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The plasma catecholamine responses to ventricular pacing: implications for rate responsive pacing.
1Cardiac Electrophysiology Laboratory, Medical College of Virginia, Richmond 23298.
Pacing and Clinical Electrophysiology : PACE
|November 1, 1990
Summary
Ventricular pacing in patients with pacemakers can cause symptoms due to changes in catecholamines. This study found that norepinephrine and epinephrine levels increase during ventricular pacing, potentially explaining patient symptoms.
Area of Science:
- Cardiology
- Neuroscience
- Physiology
Background:
- Patients with VVI/VVIR pacemakers experience rhythm shifts between sinus rhythm and ventricular pacing.
- These rhythm shifts can be poorly tolerated, with potential contributions from altered plasma catecholamine levels.
Purpose of the Study:
- To investigate the acute changes in plasma catecholamine levels (norepinephrine, epinephrine, dopamine) during ventricular pacing in patients with VVI pacemakers.
- To correlate these catecholamine changes with hemodynamic parameters like blood pressure and ejection fraction.
Main Methods:
- Nine patients with normal left ventricular ejection fractions and VVI pacemakers were studied.
- Blood pressure, ejection fraction, and plasma catecholamines were measured at baseline (sinus rhythm) and during ventricular pacing at 10 bpm above sinus rate, 100 bpm, and 130 bpm.
Main Results:
- Plasma norepinephrine levels significantly increased during ventricular pacing, with peak increases at 100 bpm (33% change, P=0.002).
- Plasma epinephrine levels also increased, particularly at 130 bpm (89% change, P=0.02).
- Increases in norepinephrine and epinephrine at 100 bpm were inversely correlated with changes in systolic blood pressure.
Conclusions:
- Ventricular pacing acutely increases plasma norepinephrine and epinephrine levels in patients with VVI pacemakers.
- These catecholamine responses may contribute to symptoms experienced by patients during rhythm shifts associated with ventricular pacing.