Hyper osmolality does not modulate natriuretic peptide concentration in patients after coronary artery surgery.

BACKGROUND: The heart secretes natriuretic peptides (NPs) in response to myocardial stretch. Measuring NP concentrations is a helpful tool in guiding treatment. It has been suggested that sodium ion and hyperosmolality could affect NP excretion. If this is true, peri-operative NP measurements could be inconsistent when hypertonic solutions are used. With different osmolalities but equal volumes of hydroxyethyl starch (HES)--and hypertonic saline (HS)--infusions, this double-blinded study tested the hypothesis that osmolality modulates the excretion of NPs. METHODS: Fifty coronary surgery patients were randomized to receive within 30 min 4 ml/kg either HS or HES post-operatively. Samples for analysis of atrial NP (ANP), brain NP (BNP), plasma and urine sodium and osmolality and urine oxygen tension were obtained before and 60 min after starting the infusions and on the first post-operative morning. The haemodynamic parameters were measured at the same time points. RESULTS: Plasma osmolality and sodium increased only in the HS group. Changes in plasma BNP and ANP levels did not differ between the groups (P=0.212 and 0.356). There were no correlations between NP levels and osmolality or sodium at any time point. In the HS group, urine volume was higher (3295 vs. 2644 ml; P<0.05) and the need for furosemide treatment was less (0.4 vs. 3.8 mg; P<0.01) than in the HES group. CONCLUSIONS: The absence of effects of plasma sodium content or hyperosmolality on NP release validates the value of NPs as a biomarker in peri-operative patients.

Cardioprotective effect of adenosine pretreatment in coronary artery bypass grafting.

OBJECTIVE: There are several reports of the use of adenosine as a cardioprotective agent during cardiac surgery. Adenosine treatment might affect neutrophils and inflammatory mediators. The present prospective randomized study was designed to investigate the effect of adenosine pretreatment on myocardial recovery and inflammatory response in patients undergoing elective coronary artery bypass surgery. DESIGN: A prospective, randomized, controlled study. SETTING: Operative unit and ICU in a university hospital in Finland. PATIENTS: Thirty male patients undergoing primary, elective coronary revascularization. INTERVENTIONS: Patients in the adenosine group received a 7-min infusion of adenosine (total, 650 microg/kg) before the initiation of cardiopulmonary bypass. MEASUREMENTS: Postoperative creatine kinase (CK)-MB release and hemodynamics were recorded. Perioperative leukocyte and cytokine release were measured. RESULTS: Adenosine pretreatment resulted in less CK-MB release and an improved postbypass cardiac index. Similar leukocyte counts and cytokine responses were seen in both groups perioperatively. Neutrophil counts were similar between the groups before and after myocardial ischemia when measured simultaneously in arterial and coronary sinus blood. CONCLUSIONS: The present results support the hypothesis that adenosine pretreatment is cardioprotective in humans, but the present dose failed to regulate the inflammatory responses after coronary artery bypass grafting.

Effect of ischemic preconditioning on myocardial protection in coronary artery bypass graft patients : can the free radicals act as a trigger for ischemic preconditioning?

OBJECTIVE: To investigate the interrelationship of free radicals (FRs), ischemic preconditioning (IP), and hemodynamic function in coronary artery bypass graft (CABG) patients. DESIGN: Prospective, randomized, and controlled clinical study. PATIENTS: Forty CABG patients were randomized into an IP group (n = 20) and a control group (n = 20). INTERVENTION: The IP group was preconditioned with two cycles of two-min ischemia followed by 3-min reperfusion before cross-clamping. MEASUREMENT AND RESULTS: FR content in coronary sinus blood was measured directly using alpha-phenyl-N-tert-butylnitrone-electron spin-trapped spectroscopy. A small amount of FRs was generated after the IP protocol (5.6% above the baseline) but not in control subjects. A larger amount was generated 10 min after declamping in both groups (8.4% in IP protocol and 7.7% in control subjects). Hemodynamic function recovered better in the IP group at 1 h and 6 h after declamping. There was a significant negative correlation between FR generation after declamping and left ventricular stroke work index (LVSWI) at 1 h and 6 h after declamping (r = -0.71 and - 0.59, respectively) in the control subjects but not in the IP group. There was a significant positive correlation between FR generation after the IP protocol and cardiac index at 1 h and 6 h (r = 0.50 and 0.61, respectively) and LVSWI at 1 h and 6 h (r = 0.56 and 0.54, respectively) after declamping in the IP group but not in the control subjects. CONCLUSION: FR generation after the operation correlates with ventricular functional depression in CABG patients. IP protects the stunning heart but does not alter FR generation. The association of better hemodynamic recovery after CABG with FR generation during the IP period suggests that FRs might act as one of the triggers for IP.

