The heart is divided into four chambers; two are on the left and two are on the right. The blood pumped by the heart is oxygenated by the lungs and then carried through the arteries to the rest of the body. After the oxygen has been used, the blood returns to the heart through the veins and is pumped through the lungs again. The word murmur describes a swishing sound made as the blood flows through the heart's chambers, valves, In my case one of the chambers is blocked