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Biomedical subjects

D G Lappas

Publications and source records attributed to D G Lappas.

At least 37 records · Page 2Linked to original sources

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 = 0.0002), length of stay in the intensive care unit (p = 0.0001), and duration of hospitalization after the operation (p = 0.0001). Independent predictors of postoperative swallowing dysfunction determined by multivariate logistic regression included age (p < 0.001), length of tracheal intubation after the operation (p = 0.001), and intraoperative use of transesophageal echocardiography (p = 0.003). Dysfunctional swallowing after cardiac operations, a serious complication significantly related to postoperative respiratory morbidity and extended length of hospitalization, is more common in older patients. An association between intraoperative use of transesophageal echocardiography and swallowing dysfunction was also observed in our patients.

Aged↗

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. After collection, blood specimens were divided into two aliquots and mixed with either normal saline (NS) or aprotinin (A, 200 or 400 Kallikrein inhibiting units (KIU)/mL). Whole blood specimens were used to measure whole blood PT and APTT using CoaguChek Plus instruments. Whole blood PT results were similar between normal saline. (NS)- and aprotinin-spiked specimens before CPB (A, 12.9 +/- 1.5s; NS, 12.8 +/- 1.5s; P = 0.76) and after CPB (A, 17.5 +/- 2.4s; NS, 17.7 +/- 2.4s; P = 0.58). In contrast, whole blood APTT results were prolonged in aprotinin-spiked specimens prior to CPB (A, 63.3 +/- 32.2s; NS, 38.6 +/- 16.3s; P < 0.0001) and after CPB (A, 65.9 +/- 23.7s; NS, 45.7 +/- 14.4s; P < 0.0001). A dose-dependent prolongation of whole blood APTT by aprotinin was demonstrated by a greater mean difference in APTT (P = 0.0001) between specimens spiked with NS or 200 KIU (17.5 +/- 12.2s) vs 400 KIU (27.8 +/- 21.5s) of aprotinin.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

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. PATIENTS: Surgical patients and volunteers at a tertiary center were eligible for inclusion in this study. In vitro evaluation was performed using specimens obtained from each of five, healthy volunteers. Ex vivo evaluation was performed using specimens obtained from 30 cardiac surgical patients before and after systemic administration of heparin for extracorporeal circulation. INTERVENTIONS: Blood specimens were obtained from volunteers and added to syringes containing varying amounts of unfractionated porcine heparin for in vitro evaluation. For ex vivo evaluation, blood specimens were obtained from patients before and after systemic administration of 20 U/kg of heparin. MEASUREMENTS AND MAIN RESULTS: For the in vitro evaluation, specimens were divided into two aliquots after mixing with varying amounts of unfractionated porcine heparin. One aliquot was used to measure whole blood aPTT using a whole blood coagulation monitor immediately after blood collection and 3 mins later, and a second aliquot was used to determine plasma aPTT with a conventional, laboratory-based assay. Linear regression analysis demonstrated a high correlation (r = .94; r2 = .88) between aPTT assay systems and bias analysis demonstrated a mean aPTT measurement difference of 1.6 secs with +/- 2 SD limits of -15 to +18.2 secs. As indicated by comparable regression slopes, the in vitro aPTT responsiveness to increasing heparin concentration was similar with the two assay systems among individual subjects. Whole blood aPTT measurements after 3 mins of blood specimen storage were similar to immediate measurements. For ex vivo evaluation, blood specimens obtained from patients before and after systemic administration of heparin were divided into two aliquots. One aliquot was used to measure whole blood aPTT in duplicate and a second aliquot was used to measure plasma heparin concentration with an antifactor X active chromogenic assay. A high correlation (r = .89; r2 = .79) between whole blood aPTT and plasma heparin concentration was observed. CONCLUSIONS: Heparin responsiveness of whole blood aPTT, measured with a portable whole blood coagulation monitor, is similar to that of conventional laboratory aPTT over a clinically relevant range of heparin concentrations in vitro and ex vivo. On-site whole blood aPTT measurements should be useful in clinical situations requiring rapid aPTT results.

Blood Coagulation↗

From fisherman to fibrillation: an unbroken line of progress.

