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G L Hicks

Publications and source records attributed to G L Hicks.

At least 19 recordsLinked to original sources
PubMed2001

Association of ABO-mismatched platelet transfusions with morbidity and mortality in cardiac surgery.

BACKGROUND: The transfusion of ABO-mismatched platelets has been associated with increased morbidity and mortality during induction therapy for acute leukemia and allogeneic progenitor cell transplantation. STUDY DESIGN AND METHODS: Reported here is a cohort study of 153 patients undergoing primary coronary artery bypass graft or coronary valve replacement surgery by two surgeons in one institution during 1997 and 1998. All statistics employed nonparametric two-sided tests (Mann-Whitney; Fisher's exact test). RESULTS: Patients receiving at least one ABO-mismatched pool of platelets had a significantly longer hospital stay, more days of fever, greater total hospital charges, and more RBC transfusions. Mortality, hours in the intensive care unit, days on antibiotics, and numbers of platelet transfusions were also greater in recipients of ABO-mismatched platelets, but these differences were of less statistical significance. When the analysis was restricted to the 139 patients who received no more than two pools of platelets, the trends for increased morbidity and mortality (8.6% vs. 1.9%; p = 0.10) in recipients of ABO-mismatched platelets persisted. The number of RBC transfusions required in this latter cohort was 50 percent greater (mean, 6.1 vs. 9.2; p = 0.02), despite the fact that the number of platelet transfusions given was similar (mean, 1.2 vs. 1.3 pools; p = 0.22). CONCLUSIONS: ABO-mismatched platelet transfusions are associated with unfavorable outcomes in cardiac surgery, a relationship that remains unexplained. As this association has been found in three cohort studies in various clinical settings, further investigation of this association is warranted.

ABO Blood-Group System↗
PubMed2001

Hemodynamic effects of chest closure in adult patients undergoing cardiac surgery.

OBJECTIVE: To evaluate hemodynamic effects of sternal retractor removal and sternal closure after cardiopulmonary bypass and to correlate these changes with preoperative and intraoperative variables. DESIGN: Prospective. SETTING: University hospital. PARTICIPANTS: Fifty adults undergoing cardiac surgery. MEASUREMENTS AND MAIN RESULTS: Arterial, pulmonary artery, and transesophageal echocardiography measurements were obtained immediately before and 1 minute after removal of the sternal retractor and immediately before and 1 minute after sternal closure. Retractor removal caused a significant decrease in cardiac index by 5.6% (p < 0.01), stroke volume index by 4.0% (p < 0.05), and mean pulmonary artery pressure by 4.8% (p < 0.001). Sternal closure caused a significant decrease in cardiac index by 7.7%, stroke volume index by 10.2%, and left ventricular end-diastolic area by 9.2% (p < 0.001) There were significant increases in pulmonary capillary wedge pressure and systemic vascular resistance by 9.1% and 10.8% (p < 0.01). There was no significant change in the ejection fraction area. The magnitude of decrease in stroke volume index with sternal closure correlated positively with end-diastolic area immediately before the closure. CONCLUSION: Chest closure is associated with significant hemodynamic changes and a change in the ventricular transmural pressure-volume relationship. Patients with lower preload immediately before closure are more vulnerable to a decrease in cardiac index. Based on the results of this study, volume appears to be the appropriate preventive and treatment option to limit the impact of chest closure.

Adult↗
PubMed1998

Lack of lung hemorrhage in humans after intraoperative transesophageal echocardiography with ultrasound exposure conditions similar to those causing lung hemorrhage in laboratory animals.

This study investigated the phenomenon of ultrasonically induced lung hemorrhage in humans. Multiple experimental laboratories have shown that diagnostic ultrasound exposure can cause hemorrhage in the lungs of laboratory animals. The left lung of 50 patients (6 women, 44 men, mean age 61 years) was observed directly by the surgeon after routine intraoperative transesophageal echocardiography was performed. From manufacturer specifications the maximum derated intensity in the sound field of the system used was 186 W/cm2, the maximum derated rarefactional acoustic pressure was 2.4 MPa, and the maximum mechanical index was 1.3. The lowest frequency used was 3.5 MHz. This exposure exceeds the threshold found for surface lung hemorrhage seen on gross observation of laboratory animals. No hemorrhage was noted on any lung surface by the surgeon on gross observation. We conclude that clinical transesophageal echocardiography, even at field levels a little greater than the reported thresholds for lung hemorrhage in laboratory animals, did not cause surface lung hemorrhage apparent on gross observation. These negative results support the conclusion that the human lung is not markedly more sensitive to ultrasound exposure than that of other mammals.

