The invention concerns the use of agonists and antagonists of peripheral-type benzodiazepine receptors (PTBR) in the diagnosis and treatment of cardiac hypertrophy and other circulatory conditions. The invention specifically concerns the use of PTBR antagonists in the prevention or treatment of decompensated cardiac hypertrophy and, eventually, heart failure. The invention also concerns the use of PTBR agonists in the management of conditions calling for increased blood flow or cardiac output, including injury or functional compromise of the heart, increased demand for physical exercise, or an acquired or inherited predisposition to cardiac contractile disfunction. Pharmaceutical compositions for the treatment of such conditions and screening methods to identify PTBR agonists and antagonists are also included.