The modern era of cardiac arrhythmia surgery was initiated by Dr Will C. Sealy in May 1968, when he performed the first successful surgical division of an accessory pathway for the treatment of the Wolff-Parkinson-White syndrome. During the subsequent 25 years, arrhythmia operations evolved through a series of innovative surgical procedures capable of curing essentially all refractory clinical arrhythmias. The lessons learned during the development of these surgical procedures ultimately led to the refinement and eventual success of less invasive catheter techniques that have now replaced most of these surgical techniques. The surgical experience gained during these years also made possible the current surgical procedure that is used to treat the most complex, and the most common, of all cardiac arrhythmias, atrial fibrillation. Few areas of any specialty are as clearly defined as the unbroken line of progress that extends from Dr Sealy's first procedure in 1968 to the successful surgical treatment of atrial fibrillation in 1994.

Adult↗

Predictors, frequency, and indications for cardiopulmonary bypass during lung transplantation in adults.

The records for 162 lung transplantations performed in 158 patients were reviewed with regard to the predictors for, frequency of, and indications for using cardiopulmonary bypass during the procedure. There were a total of 8 en bloc double-lung transplantations, 83 single-lung transplantations, and 71 bilateral single-lung transplantations. Bypass was used electively for all double en bloc and three of the bilateral sequential lung transplantation procedures and for 26 unilateral lung replacement procedures in patients with pulmonary hypertension. Of the remaining patients, 1 single-lung transplant recipient required bypass for correction of a surgical mishap and 18 bilateral single-lung recipients required bypass during replacement of the second lung. No preoperative predictors for the need of bypass could be identified. Among the bilateral sequential lung recipients, the use of bypass did not seem to adversely affect outcome, as expressed in terms of the time until extubation, the time spent in the intensive care unit, and the time required to reach a room air oxygen tension greater than 60 mm Hg.

Adult↗

Comparison of cardiac output measurement by continuous thermodilution with electromagnetometry in adult cardiac surgical patients.

A pulmonary artery catheter (PAC) capable of continuous cardiac output (CCO) determination by thermodilution has recently been introduced. The purpose of this study was to compare CCO with two other methods of cardiac output (Ot) determination: electromagnetometry (EM) and standard bolus thermodilution cardiac output (BCO). Following median sternotomy and pericardiotomy, an EM ring probe was placed around the ascending aorta in 25 adult cardiac surgical patients and connected to an EM flowmeter interfaced with a calibrated strip recorder. Measurements were obtained over a 15- to 20-minute interval during a period of stable EM-determined Ot prior to initiation of cardiopulmonary bypass and in the absence of surgical stimulation. The CCO system averages Ot over a 3-minute interval, updating the measurement every 30 seconds. Cardiac output determined by the CCO system was compared with EM Ot averaged from the prior 3-minute period and with BCO obtained immediately after changing the Ot monitor from the continuous to bolus mode. Compared with EM, the bias for CCO was -0.48 L/min, precision 0.56 L/min, and the limits of agreement 1.12 L/min. Bias, precision, and limits of agreement of CCO compared with BCO were 0.41, 0.82, 1.64 L/min, respectively. Correlation between EM and CCO was r = 0.80 and between CCO and BCO r = 0.64. Cardiac output determined by CCO was within 10% of the EM determination for 37 measurements, between 10% and 20% for 17, and greater than 20% for 7 measurements.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

On-site prothrombin time, activated partial thromboplastin time, and platelet count. A comparison between whole blood and laboratory assays with coagulation factor analysis in patients presenting for cardiac surgery.

