The air that we breathe and the food that we eat reach their confluency in the mitochondria to derive the energy that the cell is dependent upon. The heart is the most aerobic of organs and has little anaerobic reserve compared to the constant demands placed upon it. At rest the arterial-venous oxygen extraction from the blood is the greatest from the heart and this only goes up with exercise. Common to all cell types residing in the heart is the need for energy and mitochondrial dysfunction is a significant contributor to cell death across the spectrum of cardiac disorders. Mitochondrial failure within any one cell type creates varying complications that eventually manifest as heart failure.