Adult↗
PubMed1998

Cardiac surgery.

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Cardiac Surgical Procedures↗
PubMed1997

Photo-irradiation improved functional preservation of the isolated rat heart.

BACKGROUND AND OBJECTIVE: Photo-irradiation causes a variety of effects in different cells and tissues. We hypothesized that photo-irradiation may improve cardiac preservation based on these observations. STUDY DESIGN/MATERIALS AND METHODS: For pre-storage treatment (Pre), the heart in an anesthetized open-chest rat was irradiated using an Argon-dye laser with a wavelength of 660 nm at a fluence of 16.8 J/cm2 or sham-operated. The heart was excised, perfused with Krebs-Henseleit Buffer, cardioplegically arrested, and stored by immersion at 0 degree C for 18 hrs. Functional recovery was evaluated by working reperfusion for 30 min. For post-storage treatment (Post), the isolated hearts were stored for 18 hrs at 0 degree C; laser irradiation at a fluence of 36 J/cm2 was administered during working reperfusion. Hearts which did not receive irradiation during reperfusion served as control. Furthermore, isolated cardiomyocytes were used to study laser effect on cellular ATP content, catalase activity, and nitric oxide (NO) release. RESULTS: Both Pre and Post groups showed significant improvement in recovery of aortic flow, cardiac output, and work compared to the corresponding control groups (P < 0.05). Combined Pre/Post laser treatment did not improve function. Investigation using isolated rat cardiomyocytes found that both end-storage ATP and end-reperfusion catalase activity in the laser-treated group were significantly higher than those in the untreated cells (P < 0.05). NO release increased by 15% in the laser group after 18 hrs of 37 degrees C incubation. CONCLUSION: Photo-irradiation improves functional recovery of the cold-stored rat heart possibly via conservation of ATP and antioxidant enzyme activity.

Adenosine Triphosphate↗
PubMed1996

Twenty-four-hour intermittent perfusion storage of the isolated rat heart. II. Perfusion pressure and functional preservation.

This study investigated the effect of intermittent perfusion (IP) pressures on functional preservation of the cold-stored isolated rat heart. The heart was flushed with cardioplegic solution #11 with ethylene diamine-tetraacetic acid and 2, 3-butanedione monoxime (CP-11EB), and stored at 0 degree C for 24 hr. During storage, the heart was intermittently perfused for 3 min at 10 and 17 hr of storage with 25 degrees C oxygenated CP-11EB. The IP pressures studied were: 20, 30, 40, 50, 60, 70, 80, and 100 mm Hg. Poststorage recovery of function was assessed with 30 min of working reperfusion. Control function of the unstored heart was: aortic flow (AF), 51.3 +/- 2.2 ml/min; coronary flow (CF), 25.8 +/- 1.2 ml/min; cardiac output (CO), 77.7 +/- 2.3 ml/min; work, 92.0 +/- 4.9 g-m/min; and coronary vascular resistance (CVR), 2.64 +/- .21 mm Hg-min/ml. Functional return in the 30,40,50,60,70, and 80 mm Hg groups was similar. Recovery in a representative group (60 mm Hg) was: AF, 52 +/- 3%; CF, 41 +/- 2%; CO, 48 +/- 3%; work, 42 +/- 3%; and CVR, 225 +/- 10% of the control. The total IP volume in this group was 71.0 +/- 1.7 ml; total lactate dehydrogenase (LDH) release during IP was 8.62 +/- .37 units/g dry; and end-storage tissue lactate was 52.6 +/- 6.4 mumole/g dry. As IP pressure decreased to 20 mm Hg, cardiac functional recovery declined significantly to AF, 35 +/- 6%; CF, 33 +/- 2%; CO, 34 +/- 5%; and work, 27 = 4% of control (P < .05 vs. 60 mm Hg group). The total IP volume decreased to 10.1 +/- .9 ml, tissue lactate content rose to 87.1 +/- 10.9 (P < .05 vs. 60 mm Hg group), but LDH release fell to 5.59 +/- .46 (P < .05 vs. 60 and 100 mm Hg groups). When IP pressure increased to 100 mm Hg, cardiac function was depressed with AF recovered to 25 +/- 3%; CF, 30 +/- 3%; CO, 26 +/- 3%; work, 21 +/- 3%; and CVR, 294 +/- 26% of control (P < .05 vs. 60 mm Hg group). IP volume increased to 100.7 +/- 2.4 ml; total LDH release increased to 19.1 +/- 1.2 (P < .05 vs. 60 mm Hg group), although tissue lactate (58.9 +/- 3.9) was not different from the 60 mm Hg group. End-storage tissue wet/dry weight ratio and myocardial adenosine triphosphate content were not different among the 20, 60, and 100 mm Hg groups. In conclusion, IP has a broad pressure optimum ranging from 30 to 80 mm Hg for 24-hr hypothermic preservation of the rat cardiac explant.

