Perioperative assessment and management of patients with valvular heart disease undergoing noncardiac surgery.

Valvular heart disease in a variety of forms is not uncommon, especially among older patients undergoing noncardiac surgery, and can be associated with increased perioperative cardiac risk. Patients with aortic stenosis are at greatest risk, although other valve lesions also can pose the risk of increased perioperative morbidity. During preoperative evaluation, attention to the presence, nature and severity of valvular heart disease allows appropriate perioperative monitoring and therapy with a goal to minimize the risk of perioperative cardiac morbidity and mortality associated with noncardiac surgery. Appropriate antibiotic prophylaxis reduces the risk of infective endocarditis. Finally, some patients with valvular heart disease and all patients with a mechanical valve prosthesis require long-term anticoagulation, which must be managed during the perioperative period.

Echocardiographic assessment of stentless aortic bioprosthetic valves.

Stentless tissue aortic valves are gaining in popularity because of advantages in hemodynamics and durability compared with stented bioprostheses. The absence of a rigid sewing ring and struts makes these valves pliable, and distortion at implantation can result in valve dysfunction. Because the anatomy and implantation techniques of stentless tissue valves are unlike those of mechanical and stented tissue valves, their echocardiographic appearance is unique on both intraoperative and subsequent transthoracic and transesophageal echocardiography. This report describes the echocardiographic appearance of normally functioning stentless tissue heterograft aortic valves as an aid to their intraoperative and subsequent echocardiographic assessment.

Effect of pharmaceutical services on adherence to criteria-for-use guidelines in the operating room.

Guidelines for the use of neuromuscular blocking agents (NMBAs) and sedatives during two- to four-hour surgical procedures were developed, and the effect of pharmacy presence on adherence to the guidelines was determined. Differences in cost per dose of the NMBAs pancuronium bromide, cisatracurium besylate, and vecuronium bromide were determined. Pancuronium was designated as the first-line agent in the NMBA guidelines, cisatracurium as the second-line agent, and vecuronium as the third-line agent. In the sedative guidelines, lorazepam was the first-line agent, midazolam was the second-line agent, and propofol was the third-line agent. Pharmacy presence in the operating room was provided during January 1997. The pharmacist made a preliminary decision about the most appropriate agent and encouraged guideline adherence. Cost and adherence data were compared with data for November 1996 and March 1997. During January, the NMBA guidelines were followed 75% of the time and the sedative guidelines were followed 15% of the time; the corresponding rates for March were 40% and 12%. Compared with November 1996, a saving of $5.61 per case was observed in January in the NMBA category and a saving of $2.77 was observed in March; between January and March, there was an increase of $2.84 per case. Pharmacy presence in the OR was associated with better adherence to criteria-for-use guidelines for NMBAs and sedatives; NMBA cost savings associated with implementation of the guidelines were higher when a pharmacist was present.

Quantitative Doppler tissue imaging for assessment of regional myocardial velocities during transient ischemia and reperfusion.

Doppler tissue imaging (DTI) is a new noninvasive imaging modality that directly interrogates myocardial velocity with high temporal and spatial resolution. This study was designed to test the hypothesis that quantitative DTI provides unique information regarding regional myocardial systolic and diastolic function during acute ischemic events. Myocardial velocities were quantified during the acute ischemic and reperfusion phases of 13 elective percutaneous coronary angioplasty procedures in 12 patients. In myocardium subtended by angioplasty vessels, peak velocities decreased during occlusive balloon inflation (from 21.2 +/- 9.8 to -0.6 +/- 4.0 mm/sec in systole [p < 0.001] and from 21.7 +/- 9.2 to -0.6 +/- 3.9 mm/sec in diastole [p < 0.001]). During early reperfusion, velocities exceeded those observed at baseline (p = 0.003). In regions remote from the treated artery, peak myocardial velocities increased in the absence of significant stenosis but remained unchanged or decreased in the presence of significant stenosis of the associated vessel. We conclude that (1) myocardial velocities rapidly decrease during acute ischemia and show a rebound increase after reperfusion, and (2) in regions remote from ischemia, velocities display distinct patterns on the basis of the presence or absence of obstructive coronary disease in the associated vessel. Quantitative DTI is a useful tool for the assessment of myocardial velocity and may provide new insights into myocardial systolic and diastolic function.

Two-dimensional and dobutamine stress echocardiography in the preoperative assessment of patients with end-stage liver disease prior to orthotopic liver transplantation.

Orthotopic liver transplantation is an established therapy for end-stage liver disease. This study evaluated the range of cardiovascular abnormalities in patients undergoing evaluation for orthotopic liver transplantation and determined the prognostic implications of abnormal echocardiographic features, including ischemia during dobutamine stress echocardiography, in predicting postoperative cardiac events. Two-dimensional echocardiography was performed in 190 patients for assessment of left ventricular function, valvular pathology, and pulmonary hypertension. Dobutamine stress echocardiography was performed in 165 patients for evaluation of inducible ischemia. Contrast echocardiography for detection of intrapulmonary shunting was performed in 125 patients at rest and in 99 during dobutamine stress. Left ventricular dysfunction, significant valvular regurgitation, and inducible ischemia were identified in <1O% of patients. Pulmonary hypertension, left ventricular hypertrophy and > or = moderate intrapulmonary shunting were present in 12%, 16%, and 26% of patients, respectively. Severe intrapulmonary shunting predicted death prior to transplantation (P=0.01). Of the 71 transplanted patients, major perioperative events included global left ventricular dysfunction in four patients and myocardial infarction in one patient with normal coronary arteries. No preoperative echocardiographic parameters, including ischemia on dobutamine echocardiography, predicted these perioperative events. No cardiac events related to obstructive coronary artery disease occurred in the 154 patients without ischemia on dobutamine stress echocardiography. The majority of patients with end-stage liver disease, including those with alcoholic cirrhosis, have normal cardiac function on two-dimensional echocardiography. Severe intrapulmonary shunting portends a poor prognosis in patients awaiting transplantation. A negative dobutamine stress echocardiogram appears useful in excluding patients at risk for perioperative cardiac events related to obstructive coronary artery disease.