Ask an Expert


Find answers to frequently asked questions about a variety of health conditions, like heart attack, high blood pressure and atrial fibrillation.

  • Why is someone with atrial fibrillation at risk for a stroke?

  • Normally, blood is constantly flowing through the atria, ventricles and blood vessels. But because blood pools in the quivering atria, it has the chance to congeal into blood clots, which can travel to the brain, blocking blood flow and causing a stroke. That’s why patients with atrial fibrillation must take some form of anti-clotting medication such as aspirin or the blood thinner warfarin (Coumadin).

    Not wanting to take lifelong blood thinners is one of the reasons people have radiofrequency ablation to rid themselves of atrial fibrillation. However, researchers in the new study advised anyone who has already had a stroke to continue taking blood thinners, since atrial fibrillation can return even after a successful radiofrequency ablation procedure.
  • Why is TAV-in-SAV used primarily for high-risk patients only?

  • Redo aortic valve surgery is the safest option for most patients with failing surgical aortic valves, associated with only a 2–7% risk of operative mortality. However, for patients that are high-risk, redo aortic valve surgery is much more dangerous, increasing risk of mortality to more than 30%. Therefore, TAVI may be a better and safer option for high-risk patients.
  • Why is stroke so prevalent worldwide?
  • Due to better lifestyle guidelines and medical advances, more people are living longer. Older individuals have increased risk for stroke based on age, so a larger proportion of populations are at high risk. Also, major risk factors such as hypertension, diabetes and obesity are increasing worldwide, which can increase the incidence of stroke.
  • Why would air pollution trigger heart attacks?

  • Although further research is needed to better understand the relationship between pollution and heart attacks, experts believe that short-term exposure to air pollution may trigger inflammation and promote blood clotting, increasing risk for a cardiac event.
  • Why does the stroke belt have increased cardiovascular risk?

  • There are many explanations for increased cardiovascular risk in the region, such as poor diet and reduced physical activity among residents. Race also plays a large factor, as there is a high African-American population, which is affected by heart disease and stroke more than other races.
  • Why does heart failure limit exercise capacity?

  • Chronic heart failure can cause a variety of symptoms such as fatigue, swelling and shortness of breath, which can limit one’s ability to exercise. However, increasing physical activity despite these symptoms has been shown to strengthen the body, reduce symptoms and improve quality of life in heart failure patients.
  • Why does exercise help conditions such as diabetes and peripheral artery disease?

  • Despite symptoms of fatigue and pain, exercising can help condition muscles to use oxygen more efficiently. As patients exercise regularly, their stamina will often increase and symptoms may become lessened over time, improving quality of life.
  • Why is FDG-PET good at finding inflammation?

  • The “G” in FDG stands for glucose, which is a type of sugar. Inflamed tissues burn through a lot of energy. They take up the glucose to use as fuel. Normal tissues don’t burn through as much energy, so they take up less glucose.

    When doctors are looking for inflamed or cancerous tissue, they use FDG that has been labeled with a small amount of radioactivity. The FDG is injected into a vein and is taken up by inflamed tissues as it circulates through the body. The PET camera can see how much glucose the inflamed tissue is using by measuring the radioactive particles the FDG releases.

  • Why is femoral access currently used more often than radial access for percutaneous coronary intervention (PCI)?

  • Many medical professionals believe that radial access may have significant medical benefits over femoral access. However, there has not been substantial research comparing the two access points on a larger-scale until now, through the RIVAL study. As a result, a lack of research and practice with radial access has led most surgeons to favor femoral access for PCI.
  • What medications are recommended to treat patent foramen ovale (PFO)?

  • Antiplatelet and anticoagulant medications have both been used to treat patients with PFO who have heart conditions or history of stroke. While both types of medication have helped reduce risk of recurrent stroke in patients, the optimal medication therapy for patients with PFO is unknown.
  • What kind of research is currently underway for pulmonary artery hypertension (PAH)?

  • Several long term studies are currently underway or have been recently completed that look at how PAH medications can be used as individual therapies and in combination for the greatest patient benefits. The website, run by the National Institutes of Health (NIH), maintains an up-to-date list of clinical trials underway or recently completed. Talk to your doctor if you think you might be interested in taking part in a clinical research study on PAH.
  • What should I do if I experience heart attack symptoms?

  • Call 911 at the first signs of heart attack. Do not delay and do not attempt to drive yourself to the hospital. Calling 911 and taking an ambulance to the hospital will provide you with the most immediate and effective treatment possible for a heart attack, reducing likelihood of long-term damage to the heart and death.
  • What is the difference between hypertension and prehypertension?

  • Those considered “prehypertensive” have blood pressure levels greater than what’s considered “normal,” but not high enough to be considered hypertensive. For most adults, normal blood pressure is a systolic (top number) less than 120 and a diastolic (bottom number) less than 80.
  • What is the difference between pulmonary embolism and deep-vein thrombosis?

  • Deep-vein thrombosis is clotting in the veins deep within the body. Pulmonary embolism is often a complication of deep-vein thrombosis, which occurs when the clot travels to the lungs, blocking the flow of blood. Both conditions require immediate treatment with anticoagulant medications to help break up the clot and restore normal blood flow.