Adenosine Triphosphate↗
PubMed1996

Enalaprilat, an angiotensin-converting enzyme inhibitor, enhances functional preservation during long-term cardiac preservation. Possible involvement of bradykinin and PKC.

We investigated the effect of enalaprilat (ET) on long-term preservation of cardiac explant. Isolated rat hearts (n = 7/group) were pretreated with 0 to 40 nM ET and stored at 0 degree C for 16 h. Functional viability was assessed after 30-min working reperfusion without ET. Prestorage control function (mean +/- S.E.M.) (n = 7) included heart rate (HR), 291 +/- 12 bpm; aortic flow (AF). 49.8 +/- 1.9 ml/min; coronary flow (CF), 25.2 +/- 1.3 ml/min; cardiac output (CO), 75.0 +/- 1.2 ml/min; and work, 89.4 +/- 4.7 g-m/min. Post-storage function of untreated hearts was: AF, 61%; CF, 43%; CO, 55%; work, 48% of control. ET (20 nM) enhanced AF recovery to 85%; CF, 58%; CO, 76%; work, 73% of control (P < 0.05 v untreated). Hoe 140 (D-Arg-[Hyp2, Thi5,8, D-Phe7]BK) (1 nM) a bradykinin receptor antagonist, inhibited ET effect; function returned to the untreated level. Protein kinase C (PKC) inhibitors staurosporine (15 nM) and bisindolylmaleimide I (0.5 microM) also blocked ET effect. After 4 h of cold storage, membrane PKC activity changed little from the prestorage level in the untreated hearts, but was elevated significantly from 52.8 +/- 5.2 pmol/min/mg to 74.7 +/- 8.2 by 20 nM ET (P < 0.05 v untreated). Cytosol PKC did not change during 4 h cold storage with or without ET. Neither end-storage nor end-reperfusion myocardial ATP content was affected by 20 nM ET treatment. In conclusion, ET improves cardiac preservation possibly via bradykinin receptor and PKC without affecting ATP metabolism.

Adenosine Triphosphate↗
PubMed1996

Obliteration of empyema tract with deepithelialized unipedicle transverse rectus abdominis myocutaneous flap.

Four patients with chronic empyema after pneumonectomy have undergone successful obliteration of the empyema tract with a deepithelialized transverse rectus abdominis myocutaneous flap. The deepithelialized skin island has provided sufficient bulk for tract obliteration. Rotation of the skin island into the long axis of the rectus muscle has added considerable length to this flap, allowing it to reach the apex of the thoracic cavity. A recurrent loculation developed 4 months after the obliteration procedure in one patient. This was successfully treated with open pleural drainage and a second Clagett procedure. Over a mean follow-up period of 35 months, all four patients are free of further infectious sequelae. Chest roentgenograms have confirmed eradication of the tracts in all four patients.

Aged↗
PubMed1994

Enhanced functional preservation of cold-stored rat heart by a nucleoside transport inhibitor.

