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Hyperkalemia induced failure of pacemaker capture and sensing
Fernando Schiraldi1, Giovanna Guiotto, Fiorella Paladino
1San Paolo Hospital Naples, Italy. schirald@libero.it
Resuscitation
|July 12, 2008
Summary
Hyperkalemia can disrupt pacemaker function by altering myocardial electrical potential. Intravenous calcium chloride rapidly restored normal pacemaker function in a patient experiencing these dangerous effects.
Area of Science:
- Cardiology
- Electrophysiology
- Internal Medicine
Background:
- Hyperkalemia can impair cardiac pacemaker (PMK) function by reducing myocardial resting potential electronegativity.
- Both pacemaker sensing and capture can be affected, posing life-threatening risks.
Observation:
- A 75-year-old woman presented with weakness, wide QRS complexes, and PMK type II exit block.
- She exhibited pacemaker sensing failure and the "spike-on-T" phenomenon.
Findings:
- Immediate intravenous calcium chloride administration corrected PMK malfunctioning.
- ECG showed rapid improvement in pacemaker function and intraventricular conduction.
Implications:
- Intravenous calcium chloride is effective in counteracting hyperkalemia-induced PMK dysfunction.
- This supports the electrophysiological principle of calcium's effect on myocardial threshold potential.
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