premature atrioventricular junctional complex (JPC)

Premature depolarizations originating in the AV node or the proximal segment of the His-Purkinje system. Most JPCs occur in the absence of structural heart disease & result from increased automaticity. Etiology: 1) myocardial infarction 2) drug toxicity 3) catecholamine excess 4) electrolyte imbalance 5) tobacco 6) alcohol 7) caffeine Clinical manifestations: 1) patients may be asymptomatic 2) feeling of skipped beats Special laboratory: - electrocardiogram: 1) premature, normally conducted QRS 2) intact retrograde AV nodal conduction - inverted P wave during or just after QRS complex 3) retrograde AV block a) retrograde p-wave is absent b) delay in next p-wave c) anterograde AV block may occur Management: - Generally no therapy is required.

References

Manual of Medical Therapeutics, 28th ed, Ewald & McKenzie (eds), Little, Brown & Co, Boston, 1995, pg 140