Currently, Midwest Internal Medicine PLLC specializes in Cardiovascular Disease, Hepatology, Internal Medicine and Gastroenterology with 7 physicians. Midwest Internal Medicine PLLC Office Locations. Midwest Internal Medicine Pllc. 1840 Mesquite Ave Ste B Lake Havasu City, AZ 86403 (928) 453-8500. Monday : 8:00 AM - 5:00 PM:.