Transvenous Pacemaker Failure to Capture: A Case Report

A transvenous pacemaker failure to capture can be a serious and debilitating condition that affects patients who rely on these devices to regulate their heartbeat. In this case report, we present the story of an 81-year-old man who experienced intermittent pacing failure despite maximal output from his Micra AV transvenous pacemaker.

The patient was referred to our hospital for treatment of complete heart block after experiencing a syncopal attack. Initial implantation of the device had taken place six months prior, with no significant changes in device parameters noted except for an increase in capture threshold two months later. The pacing threshold, obtained through remote monitoring, gradually increased over time.

Fluoroscopy revealed that two of the tines on the pacemaker were fractured, with one completely isolated from the device and buried in the myocardium. Despite maximal output, intermittent pacing failure was observed (Figure 2A). The patient presented to our hospital with fatigue at six months after implantation.

The device parameters did not change significantly between initial implantation and final measurement except for an increase in capture threshold and a decrease in pacing impedance. However, the engagement of the device was confirmed through the standard pull-and-hold test, showing that at least three of the four tines were fixed.

A venogram and right ventriculography were performed to exclude any anatomical abnormalities or tortuosity of the femoral veins. The patient's chamber sizes were normal for body surface area, with no evidence of cardiac hypertrophy, atrial enlargement, intracardiac thrombus, or infiltrative disease on echocardiography.

The patient remained relatively active despite having thrombocytopenia and diabetes mellitus. The diagnosis was confirmed through fluoroscopy and device parameters, which showed a failure to capture despite maximal output.

In conclusion, this case report highlights the importance of close monitoring and follow-up in patients with transvenous pacemakers to detect any signs of failure to capture early on. Further research is needed to better understand the causes of this condition and to develop effective treatment strategies.

Transvenous pacemaker failure to capture