Symptoms of Bundle Branch Block and Treatments

The bundle branch block has several classifications depending on the level of heart rhythm involvement. Therapy can help control the disease in a large majority of cases.
Symptoms of Bundle Branch Block and Treatments
Diego Pereira

Written and verified by the doctor Diego Pereira.

Last update: 27 May, 2022

A bundle branch block is when one of the heart structures doesn’t function properly. In addition, these structures are made of specialized tissue capable of transmitting electrical impulses that divide into two branches (one right and one left) to cover both sides of the organ.

It results in the inability of the heart to engage in a normal rhythm, which increases the possibility of cardiovascular complications. Are you interested in learning a little more about this condition? Read on!

What causes a bundle branch block?

The conditions that most commonly cause a bundle branch block include:

  • Myocardial infarction
  • High blood pressure
  • Myocarditis
  • Cardiomyopathies

In most cases, the irrigation of the tissue that’s responsible for transmitting electrical impulses in the heart is deficient, as is the case in infarction. Here, the rupture of an atheroma plaque can obstruct blood flow in the coronary arteries. Those that carry oxygen and nutrients to the myocardium.

The latter causes progressive tissue deterioration which, in many cases, is irreversible. For this reason, a bundle branch block is a common complication of some cardiovascular events.

In contrast, myocarditis is the inflammation of the myocardium that occurs as a result of infection. One of the microorganisms involved is Trypanosoma cruzi, the causative agent of Chagas disease.

A man having a heart attack.
Cardiovascular events affecting the myocardium may worsen due to a bundle branch block.

Symptoms of a bundle branch block

There are several types, depending on the heart rhythm characteristics that result from it. Fortunately, most patients have a mild block and don’t develop symptoms. In these cases, a diagnosis is common as part of a routine medical evaluation.

However, those who develop overt signs may present palpitations and fainting (syncope). Furthermore, they usually have other associated cardiovascular or metabolic diseases, such as high blood pressure or diabetes mellitus.

There may be more symptoms depending on the degree of involvement of the various organs (such as the kidneys). Also, the heart is unable to perform its function properly in severe cases and it could lead to hemodynamic instability. This includes a progressive drop in blood pressure, which can lead to shock if not corrected.


A physician may arrive at the diagnosis with a combination of clinical elements and complementary tests. Additionally, they may conduct a thorough physical examination in order to detect the heart rhythm disturbance. Only if it’s considerable though.

In any case, they confirm it through an electrocardiogram. The main characteristic here is a measurement of the electrical activity of the heart, which includes the frequency with which the heartbeats appear. This last characteristic doesn’t function as it should in patients with bundle branch block.

Moreover, it’s also possible to do an echocardiogram, which is a more expensive imaging technique and only a specialist can perform it. The advantage of its use is that it makes it possible to determine structural alterations that explain the origin of the disease.

Find out What’s Ischemic Heart Disease?

Treatments for bundle branch block

There are several therapeutic modalities, depending on the clinical severity and the risk of developing fatal arrhythmias. Below are the most important ones, in general.


As we mentioned above, most cases correspond to asymptomatic patients. For this reason, the professional doesn’t usually prescribe anything specifically for a bundle branch block. However, it’s necessary to prescribe drugs against the cause of the disease.

For example, it’s common to prescribe antihypertensive drugs and diuretics for a hypertensive patient. This is a large group of drugs and the differences lie in their mechanism of action.

Some of the most commonly used ones are losartan, amlodipine, and enalapril, and hydrochlorothiazide and furosemide stand out in the group of diuretics.


A doctor holding a pacemaker.
Pacemakers are devices that take command of the heartbeat to give regularity to the heart.

This device can adjust the electrical activity of the heart to a normal rhythm. It was originally a costly and problematic treatment with several side effects but it’s currently safe and easy to maintain.

There are two types of pacemakers according to a publication by the Spanish Heart Foundation: temporary and permanent. The latter require subcutaneous implantation, for which the physician must also introduce a wire through one of the veins that drain on the right side of the heart.

Cardiac resynchronization therapy

This treatment is for more severe cases where there’s poor coordination between the activity of the left and right sides of the heart. The device used is also known as a biventricular pacemaker, according to a Mayo Clinic publication.

The benefit is so great that some models include an implantable cardioverter-defibrillator. This means that the device can send a defibrillating impulse in emergency cases where the heart rhythm has significantly altered.

Preventing complications

Finally, people with risk factors must have a routine medical consultation due to the possibility of developing fatal cardiovascular events. Family physicians and internists are a valid option though, on some occasions. However, they may refer a patient to a cardiologist.

All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.

  • Burri H, Lerch R. Echocardiography and patient selection for cardiac resynchronization therapy: a critical appraisal. Heart Rhythm 2006; 3: 474-9.
  • Garillo R, et al. Terapia de resincronización cardíaca. Cruzando la frontera de las indefiniciones. Rev Urug Cardiol 2011;26:71-76.
  • Geiter H. Los bloqueos de rama cardíacos. Nursing 2004;22(1):21-24.
  • Lozano J. Arritmias cardíacas y su tratamiento. OFFARM 2001;20(11):11-153.
  • Ostabal M, et al. Los marcapasos cardíacos. Med Integral 2003;41(3):151-61.
  • Vogler J. Bradiarritmias y bloqueos de la conducción. Rev Esp Cardiol 2012;65(7):656-667.

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.