Isolation and characterization of new lignans from the leaves of Cestrum parqui.

Three new compounds, a sesquilignans, an oxyneolignan and a norlignan, have been isolated from the aqueous fraction of Cestrum parqui. All of the compounds have been identified on the basis of their spectroscopic properties and tested on the species Lactuca sativa and Lycopersicon esculentum to evaluate their phytotoxic activity.

Single-clamp technique for aneurysms of the descending thoracic aorta: report of 132 consecutive cases.

OBJECTIVE: To determine the efficacy of a single-clamp technique in preventing spinal cord ischemia during repair of aneurysms of the descending thoracic aorta. PATIENTS AND METHODS: From January 1989 to May 1999, 132 consecutive patients (91 men and 41 women, aged 31-86 years), with aneurysms of the descending thoracic aorta underwent repair using a single-clamp technique and temporary partial distal exsanguination. The diseased aortic segment was replaced with a Dacron graft. Blood was re-infused from an auto-transfusion device, and the segmental vessels were over-sewn but not implanted into the graft. RESULTS: The average aortic cross-clamp time was 26.4 min (range, 11-67 min) for the overall group and 37.4 min for patients who had spinal cord complications. An average of 2066 ml of blood was auto-transfused (range, 450-6100 ml). During the first 30 postoperative days, 17 patients (12.9 %) died. Eleven patients (8.3%) had spinal cord dysfunction, six patients (4.5%) had lower-extremity paraparesis, and five patients (3.8%) had paraplegia. Nine patients (6.8%) had renal failure necessitating hemodialysis. Other complications included bleeding in 15 cases (11.4%), respiratory failure in 12 cases (9.1%), wound-related sequelae in five cases (3.8%), distal embolism in five cases (3.8%), and bowel ischemia in two cases (1.5%). CONCLUSION: The single-clamp technique yielded an acceptable complication rate, and the mortality was comparable to that seen after the use of more complex methods. For satisfactory results, the cross-clamp time should not exceed 30 min.

[The usefulness of bioimpedance in patient monitoring in an intensive-therapy heart-surgery unit: a comparison with thermodilution]. / Utilità della bioimpedenza nel monitoraggio del paziente in unità di terapia intensiva di cardiochirurgia: comparazione con la termodiluizione.

Haemodynamic monitoring of intensive care unit (ICU) patients can be carried out by thermodilution system. This method is invasive, does not give a continuous monitoring and complications can occur. Thoracic electrical bioimpedance (TB), a non invasive, fast, easily repeatable method, is able to measure some important haemodynamic parameters: end diastolic volume (EDV), stroke volume, cardiac output (CO), ejection fraction (EF), some contractility indexes, systemic vascular resistances (SVR) and cardiac work. The aim of the present study is to compare CO and SVR obtained by thermodilution with the same indexes obtained by TB. Therefore, 20 ICU patients (12 males and 8 females, mean age 54 +/- 11 years) were studied. Out of them, 16 had been submitted to cardiac surgery in the previous 7 days and 4 were waiting for cardiac surgery. The patients were divided in 2 groups: Group A (N 4) included patients with valvular malfunction and/or cardiac arrhythmias and Group B (N 16) included patients with normal valvular function and sinus rhythm. CO obtained by TB was well related with the one obtained by invasive (INV; r = 0.878; p < 0.001). The mean value of difference of the 2 methods was 12.29 +/- 11.83 for the whole group of 20 patients but it was 26.07 +/- 14.16 in the Group A and 8.84 +/- 8.09 in the Group B confirming the less reliability of the method in patients with abnormal valvular function or in the presence of cardiac arrhythmias. As a consequence, SVR obtained by TB and INV resulted well related (r = 0.752; p < 0.001). The mean value of differences was 11.14 +/- 9.01 in the group of 20 patients and particularly 19.55 +/- 10.87 in the Group A and 9.04 +/- 7.07 in the Group B. In a subgroup of 9 patients, CO was measured at successive times (0, 30, 60, 90 min) by both TB and INV; when comparing the 2 CO values a significant correlation was observed. In conclusion, TB represents a valid method in haemodynamic monitoring of the ICU patients.

[Use of enoximone in the postoperative course of heart surgery]. / Impiego dell'enoximone nel decorso postoperatorio in cardiochirurgia.

