Sustained Accelerated Idioventricular Rhythm in a Centrifuge-Simulated Suborbital Spaceflight

Area of Science:

• Aerospace medicine
• Cardiovascular physiology
• Human centrifuge research

Background:

• Human centrifugation can induce cardiac dysrhythmias, typically transient.
• Previous studies noted sinus dysrhythmias and premature contractions under hypergravity.
• This report details a sustained ectopic rhythm following high G exposure.

Observation:

• A healthy male subject underwent centrifuge testing simulating suborbital flight.
• Following combined +Gx and +Gz exposure, a sustained accelerated idioventricular rhythm (AIVR) was observed.
• The AIVR persisted for over two minutes at a rate of 91-95 bpm during low G rest.

Findings:

• The observed dysrhythmia was a prolonged, wide-complex ectopic ventricular rhythm (AIVR).
• The event was asymptomatic and self-limited, resolving spontaneously to normal sinus rhythm.
• Hemodynamic data confirmed the rhythm change post-acceleration exposure.

Implications:

• Accelerated idioventricular rhythm is a likely physiological response to G-force exposure.
• Conservative management is appropriate for asymptomatic, self-limited AIVR.
• Distinguishing AIVR from malignant arrhythmias is crucial for operational safety in aerospace medicine.