The protective effects of preconditioning decline in aged patients undergoing coronary artery bypass grafting.

OBJECTIVE: We sought to investigate the effects of myocardial ischemic preconditioning in adult and aged patients undergoing coronary artery bypass grafting. METHODS: Eighty patients with 3-vessel disease undergoing coronary artery bypass grafting were randomized into one of the following groups: adult ischemic preconditioning, adult control, aged ischemic preconditioning, and aged control. Hemodynamic data and cardiac troponin I values were compared between the groups. The ischemic preconditioning groups received 2 periods of 2 minutes of ischemia, followed by 3 minutes of reperfusion. The Student t test, chi(2) test, and analysis of variance for repeated measures were used for the statistical analysis. RESULTS: The baseline for right ventricular ejection fraction and cardiac index was similar. Right ventricular ejection fraction was depressed after the operation in all groups. Ischemic preconditioning significantly improved the recovery of right ventricular ejection fraction and cardiac index after the operation in adult patients (P =.013 and.001, respectively), but in the aged group there was no difference in the changes of ejection fraction and cardiac index (P =.232 and.889, respectively). The cardiac troponin I value in the adult patients subjected to ischemic preconditioning was lower than that in the adult control subjects (P =.046), but in aged patients undergoing ischemic preconditioning, the value was similar to that in aged control subjects (P =.897). Ischemic preconditioning also resulted in a shorter postoperative mechanical ventilation time and in less inotropic use in the adult group. CONCLUSION: Ischemic preconditioning protects the heart from ischemic reperfusion injury in adult patients undergoing coronary artery bypass grafting. The beneficial effects of ischemic preconditioning are manifested as a better recovery of right ventricular and global hemodynamic function, cellular viability, and surgical outcome. The protective effect of ischemic preconditioning is diminished in aged patients undergoing coronary bypass.

Beneficial effects of ischemic preconditioning on right ventricular function after coronary artery bypass grafting.

BACKGROUND: Preservation of right ventricular myocardium is unsatisfactory in patients with critical stenosis or occlusion of the right coronary artery. The aim of this study was to investigate whether ischemic preconditioning (IP) improved the recovery of right ventricular function after coronary artery bypass grafting. METHODS: Forty patients with three-vessel disease who had coronary artery bypass grafting were randomly assigned to the IP group (n = 20) or control group (n = 20). In the IP group, two cycles of two minutes of ischemia after three minutes of reperfusion were given before cross-clamping. Hemodynamic data were collected. Right ventricular ejection fraction was measured by thermodilution. RESULTS: Right ventricular ejection fraction and right ventricular systolic volume index were decreased post-operatively (lowest value at 6 hours postoperatively). The changes in right ventricular ejection fraction were significantly milder in the IP group postoperatively (p = 0.012). The decrease in right ventricular systolic volume index postoperatively was also less in IP patients (p = 0.002). Fewer inotropic drugs were used in the IP group compared with controls. CONCLUSIONS: Ischemic preconditioning had a myocardial protective effect on recovery of right ventricular contractility in patients who had coronary artery bypass grafting.

Seral, uterine and fetal salicylate concentrations after oral administration.

Salicylate concentrations in serum, endometrium, myometrium and fetus were determined 3 h after an oral dose of 1 000 mg of acetylsalicylic acid. The material consisted of 19 females (11 for legal abortion and 8 for operative treatment of fibroids). Tissue salicylate concentrations were at a level at which prostaglandin synthetase is inhibited.

Ischemic preconditioning protects right ventricular function in coronary artery bypass grafting patients experiencing angina within 48-72 hours.

