The health concern: An abnormality in the cardiac electrical system known as a bundle branch block.

Why it's in the news: It's not, actually. This topic actually came to me from a concerned colleague who, during a routine annual check-up was told that an "electric bundle" showed up on her electrocardiogram. The doctor told her that the bundle was on her right side, and that she likely didn't have to worry.

He did order an echocardiogram for her, which showed that she was "normal." But she never got an details about what an electric bundle was or why it mattered which side it was on.

More Information

"Should You Worry?" is a feature in which we take a much-covered health concern and ask local experts how worried you should actually be. Got a health scare you want answers about? Email

Experts in the region said my colleague likely had something called a right branch bundle block. The heart's electrical system has two bundle branches -- a right bundle branch and a left bundle branch -- which work to evenly distribute electrical impulses to the ventricles. This regulation of electricity is important to helping the ventricles, which pump blood to the body, function properly.

A bundle branch block happens when one of the bundle branches becomes diseased or damaged and stops conducting electrical impulses. As a result, the ventricles stop working in sync.

This tends to be more common as people age, said Dr. Joseph Tiano, medical director of the electrophysiology laboratory at St. Vincent's Medical Center in Bridgeport. He compared the heart's electrical system to that of a building -- older systems are just more likely to have problems. "It's the normal degeneration of wires," Tiano said.

What my colleague has is a block to the right bundle branch. This means the right bundle branch is no longer conducting electricity, and that the heart's electrical impulses enter the ventricle using only the left branch. Thus, the left ventricle receives the signal first and the impulse then slowly makes its way to the right ventricle. When the block is to the left bundle branch, the opposite happens.

Should you worry?: That depends on various factors including, as my colleague's doctor suggested, the side your block is on. Right bundle blocks are more common, and typically more benign, Tiano said. If a patient, like my co-worker, is otherwise healthy, there's probably nothing major wrong.

"It may just be a change in the pattern of conduction that doesn't change the way a person feels," said Dr. Craig A. McPherson, director of cardiac electrophysiology service at Bridgeport Hospital.

Dr. Sandhya Dhruvakumar, director of electrophysiology at Stamford Hospital, agreed. "The electricity is pretty much getting where it needs to go," she said, adding that the bundle branches are "the weakest link in the heart's electrical system. They can just stop working sometimes."

That doesn't necessarily mean there's anything wrong, but doctors suggest tests to rule out the possibility that it's being caused by an underlying problem, such as chronic obstructive pulmonary disease or coronary artery disease. "We want to make sure (the block) is not symptomatic of something else," Dhruvakumar said.

A left bundle branch block is less common than a right bundle branch block. And, while that, too, might occur in an otherwise healthy person, a left block is more likely to signal a serious problem than a right block. It's sometimes seen with such conditions as aortic valve disease, hypertension, coronary artery disease and other issues.

Sometimes there's a block to both bundle branches, and Dhruvakumar said that's a real problem that would likely need to be treated with a pacemaker. "It means there's going to be a long pause in your heart (pumping)," she said.

In its early stages, this block can result in light-headedness or weakness. It can be fatal in some cases, but Dhruvakumar said most people seek medical attention before that happens.; 203-330-6290;;