The Inflamed Heart: Endocarditis, Pericarditis, Valvular Disease, and Cardiomyopathy

Heather Murphy

Welcome to the show, future nurses! I'm Professor Heather Murphy. And I want you to picture a patient walking into your ED. They've got a fever of 102, chills, and little red dots -- PETECHIAE -- all over their chest. But the kicker? When you put your stethoscope to their chest, you hear this entirely new, harsh, whooshing sound. A brand new systolic murmur.

Heather Murphy

That right there is the sound of endocarditis. And today, we are diving deep into the structural and inflammatory disorders of the cardiovascular system. We're talking endocarditis, pericarditis, valvular diseases, and cardiomyopathies. This is the stuff that separates a GOOD nurse from a GREAT one -- and definitely the stuff the NCLEX loves to test.

Heather Murphy

So let's start with that inflamed heart. You have to know your layers. Endocarditis is the inner layer. The endocardium. This is where the valves live. Bacteria -- most commonly Staphylococcus aureus, about 50 percent of the time -- gets into the bloodstream. Maybe from IV drug use, maybe a central line, maybe a dental procedure. It travels to the heart and sets up camp directly on the valves, forming these little clumps of bacteria, fibrin, and platelets called... VEGETATIONS.

Heather Murphy

Those vegetations eat away at the valve, which is why you hear that new murmur. But they can also break off. If a piece breaks off the left side of the heart, it shoots out to the body. BOOM -- stroke, kidney damage, spleen infarction. If it breaks off the right side? It goes straight to the lungs. Pulmonary embolism.

Heather Murphy

Because this infection is LITERALLY inside the heart, a quick Z-Pak is not going to cut it. We are talking four to six weeks of long-term IV antibiotics. We need repeat blood cultures to prove we are actually clearing the infection. And if the valve gets too destroyed? They're heading to the OR for a valve replacement.

Heather Murphy

Now, let's zoom out to the outside of the heart. The pericardium. This is the sac holding the heart. When that gets inflamed, we call it pericarditis. Imagine rubbing two pieces of sandpaper together. That's what the inflamed layers of the pericardial sac sound like. We call it a PERICARDIAL FRICTION RUB. And it hurts. The patient will tell you the pain gets worse when they take a deep breath or lay flat, and it feels better when they sit up and lean forward.

Heather Murphy

How do we treat pericarditis? Our target is the inflammation. We hit them with high-dose NSAIDs -- Advil, Aspirin, Indocin. We also commonly use Colcrys, which is colchicine, an anti-inflammatory that works wonders here. If they absolutely cannot tolerate NSAIDs, maybe due to GI bleeds, then we pivot to glucocorticoids like Deltasone.

Heather Murphy

But here is the trap. Pericarditis can cause fluid to build up inside that sac. That's a pericardial effusion. If too much fluid builds up too fast, it squeezes the heart. The heart can't expand, it can't fill, and if it can't fill... it can't pump. Cardiac output drops to zero. This is CARDIAC TAMPONADE, and it is a massive medical emergency.

Heather Murphy

When that happens, the doctor has to grab a needle and do a pericardiocentesis -- literally stabbing through the chest wall into the sac to drain the fluid and instantly relieve the pressure. If this is a chronic issue, maybe from cancer, the surgeon might cut a literal "pericardial window" -- snipping a piece of the sac out so the fluid just drains continuously into the chest cavity where the body absorbs it. Incredible, right?

Heather Murphy

So we mentioned valves taking a hit during endocarditis, but let's talk about valvular dysfunction as its own beast. You really just need to understand two words: STENOSIS and REGURGITATION.

Heather Murphy

Stenosis means STIFF. The valve door won't open all the way. It's calcified, it's narrowed. So the heart has to squeeze extra hard to push blood through a tiny little slit. Take Aortic Stenosis. The left ventricle is trying to push blood out to the entire body through a stiff aortic valve. The classic symptom triad here is SYNCOPE, ANGINA, and EXERTIONAL DYSPNEA. Fainting, chest pain, and shortness of breath. The murmur you'll hear is a harsh, systolic crescendo-decrescendo.

