Chronic Lunar Cardiac Atrophy Syndrome
Earth designation: Chronic Cardiac Deconditioning
Chronic presentation of Cardiac Deconditioning in lunar residents. Progressive reduction in cardiac muscle mass, stroke volume, and aerobic capacity resulting from reduced gravitational load on the cardiovascular system. In lunar gravity, the heart does not need to pump against the same hydrostatic pressure gradient as on Earth. Without mitigation, significant card...
Lunar Risk Factors
Reduced gravitational load decreases cardiac workload. Fluid redistribution reduces preload. Physical inactivity, even inadvertent, accelerates deconditioning. Maximum risk in first 6 months without exercise protocol adherence.
Symptoms
Reduced exercise tolerance, dyspnea on exertion, fatigue, decreased maximum heart rate and VO2 max.
Lunar Presentation
Subtle at first — residents often attribute symptoms to habitat conditions. Monitoring via wearable cardiac sensors shows declining performance metrics before symptoms appear.
Diagnosis
Serial VO2 max testing, echocardiogram via portable ultrasound, cardiac output measurement, exercise tolerance testing.
Treatment
Structured aerobic and resistance exercise program, cardiac monitoring, possible pharmacological support.
Lunar Medical Bay Protocol
Mandatory exercise protocol enforcement. Resistance treadmill with lower-body negative pressure (LBNP) suit. Target: maintain pre-mission baseline ±10% at 6-month review. Quarterly echocardiography. If >15% decline, mandatory Earth telemedicine cardiology consult.
Evacuation Criteria
VO2 max decline >30% from baseline. New arrhythmia. Ejection fraction <45%. Symptomatic heart failure.
Prevention
Mandatory 90-minute daily exercise protocol, LBNP suit use, cardiovascular monitoring every 3 months, nutrition optimization.