BACKGROUND: To test whether ischemic preconditioning (IP) is able to protect the myocardium in recently unstable CABG patients. EXPERIMENTAL DESIGN: prospective, randomised, controlled clinical study. SETTING: University Hospital. PATIENTS: Forty CABG patients with recent unstable angina were randomised into an IP group (n=20) and a control group (n=20). Subgroup was divided based on the time of the most recent ischemia onset before the operation. INTERVENTION: The IP group was preconditioned with 2 cycles of 2-min ischemia followed by 3-min reperfusion before cross clamping. MEASURES: Hemodynamic data were monitored till the 1st POD. Biochemical markers were measured till the 2nd POD. RESULTS: There were no differences in cardiac index (Cl) and right ventricular ejection fraction (RVEF) in patients experiencing angina within 48 hours prior to operation. The percentage changes in CI and RVEF at 1 hour after declamping were significantly better in the IP group in patients experienced angina within 48-72 hours (106% vs 88% of baseline, p=0.027 and 103% vs 81% of baseline, p=0.023). No difference in postoperative cardiac troponin I (CTnI) and CK-MB was found between the IP and controls in either subgroup. CONCLUSIONS: IP has a beneficial effect on global and right ventricular hemodynamic functional recovery in unstable CABG patients experiencing angina within 48-72 hours prior to the operation. However, IP has no additional protective effects in unstable CABG patients who experience angina within 48 hours.

Chlamydia trachomatis in term pregnancy. isolation and serological study with a case report.

The prevalence of cervical Chlamydia trachomatis infection in healthy, symptomless full-term pregnant women (n = 92) was found to be low (1.1%). Chlamydial cervical IgA antibodies, as measured by solid-phase radioimmunoassay (RIA), were found in 5.3%, but amniotic fluid chlamydial RIA IgA antibodies were almost absent. Serum IgG antibodies were measured with indirect immunofluorescence (IF). Of the mothers 9.8% had a titer greater than or equal to 1:64, correlating closely with the figure of 10.9% for infants' cord-blood IF serology. Finally, a case report is presented. A child born to a Chlamydia trachomatis positive mother developed isolation positive chlamydial pneumonia.

Antibacterial capacity in amniotic fluid in normal and complicated pregnancies.

The antibacterial activity against Escherichia coli K 12 in 153 samples of amniotic fluid (AF) in 15 to 40 weeks of pregnancy were investigated by a new micromethod. Fifty-six mothers had an uncomplicated pregnancy while various complications (maternal diabetes, cholestasis of pregnancy, pregnancy induced hypertension, blood group isoimmunization and fetal growth retardation) were present in 97 cases. A significant (p less than 0.001) improvement of antibacterial activity was observed with advancing pregnancy. The highest antibacterial activity in AF was observed in cases with intrauterine growth retardation. In other respects the effect of various diseases was negligible.

Micromethod for determination of antibacterial capacity in amniotic fluid.

A new method for assessing antibacterial activity in amniotic fluid (AF) is presented. Sample sizes of 100 microliter were incubated at 37 degrees C in an equal amount of growth medium with inoculated bacteria. The quantification of bacterial growth was established by measuring the change in optical density with an automated spectrophotometer. In this study, Escherichia coli, type K 12, was used for inoculation and the bacterial growth was assessed after 6, 18, 30, 42, and 54 hours' incubation. The variation coefficients in intra-assay and interassay measurements were 3.8 and 5.2%, respectively. Shaking of the incubated sample significantly changed the results by increasing the number of viable cells in the most probable number method and decreasing the optical density difference in the spectrophotometric method. Nevertheless, the correlation between the results in both methods was good (r = 0.94, p less than 0.05, and r = 0.98, p less than 0.01, respectively). By filtering the AF sample before incubation, a great deal of antibacterial activity was removed. The reproducibility, simplicity, and rapidity of this spectrophotometric method of assessing antibacterial activity in AF may make it a useful clinical tool.

Estrogen in the treatment of abnormal cervical mucus infertility.

