Notes

When the left side of the heart doesn't function properly, there is a buildup of fluid and blood in your lungs. This leads to heart failure and specifically Congestive heart failure. Symptoms include being tired and short of breath.

One factor that controls blood pressure is the sympathetic and parasympathetic response. Sympathetic is flight or flight where the blood is pumped harder so more blood can carry oxygen to the body, cuasing more resistance and increasing blood pressure. The parasympathetic response is for when the body is at rest, causing heart rate and blood pressure to decrease. High sodium also increases blood pressure, as there is more fluid in the blood causing resistance.

ecg=diagnosis and treatment of heart disease
they measure the electrical activity of the heart, since it is also an electrical pump.
The ecg measures the p,QRS, and t waves. They measure atrial and ventricular depolarization and repolarization.
the heartbeat and rhythm are derived from this pattern. If someone does not have a normal sinus rhythm, they have heart problems such as a 2nd-heart block where there are more p waves than qrs waves.