What would influence the number of beats per minute

So many things can influence the number of beats per minutes. among them are the adrenalin level, the blood pressure itself, the water level in the blood and the 'viscosity' of the blood. Exercise in general can increase the beat per minute. reduce in blood pressure will result in increase beat per minute to compensate the reduction in blood pressure.
in general, the beat per minute will increase if there are an increase demand of oxygen to vital organ such as brain, heart itself and the kidney.