cardiasthenia

orthostatic intolerance

A condition (OMIM:604715) characterised by lightheadedness, fatigue, altered mentation, syncope and tachycardia upon assuming an upright position, and markedly elevated serum norepinephrine. 

Molecular pathology
Defects in SLC6A2, which encodes a member of the sodium:neurotransmitter symporter that regulates norepinephrine homeostasis, are a cause of orthostatic intolerance.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.

cardiasthenia

(kăr″dē-ăs-thē′nē-ă) [″ + astheneia, weakness]
An obsolete term for a somatization disorder with prominent cardiac symptoms.
Medical Dictionary, © 2009 Farlex and Partners