Q. On the day I stopped smoking a few weeks ago, I started using a nicotine patch. When I smoked, my blood pressure was great — 100/70. Now it is up to 160/90. I would hate to stop the patch, since it really helps, but I'm worried that it could cause high blood pressure..

A. First off, congratulations for trying to stop smoking. Every part of your body will benefit if you quit.

Q: What are the best ways to increase HDL (good) cholesterol levels?

A: Before I answer that question, why bother to increase HDL cholesterol at all? Many studies have found that people with low levels of HDL are at increased risk for heart attacks, strokes, and other complications of arteries diseased by atherosclerosis: that's why we call HDL the "good" cholesterol. Given that, you'd think that raising HDL levels would reduce a person's risk for atherosclerosis. Unfortunately, despite a lot of research, we don't yet know if that's true, nor how best to raise HDL levels.

Q. I have allergies. Could they be the reason I have high blood pressure?

A. Although allergies don't usually directly increase blood pressure, they can contribute indirectly to high blood pressure in two very different ways.

Symptoms, heart measurements guide the need for mitral valve surgery.

The heart is a marvel of biological engineering. Four strategically placed valves ensure that every contraction propels blood forward with little or no backflow. On the right side of the heart, the tricuspid and pulmonary valves direct the orderly flow of blood; on the left side, the mitral and aortic valves. Although all four valves are essential for good health, we focus on the mitral valve and mitral valve regurgitation in this article.

If the mitral valve is damaged or becomes misaligned, it can't close completely with each heartbeat. Some blood spurts backward with each contraction. This backflow, called mitral regurgitation, puts a strain on the heart. It can provoke symptoms such as breathlessness and fatigue and lead to atrial fibrillation or heart failure.

Ask the doctor

Q. What causes high blood pressure?

A. My answer is going to start in your back yard; stay with me. You're holding a hose, you turn on the water, and it shoots through the hose and out the nozzle. The water is moving because it's under pressure. Similarly, when your heart beats it creates pressure that enables your blood to "water" your body with the nutrients that are in your blood.

Three things affect the amount of pressure that pushes blood through your body: how forcefully the heart pumps, how much blood there is, and how narrow the smallest blood vessels are. That last one may need some explanation. When you're watering plants, and you want the stream of water to go farther, what do you do? You make the nozzle smaller. Narrowing the opening through which the water flows increases the pressure, and the water then is able to reach the distant flowerbed.

New guidelines provide advice on the role of drugs, weight loss, and procedures to cope with this common heart rhythm disorder.

The classic symptom of atrial fibrillation — a fluttering or thumping sensation in the chest — can leave you breathless, dizzy, and tired. Caused by electrical misfires in the heart's upper chambers (atria), this condition affects an estimated one in 11 people ages 65 and older.

While the symptoms of atrial fibrillation (often called afib) can be unsettling, the real danger is a heightened risk of serious strokes (see "How afib can lead to a stroke"). As many as 30% of strokes from afib prove fatal, notes Dr. Christian Ruff, a cardiologist at Harvard-affiliated Brigham and Women's Hospital.

Ask the doctor

Q. I had an echocardiogram and the report says I have mild diastolic dysfunction. What does that mean?

A. Diastolic dysfunction means that your heart is having trouble relaxing between beats. Every heartbeat has two distinct phases: when the heart contracts and pushes blood out to the body (the systolic phase) and when the heart relaxes and refills with blood (the diastolic phase).

So far, the evidence that foods and drinks rich in good bacteria can improve cardiovascular health is promising but limited.

A number of foods — yogurt, sauerkraut, as well as some less-familiar ones such as kimchi and tempeh — are made by fermentation, an age-old tradition for preserving food. These foods, as well as the fermented drinks kombucha and kefir, have been getting buzz in recent years, mostly focused on their potential to enhance gut health. Fermented products contain naturally occurring beneficial bacteria known as probiotics, which are thought to improve digestion.

Probiotics found in fermented foods may also provide modest heart-related benefits, according to a review article published in the Journal of the American College of Cardiology last year. One study found that eating kimchi (see "What are fermented foods?") daily helped people lose weight and lowered their blood pressure. Another noted improvement in blood sugar and cholesterol levels.

Walking or hiking in a natural area may benefit your heart more than working out indoors.

For many people, summer's long days and warm weather make it a great time to exercise outdoors. And that just might be a great way to boost the rewards from your workout, says Dr. Edward Phillips, assistant professor of physical medicine and rehabilitation at Harvard Medical School.

"When you're moving your body, your heart, lungs, and muscles don't know or care where you are. But your mind does," says Dr. Phillips. And if you're exercising outdoors in a beautiful natural setting, you might be tempted to go a little farther than if you set out to walk for just 30 minutes around your neighborhood, he notes. "Some people say it's hard to rack up 7,000 steps a day walking a familiar route. But they often find they can go twice as far on a hike, especially if there's a nice vista at the destination," he says. If you choose a trail that includes some hills, which will force your heart to work harder, that will also increase your fitness.

Even though "nut" is in its name, a peanut is actually a legume. Like soybeans, lentils, and other legumes, peanuts are edible seeds that grow in pods. Still, most people think of them as nuts, along with tree nuts such as walnuts, almonds, and hazelnuts. (Unlike other legumes, which grow on vines or shrubs, peanuts grow underground.)

Nutritionally speaking, peanuts and tree nuts are fairly similar: they're all rich in healthy unsaturated fats and fiber, as well as several vitamins and minerals. Numerous studies suggest that people who eat peanuts or tree nuts frequently have lower rates of heart disease compared with people who rarely eat them. One added bonus for peanuts: they're not as pricey as tree nuts, making them a more affordable addition to your daily menu.