  • What is the difference between unstable angina, ST Segment Elevation Myocardial Infarction (STEMI) and Non-ST Segment Elevation Myocardial Infarction (NSTEMI)?
  • STEMI and NSTEMI are two classifications for a heart attack. Although both result from the interruption of blood supply to a part of the heart, STEMI results in ST-elevation (elevation of a cardiac enzyme) while NSTEMI does not. Unstable angina, on the other hand, is a condition characterized by chest pain or discomfort that is unexpected and usually occurs at rest. Unstable angina is often accompanied by shortness of breath, indigestion and/or dizziness. Unlike STEMI and NSTEMI, which cause muscle damage in the heart, unstable angina is not associated with muscle damage. However, unstable angina is very dangerous, may progress to a heart attack, and needs emergency treatment.

    Unstable angina and NSTEMI often appear identical at first presentation. The difference can be ascertained only after an ECG and blood tests to look for markers that indicate heart muscle damage.

    Call 9-1-1 immediately if you have the following symptoms:

    • Chest pain, pressure, tightness, or heaviness.  This discomfort may radiate to the neck, jaw, shoulders, back, or one or both arms.
    • Weakness, dizziness, lightheadedness, loss of consciousness.
    • Indigestion or “heartburn”; nausea and/or vomiting associated with chest discomfort
    • Shortness of breath that does not go away
  • What is the connection between gum disease and heart disease?
  • It’s not completely clear. Scientists don’t know whether gum disease actually causes cardiovascular disease. It’s possible that something else is causing both problems. One theory is that bacteria from diseased gums invade the artery wall and cause inflammation to erupt there too. The bacteria may also provoke the body to release several chemicals that cause inflammation in the arteries.
  • What is the difference between an ICD and a pacemaker?
  • The biggest difference between an ICD and pacemaker is that an ICD continually monitors heart rhythm and can send low- or high-energy electrical pulses to correct an abnormal heart rhythm. ICDs will initially send low-energy pulses to restore heart rhythm but switch to high-energy pulses when the low-energy shocks are ineffective. Pacemakers, however, only give low-energy electrical pulses to restore regular heartbeat. Therefore, ICDs are more effective in patients at high-risk for or history of sudden cardiac arrest, who may need these more powerful, high-energy electrical pulses to restore their regular heartbeat.
  • What is the difference between elective and emergency percutaneous coronary intervention (PCI)?

  • Emergency PCI is performed on patients suffering a serious type of heart attack known as a STEMI, in which there is complete blockage of a coronary artery, preventing blood flow and killing heart muscle. In this case, emergency PCI is used to restore blood flow to avoid long-term damage or death. Elective PCI, on the other hand, is when the procedure is planned ahead of time due to significant blockage of the arteries, in an effort to prevent future heart attack or stroke.
  • What is the risk of developing cardiac arrest during or after a marathon?

  • Based on recent research, risk of cardiac arrest among marathon runners is about 1 in 184,000, with risk of sudden death being much lower (1 in 259,000). In contrast, risk of death among relatively healthy middle-aged joggers is significantly higher (about 1 in 7,620).
  • What is venous thromboembolism and why is it dangerous?

  • Venous thromboembolism occurs when a clot forms in a vein, which can slow or completely block blood flow. The danger is that if these clots form in deep veins (most often in the leg or pelvis), they can break off and travel to the lungs or heart causing a pulmonary embolism. A pulmonary embolism can prevent your body from getting the oxygen that it needs, inflicting serious damage on internal organs.
  • When do I need to see a cardiologist?

  • If you have any risk factors for heart disease, you should see a cardiologist. These risk factors include overweight or obesity, high blood pressure, high cholesterol, diabetes and family history of heart disease, heart attack or stroke. Because cardiologists are specifically equipped to help patients manage and reduce their cardiovascular risk, it is important to discuss any concerns regarding your heart health with them.
  • When are women at greatest risk for heart attack during pregnancy?

  • This study shows that risk for heart attack may be elevated anytime during pregnancy, delivery or within 12 weeks after delivery.
  • What vaccines can help prevent HPV?
  • Two types of vaccines — Cervarix and Gardasil — are currently available to help protect females against the types of HPV that cause most cervical cancers. Both vaccines are recommended for girls between the ages of 11 and 12, or for females 13–26 years old who did not get the recommended doses earlier. Gardasil remains the only vaccine that helps protect males against HPV. It can be administered to males between the ages 9 and 26.
  • What type of exercise is recommended for heart failure patients?

  • Aerobic activity in varying degrees of intensity for at least 30 minutes on 5 or more days a week is often recommended for heart failure patients. However, resistance training has also been shown to be beneficial for heart failure patients, in addition to stretching/breathing exercise, such as tai chi and yoga.
  • How can I help prevent heart failure?

  • By controlling any risk factors you may have for heart failure, you can help to reduce your risk. You should also avoid tobacco use and maintain a healthy lifestyle, with a well balanced diet, healthy weight and regular physical activity.

Ask an Expert

Please note that every question submitted will not receive a direct response from a Cardiologist. However, we will follow-up with suggested ways to find appropriate information related to your question. Please do not use your last name or any other confidential information in your question.

Meet our Expert

Your questions are answered by more than two dozen members of the American College of Cardiology who volunteer their time with CardioSmart.

Learn more about our volunteers