This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Aerial disorders, Subject name: Surgery
AV fistula leads to all except 
Select and explain. 
A. Sinus tachycardia, B. Increased preload, C. Cardiac arrythmias, D. Increased cardiac output
C: Cardiac arrythmias
Answer: C: Cardiac arrythmias 
Explanation: Pathophysiology of AV Fistula: When an aeriovenous fistula is formed involving a major aery like the abdominal aoa, it can lead to a large decrease in peripheral resistance. This lowered peripheral resistance causes the hea to increase cardiac output to maintain proper blood flow to all tissues. An aeriovenous fistula can increase preload. AV shunts also decrease the afterload of the hea. This is because the blood bypasses the aerioles which results in a decrease in the total peripheral resistance (TPR). AV shunts increase both the rate and volume of blood returning to the hea.