Bypass heart surgery risks?

Many but uncommon: Bypass surgery is major surgery. There are risks although the majority of patients don't get them or at most one. Rhythm disturbances, bleeding, and infection are the commonest. Congestive failure, collapsed lung, torn sternal wire from coughing occasionally occur. Nerve damage, stroke, heart attack, death are rare but sometimes occur (<1-2% generally).

Low risk: Overall risk of complications is less than 1% in patients with minimal risk factors. The major risks are death, heat attack (mi), stroke, wound infection in the chest or in the leg and occasionally post cardiotomy syndrome that leads to chronic pericardial and pleural effusions.