Clear as mud? The Complexities of the Cardiac System!

Is everyone clear on the cardiac system??  If not, read on!  My intent is to simplify the cardiac system and the impairments that are commonly seen in Life Settlements.  In an effort to simplify the anatomy and function, I am going to compare the heart to a car!  Think of the heart muscle or myocardium (myo=muscle) as the car.  The coronary arteries feed the muscle and are like the fuel lines, if they become clogged, the car will not operate properly.  This is called coronary artery disease (CAD), and if severe, may cause a heart attack.  Procedures to open the lines include the very invasive coronary artery bypass (CABG) or if the lines are not clogged too badly, a percutaneous angioplasty (PCI or PTCA) with or without stents.  The car can also get dents, dings, fender benders or more serious damage, and possibly still drive.  The cardiac muscle injury is called cardiomyopathy and can occur from toxic medications, chronic uncontrolled HTN, chronic uncontrolled atrial fib, valve problems, sarcoidosis, or amyloidosis (and others), and still function, but not as well.  The ejection fraction (EF) measures function or loss of function in the heart.  Medications can improve the function just like body work on a car…to a point.  If the frame is bent, the car will limp along and if the myocardium is seriously diseased, the individual will be significantly impaired.  

Inside the car are four “seats”, R and L atria and ventricles (the drivers side is the on the right).  The seats pass the blood from R front to back, then to the lungs, like the drive thru for carryout (oxygen) and from L front to back (then to the rest of the body with the oxygenated blood).  The seats are separated by valves and gaskets.  Just like in a car, if there is trouble with a valve, such as leaking, the function of the car will not be optimal.  Shortness of breath (SOB) is a common symptom of severe valve leak.  Procedures to repair the valves include a full replacement which requires pulling the “engine” or a trans-catheter repair or replacement.  These procedures are highly effective at eradicating the valve leaks.  Instead of the blood flowing through the seats, the front and back seats can also develop blood clots (not good).  If a clot develops in the drivers’ side, as often happens in the case of atrial fibrillation, the clot may break off and lodge in the one or both lungs as a pulmonary emboli (PE).  Passenger side clots can disengage and reach the legs causing deep vein thrombosis (PE, DVT) or the brain causing a stroke (CVA).  This is why atrial fib is treated with a blood thinner, an anticoagulant, to prevent the clots from forming.   

​There are times when cars simply wear out, like heart failure.  The heart is not able to pump strongly enough to move the blood to the lungs for oxygen or to the rest of the body.  If the failure occurs on the driver’s side (diastolic), there will not be enough blood going to the lungs; fluid will build up in the lungs and cause shortness of breath.  If the failure is on the passenger side, called systolic heart failure or congestive heart failure (CHF), fluids can build up in the legs (edema).  When the car is not damaged too badly, it may be drivable.  Same with the heart, medications can be used to enhance the heart pump and promote diuresis (urination), thereby decreasing symptoms and restoring function.   

In other words, many cardiac problems are very treatable, including a transplant when necessary.  The takeaway: treatment effectiveness and transplant candidacy hinge on age, response to treatment and comorbidity.