Medical Tests

Could I have had a silent heart attack?

DEAR DOCTOR K: I recently had an ECG in preparation for a surgical procedure. The doctor said it showed I'd had a silent heart attack. How could I have had a heart attack and not known about it?

DEAR READER: I know it sounds strange. After all, on television, heart attacks are portrayed in rather dramatic fashion. Typically, you see a person clutching their chest with agonizing pain. This mental image is embedded in our culture. But my colleague, Dr. Deepak Bhatt, a cardiologist at Harvard-affiliated Brigham and Women's Hospital, cites a recent study that is the latest to show that heart attacks often can be "silent."

Do I still need to fast before a cholesterol test?

DEAR DOCTOR K: I heard that fasting will no longer be required before a cholesterol test. Will the results still be as accurate?

DEAR READER: To answer your question, I need to first describe what a "cholesterol test" is. There are three types of cholesterol that typically are measured: LDL ("bad") cholesterol, HDL ("good") cholesterol and total cholesterol (basically, the sum of LDL and HDL). There is a fourth type of fat measured at the same time: triglycerides. Most doctors order all four tests as part of what's called a "lipid (fat) panel."

Can you give me some advice for measuring my blood pressure at home?

DEAR DOCTOR K: My doctor told me to check my blood pressure at home, but he didn't give me many details. Could you provide some guidance?

DEAR READER: Keeping your blood pressure in check is vital to maintaining heart health and preventing stroke. But the way most of us monitor our pressure -- by trekking to the doctor's office for occasional blood pressure checks -- is far from ideal.

I have dense breasts. Does that increase my risk of breast cancer?

DEAR DOCTOR K: My doctor says I have dense breasts, and a friend says that means I have an increased risk of breast cancer. I'm hoping you'll tell me that's not so.

DEAR READER: I wish I could fully reassure you, but I can't. A woman who has dense breasts does have a slightly increased risk of breast cancer, although not clearly an increased risk of fatal breast cancer.

What will happen during laboratory sleep testing?

DEAR DOCTOR K: My doctor thinks I may have sleep apnea, and he wants me to go to a sleep lab to be tested. What will happen during the testing?

DEAR READER: Sleep apnea is a serious health condition in which breathing stops or becomes shallower. In the most common form, obstructive sleep apnea, the tongue or throat tissues temporarily and repeatedly block the flow of air in and out of your lungs. This can happen hundreds of times each night. Laboratory sleep tests are the most reliable way to diagnose this problem.

Should I get a c-reactive protein test to check for heart disease?

DEAR DOCTOR K: Both my parents had heart disease, so I'm worried I might get it. A friend said I should get a CRP test, but my doctor hasn't ordered one. Should I ask him about the test?

DEAR READER: The answer is controversial. For full transparency, I should say that this test was developed and studied by a colleague of mine at Harvard Medical School, and revenue from the test comes to my colleague and to the hospital where I practice.

What are the risks and benefits of mammograms?

DEAR READERS: In yesterday's column, I answered a question from a 47-year-old woman who had never had a mammogram and wondered if she should have one. She had heard that one group of experts -- the American Cancer Society (ACS) -- had recently changed its recommendations on this issue.

When should I start getting mammograms?

DEAR DOCTOR K: I'm a 47-year-old woman who has never had a mammogram. Some experts recommend I get one, but others do not. I understand that the American Cancer Society recently updated its recommendations about breast cancer screening. Does it say I should have a mammogram? If so, which experts should I believe?

DEAR READER: I'm surprised when people are bothered by medical experts having different opinions. Expert politicians, expert lawyers, expert architects -- experts of all kinds disagree with each other all the time. Why? Because it is rare for the "truth" of any question to be clear beyond dispute.

What will happen during my pulmonary function tests?

DEAR DOCTOR K: My doctor ordered breathing tests to see if I have asthma. He didn't tell me what it's like to go through this. Can you explain?

DEAR READER: The tests your doctor almost surely is referring to are pulmonary function tests. The tests are painless. You breathe in and out through a tube that is connected to various machines.

Should I have my vitamin D level checked?

DEAR DOCTOR K: I've read several articles about the negative effects of a low blood level of vitamin D, but my doctor said I didn't need to have my level checked. Why not?

DEAR READER: Many of my patients are asking me the same question. Vitamin D has been in the news a lot in recent years, but we still don't have solid answers to many questions, including yours. There is strong evidence that people with a low blood level of vitamin D have higher rates of osteoporosis (thin bones).