Why there is a heart rate range for nitro? what will happen if HR is below 60bpm and above 159bpm?
The concern with nitroglycerine is that it has the potential to drop blood pressure. These heart rate ranges are put in for safety. If the heart rate is <60 or >159 you are even more at risk of causing uncompensated hypotension. With a heart rate <60 or >159 (brady or very tachy) the cardiovascular system is already stressed and further insult to the blood pressure is unlikely to be compensated for appropriately.