This study investigates the hypothesis that inhibition of nucleoside transport during hypothermic storage elevates tissue adenosine (ADO) content and improves the function of the isolated rat heart. The hearts, flushed with a cardioplegic solution containing varying concentrations (0-100 nM) of a nucleoside transport inhibitor, S-(4-nitrobenzyl)-6-thioinosine (NBTI), were immersion-stored at 0 degrees C for 9 hr. Function was assessed after 30 min of working reperfusion. Function of unstored fresh hearts served as controls and poststorage recovery is reported as percentage of control function. Poststorage heart rate in all groups returned to control level after reperfusion. Recovery of other functional parameters in the no-NBTI group was as follows: aortic flow (AF), 56.2 +/- 4.6%; coronary flow (CF), 53.9 +/- 3.2%; cardiac output (CO), 55.5 +/- 4.0%; systolic pressure, 81.6 +/- 2.5%; work, 47.0 +/- 4.2%; and coronary vascular resistance (CVR), 157.1 +/- 7.8% of control. NBTI improved functional recovery in a dose-dependent fashion; the maximal improvement was seen at a dose of 5 nM, in which the recovery was: AF, 78.1 +/- 3.4%; CF, 73.5 +/- 4.4%; CO, 76.7 +/- 3.6%; work, 70.7 +/- 5.0%; and CVR, 127.5 +/- 4.5% of control (P < 0.05 vs. no-NBTI). The ADO A1-receptor antagonist, 1,3-dipropyl-8-cyclopentylxanthine (0.1 microM) blocked the effects of 5 nM NBTI; the recovery of AF, CF, CO, work, and CVR decreased to 62.8 +/- 8.0%, 58.3 +/- 5.0%, 61.5 +/- 3.9%, 54.4 +/- 4.5%, and 163.8 +/- 12.7% of control, respectively (P < 0.05 vs. 5 nM NBTI). Tissue ADO content in 5 nM NBTI hearts at the end of storage was 0.075 +/- 0.025 mumol/g dry wt, which was significantly elevated from 0.016 +/- 0.004 mumol/g dry wt in no-NBTI hearts. Purine release during initial reperfusion was delayed in 5 nM NBTI hearts, indicating the inhibition of nucleoside transport by NBTI. But NBTI treatment did not improve end-storage or end-reperfusion myocardial ATP. In conclusion, the addition of NBTI to cardioplegic solution enhanced tissue ADO and improved poststorage function of the hypothermically stored rat heart. The effect is ADO A1-receptor mediated without invoking energy conservation.

Adenosine↗
PubMed1994

Deferoxamine given at reperfusion improves function of the cold-stored rat heart.

In this study deferoxamine (DF), a strong iron chelator, was administered either before storage or during reperfusion, in an attempt to inhibit the iron-dependent hydroxyl radical production and improve the functional recovery of the cold-stored/reperfused cardiac explant. Excised rat hearts were flushed with Krebs-Henseleit buffer (KHB), arrested with a cardioplegic solution, CP11-EB, with or without DF, and immersion stored in CP11-EB at 0 degree C for 16 hr. To assess function, the stored hearts were reperfused in the working mode with KHB for 30 min. Experimental groups included: (i) DF treatment during prestorage flush [CP11-EB + 0.01 mM (n = 5), 0.05 mM (n = 13), 0.1 mM (n = 5), 0.2 mM (n = 5), or 0.75 mM DF (n = 5)]; (ii) DF treatment during reperfusion [KHB + 0.3 mM (n = 5), 0.6 mM (n = 7), 0.75 mM (n = 11), 1.0 mM (n = 6), 1.5 mM (n = 4), or 2.5 mM DF (n = 7)]; and (iii) untreated group (n = 8) received no DF during flush or reperfusion. Function of unstored hearts (n = 7) including aortic flow (AF, 54.6 +/ 2.6 ml/min); cardiac output (CO, 76.5 +/- 3.3 ml/min), systolic pressure (SP, 135.7 +/- 1 mm Hg), diastolic pressure (DP, 70.7 +/- 3.8 mm Hg), and work (96.7 +/- 6.4 g-meter/min) served as controls. Functional recovery of the untreated group was AF, 59%; CO, 58%; SP, 71%; DP, 73%; work, 41% of control values. DF treatment at any dose during the initial flush did not improve functional recovery.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Adenosine deaminase inhibitor in cardioplegia enhanced function preservation of the hypothermically stored rat heart.

