Heart failure is a condition where the muscle of the heart is weakened and pumps inefficiently. There are many causes of this condition, and it is important to treat both the condition itself and, if possible, the underlying cause.
The valves of the heart are important to ensure that the blood flows around the heart and then around the body in the correct direction. Again, there are many causes of valve problems, although the most common cause currently is simply an ageing heart. Remember that these valves have to work 60 or so times a minute, for every minute/hour/day of your life!
The most important investigation for both heart failure and valvular problems is an echocardiogram. This is a non-invasive ultrasound scan of the heart, which lets the cardiologist assess the structure and function of the heart muscle and the valves.