Acute pericarditis resulting from an endocardial active fixation screw-in atrial lead.

We examined the occurrence of acute pericarditis after pacemaker implantation in 123 consecutive patients (61 males, 62 females, ages 17-87 years) in whom a newer atrial active fixation bipolar lead was inserted endocardially in the right atrium for dual chamber pacing. The atrial leads were positioned to obtain the best possible pacing and sensing thresholds, after an initial attempt was made for insertion into the right atrial appendage or medially into the right atrial septum. Six patients (4.9%) developed acute symptomatic pericarditis with effusion within 24 hours of implantation. Of these six patients, four had leads screwed into the lateral wall, and the other two had leads placed in the anterolateral wall. The lead implantation parameters between patients with pericarditis and those without did not show any significant difference in the atrial P wave amplitude (2.3 +/- 0.4 vs 2.9 +/- 0.9 mV), pacing threshold (1.1 +/- 0.2 vs 1.1 +/- 0.4 V), or resistance (524 +/- 112 vs 480 +/- 94 ohms). All symptomatic patients were treated with nonsteroidal anti-inflammatory drugs with symptoms resolving in 1-2 weeks. We conclude that: (1) a significant number of patients (4.9%) developed acute symptomatic pericarditis after insertion of this type of atrial fixation lead; (2) because of the lead design, the implantation parameters could not be taken to predict the occurrence of pericarditis; and (3) caution should be taken for the insertion of this lead into the thin atrial wall.