BACKGROUND: Although available hemostasis assays from institutional laboratories permit an analytical approach to diagnosis and treatment of coagulation disorders following cardiopulmonary bypass, their clinical utility has been limited by delays in obtaining results. The development of instrumentation for on-site testing allows rapid return of results. This study was designed to compare whole blood (WB) results obtained from on-site coagulation assays with values provided by our institutional laboratory (LAB). METHODS: After Institutional Human Studies Committee approval, 362 patients presenting for cardiac surgery requiring cardiopulmonary bypass were enrolled in this study. Prothrombin time (PT), activated partial thromboplastin time (aPTT), and platelet count (PLT) assays were performed in both WB and LAB systems. PT, aPTT, and PLT measurements were compared between WB and LAB assays using blood specimens obtained from at least two time points for each patient. Normal range values for both PT and aPTT methods were determined by using measurements from a normal reference population. Coagulation factor levels were measured in a subset of patients to characterize the response of PT and aPTT assays to individual and multiple factor levels. To employ Bayes' theorem and calculate predictive indexes (e.g., sensitivity, specificity), the disease or factor deficiency was determined using factor levels. Predictive indexes were used to evaluate the ability of PT and aPTT assays to identify factor deficiency. RESULTS: PLT counts were similar between systems. Linear regression and bias analysis demonstrated similar results for WB and LAB PT and discordant results for aPTT measurements. Both PT assays had a similar normal range, whereas a wider distribution of results was evident for the WB aPTT normal range. Although statistically greater slopes for factor:aPTT regressions were observed for the WB system, WB aPTT correlated better with factor V and with factor V, VIII, and XII levels (multivariate linear regression). Diagnostic performance for factor levels less than 0.3 and 0.4 U/ml was similar for both WB and laboratory PT and aPTT assays. WB and LAB PT and aPTT assays performed similarly in detecting factor deficiency in the period after cardiopulmonary bypass. CONCLUSIONS: WB PT and PLT values correlate well with those obtained from the LAB. The discrepancy between measurement systems in aPTT values is probably a reflection of both different normal ranges and responsiveness to factor deficiency. These WB assays provide coagulation results that can accurately identify patients with quantitative deficiencies in platelets and coagulation factors.

Adult↗

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. Exclusion criteria were diabetes, renal failure, recent or perioperative myocardial infarction, or use of inotropic drugs. HRV data during electrocardiographically documented episodes of myocardial ischemia were omitted. RESULTS: There were no differences in any measurement of preoperative HRV between groups during the day, but HRV was greater at night (12:00 AM to 5:00 AM) in volunteers than in patients in either surgical group. In the hour after induction of anesthesia (before cardiopulmonary bypass), the components of HRV were decreased compared with those in the preoperative daytime but were similar in the two surgical groups. After surgery, HRV in the group undergoing nonthoracic vascular surgery remained at about the same level as that observed after induction of anesthesia, whereas in the group undergoing coronary artery bypass graft surgery, HRV was further reduced and was approximately 40-50% less than that in the vascular surgery group (P < 0.05). In the coronary artery bypass group, the reduction in HRV compared with the preoperative daytime measurements persisted on postoperative day 5. CONCLUSIONS: HRV is reduced after uncomplicated coronary artery bypass graft surgery. Although we cannot exclude the effects of uncontrolled variables in this reduction of postoperative HRV, the observed changes in HRV did not appear to result from general anesthesia, perioperative stress responses, and other factors associated with the early postoperative period. These data are consistent with the supposition that cardiac autonomic nervous system function is impaired after cardiac surgery.

Autonomic Nervous System↗

In vitro reversal of heparin effect with heparinase: evaluation with whole blood prothrombin time and activated partial thromboplastin time in cardiac surgical patients.

This study was designed to evaluate the potential in vitro use of heparinase to eliminate functionally active heparin prior to performing whole blood (WB) prothrombin time (PT) and activated partial thromboplastin time (APTT) assays. A total of 250 U/kg of heparin for cardiopulmonary bypass (CPB) was administered to 30 cardiac surgical patients in three consecutive, divided doses (20, 80, and 150 U/kg) at 15-min intervals. Blood specimens were obtained prior to heparin administration (baseline) and 10 min after each heparin dose. After collection, blood specimens were fractionated into three aliquots of which the first was used for determination of heparin concentration. After gentle mixing, WB PT and APTT measurements were performed for heparinase (Aliquot 2)- and nonheparinase (Aliquot 3)-treated blood. With consecutive heparin doses of 20 and 80 U/kg, WB PT increased from a baseline of 12.3 +/- 0.1 s to 13.3 +/- 0.2 and 18.5 +/- 1.3 s, while WB APTT increased from a baseline of 28.3 +/- 1.1 s to 89.5 +/- 5.4 after the initial heparin dose (20 U/kg). When compared to baseline (no heparin) results, small, progressive increases in heparinase-treated WB PT (0.7 +/- 0.1, 1.5 +/- 0.1, 2.1 +/- 0.1 s) and APTT (2.3 +/- 0.3, 5.7 +/- 0.4, 9.5 +/- 0.5 s) were seen with increasing heparin concentration (0.23, 1.58, and 3.95 U/mL, respectively). Heparinase was highly effective in eliminating the anticoagulant effects of even large amounts of heparin in plasma from cardiac surgical patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Comparison of activated coagulation time and whole blood heparin measurements with laboratory plasma anti-Xa heparin concentration in patients having cardiac operations.

