Treatment of hypertensive crises with nifedipine (Adalat) in patients at risk of infarct during interventions on the extracranial cerebral vessels

: Nifedipine (Adalat) was used in managing acute hypertension in 20 patients with coronary heart disease during endarterectomy for carotid stenosis. Nifedipine (Adalat) was given if the cardiac index dropped below 2.5 l/min and the total peripheral resistance increased above 2,500 dyn/sec cm-5. In these patients the systolic blood pressure was 20% higher than the control value. After IV bolus injection of 1 mg nifedipine we noticed a 64% increase of the stroke volume index and a statistically significant 56% decrease of the total peripheral resistance. These values became stable under a maintenance dose. The left ventricular stroke work index increased after IV bolus injection and subsequently, by about 7%. This increase was statistically not significant. To evaluate the myocardial contractility, the heart rate and systolic pulmonary capillary wedge pressure were measured. After greatly raised values in hypertensive emergency, these parameters showed a 27% decrease following IV bolus injection and during the subsequent intraoperative course they stabilised at standard levels. The heart rate increased by about 10%, but this was statistically not significant. In accordance with the increase in heart rate, the coronary perfusion pressure decreased by about 31% (expressed in mm Hg) (mean value) and dropped even lower in some patients. The parameters for preload, central venous pressure and pulmonary capillary wedge pressure did not show any statistically significant changes. The authors conclude that nifedipine (Adalat) can be used with good results in treating hypertensive emergencies associated with low-output syndrome in patients with coronary heart disease during carotid endarterectomy.