Contrasting ultrasound findings in pacemaker lead perforation with and without cardiac tamponade.

Pacemaker lead perforation is a recognised cause of iatrogenic pericardial effusion and may progress to life-threatening cardiac tamponade. Point-of-care ultrasound (POCUS) is essential for rapid bedside evaluation, yet the distinction between a large but haemodynamically stable effusion and true tamponade physiology requires integration of sonographic findings and clinical presentation. We present two cases of pacemaker-associated haemopericardium with markedly different physiological consequences: one showed haemodynamic instability with clear tamponade and the other initially stable without tamponade despite a massive effusion. This case pair demonstrates how POCUS can be used to differentiate these states and underscores the importance of evaluating both the heart and the patient as a whole.