Coronary Artery Disease (CAD) is the gradual narrowing and hardening of the arteries. Think of it as a complex, slow-motion clogging of your heart's most critical pipes. It's the most common type of heart disease and a leading cause of heart attacks.

Let's start with the most important thing to understand: Heart failure does not mean the heart has stopped or is about to stop. It means the heart has become a weaker, less efficient pump. It's failing to keep up with its workload.

To understand heart rhythm problems, you first need to understand what makes a healthy heart beat in the first place. It's not just a random muscle squeeze. Your heart has its own sophisticated, built-in electrical system.

In summary, heart valve disease is a mechanical problem with the "doors" of the heart. They either become too narrow (stenosis) or too leaky (regurgitation). This forces the heart to work much harder, leading to symptoms like shortness of breath and fatigue.