Holter monitoring in dizziness and syncope.

Holter monitoring was used to detect the underlying mechanism among 53 patients referred for dizziness, fainting and/or syncope. The complaints were unexplained on clinical grounds in 38, suggestive of SSS in 11, and of pacemaker dysfunction in 4 patients who underwent pacemaker implantation for symptomatic A-V block. Occult dysrhythmias were revealed in 24 of 38 (61%) of the first group; the clinical impression of SSS was confirmed in 8 of 11 (72%) in the second, and ineffective pacing confirmed in 2 of 4 in the third group. Thus, the diagnosis was clarified in 34 of 53 (64%) of patients. It is concluded that Holter monitoring is most useful for detecting the underlying mechanism in the above mentioned conditions, especially in elderly subjects whose syncopal attacks remained unexplained despite routine cardiological and neurological examination. Holter monitoring should be carried out for at least 36 hours before ruling out dysrhythmias as a cause of dizziness and/or syncopal attacks.