Heather Murphy

Regurgitation, on the other hand, means FLOPPY. The door won't stay closed. You push the blood out, and half of it falls right back in. Aortic Regurgitation gives you a blowing, diastolic murmur because the blood is leaking backward during the heart's resting phase.

Heather Murphy

Either way, stenosis or regurgitation, what happens to the blood? It backs up. If the mitral or aortic valves on the left side of the heart fail, blood backs up into the lungs. Your patient gets orthopnea -- they can't breathe when lying flat -- and you'll hear crackles in their lung bases. Left-sided valve issues cause LEFT-SIDED heart failure.

Heather Murphy

We treat the symptoms with diuretics and beta-blockers, but eventually, we have to fix the plumbing. Sometimes we do a balloon valvuloplasty, where we literally inflate a balloon inside a stenotic valve to crack it open. Or, we do a TAVR -- Transcatheter Aortic Valve Replacement. Instead of cracking the chest open, we snake a new valve up through the femoral artery and deploy it right inside the old, crusty aortic valve. It's basically a stent with cow or pig tissue sewn into it. Incredible stuff.

Heather Murphy

Now, what if the valves are fine, the sac is fine, but the muscle itself is BROKEN? That's cardiomyopathy. And there are three main types I want you to know: Dilated, Hypertrophic, and Restrictive.

Heather Murphy

Dilated cardiomyopathy is exactly what it sounds like. The ventricles expand and stretch out. Think of an old, overused rubber band. It's big, it's floppy, and it has absolutely no SNAP left. It can't squeeze. Blood just pools in there.

Heather Murphy

Hypertrophic cardiomyopathy, or HCM, is the opposite. The muscle wall, especially the septum, gets incredibly thick. So thick that it actually blocks the blood from getting out of the heart. This is often genetic. It's the classic tragic story of the healthy high school athlete who suddenly collapses on the basketball court from sudden cardiac arrest.

Heather Murphy

Here is your massive nursing safety alert for Hypertrophic Cardiomyopathy: DO NOT give these patients nitrates. Nitrates vasodilate and decrease the amount of blood returning to the heart. In HCM, that thick muscle is already blocking the exit. The only way blood gets out is if the ventricle is completely FULL of fluid to prop that exit open. If you give nitroglycerin, or if they get dehydrated, the ventricle empties, the thick walls slam shut against each other, and cardiac output drops to zero.

Heather Murphy

Living with cardiomyopathy is tough. These patients face exertional dyspnea, extreme fatigue, and severe peripheral edema. We have to teach them to pace their daily activities. Break up the chores. Plan for rest periods. It's a huge psychosocial adjustment, realizing you can't just run up the stairs anymore without feeling like you're going to pass out.

Heather Murphy

Alright, let's bring it all home for the NCLEX. How are they going to test you on this? They are going to test your ability to recognize a dying patient AND your ability to keep a stable patient safe at home.

Heather Murphy

First, prioritization. I mentioned cardiac tamponade earlier. Three key assessment findings that may indicate cardiac tamponade: muffled heart sounds, jugular venous distention, and hypotension. If you see those three things together, your patient's heart is being crushed by fluid. You might also see pulsus paradoxus -- where their blood pressure literally drops when they take a deep breath. That is a medical emergency. Call the provider immediately, get the crash cart, and prep for a pericardiocentesis.

Heather Murphy

Second, discharge teaching. If your patient had endocarditis, or if they have a prosthetic heart valve, they need prophylactic antibiotics for the REST OF THEIR LIFE before any dental procedures. The mouth is full of bacteria. A simple teeth cleaning can send strep bacteria straight to that shiny new valve. We give them a dose of amoxicillin an hour before the dentist to protect the heart.

Heather Murphy

Also, if they got a mechanical valve replacement -- the metal ones that click when they beat -- they are going to be on lifelong warfarin. Metal causes blood to clot. They have to understand INR monitoring, bleeding precautions, and maintaining a CONSISTENT intake of Vitamin K.

Heather Murphy

Guys, the heart is just a pump. It has a power cord, which is the electrical system. It has doors, which are the valves. And it has the muscle. When you're studying, ask yourself: which part of the pump is broken, and what does that mean for the fluid? If you can visualize the anatomy, the symptoms and the nursing interventions will make perfect sense. You're going to do great. I'm Professor Heather Murphy, and I'll catch you next time.