What should be evaluated to confirm that mechanical capture has been achieved during transcutaneous pacing?

The goal of transcutaneous pacing is to establish effective cardiac pacing. To confirm that mechanical capture has been achieved, it is critical to evaluate the electrical response of the heart to the pacing stimuli. The presence of wide QRS complexes and tall, broad T waves indicates that the paced impulses are effectively depolarizing the ventricles and initiating a heartbeat. This electrocardiographic change is a direct sign that the pacemaker is successfully stimulating the myocardium, resulting in adequate mechanical contractions.

While assessing the presence of a pulse, the patient’s blood pressure, and their level of consciousness are important components of overall patient evaluation, they may not directly indicate that effective pacing at the myocardial level is occurring. A pulse could still be absent, yet the pacing may still be achieving capture, possibly due to other factors affecting circulation, such as severe hypotension. Similarly, blood pressure readings and conscious level can be influenced by various physiological responses and not solely by the effectiveness of the pacing itself. Thus, analyzing the QRS morphology provides the clearest indication of successful pacing.