Phenylephrine to increase blood flow in the radial artery used as a coronary bypass conduit.

Objective: The radial artery has more smooth muscle in its wall than the other arterial conduits and is known to be vasospastic. Because it is frequently necessary to use vasoconstrictors early after coronary bypass surgery we investigated the effects of phenylephrine on conduit flow in this setting.

Methods: Thirty patients undergoing coronary artery bypass with all arterial conduits in which the radial artery was used as a T-graft were randomly assigned to receive intravenous infusions of normal saline (n = 10); nitroglycerin, 0.

Occurrence of myocardial ischemia immediately after coronary revascularization using radial arterial conduits.

Objective: To assess the incidence of myocardial ischemia in patients receiving radial arterial and left internal thoracic arterial conduits (RA+LITA) during the postrevascularization period.

Design: Nonrandomized observational sequential cohort.

Setting: University hospital.

Echocardiographic characterization of left ventricular diastolic properties in patients presenting for the maze procedure.

The aim of this study is to characterize and compare the left ventricular (LV) diastolic filling patterns in patients with paroxysmal (PAF) versus chronic atrial fibrillation (CAF) undergoing the maze procedure and to examine their relation with the hemodynamic status. Fifty patients with PAF and 22 with CAF were studied. Hemodynamic measurements and transesophageal echocardiography (TEE) were performed after the induction of anesthesia but before surgical incision, at stable conditions.

Prevalence of left ventricular diastolic filling abnormalities in adult cardiac surgical patients: an intraoperative echocardiographic study.

The incidence of left ventricular (LV) diastolic abnormalities in adult cardiac surgical patients has not previously been adequately investigated. The present study was performed to characterize LV diastolic filling patterns by performing transesophageal Doppler echocardiographic (TEE) studies in patients undergoing cardiac surgical procedures and thus indirectly assess diastolic function in these patients. Doppler TEE studies were performed and transmitral flow (TMF) and pulmonary venous flow (PVF) velocities were recorded in 104 patients intraoperatively.

Effects of nicardipine and nitroglycerin on perioperative myocardial ischemia in patients undergoing coronary artery bypass surgery.

Perioperative myocardial ischemic episodes are predictive of adverse cardiac outcomes after coronary artery bypass surgery. We compared the efficacy of continuous infusions of nicardipine (group NIC) and nitroglycerin (group NTG) in reducing the frequency and severity of myocardial ischemic episodes. Patients received either a nicardipine infusion, 0.

Antiischemic effects of nicardipine and nitroglycerin after coronary artery bypass grafting.

Background: We assessed the efficacy of a continuous infusion of nicardipine and nitroglycerin in reducing the incidence and severity of perioperative myocardial ischemia during elective coronary artery bypass grafting procedures in a prospective, randomized, controlled study.

Methods: Patients received either nicardipine infusion (0.7 to 1.

An 8 1/2-year clinical experience with surgery for atrial fibrillation.

Objective: The authors analyzed the clinical results during the first 8 1/2 years' experience with the Maze procedure for the surgical treatment of atrial fibrillation.

Summary Background Data: Atrial fibrillation occurs in 0.4% to 2% of the general population and in approximately 10% of patients older than 60 years of age.

Transesophageal atrial pacing in anesthetized patients with coronary artery disease. Hemodynamic benefits versus risk of myocardial ischemia.

Background: Transesophageal atrial pacing (TEAP) provides prompt and precise control of heart rate and improves hemodynamics in anesthetized patients with bradycardia and hypotension. The authors' purpose in this study was to examine the hemodynamic benefits of TEAP versus the risk of myocardial ischemia in patients about to undergo coronary artery bypass surgery.

Methods: Hemodynamics, ventricular filling pressures, mixed venous oxygen saturation, and end-diastolic, end-systolic, and fractional area change of the left ventricle, determined by transesophageal echocardiography (TEE), were measured after anesthesia induction with 30 micrograms/kg fentanyl and at incremental TEAP rates of 65, 70, 80, and 90 beats/min (bpm) in 40 adult patients.

Evaluation of complete blood count results from a new, on-site hemocytometer compared with a laboratory-based hemocytometer.

Objective: To compare point-of-care results obtained from an on-site hemocytometer with values provided by an institutional laboratory instrument.

Design: A prospective laboratory evaluation.

Setting: The central laboratory and cardiac surgical intensive care unit of a university-affiliated tertiary care center.

Response of kaolin ACT to heparin: evaluation with an automated assay and higher heparin doses.

Background: Because previous reports suggest that the linear relationship between celite activated clotting time (ACT) values and heparin sodium is disrupted if values exceed 500 to 600 seconds, this study was designed to evaluate the relationship of kaolin activated clotting time (ACT) values to high in vitro heparin concentrations. In addition, the relationship of kaolin ACT to heparin concentration as determined manually was compared with that obtained with an automated heparin dose response assay.

Methods: Blood specimens were obtained prior to and after heparin administration from 41 cardiac surgical patients requiring cardiopulmonary bypass in this institutional human studies committee-approved study.

Factors associated with excessive postoperative blood loss and hemostatic transfusion requirements: a multivariate analysis in cardiac surgical patients.

