Conditions: Hypertension
Keywords: hypertension sympathetic nervous system
Allocation: NA | Intervention model: SINGLE_GROUP
Enrollment: 24
Healthy volunteers: no

Brief summary:
This is a study of patients with high blood pressure who are already treated with an angiotensin converting enzyme inhibitor or receptor blocker and have achieved good or fair blood pressure control. The hypothesis is that addition of the beta-adrenergic receptor blocker, sustained-release metoprolol, will provide additional blockade of the sympathetic nervous system, thereby further improving left ventricular filling and blood pressure control.

Detailed description:
Patients were to receive sympathetic cardiac innervation testing with I-123 MIBG at baseline and again after receiving a titrate dose of beta-blocker. Data were to be assesses by repeated measures testing.

Arms:
arm 1: Subjects will undergo I-123 MIBG testing before and after sustained-release beta-adrenergic blockade.

Interventions: intervention 1: Metoprolol Succinate
Intervention descriptions: intervention 1: Once daily, oral, 12.5 mg to 200 mg, dose titrated to reduce heart rate by 20% or to less than 65 beats per minute.

Protocol document: