Cardiology 101

This post may not interest everyone. But before you click away, here is a quick update. I met with my electrophysiologist last week. The ICD nurses told me last May that I had 7 months left on my ICD battery. This is why they scheduled me to meet with the doctor five months later. Apparently my device now says I have six months left! They aren’t sure why the timeline is weird but this is very good news! I really didn’t want to have an ICD surgery this fall. I have a little hope that maybe I could be transplanted before my device needs to be changed and I can forgo the entire surgery. Fingers crossed! Ok…Please read on if you are interested in learning some cardiology terms and treatments.

I throw out cardiology terms in my blog posts which assumes you have the same 26 year history I have with cardiologists. I am no doctor so my understanding is simplistic but I am sharing this information with hopes it will help you understand my cardiac issues. And maybe give you a basis of knowledge if you or someone you love encounters cardiac issues in the future.

What is the difference between a heart attack, cardiac arrest, and heart failure?

A heart attack happens when there is a blockage of blood flow to the heart. The blockage can cause damage to the heart muscle. A heart attack can disrupt the electrical signals and cause cardiac arrest. It can also cause heart failure if the blockage causes permanent damage to the heart muscle. This condition is a sudden event.

Cardiac arrest is the sudden and unexpected loss of heart function usually due to an electrical disturbance. Usually the heart starts beating very fast (ventricular tachycardia or VT) when the electrical signals are disturbed and eventually beats so fast it is quivering and stops moving blood (ventricular fibrillation or VF). This is also a sudden event.

Heart failure is a chronic condition where the heart’s ability to pump is compromised and the low function affects the rest of the body. This is not a sudden event. It is a long term condition that can be caused by different factors.

I have never had a heart attack. Cardiac arrest is a big concern with my specific genetic disease. I think my fainting episodes when I was younger were the beginnings of cardiac arrest but my heart converted back to a normal rhythm on its own. Heart failure has been my biggest challenge with ARVC because the disease turns healthy tissue into scar tissue. I have so much scar tissue that my heart can’t beat normally and move enough blood. I am very lucky all the scar tissue has not caused more electrical disturbances and cardiac arrest.

So in summary, a heart attack is a blockage, cardiac arrest is the heart stopping and heart failure is the inability of the heart to pump effectively.

What are treatments for these three conditions?

Since I don’t have any experience with heart attacks, my understanding of treatments for heart attacks is limited. I believe minor blockages can be opened with stents and major blockages require open-heart bypass surgery.

Treatment for cardiac arrest includes medications – often beta blockers or other anti-arrhythmic drugs. These drugs help stabilize your electrical rhythms and prevent VT and VF. Implantable Cardioverter Defibrillators (ICDs) are also good treatments for people at high risk of sudden cardiac arrest. ICDs are different from pacemakers. ICDs have pacing functions but also can provide very powerful shocks to restart your heart in case of VT or VF. Pacemakers deliver small pulses of electricity so the heart beats in at steady, specific rate.

Treatment for heart failure includes managing the symptoms and controlling the cause if they can. So for me, this meant stopping exercise since any stress on the heart causes the muscle to break down faster into scar tissue. I also take medications to keep my heart more relaxed which is shown to prolong the life of the heart. Doctors also often prescribe diuretics since fluid issues occur when your heart isn’t pumping enough and the fluid can leach into your tissues. I can gain 5-10 pounds of fluid in one day if I exert myself too much and don’t have my feet up enough. I also have a CardioMems implant to help control my fluid levels.

What tests do they typically perform when you have heart failure?

I have regular echocardiograms which are ultrasound pictures of your heart and its ability to pump. With heart failure, they report the amount of blood the left ventricle is able to pump expressed as a fraction called the ejection fraction. Echos rarely reflect how my heart failure is progressing. I don’t know why, perhaps because my genetic disease affects my heart differently.

The two tests they look at very carefully at this point are the cardiopulmonary stress test and the right heart cath. The cardiopulmonary stress test measures my lung function in relation to my heart function. So they put me on a treadmill with a mouthpiece which measures my lung function during activity. Typically you get a result expressed in a number. Healthy, active people will score 30-50 with the higher numbers being better. My numbers have decreased over time and I last scored an 11. So clearly my heart is struggling to provide blood to my lungs. Usually when you score 13 or below, they know it’s time to begin planning for transplant. Doctors do not want my heart affecting my lungs so much that my lung tissue is damaged and then I also need a lung transplant.

The right heart cath is an invasive test that measures blood pressure and oxygen levels on the right side of your heart. They thread a catheter into your heart through a small incision in your neck. They numb your neck and the patient is awake for the entire procedure. I could go into lots of boring details about what they typically see in heart failure patients and how I seem to be very different in my right heart cath results. Most heart failure patients have dysfunction on the left side of the heart. I have dysfunction in both my ventricles so test results don’t always look as expected. But I won’t bore you with the details. The one right heart cath measurement that seems to reflect my heart failure advancing is the cardiac index – which is a measurement of how much blood my heart is able to move every minute. I suspect this will be the measurement they use to get me admitted to the hospital and listed for transplant.

BNP blood test also reflects how my heart is doing. When your heart struggles, it releases an enzyme called BNP. The more it struggles, the more enzyme is found in your blood. Any measurement over 100 is a positive indication for heart failure. In 2009 I felt pretty sick and my BNP levels were 1200-1400. Doctors were able to stabilize me and my levels fell to 600-800. Now I’m back at 1400 and not feeling so well again. These numbers aren’t scientific but useful to know if my symptoms are heart related or to look elsewhere for answers.

Why did they tell you that you needed a transplant 18 months ago? Were they wrong?

Transplant is a very long game. The wait can be long. So having time on your side is good. The doctors need to transplant you when you are well enough to survive the traumatic surgery, but sick enough to be listed high on the list to get a heart. Patients that get too sick become ineligible for transplant because they are unlikely to survive the surgery. If my antibodies had not been so high, they would have listed me as a status 4 and I would probably have gotten matched with a heart sometime in the last 18 months while waiting at home. My antibodies didn’t allow for that and I need to be at the very top of the list to be matched.

If you have made it to the end of this post, congrats! Thanks for reading. Please feel free to ask me anything about my cardiac journey. I don’t mind sharing any of the details that are always swimming around my head.