《太空生物工程与生命支撑》（英文版）Cardiovascular Effects of Space Flight

C ardiovascular Effects of Space Flight Richard j cohen md. ph d Harvard-MIT Division of health sciences and Technology

Cardiovascular Effects of Space Flight Richard J. Cohen, M.D., P h.D. Harvard-MIT Division of Healt h S ciences and T echnology

Cardiovascular problems associated with Space Flight Orthostatic Intolerance upon Re-entry Arrhythmias Loss of cardiac mass Reduced Exercise capacity Manifestation of Pre-existing Cardiovascular Disease

Cardiovascular Problems Associated with Space Flight • Orthostatic Intolerance upon Re-entry • A r rh y t h m i a s • Loss of Cardiac Mass • Reduced Exercise Capacity • Manifest ation of Pre-existing Car d i ovascular Disease

Post Flight orthostatic Intolerance Appears to be more severe the longer the duration of space flight Women are more severely affected than men, but virtually all are affected after long duration flight Current countermeasures of salt and water loading and use of a g suit are not adequate

Post Flight Orthostatic Intolerance • Appears to be more severe the longer the duration of space flight. • Women are more severely affected than men, but virtually all are affected after long duration flight. • Current countermeasures of salt and water loading and use of a G suit are not adequate

Cardiovascular Problems associated with space Flight Venous resistance Arterial Compliance Inotropy · HR Baroreflex Parasympathetic Input 阝- Sympathetic Input Arrhythmias Cardiac Atrophy Venous Compliance Angiotensin Microvascular resistance a-Sympathetic Input Resistance Baroreflex Muscle Mass/Tone Vasoreactive al-Sympathetic Input AVP Intravascular Volume Renin-Angiotensin Salt and Water Intake · Nitric Oxide AVP ANP Mineralocorticoid

Cardiovascular Problems Associated with Space Flight V enous Resista nce Microvascular Resistance • Resistance Baroreflex • V asoreactivity • α− S ympath etic Input • AVP • R e nin￾A n giot ensin System • Nitric Oxide V enous Compliance • α-S ym p atheti c Input • Muscle Mass/Tone A rterial Compliance Heart • Inotropy • HR B arore flex • Paras ym p athetic Input • β− S ympathetic Input • Arrh ythmias • Cardiac Atrophy •Angiot ensin Intra vasc ular Volume • S alt a n d Water Intake • AVP • ANP • Mineralocorticoi ds

Cardiovascular Problems ng Atrophy Arrhythmias Human studies Human Studies core- Williams Rodent studies Alteration in Cardiovascular Regulation -Cohen Cardiovascular Deconditioning -Shoukas Renal and cardio-Endocrine responses-Williams Cardiac Atrophy -Schneider Ventricular Arrhythmias -Cohen Computer Modeling Kamm Actions Determine Magnitude of Problem Identify mechanisms Propose Countermeasures Test Countermeasures

Human Studies Human Studies Core - Williams Alteration in Cardiovascular Regulation - Cohen Renal and Cardio-Endocrine Responses - Williams Ventricular Arrhythmias - Cohen Rodent Studies Cardiovascular Deconditioning - Shoukas Cardiac Atrophy - Schneider Computer Modeling Kamm Cardiovascular Problems Deconditioning Atrophy Arrhythmias Actions Determine Magnitude of Problem Identify Mechanisms Propose Countermeasures Test Countermeasures

Effects of Microgravity on Cardiovascular Hormonal and Renal response to posture Investigators Richard Cohen. M.D. Ph. D Craig Ramsdell, MD Tom mullen ph D Natalie Sheynberg, M D Gordon Williams, MD Disciplines: Cardiology, Endocrinology, Space Medicine Primary Source National Space Biomedical Research of Funding: Institute GCRC Site Visit

Effects of Microgravity on Cardiovascular, Hormonal and Renal Response to Posture Investigators: Richard Cohen, M.D., Ph.D Craig Ramsdell, M.D., Tom Mullen, Ph.D., Natalie Sheynberg, M.D. Gordon Williams, M.D. Disciplines: Cardiology, Endocrinology, Space Medicine Primary Source National Space Biomedical Research of Funding: Institute GCRC Site Visit

Experiment Protocol 2 Days 16 Days 3 Days Extensive 4°HDT Extensive cV& Endocrine Bed rest cV& Endocrine Testing Testing Controlled Diet, NA, K and Fluid Intae/ Supine-Stand Tests Cardiovascular System d All Infusions T Wave alternans Electrolytes eg Compliance studies Norepi infusions Echocardiograms Others

Experiment Protocol 2 Days Extensive CV & Endocrine Testing 3 Days Extensive CV & Endocrine Testing 16 Days 4º HDT Bed rest Controlled Diet, NA, K and Fluid Intake • Supine-Stand Tests • Cardiovascular System ID • AII Infusions • T W ave Alternans • Ele c trolytes • Leg Compliance S tudies • Norepi Infusions • Echocardiograms • Others

Cardiovascular System Identification System Identification Results ABP ECG r ILV (Respitrace Amplifier A/D System Identification

Cardiovascular System Identification S ystem Identification Res ults ABP (Finapres) ECG A/D (Respitrac e) ILV A mplifier System Identificatio n

N ILV-+HR 00a1020.30405 BAROREFLEX CSI Autonomic Activity (Heart Rate Tachogram) Effect of SA NODE ILV Atrio-Ventricular Activation (mpule Heart Rate) Autonomic 000.102030405 CIRCULATORY MECHANIC Blood Pressure Blockade ILV-+ABP

CSI Effect of Autonomic Blockade

ILV-+HR BAROREFLEX CSI Autonomic Activity (Heart Rate tache Effect of SA NODE Autonomic (Impulse Heart Rate CIRCULATORY MECHANIC Arte Neuropathy LLv→ABP ABP 000.10.2030405

CSI Effect of Autonomic Neuropathy