An Interview with CentraCare Cardiologist Benjamin Johnson, MD, About Heart Health

Dr. Ben Johnson, a non-invasive cardiologist with CentraCare Heart & Vascular Center, spoke with WJON’s Jay Caldwell about heart health.

Question: What is a heart attack?

Dr. Johnson: A heart attack starts with cholesterol plaque building up in artery walls, which can happen throughout the body, not just in the heart. This plaque accumulation leads to the remodeling of the artery wall and narrowing of blood flow. When you lift objects or engage in activities that increase your heart rate, your heart needs more blood flow to work harder. However, if the arteries are narrowed, sufficient blood flow is compromised, leading to angina. Angina describes the symptoms people experience when their heart muscle isn't getting enough blood flow. This is the initial stage of plaque buildup and its gradual consequences over time.

Question: Does this plaque buildup happen to everyone?

Dr. Johnson: To some extent, yes. Nearly everyone will experience some plaque buildup over time. If you were to conduct a CAT scan on individuals in their eighties and nineties, you'd likely find that over 95% of them have some level of plaque in their arteries. However, certain risk factors can accelerate this buildup.

Question: What are some of the risk factors?

Dr. Johnson: There are factors you can control and those you can't. You can't control your genes. Your genetic makeup, inherited from your parents and grandparents, can predispose you to heart disease. Many patients do everything right but still have heart attacks due to family history. Other risk factors include high cholesterol levels, high blood pressure (hypertension), and lifestyle factors such as diet and exercise.

Question: Does a family history of plaque buildup increase the likelihood of family members experiencing it themselves?

Dr. Johnson: Yes, some individuals have a more favorable plaque metabolism, while others do not. Those with less favorable metabolism may have higher levels of high-risk plaque, known as low-density lipoprotein (LDL), circulating in their bloodstream. Additionally, newer cholesterol particles like lipoprotein A and apolipoprotein B have been found. A high burden of these particles increases the likelihood of rapid plaque progression at a younger age.

Question: Can plaque buildup be reversed, or is it a one-way process once it starts?

Dr. Johnson: Early identification of risk factors and intervention is key. Lifestyle changes, such as regular exercise and dietary adjustments, are crucial. The Mediterranean diet, which emphasizes olive oil, fish and tree nuts over processed snacks, has been supported by research trials for positive cardiovascular outcomes. Medications may also be recommended for those with high LDL cholesterol and a strong family history. These medications can improve cholesterol profiles and reduce plaque buildup. Other risk factors, like high blood pressure, can be managed with anti-hypertensive medications.

Question: Is it common for people to have blockage without being aware of it?

Dr. Johnson: Yes, the most common way we discover plaque in heart arteries is through tests conducted for other purposes. We then assess whether the plaque is obstructing blood flow because having plaque in your arteries doesn’t necessarily mean it’s causing a blockage.

Question: If someone notices their body isn't responding like it normally would, suggesting a possible blockage, could this result in a heart attack?

Dr. Johnson: Heart attacks occur when plaque buildup in blood vessel walls cause a tear in the inner lining, exposing cholesterol to the bloodstream. This leads to blood clot formation and vessel closure. Heart attacks can happen even with minimal narrowing of the vessel, and symptoms may not always follow. Symptoms like chest pain typically occur with greater narrowing and plaque rupture, leading to a heart attack.

Question: If someone experiences a heart attack, are there specific signs of pain in certain parts of the body?

Dr. Johnson: Not everyone experiences the classic symptoms like chest pain shooting up to their neck, jaw and down their left arm. Heart attack symptoms can vary. Women are more likely than men to present atypical symptoms, such as nausea, indigestion, sudden pain in the right shoulder or elbow. Other possible symptoms include abdominal discomfort, back pain and sometimes tooth pain. Patients often mistakenly associate heart attack pain with the location of the heart in the chest. However, heart attack pain is referred to as pain, meaning it can be felt in other areas like the shoulder, arm or neck due to how the heart is innervated by the nervous system.

Question: Can consistent heartburn be correlated with a potential blockage?

