Medical Tests & Procedures Archive

The carotid (pronounced ka-RAH-ted) arteries in the neck are the main supply route for blood to get to the brain. But atherosclerotic plaque can gum them up, just as it does the coronary arteries that provision the heart. If that plaque ruptures, blood clots can form that block the carotids or other, smaller arteries, resulting in an ischemic stroke.

Narrowed carotid arteries can be identified with an ultrasound before a stroke occurs. The examinations are noninvasive and inexpensive. Some hospitals are charging the public as little as $45 for an ultrasound of their carotid arteries.

A new study explores how people fare after surgery or nonsurgical repair.

A weakened widening of the aorta (the main pipeline for delivering oxygen-rich blood to the body) can be deadly if it bursts. This widening is called an abdominal aortic aneurysm, or triple-A for short. There are two main ways to battle this bulge: traditional surgery and a newer approach called endovascular repair.

Most people with this genetic condition develop thickened heart muscle but lead normal lives.

"You have a really big heart" is usually a wonderful compliment — except when it comes from your cardiologist and the term cardiomyopathy crops up in the conversation. An oversized heart usually isn't a good sign.

Same-day angioplasty feasible, safe

Patel M, Kim M, Karajgikar R, et al. Outcomes of patients discharged the same day following percutaneous coronary intervention. JACC Cardiovascular Interventions 2010; 3:851-8.

Chambers CE, Dehmer GJ, Cox DA, et al. Defining the length of stay following percutaneous coronary intervention: an expert consensus document from the Society for Cardiovascular Angiography and Interventions. Endorsed by the American College of Cardiology Foundation. Catheterization and Cardiovascular Interventions 2009; 73:847-58.

Collaborative approach aims to improve cardiac care.

Heart problems tend to come in clumps. Arteries clog. Valves don't open or close all the way. The heart's rhythm becomes irregular. Many people face not one but two or more treatment decisions.

Just a few years ago, someone who required multiple cardiac procedures might have had separate procedures done by specialists working in different parts of a hospital. In a catheter lab, a cardiologist would insert a stent to reopen an artery. Later, in an operating room, a cardiac surgeon would fix or replace a faulty valve. Hours might pass in between, involving transport from a sterile environment to an unsterile one and back again. In some cases, the two procedures might even require separate hospital visits.

Unnecessary blood transfusion can do more harm than good.

Blood transfusion deserves a prominent place in the pantheon of medical advances. It has saved countless lives on the battlefield and in hospital emergency departments. It is a life-prolonging treatment for people with conditions that prevent the body from making blood or blood components, from kidney disease and cancer to disorders such as hemophilia and sickle cell anemia. But whether blood should be routinely transfused during or after heart surgery is a question that more and more people are asking. The answer is tilting toward "no."

Q. You have written about low potassium in the blood and ways to improve it, but I never read about too much potassium in the blood. Can you tell me why it happens and what is done about it?

A. Relatively few people develop high levels of potassium in the blood, since the kidneys are normally quite effective in clearing this mineral from the bloodstream. A normal blood potassium measurement is 3.7 to 5.2 milliequivalents per liter.

Q. I needed angioplasty in 2007 and had a stent implanted during the procedure. Due to another health problem, my doctor now wants me to have an MRI. Could this cause any problem with the stent?

A. Stents are metallic cages that hold open a coronary artery after angioplasty. Metallic objects placed in the body can pose problems for MRI scans, which use a strong magnetic field and pulses of radio waves to see inside the body. The magnetic field could dislodge the object, while radio waves could make it heat up. That kind of movement and heating has been reported for some cardiac pacemakers and implantable cardioverter-defibrillators. (MRI-safe pacemakers and implantable cardioverter-defibrillators are being developed.)

Readers often ask us about the use and safety of Plavix after angioplasty. We turned for answers to Dr. Patrick O'Gara, a member of the Heart Letter editorial board, who helped write a clinical alert about Plavix for the American Heart Association.

Almost every medical advance raises issues that demand creative problem-solving. Take artery-opening angioplasty. It uses a tiny balloon to flatten a cholesterol-filled plaque, restoring blood flow through a narrowed or blocked coronary artery without open-heart surgery. A wire-mesh stent is usually left behind to hold open the artery. However, blood clots sometimes form on a stent. This can block blood flow through the artery, causing a heart attack or sudden cardiac arrest. Taking a drug called clopidogrel (Plavix) with aspirin can fight this problem. But this combination, often called dual antiplatelet therapy, can be hard on the stomach, interacts with some drugs, and must be taken without interruption for a specified period.

High-density lipoproteins (HDL) protect the heart and arteries by removing cholesterol lodged in artery walls and riding through the bloodstream inside of low-density lipoproteins (LDL). Here's a novel way to amplify HDL's cholesterol-busting activity: Take some blood from a person. Extract the HDL. Use a process called delipidation to remove cholesterol and other fats (lipids) from the HDL. Then put the defatted HDL particles back into the bloodstream. This seems to turbocharge HDL and make it work even more aggressively against cholesterol.

In the first clinical trial of HDL delipidation in humans, the procedure was safe and effective. Treated HDL caused cholesterol-filled plaque to shrink more than did untreated HDL (Journal of the American College of Cardiology, June 15, 2010). The trial was too small and didn't last nearly long enough to see if this prevented future heart attacks or improved survival.