Hypertension following coronary artery bypass surgery. Role of preoperative propranolol therapy.

Abstract

SUMMARY Over a 9-month period, the incidence and characteristics of hypertension followtng coronary artery bypass surgery were studied in a group of 52 patients. Hypertension occurred in 61% of the patients and was characterized by an increase in arterial blood pressure of 35 ± 2 mm Hg mean ± SEM during the early postoperative period. Preoperative blood pressures and hemodynamk variables were similar in those who developed hypertension and those who remained normotenshe. Ninety-four percent of those who developed hypertension as compared to only 40% of those who remained normotensive received propranolol during the 24 hours preceding surgery (x 1 = 15.4; p < 0.001). Maximal blood pressures during the first 5 hours following the termination of cardiopulmonary bypass were significantly positively correlated with preoperative propranolol dosage (p < 0.01). Hypertension was not associated with significant changes in plasma renin activity or angiotensin II levels, but concomitant plasma catecholamine concentrations were elevated significantly (p < 0.005). However, a similar rise in plasma catecholamine concentrations was found in those who remained normotensive. Hypertension was associated with an increase in systemic vascular resistance (p < 0.001) and left ventricular stroke work index [p < 0.05), and a fall in stroke volume (p < 0.005) and cardiac index (p < 0.001). These studies suggest that hypertension following coronary artery bypass surgery is common, results from an increase in systemic vascular resistance, is not renin-angiotensin mediated, and may, in part, be related to preoperative propranolol administration. (Hypertension 2: 291-298, 1980) KEY WORDS • hypertension • coronary artery bypass surgery • renin activity catecholamine • hemodynamics D URING a 3-month period from March to May, 1977, more than 70% of patients undergoing coronary artery bypass surgery at The Johns Hopkins Hospital experienced vasomotor instability within the first 24 hours following revascularization. While hypotension requiring the administration of vasopressor agents was occasionally noted, the more common problem was that of hypertension. Since the incidence and severity of postoperative hypertension noted in this group was both surprising and disturbing, the circumstances surrounding the development of hypertension were carefully examined. In particular, we were anxious to define the hypertensive patients' clinical characteristics and to assess the roles of the sympathetic and renin-angiotensin systems in the genesis of this form of hypertension.

Renalase, Catecholamine and Nitric Oxide Changes Before and After Sodium Nitroprusside Administration to Patients who Develop Post-Coronary Artery By-Pass (CABG) Hypertension

“…Coronary arteries that supply blood to the heart can narrow down or be blocked because of numerous risk factors over time, and this condition is corrected by coronary artery bypass grafting (CABG) operation [Aydin 2013]. One of the most common complications encountered in this surgery is hypertension that develops at about a rate of 33% to 70% during the early postoperative period [Whelton 1980]. This hypertensive condition developing in the early postoperative period is attributed primarily to elevated epinephrine and norepinephrine levels [Sealy 1967].…”

“…After CABG, hypertension may arise in association with increased adrenergic activity [de Champlain 1990], unawareness caused by anesthesia, hypothermia, and painful stimuli [Musizza 2010]. [Whelton 1980;Lomivorotov 2017].…”