Abdominal ultrasonography showed ascites with no collapse of the caudal vena cava with respiration (fig 8). (balkanvets.com)
This is because the aorta and vena cava of your heart are on the right side, so if you sleep on your left side the blood can easily circulate through your body. (mypregnancyguide.com)
Other problems that can result from heartworms include hypertension, blood clots, liver damage, kidney damage, aneurysms, pulmonary eosinophilic granulomatosis, acute vena cava syndrome, thromboembolism and death. (petpremium.com)