Adenosine (ADO) has been shown to be protective to the ischemic-reperfused myocardium. This study tested the hypothesis that inhibition of myocardial adenosine deaminase during cold storage will elevate tissue ADO content, improve the cardiac function, and preserve ATP. The isolated rat hearts (6-9 hearts/group) were flushed with a cardioplegic solution containing 0-75 microM erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA) and immersion-stored at 0 degree C for 9 hr. Function was assessed after 30 min working reperfusion. Function of the unstored hearts (n = 11, mean +/- SE) including heart rate (293 +/- 13 bpm), aortic flow (AF; 52.5 +/- 1.1 ml/min), coronary flow (CF; 23.5 +/- 1.3 ml/min), cardiac output (CO; 76.0 +/- 2.1 ml/min), systolic pressure (SP; 136 +/- 2 mmHg), diastolic pressure (DP; 63 +/- 1 mm Hg), work (90.5 +/- 3.4 g-m/min), and coronary vascular resistance (CVR; 2.77 +/- 0.14 mmHg-min/ml) served as controls. Heart rate in all stored hearts returned to normal after reperfusion. Recovery of other function in no-EHNA group was: AF, 52 +/- 7; CF, 55 +/- 5; CO, 53 +/- 6; SP, 79 +/- 4; DP, 93 +/- 3; work, 47 +/- 7; and CVR, 171 +/- 15% of control. EHNA improved functional recovery in a dose-dependent fashion. At the optimal concentration of 25 microM, the recovery was: AF, 83 +/- 6; CF, 68 +/- 4; CO, 78 +/- 5; SP, 90 +/- 3; DP, 105 +/- 5; work, 77 +/- 8; and CVR 151 +/- 9% of control. ADO A1 receptor antagonists, 8-phenyltheophylline (1 microM) and 1,3-dipropyl-8-cyclopentylxanthine (0.1 microM) blocked the effects of 25 microM EHNA; the recovery of CO was reduced to 65 +/- 3 and 50 +/- 2% of the control, respectively. Tissue ADO content in 25 microM EHNA hearts at the end of storage was 95 +/- 19 nmol/g dry wt, which was significantly elevated from 15 +/- 3 nmol/g dry wt in no-EHNA hearts. EHNA also caused a 45-fold increase in the release of ADO over no-EHNA group during the first 10 min of reperfusion. But EHNA treatment did not cause any change in either end-storage or end-reperfusion myocardial ATP levels. Thus EHNA in cardioplegic solution inhibited cardiac ADO catabolism during long-term hypothermic storage and improved function preservation partially via an ADO A1 receptor-mediated mechanism without invoking ATP conservation.

Adenine↗
PubMed1993

Transthoracic and transesophageal echocardiographic sizing of the aortic annulus to determine prosthesis size.

To assess the accuracy of 2-dimensional echocardiography versus transesophageal echocardiography (TEE) in predicting aortic annulus diameter, and to determine which part of the cardiac cycle should be used for measuring the size of the aortic valve prosthesis in patients undergoing aortic valve replacement, the aortic annulus was measured retrospectively in a blinded fashion in a group of 94 patients who had undergone aortic valve replacement: 66 had preoperative transthoracic echocardiography (TTE), 69 had intraoperative TEE, and 41 had both. Accuracy of measurements was calculated by the mean biases (differences between annular size by echo and actual valve size chosen by intraoperative mechanical sizing of the aortic annulus). TTE was compared with TEE and end-diastolic (ED) measurements with end-systolic (ES) measurements. The mean biases +/- SD were -1.7 +/- 3.4 mm by TTE-ES versus -0.9 +/- 3.5 mm by TEE-ES measurements (p = NS), and +0.03 +/- 3 mm by TTE-ED versus +0.5 +/- 2.8 mm by TEE-ED (p = NS). Examination of the magnitudes of the biases gave the same result. ED measurements were found to have a smaller amount of bias than ES measurements, both by TTE and by TEE: -1.7 +/- 3.4 mm by TTE-ES versus +0.03 +/- 3 mm by TTE-ED (p = 0.0001) and -0.9 +/- 3.5 mm by TEE-ES versus +0.5 +/- 2.8 mm by TEE-ED (p = 0.0001). Examination of the magnitudes of the biases also gave the same result.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Subzero nonfreezing storage of the mammalian cardiac explant. I. Methanol, ethanol, ethylene glycol, and propylene glycol as colligative cryoprotectants.