The effects of intravaginal estrogen treatment on the cervical mucus and PCT were investigated in ten primarily infertile patients. The abnormal cervical mucus was the only demonstrable factor of their infertility. The duration of the infertility had ranged from 5-10 years. In four cases the percentual and progressive motilities of the spermatozoa improved and the number of spermatozoa rose in the PCT. Three of the patients conceived during the test cycle. In addition the effects of intramuscular estradiol-benzoate on the cervical mucus and PCT were investigated in clomiphene-treated patients. No differences were found between the test and the control cycle.

Cervical and serum IgA and serum IgG antibodies to Chlamydia trachomatis and herpes simplex virus in threatened abortion: a prospective study.

The aetiological role of Chlamydia trachomatis (CT) and herpes simplex virus (HSV) was investigated in 189 patients with threatened abortion. Assessment of infection was based on isolation, and on determination of serum immunoglobulin (Ig)G and IgA antibodies as well as cervical IgA antibody levels with new sensitive radioimmunoassay (RIA) techniques. One third of the women were delivered of a healthy infant and two thirds aborted, but the two groups were otherwise clinically similar. By isolation, only 2.7% of the patients were CT-positive, but increased cervical IgA antibody level to CT was detected in 41.3%. The mean level of these local antibodies was similar in both study groups, but the mean levels of serum IgA and IgG antibodies were somewhat higher in the patients who aborted although the difference was not significant. None of the cervical specimens was positive for HSV by isolation but the cervical IgA antibody level to HSV was raised in 47.1% of the patients. Both cervical and serum IgA antibody levels to HSV were significantly raised among the patients who aborted, but there were no differences between the patients with spontaneous abortion and those with a blighted ovum. There was no clear association between CT and abortion, but an association between HSV and abortion is possible. The incidence of raised levels of both CT and HSV IgA antibodies in the cervix was surprisingly high in both groups and the significance of this finding remains to be investigated.

Transabdominal chorionic villus sampling and amniocentesis for prenatal diagnosis: 5 years' experience at a university centre.

The fetal loss rates and fetal congenital birth defects in 821 transabdominal (TA) chorionic villus sampling (CVS) and 771 amniocentesis (AC) cases were evaluated from a 5-year period (1987-1991) at the University Central Hospital of Turku. The parents were given the option of choosing between the two sampling procedures. CVS was performed, in most cases, at 11 weeks of gestation; and AC, at 15 weeks. The rate of total post-procedure loss was 6.7 per cent in the CVS group and 4.4 per cent in the AC group (p = 0.08). The rate of spontaneous abortions was 1.9 per cent in the CVS group and 1.0 per cent in the AC group (p = 0.10). The number of birth defects was low in both study groups. No limb reduction cases were observed. Mosaicism was noted in 14 CVS cases and in five AC cases. We conclude that TA-CVS is a safe and practical alternative to AC in prenatal fetal karyotyping.

Trace elements and antibacterial activity in amniotic fluid.

Antibacterial activity and trace element concentrations in amniotic fluid (AF) were determined in a population of 39 pregnant women in the second half of gestation. Antibacterial activity in each AF was measured by a spectrophotometric micromethod after 18 h incubation at 37 degrees C using Escherichia coli K 12 as a reference bacterium. Concentrations of zinc, iron, copper, calcium, potassium and bromine were measured by particle-induced X-ray emission method and the zinc concentration was also measured by atomic absorption spectrophotometry. Phosphate concentration was determined by direct albumin adding method. In AFs with good antibacterial activity significantly lower concentrations of potassium and bromine were found when compared to AFs with lower antibacterial activity. Concentrations of zinc, iron, copper, calcium or phosphate did not correlate with antibacterial activity in AF.

Right ventricle is protected better by warm continuous than by cold intermittent retrograde blood cardioplegia in patients with obstructed right coronary artery.

