressed by a pediatric cardiology consultation. Similarly, block in the right bundle branch causes right bundle. Methods: We assessed 542 consecutive patients presenting for the new implantation of a CRT device. If the patient has no murmur and is completely asymptomatic from a cardiac point of view, that individual does not need further assessment. Anatomical or functional block in the left bundle branch causes left bundle branch block (LBBB). Little is known about the response to CRT in patients with right bundle branch block (RBBB) or non-specific intraventricular conduction delay (IVCD) compared with traditionally studied patients with left bundle branch block (LBBB). It is a decision which can only be made by the person who has ordered the electrocardiogram the cardiologist does not have sufficient knowledge of the patient to make a recommendation. The difficulty for cardiologists reading an electrocardiogram with conduction delay without seeing the patient is that it is tempting to label it as normal since the vast majority of the patients with this, in fact, have a normal heart, but since there is a small proportion who do have some abnormality, a decision on whether or not the person should be evaluated further depends on the reasons for the electrocardiogram. Finally, there are some individuals where conduction delay may represent conduction system disease, but this is very uncommon. Sometimes medications can cause conduction delay because of indirect effects on the heart and generally that is considered safe. There are, however, some patients who have enlargement of the right heart as a cause for this, such as having an atrial septal defect resulting in enlargement of the right ventricle or perhaps partial anomalous pulmonary venous drainage of some of the pulmonary veins return to the right side instead of the left side. The most common cause of this is just being a normal variant, in other words, there is nothing wrong with the heart. In general, “ conduction delay ” refers to a slight widening of the QRS complex, especially in the right precordial leads (leads V1, V2, and V3) it is sometimes also called incomplete right bundle branch block. It may lead to delays in proper management of those heart conditions.Families and physicians often wonder what the terms“intraventricular conduction delay” (IVCD) or “incomplete right bundle branch block” (IRBBB) or “rsR’” on an electrocardiogram mean and what to do with the information.Įlectrocardiograms (abbreviated as “ECG” or “EKG”) are routinely done and best suited to the evaluation of heart rhythm, but we can sometimes infer potential heart disease or issues such as chamber enlargement or heart malformations from looking at the electrocardiogram, but the problem with this is that there are many false positives (that is, the EKG is abnormal but the patient’s heart is actually normal). A slowed heart rate may lead to fainting, irregular heart rhythms and other serious complications.īecause bundle branch block affects the electrical activity of the heart, it can sometimes complicate the accurate diagnosis of other heart conditions, especially heart attacks. The lack of signaling can slow the heart rate. If both the right and the left bundles are blocked, the main complication is a complete blockage of the electric signaling from the upper to the lower chambers of the heart. Having high blood pressure or heart disease increases the risk of having bundle branch block.

Bundle branch block is more common in older adults than in younger people. Risk factors for bundle branch block include: High blood pressure in the pulmonary arteries (pulmonary hypertension) At baseline, 1789 (15.1) patients had left bundle branch block (LBBB).Heart structure problems that are present at birth (congenital heart defects) - such as a hole in the wall separating the upper chambers of the heart (atrial septal defect).Blood clot in the lungs (pulmonary embolism).Thickened, stiffened or weakened heart muscle (cardiomyopathy).Inflammation of the heart muscle (myocarditis).Sometimes, there is no known cause.Ĭauses can include: Left bundle branch block The cause for bundle branch blocks can differ depending on whether the left or the right bundle branch is affected. As a result, the heart beats irregularly.

If one or both of these branch bundles are damaged - due to a heart attack, for example - the electrical impulses can become blocked. These impulses travel along a pathway, including two branches called the right and the left bundles.

Description of QRS morphology in this tracing might therefore better be classified as IVCD. Request an Appointment at Mayo Clinic CausesĮlectrical impulses within the heart muscle cause it to beat (contract). but rather with a LBBB (left bundle branch block) pattern.

Ivcd with lbbb