A 64-year-old retired police officer has been experiencing during the past year almost daily episodes of lightheadedness and occasionally “near-fainting”, lasting 2-5 minutes. He has been otherwise in excellent state of health and exercised regularly and  vigorously:

• Sinus bradycardia with Mobitz II 2nd degree Sino-Atrial Block. 
• Ventricular rate 31/min 
• First degree AV block (PR = 244 msec.)

The patient is admitted to the hospital and a pacemaker is implanted:

• DDD pacing (Atrial paced, ventricular paced rhythm, 61/min)

Comment: This type of rhythm is also known as AV sequential pacing. Although the patient had intact AV nodal conduction at baseline with prolonged PR interval, the paced AV delay of the pacemaker is 180ms and thus all beats are paced in the ventricle. At follow-up, consideration could be made to lengthen the programmed AV delay in order to allow intrinsic conduction and minimize ventricular pacing.