Cardiovascular changes in Pregnancy.

How much does heart rate increase in pregnancy?

15-25%

How much does CO increase in Pregnancy?

50%

What structural changes occur with the heart in pregnancy?

Upward and leftward deviation of the apex from the diaphragm. Left ventricular hypertrophy and dilation occur.

From what gestation is aorto-caval compression apparent?

20 weeks

How much does PVR decrease in Pregnancy and what causes it?

20% decrease in MAP due to progesterone mediated vasodilation

How much does SV increase in pregnancy?

35%

What are the consequences of A-C compression?

Decreased venous return to the heart = decreased cardiac output. "Aorto-caval Syndrome" is the presence of signs and symptoms of decreased cardiac output, similar to those seen in shock; tachycardia, presyncope, agitation all occur in women lying supine with clinically significant compression. A-C Syndrome has been documented to cause maternal and fetal death.

What physiological compensation occurs in response to AC compression?

Dilation and increased flow through the azygous, epidural and para-vertebral venous drainage.

What relevance does AC-compression have to the anaesthetist?

In neuraxial anaesthesia, blunting of the normal sympathetic response to AC compression can lead to rapid onset of symptoms usually first manifest as hypotension with nausea and vomiting. In general anaesthesia the patient should be positioned with a wedge tilting the body to the left side to prevent compression of the IVC.

What ECG changes can be seen in pregnancy?

LAD LVH Non-specific TW changes in V3