Dr. Roach: Decoding the results of an electrocardiogram
Dear Dr. Roach: I recently had an EKG that showed first-degree heart block and “inferior infarct, age undetermined.” What does that mean? What should I do to make sure it doesn’t get worse? I will be seeing a cardiologist in a few months to get an exercise stress echo. What is that?
Dear C.P.: The EKG uses the electrical activity in the heart to get important information about the structure and function of the heart. Although it is a very useful test, it isn’t perfect.
“First-degree heart block” just means that the electrical impulse in the heart is a little slow. By itself, it is not concerning, but it does suggest that there is a risk of other heart problems, such as second- or third-degree heart block. These sometimes do need treatment (a pacemaker). It’s something to keep an eye on, but it’s possible to have first-degree heart block for decades without progression.
An “infarct” is a heart attack. The EKG has characteristic findings of heart attack, which can be localized to a particular part of the heart. In your case, that is the bottom part of the heart, which is supplied by the right coronary artery. This type of heart attack is often complicated by first-degree heart block, which may explain why you have that.
A stress test looks for damage to the heart, and especially looks to see if part of the heart is at risk for another heart attack. With a stress echocardiogram, the heart is “stressed” by exercise or by medication to speed it up, and the movement of the heart is carefully examined by sound waves. This test can help determine whether you really did have a heart attack and whether you need treatment to help prevent another one.
Many people who have had a heart attack never knew it. Either they had no symptoms or they thought it was something else, such as stomach upset. Heart attacks in the inferior part of the heart often feel like stomach problems.
But if you have had a heart attack, then certain medicines, such as aspirin, beta blockers and a statin drug are very helpful in preventing another. If the stress echo is worrisome, the cardiologist may recommend an angiogram, which is the best test we have to identify parts of the heart at risk for heart attack. It also allows the doctors sometimes to open up blockages in the arteries.
Dear Dr. Roach: My cardiologist just started me on rosuvastatin (Crestor). What’s the best time of day to take this medicine?
Dear J.M.: The majority of cholesterol synthesis in the body happens at nighttime, so for statin drugs that don’t last very long in the body, it’s better to take them at night. This is particularly true with fluvastatin (Lescol), lovastatin (Mevacor) and simvastatin (Zocor). The other statin drugs last so long in the body, it doesn’t really matter what time of the day you take them, although it’s best to take them the same time every day.
Many people take high blood pressure medicines along with a statin, and the data suggests improved outcomes when taking blood pressure medicines at night, so it is better for many people to take all of their medicines at the same time for convenience.
Readers may email questions to ToYourGoodHealth@med.cornell.edu.