How does anaesthesia put a strain or stress on the heart and cause stroke? also how likely is it to get and die of gas embolism during laparoscopy?

Physiology: The medicines used to induce anesthesia cause the heart to work harder and the peripheral blood vessels to dilate or constrict, either of which can affect the delivery of oxygen to everywhere, including the brain. This can cause a heart attack or a stroke in people who already have compromised blood flow to those areas. Gas emboli from laparoscopy are rare, but not unheard of and can be fatal.