Dr. Johnson: Patients often experience a burning sensation and blame their gastric reflux, potentially delaying their heart attack presentation. If patients are taking their typical gastric medications and their symptoms aren't improving, it's time to get checked out.

Question: How would you describe the difference between plumbing and electrical when it comes to heart health?

Dr. Johnson: I describe the heart to my patients like a house. Both plumbing and electrical systems have unique functions. Plumbing refers to the arteries bringing blood flow to the heart muscle, while the electrical system controls the heart's rhythm. Nerves carry electrical signals that tell the heart when to squeeze. When working correctly, you get a coordinated contraction between the top and bottom chambers, allowing blood to circulate around the body.

Question: When you experience issues with blockage or heart attacks, is that related to the plumbing or the electrical part of the heart?

Dr. Johnson: When you have a heart attack, blood flow to the heart muscle is limited. The heart gets "angry" because it's not getting enough blood flow, so it becomes electrically upset. This can cause the heart to go out of rhythm, leading to life-threatening arrhythmia like ventricular tachycardia or ventricular fibrillation. These are the rhythms you see on TV shows when people come running in with paddles to shock the heart. These rhythms are common in people experiencing a heart attack.

Question: At what point would it be determined that someone may need a pacemaker?

Dr. Johnson: A pacemaker constantly monitors the heart. If your heart rate drops below a preset rate, the pacemaker kicks in and starts pacing your heart. Sometimes, when people have a heart attack, blood flow can be cut off to an important electrical spot in the heart called the AV node. This can cause heart block, where signals from the top chamber can't reach the bottom chamber, leading to a very slow heart rate. These patients may need a temporary or permanent pacemaker.

Question: When someone has a pacemaker, do they know when it is being used?

Dr. Johnson: There are two different devices. A pacemaker itself cannot shock the heart. For that, we use a defibrillator, which can shock the heart out of life-threatening arrhythmias. Defibrillators can also pace the heart like pacemakers.

Question: Is it possible for someone to have both a pacemaker and a defibrillator?

Dr. Johnson: Yes, when people come in with a heart attack and have heart block, a temporary pacemaker usually resolves the issue. If not, they may need a permanent pacemaker. For those with life-threatening arrhythmias like ventricular tachycardia or ventricular fibrillation, they may need a defibrillator to constantly monitor their heart.

Question: If someone has a heart attack, are they more vulnerable to having a stroke?

Dr. Johnson: Yes, a heart attack can reduce heart function. Normally, the heart should squeeze out 55% to 75% of its contents, known as the ejection fraction. After a heart attack, the ejection fraction can drop, and the heart may not squeeze out as much blood. This can lead to blood clots forming in the heart, which can break off and cause a stroke. Heart attack patients can also develop atrial fibrillation (AFib), an abnormal heart rhythm that can cause blood clots to form and lead to a stroke. AFib is a common cause of stroke.

Question: If someone is in AFib, what can they do to get out of it?

Dr. Johnson: As a cardiologist, if patients come in with their first diagnosis of AFib, we decide whether to keep them in AFib and control their heart rate or try to get them out of it, known as a rhythm control strategy. Studies show no difference between these strategies, but I usually offer patients at least one chance to get out of AFib. We often perform a cardioversion, where we place patches on their chest and back, sedate them, and administer an electrical shock to reset the heart's rhythm.

Question: To prevent AFib, heart attacks and strokes, should you consider making lifestyle changes?

Dr. Johnson: Absolutely. The best time to start preventative measures is now. Staying active, modifying your diet, and treating risk factors like high cholesterol or high blood pressure are crucial.

Question: How often do you follow up with your patients?

Dr. Johnson: For patients with low heart function and congestive heart failure, we see them every two to three months. Stable patients are typically seen annually, but follow-up can be extended to every other year or as needed.

Question: If people want to find out more or are concerned about their heart health, what do you suggest they do?

Dr. Johnson: For those with risk factors or family history but no symptoms, I recommend a non-invasive screening test called a calcium score, also known as a heart scan or CAT scan of the heart. We offer this test at CentraCare, and it provides valuable prognostic information. A calcium score of zero indicates an excellent prognosis for up to 10 years. Higher scores help us determine appropriate treatment plans, which may include stress testing or other heart testing.