Previous reports suggest that activated clotting times do not correlate with heparin concentration during cardiopulmonary bypass. This study was designed to compare whole blood heparin concentration and activated clotting time measurements with laboratory-based plasma heparin concentration. Sixty-two patients having cardiac operations requiring cardiopulmonary bypass were enrolled in this study. The study was conducted in two phases. In phase I of this trial, blood specimens were obtained from 30 patients before heparin administration and after each of three heparin doses (20, 80, and 150 U/kg). In phase II, blood specimens were obtained from 32 patients before heparin administration and 10 minutes after each of the following: heparin administration (250 or 300 U/kg), initiation of cardiopulmonary bypass, achievement of hypothermia, initiation of rewarming, and immediately before discontinuation of bypass. Blood specimens were used to measure activated clotting time (kaolin and celite), whole blood heparin concentration, and anti-factor Xa plasma heparin concentration. In phase I, activated clotting time (celite: r = 0.91; kaolin: r = 0.93) and whole blood heparin concentration (r = 0.98) measurements correlated well with plasma heparin concentration. After initiation of cardiopulmonary bypass (phase II), weak correlations for activated clotting time measurements (celite: r = 0.34; kaolin: r = 0.59) and a strong correlation for whole blood heparin concentration (r = 0.95) were evident when compared with plasma heparin concentration. During bypass, activated clotting time measurements also inversely correlated with temperature (celite: r = -0.21; kaolin: r = -0.19) and hematocrit (celite: r = -0.26; kaolin: r = -0.21). A weak correlation between activated clotting time measurements and plasma heparin concentration is evident during the cardiopulmonary bypass period, probably because of the influence of both reduced hematocrit and temperature on the activated clotting time assay. In contrast, whole blood heparin measurements correlate well with plasma heparin concentration before and during bypass. Further studies are needed to determine whether maintaining heparin levels during cardiopulmonary bypass by monitoring heparin concentration is more effective in preventing consumptive activation of the hemostatic system, reducing bleeding, and minimizing the use of blood products after cardiopulmonary bypass when compared with a protocol based on activated clotting time.

Blood Coagulation↗

Prospective evaluation and clinical utility of on-site monitoring of coagulation in patients undergoing cardiac operation.

Although laboratory coagulation tests permit a rational approach to both diagnosis and management of coagulation disorders after cardiopulmonary bypass, their clinical utility is limited by delays in obtaining results. This study was designed to evaluate prospectively the impact of on-site coagulation testing on blood product use, operative time, and intraoperative management of microvascular bleeding. Patients who underwent cardiac procedures involving cardiopulmonary bypass and subsequently developed microvascular bleeding were randomly assigned to receive either standard therapy (n = 36) or therapy defined by a treatment algorithm based on results from an on-site coagulation monitoring laboratory (n = 30). No differences were found between treatment groups in hematologic assay data, operative procedures, or duration of cardiopulmonary bypass. Patients treated in accordance with on-site laboratory results (algorithm therapy) received significantly less intraoperative fresh frozen plasma (0.4 +/- 1.1 U versus 2.4 +/- 2.8 U; p = 0.0006) during the treatment interval, had shorter operative times, and had less mediastinal chest tube drainage during the initial perioperative interval (158 +/- 169 ml versus 326 +/- 258 ml; p = 0.003) than did patients in the standard therapy group. Patients who underwent algorithm therapy also received fewer platelet (1.6 +/- 5.9 versus 6.4 +/- 8.2 U; p = 0.02) and red blood cell (1.9 +/- 1.7 U versus 4.1 +/- 4.1 U; p = 0.01) transfusions after the operation. Nine of 36 (25%) standard group patients received initial therapy which differed from that which would have been guided by the on-site algorithm protocol. Our findings indicate that rapid and accurate coagulation test results can guide specific therapy and optimize treatment of microvascular bleeding in patients who undergo cardiac operations.

