Low ventricular performance and high resistance in established hypertension in adults.
OBJECTIVE
To investigate the relationship between left ventricular performance and sympathetic nervous activity.


METHODS
We studied the alpha- and beta-adrenergic responsiveness of the subjects and assessed their left ventricular performance.


METHODS
Fifty-four adult established hypertensive patients, all with apparent left ventricular hypertrophy, and 36 age-matched normotensive controls were studied. Thirty-four of the hypertensive patients were within the +/- 2SD confidence area of fractional shortening/end-systolic stress relation of the normotensive controls and are denoted subgroup A; 19 patients were below the lower limit and are denoted subgroup B. Isoproterenol and neosynephrine injection tests were used to assess beta- and alpha-adrenergic responsiveness, respectively. Intravenous infusion tests using regitine and isoproterenol were performed in 16 patients to assess the effects of sympatho-adrenergic responsiveness on changes in left ventricular performance.


RESULTS
Afterload and left ventricular mass were similar in the two subgroups. Left ventricular performance and beta-adrenergic responsiveness in subgroup A were comparable with the corresponding levels in the normotensives, whereas in subgroup B both were markedly decreased. The regitine infusion test induced a fall of 25% in peripheral resistance from baseline, but no significant improvement in left ventricular performance. In contrast, isoproterenol infusion test resulted in striking improvements: left ventricular performance increased by 60%, afterload decreased by 48% and peripheral resistance fell by 50% from baseline.


CONCLUSIONS
The diminished ventricular performance and high resistance observed in adult established hypertension may be due to synergic effects of significantly reduced beta-adrenergic responsiveness coupled with enhanced alpha-adrenergic responsiveness.
Yi
G
G
Department of Internal Medicine, Baogang Hospital, Shanghai Second Medical University, Shanghai, People's Republic of China.
Stone
S
S
Dao
B
B
D000328:Adult; D005260:Female; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D010646:Phentolamine / Q000494:pharmacology; D011942:Receptors, Adrenergic, alpha / Q000502:physiology; D011943:Receptors, Adrenergic, beta / Q000502:physiology; D014655:Vascular Resistance / Q000187:drug effects; D016277:Ventricular Function, Left
D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D007545:Isoproterenol; D010646:Phentolamine