Cigarette do not directly affect the heart but rather it targets the respiratory system, when one smokes, chemicals like nicotine are consumed by the lungs which the heart pumps blood to the lungs, making the chemicals from smoking being carried by blood cells, the blood does not only go through the heart but to the other parts as well. But the lungs suffer pollution from the smoke and cause it to malfunction. So if the lungs does that, the heart and other body organs will malfunction as well.