Blood Coagulation Tests↗

Five-year experience with the maze procedure for atrial fibrillation.

Between September 25, 1987, and December 31, 1992, 75 patients (53 men, 22 women; average age, 52 years) underwent the maze procedure for the treatment of atrial fibrillation. Six patients had undergone a previous cardiac operation and 28% underwent concomitant cardiac procedures in addition to the maze procedure. One patient (1.3%) died 10 days after undergoing a combined maze procedure and Morrow procedure for the management of chronic atrial fibrillation and hypertrophic obstructive cardiomyopathy. Postoperative atrial pacemakers were required in 40%: 26% for preoperative sick sinus syndrome and 6% for iatrogenic injury of the sinus node, and 8% had pacemakers in place preoperatively. As of December 31, 1992, 65 patients had been followed up for at least 3 months after operation (range, 3 to 63 months). The maze procedure cured atrial fibrillation, restored atrioventricular synchrony, and preserved atrial transport function in 64 of 65 patients (98%). The procedure has been curative without the need for medications in 58 of 65 patients (89%) and with the need for medications in 6 of 65 (9%), with medications failing in only 1 of the 65 patients (2%). The results support the maze procedure as the treatment of choice in patients with medically refractory symptomatic atrial fibrillation.

Adult↗

Perioperative myocardial ischemia. Its relation to anatomic pattern of coronary artery stenosis.

BACKGROUND: Recently, the frequency of intraoperative myocardial ischemic episodes in patients with steal-prone coronary anatomy, compared with other groups of patients undergoing coronary artery surgery (CABG), has been characterized. Because the relationship between anatomic distribution of coronary stenosis and myocardial ischemic episodes over the entire perioperative period has not been well defined, the authors sought to examine this relationship in 100 adult patients undergoing CABG surgery. METHODS: Continuous electrocardiographic (ECG) monitoring was performed in the pre-, intra-, and postoperative periods, quantifying the frequency (episodes/hour of monitoring [epis/h]) and duration (minutes/hour of monitoring [min/h]) of ECG ischemic episodes defined as a reversible ST segment shift > or = 1 mm at J + 60 ms of > or = 1 min duration. Based on preoperative coronary angiography, patients were categorized into the following groups: group 1 (n = 40), steal-prone coronary anatomy (occluded major coronary artery and > or = 50% stenosis of left main coronary artery or > or = 70% proximal stenosis 2 (n = 17), left main or equivalent coronary stenosis (> or = 50% stenosis of left main coronary artery or > or = 70% proximal stenosis of the left anterior descending and circumflex coronary arteries); and group 3 (n = 43), coronary artery stenosis > or = 70% not fitting the preceding categories. RESULTS: Compared with group 3, patients in group 1 had more frequent and longer ECG ischemic events preoperatively, and were nearly two times more likely (relative risk 1.82, 95% confidence interval 1.07-3.10) to develop an ischemic event during this period. There were no differences in the relative risk, frequency, or duration of an ischemic episode between groups 1 and 3 during the intraoperative and postoperative periods, or between groups 1 and 2 or groups 2 and 3 during any perioperative period. In group 2 patients, the frequency of ischemic epis/h was less intra- compared with preoperatively, while, in group 3, the ischemic epis/h decreased postoperatively compared with the intraoperative period. The duration of ischemic episodes (min/h) in group 3, however, increased postoperatively compared with the pre- and intraoperative periods, while, in group 2, the duration of ischemic episodes (min/h) was less intraoperatively compared with the preoperative period. Ninety-seven percent of preoperative ECG ischemic episodes occurred without symptoms. Postoperative myocardial infarction occurred in three patients in group 3, two in group 2, and one in group 1. There were no perioperative deaths. CONCLUSION: These data indicate that, compared with patients with non-left main or equivalent coronary stenosis, those with steal-prone coronary anatomy have more frequent and longer ECG ischemic episodes preoperatively. The data also indicate that there are no other differences in the risk, frequency, or duration of ischemic episodes between groups perioperatively. Thus, different distributions of coronary artery stenosis may be associated with changes in the perioperative characteristics of ECG ischemic episodes.