The aim of this study was to evaluate the efficacy and safety of enoximone, an imidazolonic compound inhibiting cardiac phosphodiesterase III, during the postoperative period. The drug was administered prior to the usual stages of weaning the patient off extracorporeal circulation, to a group of 20 subjects who presented an ejection fraction of less than 35% following hemodynamic studies. Patients were randomly subdivided into 4 groups each of which received a different dose of enoximone according to the following protocol: Group A, 1 mg/kg bolus and slow infusion at 10 gamma/kg/min; Group B, 0.5 mg/kg bolus and slow infusion at 15 gamma/kg/min; Group C, 0.5 mg/kg bolus and slow infusion at 10 gamma/kg/min; Group D, slow infusion at 10 gamma/kg/min. The best results in hemodynamic terms and with regard to the positive inotropic and vasodilatory action of the drug in question were obtained in Group C. Increased cardiac output was observed in all patients within 120 minutes of enoximone administration and reduced systemic vascular resistance after approximately 6 hours of infusion. Special attention should be drawn to the use of the drug in patients who do not respond to conventional therapy due to its mechanism of action which is not dependent on beta receptors, thus enabling good results to be achieved even when these are down regulated. Special care must be taken however in administrating enoximone to platelet-deficient patients since the reduction of platelet levels is one of its collateral effect. Other collateral effects observed were: supraventricular arrhythmias and ventricular tachyarrhythmias.

Clinical experience with the transvenous Medtronic Pacer Cardioverter Defibrillator (PCD) System.

We review our experience with the transvenous Medtronic Pacer Cardioverter Defibrillator System (Model 7217B), a multifunction implantable pacer defibrillator combined with a transvenous lead system (Transvene). From April 1991 to October 1992, we implanted this device in 19 consecutive patients (11 men and 8 women; average age, 56.5 years). Nine patients (47.4%), 5 with coronary artery disease and 4 with dilated cardiomyopathy, had an ejection fraction of < 30%. The average operative time was 129 minutes. In 18 patients (94.7%), the transvenous lead system provided effective sensing, pacing, and defibrillation during intraoperative testing. In each of these cases, the defibrillation threshold was less than 18 J. In 1 patient (5.3%), it was necessary to switch to epicardial leads, which were implanted through a left thoracotomy. All patients were extubated in the recovery room. The average hospital stay was 8 days. There was no early mortality or morbidity. During a maximum follow-up period of 17 months (mean, 9.2 months), no sudden death occurred. The implantable system terminated 245 ventricular tachycardia episodes in 14 patients (73.7%) and 82 ventricular fibrillation episodes in 13 patients (68.4%). Two hundred eleven (86.1%) of the ventricular tachycardia episodes were resolved by antitachycardia pacing alone. In 2 patients (10.5%), the caval electrode became dislocated; repositioning of the electrode was followed by repeat defibrillation threshold evaluation. Our experience shows that the transvenous Medtronic Pacer Cardioverter Defibrillator System provides safe, effective treatment of ventricular tachyarrhythmias. Because the perioperative mortality and morbidity are extremely low, use of this device may be particularly beneficial in patients with a high operative risk. Moreover, the lower number of unpleasant therapeutic shocks should increase patient a acceptance of the device.

Bioprosthesis replacement with mechanical valve implantation on the bioprosthetic ring. Surgical and 2D echo considerations.

Removal of a failing bioprosthesis can be a delicate operation and extensive damage can be caused. Eighteen patients with failing bioprostheses underwent excision of the leaflets, then the "new" mechanical valve was sewn onto the "old" bioprosthetic ring. At follow-up, clinical and 2D color-flow echo-Doppler evaluations showed good hemodynamic performance of the mechanical valves.

Leishmaniasis in a heart transplant patient.

Infection is a well-recognized complication of immunosuppressive therapy. We describe a case of leishmaniasis in a 62-year-old man who was undergoing immunosuppressive therapy because of heart transplantation. A geologist and native Texan, the patient had traveled extensively in south-central Texas, but not outside of the continental United States. Cutaneous lesions of the extremities developed, which were diagnosed histologically as leishmaniasis and confirmed by means of transmission electron microscopy. Cultures grew Leishmania mexicana. Treatment with sodium antimony gluconate was successful in healing the infective lesions.

Myocardial revascularization in women.

