2. 2 Heartworms and Heart Murmurs Partnership for Environmental Education and Rural Health Texas A&M University http://peer.tamu.edu An introduction to problems that can occur in the heart

3. 2 The Heart

4. 2 Basic Anatomy Arteries – Carry blood away from the heart Veins – Carry blood to the heart Capillaries – Site of gas exchange

5. 2 The Heart as a Pump The heart works as a pump, forcing blood forward into the arteries. Blood returns to the heart in veins. Veins have valves. Valves work to keep the blood from flowing backwards, even when the heart isn’t contracting.

6. 2 Blood Flow

7. 2 Heartworms

8. 2 What are they? Parasitic worms that live in the heart and blood vessels of animals. Heartworms (Dirofilaria immitis) affect dogs, coyotes, sea lions, ferrets and cats. They are transmitted by mosquitoes

9. 2 Life Cycle of a Heartworm Microfilaria develop into larva (L3) in the mosquito Larvae are transmitted to the dog when the mosquito takes a blood meal Larvae continue to mature in the dog until they become adults Adult heartworms live in the heart and mate to produce microfilaria Microfilaria are released into the bloodstream Microfilaria are transmitted to a new mosquito when it bites the infected dog

10. 2 Microfilaria Seen at 400x magnification

11. 2 Adult Heartworms

12. 2 Clinical Signs Coughing Exercise intolerance Syncope (Fainting) Ascites (Fluid in the belly)

13. 2 Radiographs of Heartworm Disease Enlarged Right Atrium Widened Caudal Vena Cava (Caval Syndrome) Lung Disease (Heartworm Pneumonitis) Enlarged Pulmonary Arteries

14. 2 Prevention Prevention products make sure dogs don’t get heartworms in the first place Include: Heartgard, Interceptor, Sentinel, Revolution, Filaribits As long as the animal is medicated every month, it prevents any larvae from maturing and reaching the heart, thus stopping heartworm disease.

15. 2 Treatment Treatment products help cure the animal once it already has heartworms –Elimination of heartworms is a two step process –Must get rid of adult worms and larvae separately Consists of two shots in the muscle of Immiticide and 4 weeks of strict cage rest

16. 2 Surgical Removal

17. 2 Heart Murmurs What is a heart murmur? –A heart murmur is an extra or unusual sound heard during a heartbeat. –There are many kinds of murmurs, some that are insignificant and some that indicate a heart problem is present.

18. 2 Patent Ductus Arteriosus Special type of heart problem Breakdown the words: –Patent: to make open –Ductus: tube or canal –Arterio: relating to an artery Put the words together to see that it means there is an artery that is open (that should be closed!)

19. 2 PDA in canines Most common canine congenital (present at birth) heart problem Affects 5 out of 1000 dogs, in any size or breed 65% of dogs with this problem will die by 1 year of age if it is not fixed Most have the problem diagnosed between 1 month and 3 ½ years of age

20. 2 PDA in humans The estimated incidence is from 6 out of every 100,000 live births up to 2 out of every 10,000 live births. This incidence is increased in children who are born prematurely. The death rate is very low except in extremely premature infants. It occurs twice as often in girls as in boys.

21. 2 Return to Anatomy

22. 2 Normal versus PDA heart

23. 2 Symptoms Can a patient live normally? –Sometimes there are no symptoms –In large PDAs, symptoms can include: Exercise intolerance Sweating Dyspnea (difficulty breathing) Poor weight gain Audio of a normal heart Audio of a PDA murmur

24. 2 Management Options Observation and monitoring Medical Management –Medications may be prescribed to reduce blood pressure, maintain normal heart rhythm, and prevent fluid overload. Surgical –Surgical repair Ligating (suturing closed) the patent artery –Catheter based occlusion Placing a “coil” inside the artery to stimulate closure

25. 2 Surgical Ligation Aorta Pulmonary Artery PDA

26. 2 Catheter Based Occlusion With a surgery called Transarterial Ductal Occlusion With Coils –Very safe procedure –Very successful procedure (95% need nothing else)

27. 2 Transarterial Ductal Occlusion Aorta (with catheter inside) Pulmonary Artery PDA Coil within PDA *Notice how no dye is visible in the pulmonary artery anymore!

28. 2 Any Questions?