Aged↗

Perioperative evaluation of a new mixed venous oxygen saturation catheter in cardiac surgical patients.

Fiberoptic pulmonary artery flotation catheters have gained clinical acceptance for continuous monitoring of mixed venous oxygen saturation (SvO2), especially in the management of hemodynamically unstable patients. Therefore, the performance of the oximetry system used is extremely important. The accuracy and stability of a new two-wavelength oximetry pulmonary artery catheter and SAT-2 oximeter were assessed in adult patients during and following cardiac surgery. After in vitro calibration of the system, the catheter was inserted through the right internal jugular vein and positioned in the pulmonary artery prior to induction of anesthesia. During the study period, the system was updated for hemoglobin changes of 1.8 g/dL or more. In vivo SvO2 values obtained by the oximetry catheter were compared with those determined with a reference oximeter from simultaneously drawn mixed venous blood specimens at different intervals. A total of 604 paired data points from 52 patients were analyzed, 572 (94.7%) of which were within the 95% confidence interval. Overall bias was -1.7% +/- 3.5% (SD). The results suggest that over the time course of the study, in vivo SvO2 values obtained with the two-wavelength catheter and the SAT-2 oximeter closely approximated SvO2 measured with a reference oximeter from mixed venous blood samples (r = 0.917; SEE 3.5%) in cardiac surgical patients in whom marked physiological changes occur.

Adult↗

Successful surgical treatment of atrial fibrillation. Review and clinical update.

Atrial fibrillation is the most common of all sustained cardiac arrhythmias, yet it has no effective medical or surgical therapy. During the past decade, multipoint computerized electrophysiological mapping systems were used to map both experimental and human atrial fibrillation. On the basis of these studies, a new surgical procedure was developed for atrial fibrillation. Between September 25, 1987, and July 1, 1991, this procedure was applied in 22 patients with paroxysmal atrial flutter (n = 2), paroxysmal atrial fibrillation (n = 11), or chronic atrial fibrillation (n = 9) of 2 to 21 years' duration. All patients were refractory to all antiarrhythmic medications, and each patient failed to receive the desired therapeutic benefits of an average of five drugs administered preoperatively. There were no operative deaths and all perioperative morbidity resolved. All 22 patients have been successfully treated for atrial fibrillation with surgery alone. Three patients developed one late isolated episode of atrial flutter at 5, 6, and 15 months postoperatively, and each of these patient's symptoms is now controlled by a single antiarrhythmic drug. Preservation of atrial transport function has been documented in all patients postoperatively, and all have experienced marked clinical improvement.

Adult↗

Operations for atrial fibrillation.

Atrial fibrillation is the most common of all sustained cardiac arrhythmias, yet it has no effective medical or surgical therapy. During the past decade, multipoint computerized electrophysiological mapping systems were used to map both experimental and human atrial fibrillation. On the basis of these studies, a new surgical procedure was developed for atrial fibrillation. Between September 25, 1987, and May 1, 1991, this procedure was applied in 22 patients with either paroxysmal atrial flutter (n = 2), paroxysmal atrial fibrillation (n = 11), or chronic atrial fibrillation (n = 9) of 2 to 21 years' duration. All patients were refractory to all antiarrhythmic medications and each patient failed an average of 5.2 drugs preoperatively. There were no operative deaths and all perioperative morbidity resolved. All 22 patients have been cured of atrial fibrillation with surgery alone. One late isolated episode of atrial flutter occurred in a patient who is now receiving encainide. Preservation of atrial transport function has been documented in all of the patients postoperatively and all have experienced marked clinical improvement.

Adult↗