We employed hyperosmotic concentrations of penetrating cryoprotective agents (CPA) to store the isolated rat hearts unfrozen at subzero temperatures. The effect of acute exposure to CPA was assessed by flushing the hearts with CP-14, a cardioplegic solution, containing methanol (MeOH), ethanol (EtOH), ethylene glycol (EG), or propylene glycol (PG) for 2 min and reperfusing immediately with Krebs-Henseleit buffer in a working-heart model. The maximal doses that did not cause irreversible suppression of heart function were: MeOH, 1.78 M; EtOH, 1.27 M; EG, 0.84 M; and PG, 0.87 M. For nonfreezing storage, the hearts were flushed with CP-14 containing the highest tolerable concentrations of MeOH, EtOH, EG, or PG, stored for 6 h at -3.7, -2.8, and -1.4 degrees C, respectively, and then reperfused. Control cardiac output (CO) was 76.2 +/- 1.8 ml/min. Post-reperfusional recovery of CO was 86% in MeOH hearts, 82% in EtOH hearts, 76% in EG hearts, and 79% in PG hearts. Thus MeOH offered not only the least cardiac-suppressing effect but the lowest nonfreezing storage temperature. When storage time was extended, recovery and myocardial ATP level decreased with time in hearts flushed with CP-14 + 1.78 M MeOH and stored at -3.7 degrees C. The decay of function was faster than the decay of ATP level, suggesting energy was better preserved than function. The low return of function, however, may be related to CPA toxicity, osmotic stress, and ischemia/reperfusion injury. Nonfreezing storage at subzero temperatures using these CPAs may provide a novel approach to long-term cardiac preservation.

Adenine Nucleotides↗
PubMed1992

Patterns of referral and recovery in women and men undergoing coronary artery bypass grafting.

This study compares women and men undergoing coronary artery bypass grafting. Factors before and after coronary surgery were examined to identify variables related to mortality and morbidity. The study population included 465 women and 465 men matched for age (mean age 64.2 years) who underwent first time isolated coronary artery bypass grafting between 1983 and 1988. There were higher incidences of systemic hypertension, diabetes mellitus, postmyocardial infarction angina, thyroid gland disease, arthritis (p less than 0.001 for all), acute myocardial infarction (p = 0.03), congestive heart failure (p = 0.03), and emergency surgery (p = 0.02) in women, whereas more men had peptic ulcer disease (p less than 0.001). The in-hospital death rate was not significantly different (women 4.3% vs men 3.7%). For all subjects, emergency surgery (p less than 0.001), significant left main narrowing (p less than 0.05) and renal disease (p less than 0.001) were related to death, whereas history of myocardial infarction (p less than 0.05) and diabetes (p less than 0.05) were related to death only in men. Age and body surface area were not related to death. After surgery men had a higher incidence of atrial arrhythmia (p less than 0.001), and women had a higher incidence of congestive heart failure (p less than 0.001). Although women did not have a higher mortality rate, the data suggest that women and men do not share all the same predictors of mortality after surgery.

Adult↗
PubMed1992

Coronary artery operation in radiation-associated atherosclerosis: long-term follow-up.

