Final answer:
The correct trigger setting on the EKG for an IABP is balloon inflation on the R wave, balloon deflation on the middle of the T wave, which optimizes coronary artery perfusion and decreases cardiac workload.
Step-by-step explanation:
The proper trigger setting for balloon inflation and deflation of an Intra-Aortic Balloon Pump (IABP) based on the EKG is: balloon inflation on the R wave, balloon deflation on the middle of the T wave. The R wave marks the beginning of ventricular depolarization and contraction (ventricular systole), and it is immediately followed by the increase in arterial blood pressure when the ventricles pump blood through the body. Balloon inflation at this point would counteract the benefits by impeding blood flow. Instead, balloon inflation should occur immediately after the T wave, which corresponds with the onset of ventricular repolarization and relaxation (ventricular diastole), optimizing diastolic augmentation and coronary artery perfusion. Conversely, deflation prior to the R wave reduces afterload, thus minimizing cardiac workload and oxygen demand during systole.