Preservation of the right-ventricular (RV) myocardium is a clinical challenge especially in patients with occluded right coronary artery, in whom antegrade cardioplegia cannot reach areas distal to the stenosis. Retrograde administration of cardioplegia has been thought to overcome the problem, but it has been blamed for inadequate distribution to the RV and possibly poorer functional recovery of this ventricle. Adapting the hypothesis that warm blood cardioplegia may offer better distribution and a more effective supply of oxygen to the arrested heart, we compared RV function in a randomised trial in patients with significant right and left coronary artery disease, after either warm continuous (warm group, n = 15) or intermittent cold (cold group, n = 14) retrograde blood cardioplegia. Right-ventricular function was assessed by determining the ejection fraction (fast-response thermodilution) and preload-related RV stroke work in repeated measurements. The RV ejection fraction remained steady in the warm group during the postoperative course, while it declined significantly in the cold group after operation and differed from that in the warm group until the second postoperative day (p < 0.05-0.001). The ratio of RV stroke work to right atrial pressure was greater postoperatively in the warm than in the cold group until 6 hours after cardiopulmonary bypass (p < 0.05-0.01). Creatine kinase cardiac isoenzyme release was greater in the cold group (p < 0.01). The relationship between left-ventricular stroke work and corresponding preload did not differ between the groups. It can be concluded that recovery of RV function after coronary surgery was better in terms of ejection fraction and preload-related stroke work with warm continuous cardioplegia than with intermittent cold cardioplegia, this along with lower cardiac enzyme release suggesting better RV protection.

Myocardial cooling and right ventricular function in patients with right coronary artery disease: antegrade vs. retrograde cardioplegia.

BACKGROUND: Protection of the right ventricular (RV) myocardium during ischaemia in cardiac surgery is difficult, especially in patients with severe right coronary artery (RCA) disease. Retrograde coronary sinus cardioplegia is thought to distribute uniformly, but doubts still remain as to its adequacy in RV preservation. This study evaluated distribution of antegrade vs. exclusively retrograde coronary sinus cold blood cardioplegia by assessing myocardial cooling and compared the effects on RV function. METHODS: Fifty-eight patients scheduled for elective coronary artery surgery-29 patients with significant RCA disease and another 29 with no significant RCA stenosis (controls)-were randomised to receive either antegrade or retrograde cold blood cardioplegia through either aortic root or conventional self-inflating coronary sinus catheter (RCA-ante, RCA-retro, C-ante and C-retro groups). RV function was assessed by fast-response thermodilution. Myocardial temperatures were measured in the anterior and posterior wall of the right and left ventricle. RESULTS: Cooling of the posterior wall of the RV was effective only in the control patients given antegrade cardioplegia (14.7 degrees C), whereas in the other groups the lowest myocardial temperatures there remained above 20 degrees C (P < 0.001). In patients with obstructed RCA both antegrade and retrograde cold cardioplegia led to uneven cooling of the myocardium. After cardiopulmonary bypass the RV ejection fraction (RVEF), RV stroke work index (RVSWI) and cardiac index (CI) were significantly reduced in the RCA-retro group, and RVSWI and CI in the C-retro group, too. Regression analysis showed an inverse relationship between the temperatures of the posterior walls of the ventricles and changes in the RVEF and CI. CONCLUSIONS: Retrograde and antegrade cardioplegia alone were not effective in reducing the temperature of the posterior wall of the RV in the patients with obstructed RCA, in whom with retrograde cardioplegia RV haemodynamics were impaired for 1 hour following bypass. Neither retrograde nor antegrade cardioplegia alone can be relied on to protect the posterior wall of the RV in the patients with obstructed RCA.

Combined antegrade-retrograde blood cardioplegia does not protect right ventricle better than either technique alone in patients with occluded right coronary artery.

To study the hypothesis that combined antegrade-retrograde delivery of cardioplegia might overcome the limitations in myocardial protection of either technique alone, we compared the distribution of the different cardioplegic approaches by assessing myocardial cooling and evaluated the effects on right ventricular (RV) function in elective coronary artery bypass grafting (CABG) patients with occluded right coronary artery (RCA). In a randomized trial, 15 patients received exclusively antegrade (ante group), 14 patients received exclusively retrograde (retro group) and 15 patients received combined, alternating antegrade-retrograde (combi group) cold blood cardioplegia. Myocardial temperatures were measured at four sites in the heart. Right ventricular function was assessed by determining the ejection fraction (fast-response thermodilution) and preload-related RV stroke work in repeated measurements. Myocardial cooling was similarly uneven and the posterior wall of the RV remained above 20 degrees C after all three methods of delivering hypothermic (5-7 degrees C) cardioplegia. The RV ejection fraction and preload-related (right atrial pressure) RV stroke work decreased postoperatively similarly in all groups. The results suggest that combined antegrade-retrograde cold blood cardioplegia could not provide more homogeneous myocardial cooling or better RV recovery than either technique alone in three-vessel-diseased CABG patients with occluded RCA.