Radiation-associated coronary atherosclerosis is a potential problem for patients who have had mediastinal irradiation for malignant tumors. This study identified 14 patients with radiation-associated coronary atherosclerosis, defines unique population characteristics, and analyses postsurgical problems and long-term outcome. Fourteen patients with radiation-associated coronary atherosclerosis and class III and IV New York Heart Association symptoms were identified because of mediastinal or chest wall irradiation (30 Gy) associated with anterior epicardial discoloration or fibrosis, aortitis with adventitial thickening, and inflammatory process over a proximal coronary artery. Two distinct treatment groups were analyzed. Coronary artery operation resulted in one hospital death, with vein grafts being used predominantly. The internal mammary artery could only be used in 3 patients because of vessel friability and mediastinal fibrosis. Postoperative right ventricular dysfunction and pulmonary problems were frequent. Severe pericardial inflammatory complications (fibrosis with graft closure, and constrictive pericarditis) present in 2 early patients resulted in routine anterior pericardiectomy after coronary artery operation without further problems. Long-term follow-up (100%) (range, 11 to 74 months) revealed that 1 patient died late and of the remainder (12 patients), 11 were in New York Heart Association class I and 1 in class II, experiencing three myocardial events. Thus, patients with radiation-associated coronary atherosclerosis have a low operative mortality but have risk of early right ventricular and pulmonary dysfunction. The routine use of internal mammary artery may not be possible and anterior pericardiectomy is recommended. Long-term results are excellent and no evidence of accelerated disease has been noted.

Adult↗
PubMed1992

Freezing preservation of the mammalian cardiac explant. II. Comparing the protective effect of glycerol and polyethylene glycol.

We compared the cryoprotective ability of glycerol and polyethylene glycol (PEG) during freezing. Isolated rat hearts were flushed with one of three cardioplegic solutions (CP-14, CP-15, and CP-16), frozen at -1.4 degrees C, and reperfused after thawing to assess function. After 3 h freezing, cardiac output (CO) in CP-14-flushed hearts recovered to 58.1% of control. CP-16 (CP-14 with 5% PEG) improved CO to 77.5%. Five hours of freezing abolished recovery in CP-14 hearts, but CP-15 (CP-14 with 50 mM glycerol) and CP-16 hearts produced 40.0 and 49.0% CO, respectively. With 6 h freezing, CP-15 hearts did not recover, whereas CP-16 hearts recovered 37.5% CO. In CP-14 hearts frozen for 3 h, 37.4% of the tissue water was ice that increased to 44.7% with 5 h freezing. CP-15 and CP-16 hearts had 34.4 and 30.9% tissue ice, respectively, after 5 h freezing. Tissue water contents in CP-14 and CP-15 hearts (3.83 to 3.96 g H2O/g dry) were 14 to 24% higher than that in CP-16 hearts. Six hours of freezing elevated AMP and ADP contents and reduced ATP levels in CP-15 and CP-16 hearts. Total adenine nucleotide (TAN) content of CP-15 hearts was 72% of control, while that of CP-16 hearts was normal. In conclusion, both glycerol and PEG offered cryoprotection by reducing tissue ice formation. PEG was superior by reducing tissue ice content further via dehydration and by better preserving TAN content.

Adenine Nucleotides↗
PubMed1992

Freezing preservation of the mammalian cardiac explant. V. Cryoprotection by ethanol.

We studied the colligative cryoprotective effect of ethanol (EtOH) in preserving the isolated rat heart frozen at -3.4 degrees C or unfrozen at -1.4 degrees C. Addition of 4.7% (v/v) EtOH to a cardioplegic solution, CP-14, raised the osmolality from 280 to 1100 mOsm/kg H2O and lowered the melting point from -0.52 to -2.1 degrees C. Freezing of the cardiac explant at -3.4 degrees C for 6 h resulted in 34.3 +/- 1.9% of the tissue water as ice; recovery of cardiac output (CO) was 50%. Polyethylene glycol, which at 5% (w/v) has been shown to cryoprotect the hearts during freezing at -1.4 degrees C, did not improve the protective effect of 4.7% EtOH. CP-14 + 4.7% EtOH did not freeze at -1.4 degrees C. After 6 h storage, CO in hearts flushed with CP-14 + 4.7% EtOH oxygenated with 95% O2/5%CO2 returned to almost control level and was much higher than that in hearts flushed with 100% O2 saturated-CP-14 + 4.7% EtOH. Storage of 8 and 12 h reduced CO to 87 +/- 9 and 60 +/- 5% of control. By employing EtOH as a colligative cryoprotectant, we preserved the adult mammalian heart frozen at -3.4 degrees C or unfrozen at -1.4 degrees C, suggesting that this small molecular weight, penetrating substance may be a suitable cryoprotectant for long-term storage of the cardiac explant at high subzero temperatures.

Animals↗