Comparison of the Effects of Nitroglycerin and Nitroprusside on Transmitral Doppler Flow Parameters in Patients with Hypertensive Urgency

BACKGROUND: Sodium nitroprusside (NIP) and nitroglycerin (NIT) are frequently selected agents for acutely reducing blood pressure. However, it is not clear which agent is more efficacious in improving left ventricular filling pressure in hypertensive crises. OBJECTIVE: To compare the acute effects of nitroglycerin (NIT) and nitroprusside (NIP) on transmitral Doppler filling parameters in patients with hypertensive urgency. METHODS: We identified 37 patients from our emergency department with hypertensive urgency and left ventricular filling abnormalities. Hypertensive urgency was defined as a severe blood pressure elevation without evidence of progressive end-organ injury. Patients were randomized to receive an infusion of NIT or NIP. NIT was infused at a starting dose of 10 microg/min; NIP was infused at a starting dose of 0.25 microg/kg/min. The infusion rates were adjusted to decrease mean arterial pressure by 25%, and this reduction was obtained within 2 hours in all patients. Diastolic filling parameters were measured by using echocardiography before and after treatment. Pulsed-wave Doppler transmitral flow velocities were used. Early diastolic flow, atrial contraction signal, early diastolic flow/atrial contraction signal, deceleration time, and isovolumetric relaxation time (IVRT) were measured. RESULTS: There were no differences between groups in baseline demographic and echocardiographic parameters. Blood pressure decreased significantly in both treatment groups. In posttreatment echocardiographic examinations, atrial contraction signal, deceleration time, and IVRT were significantly decreased in both treatment groups. Early diastolic flow was significantly decreased in the NIT group. There were no significant differences between the groups in terms of posttreatment early diastolic flow, atrial contraction signal, deceleration time, and IVRT values. CONCLUSIONS: In hypertensive urgency with left ventricular filling abnormalities, reduction of blood pressure associated with NIT or NIP treatment may improve transmitral Doppler filling parameters. There were no differences demonstrated between the 2 agents.