Medical mystery: An undiagnosed heart murmur signaled a larger concern

I recently saw a 49-year-old man in my office because of shortness of breath with activity. This had been occurring for almost six months. It had not worsened, but was not getting better.

He was new to town and referred to me by his new primary-care doctor, who heard a heart murmur. He had never been told that he had any kind of cardiac or medical issues in the past.

A murmur is best described as the sound the heart makes when blood flows through one of the four valves. It can be benign, often caused by normal flow through an aging heart, or pathologic, where it can cause harm if not treated quickly.

He had a loud murmur, heard everywhere in the upper left chest, but it was especially loud above the aortic valve. It did not sound benign. His electrocardiogram showed a regular rhythm and a blockage in the right bundle branch. This is a minor electrical disturbance, also usually benign, but he had never had a prior EKG tracing to compare it to.

He then had a test called an echocardiogram, or ultrasound of the heart, which showed severe aortic stenosis, a narrowing of the aortic valve opening. The rest of his heart function looked normal, including a cardiac catheterization, which showed that his coronary arteries were normal. My colleague Kenji Minakata, a cardiothoracic surgeon at Temple, advised a surgical aortic valve replacement as soon as possible.

He underwent surgery at Temple to replace his failing aortic valve with a bioprosthetic valve. He experienced a somewhat rocky post-op, but was discharged after six days.

The next day, he called my office because his sister, who is a nurse practitioner, saw him have two short seizures. He was advised to go immediately to the ER.

Upon arrival at the ER, he was placed on a heart monitor, which showed intermittent complete heart block. The electrical system of the heart is located near the aortic valve, and in rare cases, the manipulation required in surgery can permanently damage the conduction system. It is more likely to occur if, as in this case, there is a pre-existing right bundle branch block seen on the EKG.

A permanent pacemaker was implanted the next morning to help control his heartbeat and fixed the problem. He was sent home from the hospital the next day, and has been doing well ever since.

Complete heart block, where the atrium and ventricle do not beat together, occurs 5% to 6% of the time after aortic valve surgery, and usually will not fix itself. It can also occur after transcatheter aortic valve replacement (TAVR). A permanent pacemaker is needed to avoid sudden cardiac death.

Why did this man have this problem at a young age? Aortic stenosis is usually thought of as an older person’s disease. The aortic valve, which separates the left ventricle from the aorta, has three individual leaflets. When the valve was replaced, it was sent to the pathologist for further examination. His valve only had one leaflet.

A unicuspid aortic valve is an extremely rare congenital malformation that occurs during fetal development. With only one leaflet to open, often valve surgery is needed between ages 30 to 50. The more commonly seen bicuspid aortic valve (two valve leaflets rather than three) is also a congenital problem. Often associated with aortic dilation and aneurysm, bicuspid aortic valves are sometimes inherited, and close relatives of those diagnosed should be screened.

In this case, the patient’s loud heart murmur did not develop overnight. It was related to a congenital problem, and the murmur had been developing for years. No one, before the smart internist who first heard it, had probably ever listened closely enough to his heart with a stethoscope, and until six months ago he was entirely asymptomatic.

His shortness of breath could have easily been blamed on being in less than ideal shape because of the pandemic. This underscores the importance of a good physical exam as part of a routine doctor’s visit.

David Becker is a frequent Inquirer contributor and a board-certified cardiologist with Chestnut Hill Temple Cardiology in Flourtown. He has been in practice for more than 25 years.