To compare the results of coronary artery bypass in women and men, we reviewed our experience from January 1976 through June 1989. During this period, 170 women with coronary artery disease but with no other cardiac abnormalities underwent coronary artery bypass. We compared this group with a group of 150 men, matching them according to age, presence of angina, extent of disease, and surgical treatment. Preoperative clinical features, surgical data, and early and late results were analyzed. The operative mortality was similar between groups (2.9% for women vs 2.6% for men). The women, however, were more frequently overweight (54% vs 15%; p <0.001) and more often had the following: diabetes mellitus (34% vs 20%; p <0.01), a coronary artery diameter of <1.8 mm (64% vs 29%; p <0.001), poor saphenous vein quality (50% vs 16%; p <0.001), and incomplete revascularization (20% vs 4%; p <0.001). After a mean follow-up of 6 years, the women also had a higher incidence of recent-onset myocardial infarction (31% vs 12%; p <0.001) and a greater tendency to be symptomatic (48% vs 19%; p <0.001). The 12-year cumulative survival rates were similar in both groups (76.2% for women vs 77.1% for men). According to logistic regression analysis of the significantly different variables, the only independent determinants of postoperative asymptomatic status were satisfactory coronary artery caliber, good saphenous vein quality, and complete revascularization. We conclude that poorer functional results after coronary artery bypass surgery in women may be caused by a poorer quality of revascularization, which in turn is a result of smaller coronary artery diameter, worse distal runoff, and less satisfactory vein quality.

Double valve Implantation. Long-term evaluation of 8 different bioprostheses.

From January 1976 through December 1987, 194 patients with a mean age of 43.3 +/- 13.7 years (range, 11 to 74 years) underwent double (mitral and aortic) replacement of native valves with 8 types of bioprostheses: Carpentier-Edwards, 127 valves; Hancock, 76 valves; Liotta-Bioimplant, 57 valves; Ionescu-Shiley, 53 valves; Vascor, 27 valves; Carpentier-Edwards Pericardial, 22 valves; Angell-Shiley, 20 valves; and Implamedic, 6 valves. Concomitant cardiac procedures were performed in 25 patients (12.8%). There were 18 operative deaths (9.27%). Our retrospective analysis was restricted to 352 bioprostheses implanted in the 176 patients who survived surgery and were considered at risk for valve tissue failure. The overall cumulative duration of follow-up was 1,174.1 patient-years (range, 1 to 13 years). The durations of follow-up for specific valves were: Carpentier-Edwards, 920.2 valve-years; Hancock, 383.8 valve-years; Liotta-Bioimplant, 310.2 valve-years; Ionescu-Shiley, 357.7 valve-years; Vascor, 131.2 valve-years; Carpentier-Edwards Pericardial, 52.0 valve-years; Angell-Shiley, 167.0 valve-years; and Implamedic, 31.0 valve-years. Thirty patients had thromboembolic accidents, for a linearized incidence of 2.5% per patient-year. At 13 years, the actuarial freedom from thromboembolic accidents was 85.8% +/- 10.7%. Nine patients had endocarditis, for a linearized incidence of 0.7% per patient-year. At 13 years, the actuarial freedom from endocarditis was 92.0% +/- 1.5%. Twenty-four patients had valve tissue failure, for a cumulative linearized incidence of 1.87% per valve-year. The cumulative actuarial probability of freedom from valve tissue failure was 78.6% +/- 3.7% at 10 years and 51.2% +/- 10.7% at 13 years. The 24 patients with valve tissue failure all underwent reoperation: 20 of these had double valve replacement, 3 had aortic valve replacement alone, and 1 had mitral valve replacement alone. The mean interval between initial valve implantation and reoperation was 66.9 +/- 28.8 months. At reoperation, the hospital mortality was 15.1% (5 patients). This study showed that the long-term results of valve implantation are not significantly influenced by either prosthesis design or material. Moreover, the incidence of degenerative change was similar in the aortic and mitral positions.

A preliminary report on low-profile and pericardial bioprostheses: a new combination in particular anatomical situations.

Bovine pericardial bioprostheses (BPB), such as the Ionescu-Shiley or the Vascor, and low-profile porcine bioprostheses (Liotta, LPB) have particular features that make them useful in certain anatomical situations, such as aortic stenosis with hypoplastic annulus, pure mitral stenosis with little ventricle and double valvular stenosis with hypertrophic ventricular wall. In such situations, the use of traditional porcine bioprostheses causes problems. We report our experience with BPB and LPB in 25 cases of double valvular stenosis. Operative results were fairly good, and, with the excellent mid-term follow-up by 2-D echo and haemodynamic evaluation, the present authors are confident that these bioprostheses can be considered to be a good alternative to traditional ones and the first choice in particular anatomical situations.

[Isolated traumatic rupture of the ascending aorta. Clinical case and review of the literature]. / Rottura traumatica isolata dell'aorta ascendente. Caso clinico e revisione della letteratura.

Rupture of the descending aorta after severe blunt chest trauma is a well recognised injury. Instead, isolated traumatic rupture of the ascending aorta is rarely diagnosed, with only five cases reported in the literature. A case of isolated traumatic rupture of the ascending aorta is here reported and the role of medical treatment is described.