The purpose of this study was to prospectively evaluate whether heparin and protamine doses administered using a standardized protocol based on body weight and activated clotting time values are associated with either transfusion of hemostatic blood products (HBPs) or excessive postoperative bleeding. Analysis using 10 multiple logistic or linear regression models in 487 cardiac surgical patients included perioperative variables that may have an association with either transfusion of HBP and/or excessive postoperative chest tube drainage (CTD). Prolonged duration of cardiopulmonary bypass (CPB), lower pre-CPB heparin dose, lower core body temperature in the intensive care unit, combined procedures, older age, repeat procedures, a larger volume of salvaged red cells reinfused intraoperatively and abnormal laboratory coagulation results (prothrombin time, activated partial thromboplastin time, and platelet count) after CPB were associated with both transfusion of HBP and increased CTD.

Alterations in heart rate variability in patients undergoing dobutamine stress echocardiography, including patients with neurocardiogenic hypotension.

Frequency-domain analysis of heart rate variability (HRV) appears to distinguish sympathetic and parasympathetic modulation of heart rate. The effects of acute reflex, as opposed to tonically augmented, cardiac vagal tone on HRV are not clearly defined. Power spectral components of HRV were measured in 36 patients undergoing dobutamine stress echocardiography including during episodes of neurocardiogenically mediated hypotension.

Aprotinin prolongs whole blood activated partial thromboplastin time but not whole blood prothrombin time in patients undergoing cardiac surgery.

Aprotinin is being used increasingly to limit cardiopulmonary bypass (CPB)-induced coagulation derangements. Since whole blood prothrombin time (PT) and activated partial thromboplastin time (APTT) assays are beneficial in the treatment of bleeding after CPB, we studied the potential effect of aprotinin on these whole blood assays. Blood specimens from 151 cardiac surgical patients were obtained in two phases: prior to heparin administration, before CPB, and subsequent to heparin neutralization after CPB.

Effect of heparin on whole blood activated partial thromboplastin time using a portable, whole blood coagulation monitor.

Objectives: To evaluate the responsiveness of whole blood activated partial thromboplastin time (aPTT) to varying heparin doses in vitro and to examine the ex vivo relationship of whole blood aPTT to plasma heparin concentration.

Design: Prospective, controlled laboratory study.

Setting: Surgical suites and laboratory at a tertiary center.

Pressure gradient across the pulmonary artery anastomosis during lung transplantation.

Background: Perioperative monitoring of pulmonary artery (PA) pressures in lung transplant recipients is critical. This report characterizes an intraoperative gradient across the PA anastomosis in a series of patients undergoing bilateral sequential lung transplantation.

Methods: Hemodynamic measurements were obtained in a series of 10 patients before anesthetic induction, during one-lung ventilation/perfusion of the newly transplanted first lung with the PA catheter proximal and distal to the anastomosis and after arrival in the intensive care unit.

Swallowing dysfunction after cardiac operations. Associated adverse outcomes and risk factors including intraoperative transesophageal echocardiography.

The frequency, importance to patient outcomes, and independent predictors of postoperative swallowing dysfunction documented by barium cineradiography were examined in 869 patients undergoing cardiac operations over a 12-month period. Swallowing dysfunction was diagnosed in 34 patients (4% incidence) and was associated with documented pulmonary aspiration in 90% of these patients, increased frequency of pneumonia (p < 0.0001), need for tracheostomy (p = 0.

Modification of the maze procedure for atrial flutter and atrial fibrillation. I. Rationale and surgical results.

The original maze procedure that was described for the treatment of patients with atrial fibrillation was followed by an unacceptable incidence of two problems: (1) the frequent inability to generate an appropriate sinus tachycardia in response to maximal exercise and (2) occasional left atrial dysfunction. In an effort to overcome these problems, we modified the original technique (maze I) twice. The results of these modifications culminated in the maze III procedure, which is associated with a higher incidence of postoperative sinus rhythm, improved long-term sinus node function, fewer pacemaker requirements, less arrhythmia recurrence, and improved long-term atrial transport function.

The impact of heparin concentration and activated clotting time monitoring on blood conservation. A prospective, randomized evaluation in patients undergoing cardiac operation.

A whole blood hemostasis system (Hepcon) provides both activated clotting time and accurate whole blood heparin concentration measurements via an automated protamine titration method. This study was designed to prospectively evaluate the impact of heparin and protamine administration using this system on the incidence and treatment of bleeding after cardiopulmonary bypass. Two hundred fifty-four patients requiring cardiopulmonary bypass were enrolled in this prospective study over a 7-month period.

Effect of aprotinin on activated clotting time, whole blood and plasma heparin measurements.

Twenty cardiac surgical patients requiring cardiopulmonary bypass were enrolled in this study designed to evaluate the effect of aprotinin on activated clotting time (kaolin and celite), whole blood, and laboratory-based plasma (anti-Xa) heparin measurements. Whole blood heparin measurements were not different (p = 0.98) between aprotinin-treated (3.

Alterations in temporal patterns of heart rate variability after coronary artery bypass graft surgery.

Background: Preliminary studies have indicated that autonomic nervous system dysfunction may be present in patients after cardiac surgery. The purpose of this study was to evaluate cardiac autonomic nervous system function, as assessed by analysis of heart rate variability (HRV), in adult patients undergoing uncomplicated coronary artery bypass graft surgery.

Methods: Longitudinal changes in HRV were determined perioperatively by continuous electrocardiographic monitoring in 40 adult patients undergoing elective coronary artery bypass graft surgery and were compared with HRV in two groups of control subjects: 15 patients undergoing nonthoracic major vascular surgery and 19 healthy volunteers.