A Fib

[mwhaples]

My father recently went through a valve replacement in his heart about 1 week ago. He was sent home and 4 days later here we are back in the hospital for a buildup of fluid around the heart. So far they have drained more than a liter of fluid off his heart. The question is why is is heart rate going from the range of about 150- back down to 60-70?
What causes this?

[Smitty150]

That is a question for his cardiologist

[Jack54]

This is a possible explanation as to why your husbands heart rate is fluctuating, but remember that I am a patient with heart disease and not a doctor.

The pericardium is a "sac within a sac". The inner sac holds the heart. The outer sac, or outer pericardium, is fibrous and does not expand well. There is a certain amount of fluid maintained between these two sacs, or in the pericardial space, that prevents friction.

Once enough fluid has entered this pericardial space, the outer pericardial does not expand well, and if enough fluid accumulates,  then with each successive diastolic phase (when the heart rests), less and less blood enters the ventricles, as the increasing pressure presses on the heart and forces the septum to bend into the left ventricle. This leads to decreased stroke volume and cardiac output.

This would cause your husband's blood pressure to decrease. In an autonomic system response, the heart rate would increase attempting to compensate for the low BP and output. If fluid is drained from the pericardium, the heart function is restored to normal (no interference from the pericardial fluid) whereby the stroke volume, cardiac output and BP would increase. The autonomic system that regulates our heart rate, once again responds to the increasing BP and will decrease the heart rate.

You should be able to correlate a drop in BP with an increase in heart rate and accumulated pericardial fluid.

Hope this helps a bit. One cause of pericardial effusion is damage to the lymphatic drainage system around the pericardium and lungs during surgery.

Jack