On Tuesday evening, March 16, the Navigating the Medical System Lecture Series featured an informative virtual lecture with David J. Slotwiner, MD, FACS, FHRS, Chief of Cardiology at NewYork-Presbyterian Queens, hosted by Congregation Etz Chaim of Kew Gardens Hills.
Dr. Mel Breite, Director and Founder of the Navigating the Medical System Lecture Series, introduced Dr. Slotwiner. Dr. Breite emphasized that “this is one of the most important talks that we’re having.” He explained that most people don’t know why they’re getting tests that they think they don’t need.
Dr. Slotwiner shared that we’ll all undergo one of these types of tests and it’s important to ask your doctor why he is ordering a particular test. It’s important to have a broad understanding of the various cardiac tests.
He began the lecture by displaying an illustration of the physiology of the heart. He explained that coronary arteries sit outside the heart muscle and they supply oxygen and nutrients to the heart. If one of them is blocked, this results in a heart attack. Heart valves are critical structures in the heart that make sure the blood flows forward. They can fail or leak or not open properly. It’s critical that the heart muscle itself is pumping well; the heart muscle’s strength is tested to see if anything is abnormal. Dr. Slotwiner taught about the electrical conduction system, which causes muscles to contract. “The heart has an exquisitely designed electrical system that makes sure it is pumping properly.
Next, he shared a list of tests starting with the least invasive test, the treadmill stress test, which is given to those who experience chest pain or shortness of breath when they exert themselves. The doctor tests to see if the arteries are blocked, and he evaluates how well the blood is flowing to the coronary arteries. He added that there is no perfect test. During this test, you have an EKG on your chest and you exercise at progressively higher speed and incline. The doctor looks to see if the blood flow is insufficient. There is concern if there is a narrowing or a blockage. This is a very good screening test for someone who has no previous history of heart problems.
Another test is the echo stress test, which supplies more information in terms of which artery may have narrowing or blockage. It’s an ultrasound of the heart. It takes pictures of the heart muscle while the patient exercises. The doctor can see which part of the heart doesn’t squeeze as well because it’s not getting enough blood.
Another test is the nuclear stress test, where the patient lies under a scanner. He has a radioactive injection that tags the red blood cells. This way, the doctor can see if all of the heart muscle is getting appropriate blood or which part is not getting sufficient blood flow.
Then there is a cardiac angiogram, where dye is injected into the arteries. This is an invasive study and the patient receives some anesthesia to relax him. An IV catheter is placed in the arm or groin and there is an x-ray so the doctor can see an image of the arteries.
He noted that a heart beats once in a second. A cardiac CT scan now offers fine resolution. This is a useful tool to see the cardiac arteries. It can sometimes be used instead of the stress tests or angiogram.
If the doctor perceives a heart murmur, this means the blood flow through the valves is turbulent. It may be restricted, which means the valves don’t open or they don’t close properly, causing a leak. The echocardiogram or the ultrasound tests the valves. A transesophageal echocardiogram (TEE) is done through the esophagus and allows different views. This is done with anesthesia.
Cardiac catherization measures the blood in the chambers and across the heart valves. An echocardiogram is often done in the doctor’s office and it tells about the blood flow across the valves. MRI technology is improving and helps doctors to evaluate how well the heart muscle is squeezing. A cardiac MRI scan is only done when looking for a specific abnormality.
He then taught that the electrical system generates the heart rhythm. He explained about the different ECG electrocardiogram tests. There is the ECG 24-hour heart monitor, the seven-day or 30-day heart monitor, and the implantable three-to-five-year monitor. He spoke about the Apple Watch and the KardiaMobile device by AliveCor.
He shared about the 24-hour Holter monitor, named after Norman Holter, the biophysicist who invented it; the monitor has been a critical tool in diagnosing heart rhythm disorders that occur intermittently. The implantable monitor can be used for up to five years, and data is sent to the doctor who monitors them remotely. This is good for people with rare fainting incidents. It’s also an important tool for people with active strokes. One of the most common causes of stroke is abnormal heart rhythm, which could be treated to prevent stroke.
He advised everyone to take his or her blood pressure at home. Do it one time a day when you are relaxed, and sit in one position for five minutes. Home data is more valuable than data in a doctor’s office, because people are more nervous there. You can record the speed of your heart with the Apple Watch ECG. This reveals the trend of your heart rate during the day. The KardiaMobile by AliveCor records ECG. These 30-segment EKGs are valuable. They can be sent to the doctor when you feel a palpitation, and he can evaluate it in real time and decide if you need to go to the hospital.
Dr. Slotwiner imparted, “It helps when patients engage in their care. That helps us give the highest quality care.” He advised that when your doctor orders a test, make sure you understand why he is recommending it for you. It’s a good idea to bring a second person with you when you visit your doctor.
He shared specific questions we should ask when faced with a cardiac test: 1. How might this result change my treatment. 2. What is the risk if I don’t have the test? 3. Are there alternative tests I should consider? He taught that every test has risks and benefits. You need to know them so you can weigh them. “An engaged, knowledgeable patient is one we appreciate.”
By Susie Garber