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 ninA 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