Congestive heart failure is a change in the hearts ability to cope with the amount of load its put under so it cannot fully cope with the circulating volume of blood. Generally caused by hypertrophy (thickening) of the walls of the ventricles. It can also be caused by heart attack, Ischaemic heart disease, Hypertrophic cardio myopathy (HCM) and long term hypertension. The thickening walls of the ventricles causes a reduced stroke volume and a reduced cardiac output. This can result in fluid pooling - oedema, shortness of breath and a reduced exercise tolerance.
Fortekor is an ACE inhibitor which has an effect on the kidneys causing the production of angiotensin 2 which causes vaso dilation (opening) of the blood vessels. this reduces vascular resistance and lowers blood pressure helping the heart in maintaining a good circulation.
In human patients, they generally have to stick to a fluid restriction so not to overload the circulating volume and are weighed regularly to determine how much fluid is being retained or lost. Diuretics are used to increase urine output so reducing the circulating volume and reducing the load on the heart.
Hope this helps.