Medical Tests & Procedures Archive

Research we're watching

Taking supplements that contain high levels of biotin (vitamin B₇) can lead to falsely low results on a blood test used to detect heart attacks, according to an FDA warning issued late last year.

For adults, the recommended dietary allowance (RDA) for biotin is 0.03 milligrams (mg), which is easily obtained through a healthy, varied diet. Many multivitamins and prenatal vitamins contain far more biotin than the RDA. And some supplements — particularly those marketed to improve hair, nails, and skin — contain 20 mg, or nearly 650 times the RDA.

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Q. I'm 80 and no longer do colon cancer screening. However, I recently noticed some bleeding from my rectum. Does that change my need for a colonoscopy?

A. Screening for a disease means the person has no symptoms. Since you now have rectal bleeding, a colonoscopy would be considered not a screening test, but a diagnostic test. Whether you have it now or wait to see if more bleeding occurs depends upon many factors. The most important question is whether anything found on the colonoscopy will lead to treatment that improves your quality of life.

Several new technologies and medications that may benefit the heart are moving into cardiology care.

As regular readers of the Heart Letter know, our features tend to focus on lifestyle advice and currently available therapies for heart disease. As the new decade begins, we're also looking to the future. Editor in Chief Dr. Deepak L. Bhatt selected five promising new developments in cardiovascular research that you may be hearing more about in the coming years.

1. Digital stethoscopes

First developed more than 200 years ago, the instrument doctors use to listen to the heart and lungs has undergone some high-tech improvements in recent years. The latest digital stethoscopes feature specialized microphones and sensors that filter, buffer, and amplify sounds from the heart. The sounds are then converted to a digital signal and sent wirelessly to a smartphone, where the patterns can be visualized and further analyzed. Some models are so sensitive they can detect turbulent blood flow in the arteries of the heart, possibly enabling doctors to detect coronary artery disease. Studies assessing that potential use are currently under way.

They often lead to follow-up appointments and more testing.

Modern medical imaging saves lives: it can find a blocked artery, a bulging blood vessel, or a suspicious mass. But many times, an x-ray, CT scan, MRI scan, or ultrasound exam looking for one kind of problem can reveal an anomaly that's unrelated and unexpected. Such incidental findings can lead to more testing, more medical bills, and a great deal of anxiety.

"Frequently radiologists will point out something and say it's probably benign, but recommend an MRI. Once you've been told something might be abnormal, you might feel nervous until you know what it is," says Dr. Suzanne Salamon, associate chief of gerontology at Harvard-affiliated Beth Israel Deaconess Medical Center.

The once-a-year appointment can reveal vital health information for both you and your doctor.

It's usually covered by your health insurance, it doesn't take much time, and it's a great way to learn about your present and future health.

While men often call it the yearly physical, the annual ritual is better named a wellness visit or preventive health appointment. Whatever you call it, men should still have one every year as it remains an important part of primary care, according to Dr. Asaf Bitton, executive director of Ariadne Labs and primary care physician at Harvard-affiliated Brigham and Women's Hospital.

Here is what men need to know to minimize discomfort of a prostate biopsy and get the best results.

What Is It?

The cornea is the clear, round, "window" of tissue that allows light to enter the front of the eye. If the cornea becomes severely diseased or damaged, it can distort or even block the normal path of light into the eye. When this happens, light does not focus normally on the retina, the layer at the back of the eye that is responsible for sight. As a result, there can be a significant loss of vision in the affected eye.

When corneal conditions cause serious, irreversible vision problems, a corneal transplant often is the best solution. In a corneal transplant, an eye surgeon first removes the diseased or damaged area of cornea. The removed tissue then is replaced by a section of healthy cornea that has been taken from the eye of a dead donor.

What Is It?

A heart transplant is surgery in which a patient with a life-threatening heart problem receives a new, healthy heart from a person who has died. In a heart transplant, the patient who receives the new heart (the recipient) is someone who has a 30 percent or greater risk of dying within 1 year without a new heart. Although there is no absolute age limit, most transplants are performed on patients younger than 70 years old.

The person who provides the healthy heart (the donor) is usually someone who has been declared brain dead and is still on life-support machinery. Heart donors are usually younger than 50, have no history of heart problems, and do not have any infectious diseases.

What Is It?

A heart-lung transplant is surgery for someone with life-threatening heart and breathing problems. Surgeons remove the damaged heart and lungs and replace them with a healthy heart and lungs from a person who has died.

The person receiving the new heart and lungs (the recipient) is someone with a high chance of dying within one to two years without a transplant. The person providing the healthy heart and lungs (the donor) is someone who is brain dead, but still on life-support machinery.

What Is It?

In lung transplant surgery, someone with life-threatening respiratory problems is given one or two healthy lungs taken from a person who has died. If one lung is transplanted, the procedure is called a single-lung transplant. If both lungs are transplanted, it is a bilateral or double-lung transplant.

Lungs for transplantation usually come from young, healthy people who have had severe brain damage because of trauma or cardiac arrest (a stopped heart). Their lungs and other organs are maintained with life-support machinery.