Atrial natriuretic peptide and N-terminal atrial natriuretic peptide in plasma reflect right ventricular volumes following coronary artery surgery.

BACKGROUND: Atrial natriuretic peptide (ANP) and the more stable N-terminal fragment (N-ANP) of prohormone are peptides, released in equimolar amounts from cardiac myocytes in response to atrial stretch or ventricular overload and myocardial ischaemia. Protection of the right ventricular (RV) myocardium during ischaemia in cardiac surgery is difficult, especially in patients with severe right coronary artery (RCA) disease. This prospective study was designed to ascertain a possible relationship between changes in plasma ANP/N-ANP concentration and RV function in RCA-diseased patients. METHODS: Plasma ANP and N-ANP concentrations and RV function, measured by fast-response thermodilution, were determined serially in 15 patients with total RCA stenosis and in another 15 with no significant RCA disease (controls) before, during and after coronary surgery. RESULTS: The RV ejection fraction was lower and the RV end-systolic volume index higher in the RCA-diseased patients than in the controls (P < 0.05) on the second postoperative day, and both ANP and N-ANP were higher in the RCA patients (P < 0.05) from 6 h after cardiopulmonary bypass till the second postoperative day. At the same time the changes in N-ANP concentrations from the levels before induction of anaesthesia correlated with RV ejection fraction and RV volume indexes, but not with heart rate or parameters indirectly reflecting left-sided loading. Right atrial pressure did not differ between the groups nor did it increase significantly during the study. CONCLUSIONS: The relationships found between N-ANP and RV volume indexes and RV ejection fraction suggest ventricular expression of ANP: ANP release may be stimulated by RV distension, the more so the poorer the RV function.

Stenosis of the right coronary artery and retrograde cardioplegia predispose patients to atrial fibrillation after coronary artery bypass grafting.

It is assumed that stenosis of the right coronary artery (RCA) predisposes CABG patients, by way of incomplete atrial myocardial protection, to postoperative atrial fibrillation (AF). Sixty patients with high-grade RCA lesion were randomized into four groups according to the technique of delivery of cold blood cardioplegia: antegrade, retrograde, retrograde without catheter cuff, and combined antegrade and retrograde. As controls, 34 patients without RCA lesion were randomized to receive antegrade or retrograde cardioplegia. Postoperative atrial fibrillation episodes were recorded. Patients with RCA lesion were more prone to develop AF; odds ratio (OR)=3.75 (95% confidence interval [CI]=1.22-11.5). Retrograde delivery in these patients was more often associated with AF, OR=4.97 (95% CI = 1.02-24.1). Other risk factors for AF were an increasing number of preoperative infarcts (p < 0.05) and more advanced coronary artery disease (p < 0.05). Prolonged stay in the intensive care unit (p < 0.001) and occurrence of postoperative ventricular tachycardia (p < 0.05) were associated with AF. RCA stenosis and retrograde cardioplegia delivery in RCA-affected patients were risk factors for postoperative atrial fibrillation. Retrograde cardioplegia may offer poorer protection at the atrial level.

Serum levels of free fatty acids in the first trimester of pregnancy: effect of acetylsalicylic acid.

The serum levels of free fatty acids were determined before and after an oral dose of 1000 mg acetylsalicylic acid (ASA) during the 7-11th weeks of pregnancy in 11 women admitted to hospital for legal abortion and in 8 women admitted for operative (hysterectomy) treatment because of fibroids. Thirteen healthy women of reproductive age served as controls. The levels of linoleic, alpha-linolenic, myristic, oleic, palmitic and palmitoleic acids were significantly lower in pregnant women than in the hysterectomy group. The level of arachidonic acid was higher in the pregnant and hysterectomy groups than in controls. Serum free fatty acids had a negative correlation with the duration of pregnancy. ASA treatment tended to increase the levels of many fatty acids in serum. Serum arachidonic acid levels after ASA treatment correlated significantly with the salicylate concentrations in myometrium and the levels of most other fatty acids with the salicylate concentration in endometrium.