Most types of EKGs are safe, routine procedures without risks or complications. These EKGs include a standard EKG, 24-hour EKG, and cardiac event recorder. A cardiac stress test (exercise EKG or treadmill test) carries a small risk of complications including: Abnormal heartbeats, also called cardiac arrhythmia Breathing problems such as wheezing and shortness of breath Chest pain, also called angina Heart attack (rare) Low blood pressure and fainting Your care team will watch you closely during a cardiac stress test. The team will stop the test if you have any problems. Be assured that your team is trained and equipped to treat complications. Reducing your risk of complications You can reduce the risk of certain complications of a cardiac stress test by: Ensuring that your care team is aware of your complete medical history including a history of allergies and heart problems Notifying your care team right away of any concerns, such as chest pain, palpitations, dizziness, or shortness of breath Telling all members of your care team if you have any allergies