No intervention is indicated. This octogenarian has first-degree atrioventricular (AV) block (PR interval >200 ms), right bundle branch block, and left posterior fascicular block. The combination of first-degree AV block and bifascicular block is often referred to as “trifascicular block,” although this term is not correct because true trifascicular block would imply complete AV block. There is no indication for pacing in patients with first-degree AV block and bifascicular block who have no symptoms due to bradycardia. The risk of this type of block progressing to complete heart block is less than 2% to 3% per year.

The patient is asymptomatic, has no evidence of left ventricular dysfunction, and no clinical evidence of ischemia. Therefore, stress testing, including adenosine perfusion imaging, is not indicated. Because right coronary artery ischemia can cause paroxysms of bradycardia, stress testing for ischemia may be indicated in patients with paroxysmal bradycardia or clinical findings suggestive of ischemia, neither of which is present in this patient. In patients in whom symptomatic bradycardia is a concern, treadmill stress testing may be helpful in evaluating whether there is an appropriate chronotropic response to exercise.

Permanent pacing is only indicated in two clinical situations. First, pacemakers are indicated in patients with symptomatic bradycardia in the absence of a reversible cause. Second, pacemakers are indicated in patients with evidence of AV conduction disturbances that have a high likelihood of progression to complete heart block or life-threatening sudden asystole. Second-degree Mobitz II block, alternating bundle branch block, atrial fibrillation with pauses greater than 5 seconds, and complete heart block are all indications for permanent pacing. This patient has none of these conditions, and neither dual-chamber nor single-chamber pacing is indicated.