Dear Doctors: I am 65 years old, and I have never been to a cardiologist. I am concerned about heart disease and the possibility that I may have blocked arteries. I would like to know what screenings -- an MRI? an exercise stress test? -- I should get.

Dear Reader: As someone who has not undergone the screenings commonly used to evaluate cardiac health, it's best to start with the basics. These can be done by your regular doctor.

The appointment typically begins with a discussion of your medical history. This includes information about any diseases or conditions for which you are currently being treated, and any in your past that may have a residual effect on general health. Family history, which can suggest a genetic predisposition for certain diseases and conditions, is an important factor, as well.

Your weight, and possibly your BMI, will be recorded, and your doctor will obtain readings for heart rate and blood pressure. Testing will also include a blood lipid profile and a blood glucose level. Taken together, this information offers important insights into health risks that you may face. If the test results suggest a problem beyond the scope of your primary health care provider, such as a heart condition or heart disease, they will refer you to a cardiologist.

When visiting a cardiologist, expect them to review the test results that brought you under their care, and to explain how the results are a factor in the health of your heart. Depending on those results, you may also be asked to undergo additional tests that assess various aspects of cardiovascular health. These can include an EKG, which measures electrical activity in the heart; echocardiography, which uses ultrasound to create moving pictures of the heart; and scans that measure blood flow in the veins or that identify the presence of calcium deposits. A test known as CCTA, or coronary computed tomography angiography, produces 3D images that can help detect abnormalities in blood flow and identify possible blockages. An exercise cardiac stress test measures heart rate and rhythm, blood pressure and electrical activity of the heart as the patient performs increasingly strenuous exercise.

The cardiologist will also discuss specific aspects of your lifestyle. This includes a review of your diet, exercise habits, use of alcohol or tobacco products and your perceived level of stress. You will be asked about medications you are currently taking. It's important to provide the doctor with a complete and accurate list, and to also include any dietary supplements that you may be using. They will also want to know about any family history of heart disease.

Depending on the findings, you may be prescribed medications to manage high blood pressure or high cholesterol. You may also be advised to make lifestyle changes. These can include reaching a healthier weight, exercising more or more frequently, adjusting your diet, moderating the use of alcohol and quitting tobacco products. Your cardiologist will also schedule additional appointments to evaluate the efficacy of your treatment program. For the health of your heart, and your general well-being, it's important that you follow through.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Hello, dear readers, and welcome back to our monthly letters column. We're getting closer to autumn, but in much of the country, heat waves continue. Please be sure to take precautions. Drink enough water throughout the day to fuel your body's natural cooling system, which is sweating. When possible, stay indoors during the hottest hours. And, if needed, take shelter in public places in your area with air conditioning, such as malls, community centers, libraries or local cooling centers. Even a short break in a cooler environment can be helpful. And now, onward to the mail:

-- We recently wrote about spinal stenosis, which is when the spaces and hollows of the spinal column begin to narrow. The resulting pressure on the spinal cord and nerve roots causes symptoms that include pain, burning, numbness and weakness in the back, legs or feet. That prompted a question from a reader who developed these symptoms. "I had an MRI two years ago, and it showed some spinal stenosis and a mild protrusion on the disc," he wrote. "I developed numbness in my left leg and tingling in both feet, but no buttock or thigh pain. Two chiropractors and a physical therapist have offered conflicting advice, and none of their suggestions seem to work. What kind of specialist should I see?"

You would be best served by seeing a spine specialist, either a neurosurgeon or an orthopedic surgeon. A disc protrusion, if mild, can be treated with physical therapy and anti-inflammatories. It can sometimes require an epidural steroid injection. Some people with spinal stenosis are helped by a minimally invasive procedure called Vertiflex, which uses a small implant to lessen pressure within the spine to ease symptoms.

-- We recently discussed a sensitive and accurate blood test known as A1C, which measures someone's average blood sugar levels over the previous eight- or 12-week period. It is used to diagnose Type 2 diabetes. This is a condition in which the body stops responding properly to insulin, which leads to chronic high blood sugar.

A reader with high A1C results sent us a question. "I need to lower my A1C -- can diet and exercise be effective?" they asked. "How much of a reversal can you see?" The answer is, yes, A1C can be lowered by lifestyle modifications. This is achieved by minimizing added sugar in the diet, avoiding refined carbohydrates and highly processed foods, getting regular exercise and reaching a healthy weight. Each of these contribute to improving the body's response to insulin. How much you can lower your A1C with lifestyle changes depends on each person's general health, metabolism and genetics. If your doctor has outlined a treatment plan that includes medication, it's important to follow through.

Thank you, as always, for taking the time to write. It's wonderful to hear when a column has helped you, or that you simply find the information useful or instructive. We read every letter, and we will continue to try to respond to as many as possible.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctors: I would like to know about the new COVID-19 variant called Eris. Will there be a new booster for it? Also, I read that you'll get better immune response if you get all of your COVID shots in the same arm each time. Is this true?

Dear Reader: From the earliest days of the pandemic, health authorities have kept a watchful eye on the emergence of variants of the coronavirus that causes COVID-19. More specifically, they have tracked what are known as variants of interest. These are mutated forms of the original coronavirus that, due to small changes to the genetic code, become more successful at breaking into and infecting host cells.

Among the newest of these is a variant called EG.5, which has come to be known as Eris. It is now the dominant variant in many parts of the world, including the United States. The Centers for Disease Control and Prevention reports that, as of Aug. 21, Eris made up close to 21% of all new COVID-19 infections in the U.S. That's a marked increase over the previous month. However, in terms of symptoms and severity of disease, Eris does not appear to be significantly different from previous variants.

Eris, along with a handful of other variants that are under close scrutiny at this time, is a descendant of the XBB strain of the coronavirus. That strain is the target of the newest generation of coronavirus booster shots. The new coronavirus booster, which still needs regulatory approval from the FDA, is expected to become available sometime this fall. To simplify what has often been a confusing process, the U.S. is shifting to an annual model for COVID-19 boosters for all age groups.

As for your question about which arm to choose for your coronavirus vaccine, new research suggests the decision may play a role in immune response. A recent study found that immune response may indeed be stronger when the COVID-19 vaccine goes into the same arm each time.

Researchers arrived at this conclusion by analyzing data from 303 individuals receiving the original two-dose coronavirus vaccine series. Those who got both shots in the same arm had levels of T cells that were 75% higher than those who switched arms for the second shot. T cells, which are a type of white blood cell, play a crucial role in immune response. Sometimes known as “killer T cells,” they roam throughout the body and attack suspected pathogens.

The researchers suspect the link between vaccine location and higher T cell numbers is due to the proximity of the armpit. T cells are present in lymph nodes, including those located in the armpits. When the immune cells in those lymph nodes are repeatedly stimulated by the vaccine, this could lead to a more robust immunological response. Proving whether this is actually the case will require a larger and longer study. But in the meantime, there is no harm in picking one arm in which to receive all of your COVID vaccines.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)