Failure to Capture in Pacemakers and ICD

Definition: Failure to capture means when the pacemaker initiates a stimulus, but it fails to depolarise the myocardium. It is depicted on ECG by the presence of spikes of pacemaker but there is no associated depolarisation of the concerned chamber. Causes of failure to capture are: This ECG shows: Cause: Intermittent Failure to Capture. If we carefully see lead V1, we can see progressive widening of QRS. But, at the same time we can see that P waves are preceded by QRS complex every time. What could be the reason? This is rate-dependent widening of QRS also known as use-dependent … Read more