Holter monitoring and provocative maneuvers in assessment of unipolar demand pacemaker myopotential inhibition.

Myopotential inhibition was produced by a combination of different provocative maneuvers in 423 (77%) out of 550 consecutive unipolar pacemaker patients. The most useful maneuvers were the hand-to-shoulder press (90% positivity) and the hand-to-hand press (60% positivity). Three groups of 20 patients were then submitted to 24 hours of Holter monitoring. Group A during the provocative maneuvers had shown myopotential inhibition and symptoms of cerebral ischemia. In group B symptomless myopotential inhibition had been induced. Group C had no myopotential inhibition nor symptoms during the tests. Abnormal pacemaker pauses related to myopotential inhibition were recorded during Holter monitoring in 90% of group A and in 80% of group B patients, but only group A patients showed symptoms. Thus in patients who are able to practice provocative isometric maneuvers and who can be selected according to their response, Holter monitoring seems to offer few advantages in discovering myopotential inhibition and related symptoms.