Hyperthermia Severely Affects the Vascular Effects of MDMA and Metabolites in the Human Internal Mammary Artery In Vitro.

3,4-Methylenedioxymethamphetamine (MDMA or "ecstasy") is a recreational drug used worldwide for its distinctive psychotropic effects. Although important cardiovascular effects, such as increased blood pressure and heart rate, have also been described, the vascular effects of MDMA and metabolites and their correlation with hyperthermia (major side effect of MDMA) are not yet fully understood and have not been previously reported. This study aimed at evaluating the effects of MDMA and its main catechol metabolites, alpha-methyldopamine (α-MeDA), N-methyl-alpha-methyldopamine (N-Me-α-MeDA), 5-(glutathion-S-yl)-alpha-methyldopamine [5-(GSH)-α-MeDA] and 5-(glutathion-S-yl)-N-methyl-alpha-methyldopamine [5-(GSH)-N-Me-α-MeDA], on the 5-HT-dependent vasoactivity in normothermia (37 °C) and hyperthermia (40 °C) of the human internal mammary artery (IMA) in vitro. The results showed the ability of MDMA, α-MeDA and N-Me-α-MeDA to exert vasoconstriction of the IMA which was considerably higher in hyperthermic conditions (about fourfold for MDMA and α-MeDA and twofold for N-Me-α-MeDA). The results also showed that all the compounds may influence the 5-HT-mediated concentration-dependent response of IMA, as MDMA, α-MeDA and N-Me-α-MeDA behaved as partial agonists and 5-(GSH)-α-MeDA and 5-(GSH)-N-Me-α-MeDA as antagonists. In conclusion, MDMA abuse may imply a higher cardiovascular risk associated both to MDMA and its metabolites that might be relevant in patients with underlying cardiovascular diseases, particularly in hyperthermia.

Coronary surgery with non-cardioplegic methods in patients with advanced left ventricular dysfunction: immediate and long term results.

OBJECTIVE: To evaluate perioperative results and long term survival in patients with severe left ventricular (LV) dysfunction undergoing coronary artery bypass grafting (CABG) using non-cardioplegic methods. METHODS: From April 1990 through December 1999, 4100 consecutive patients underwent isolated CABG using hypothermic ventricular fibrillation. Of these, 141 (3.4%) had severe LV dysfunction (ejection fraction < 30%). Mean age was 58.3 (9.6) years. 64 patients (45.4%) were in Canadian Cardiovascular Society class III or IV and 16 (11.3%) were subjected to urgent or emergent surgery. A previous myocardial infarction was recorded in 127 (90.1%). The majority (89.4%) had triple vessel and 26 (18.4%) had left main disease. The mean number of grafts per patient was 3.1. At least one internal thoracic artery was used in all patients and 21 (14.8%) had bilateral internal thoracic artery grafts (1.2 arterial grafts per patient). RESULTS: Perioperative mortality was 2.8% (4 patients) and the incidence of acute myocardial infarction 2.8%. 50 (35.5%) patients required inotropes but only 16 (11.3%) required it for longer than 24 hours; 5 patients (3.5%) needed mechanical support. The incidence of renal failure was 3.5%. Mean duration of hospital stay was 9.6 (8.3) days. Follow up was 95% complete and extended for a mean of 57 (30) months. Late mortality was 11.5%. Actuarial survival rates at 1, 3, and 5 years were 96%, 91%, and 86%, respectively. CONCLUSIONS: Non-cardioplegic techniques are safe and effective in preserving the myocardium during CABG in patients with coronary artery disease and poor LV function, with low operative mortality and morbidity, and encouraging medium to long term survival rates.

[Coronary surgery after 70 years of age]. / Cirurgia coronária depois dos 70 anos.

Previous reports on coronary artery bypass grafting in elderly patients have not usually addressed the current era of aggressive percutaneous angioplasty. To investigate this important subgroup of patients, we analyzed our recent coronary artery bypass grafting experience with patients 70 years of age or older from May 1988 to August 1993, 158 consecutive patients in this age range (mean age 70.3 years) underwent surgical revascularization at our institution. Overall operative mortality was 4.4% (7/158), with 71.4% (5/7) of deaths due to cardiac causes. Postoperative morbidity occurred in 50.6% (80/158) of patients but was of a serious nature in only 12.0% (19/158). Surgical priority was significantly correlated with operative mortality: 1.6% (2/122) for elective cases and 17.2% (5/29) for urgent or emergency cases (p < 0.01). Univariate analysis isolated the need for postoperative inotropic support or mechanical assistance, perioperative myocardial infarction and reoperation for bleeding as significant risk factors for operative mortality (p < 0.01). Of the patients discharged from the hospital, 144 (95.4%) were followed up for a mean of 23 months (3-62). During the follow-up period there were 3 deaths, all from non cardiac causes, and 92.3% of the patients were in Canadian Cardiovascular Society class I (CCS). These results indicate that, although with somewhat higher morbidity and mortality rates, elderly patients have a very acceptable operative risk in the current era of high-risk coronary artery bypass grafting, particularly if elective revascularization is possible.

Non-cardioplegic coronary surgery in patients with severe left ventricular dysfunction.

OBJECTIVES: Although most surgeons use cardioplegia for myocardial protection during coronary artery bypass grafting (CABG), some still use non-cardioplegic methods with very good early and long-term outcome. However, the results in patients with severe left ventricular dysfunction remain unproved. This study evaluates the perioperative mortality and morbidity in patients with severe left ventricular dysfunction submitted to CABG using non-cardioplegic methods. METHODS: From April 1990 through December 1997, 3,180 patients were consecutively subjected to isolated CABG using non-cardioplegic methods, for construction of the distal anastomoses. This prospective study is based on the 107 (3.4%) patients with severe impairment of the left ventricular function (ejection fraction < 30%). The mean age at operation was 57.0 +/- 9.2 years and 95.3% of patients were male. Fifty three patients (49.5%) were in class CCS III/IV and 12 (11.2%) were subjected to urgent surgery. A history of previous myocardial infarction was recorded in 99 (92.5%) patients. Ninety seven (90.6%) patients had triple vessel and 17 (15.9%) left main stem disease, and 77 (71.9%) had a left ventricular end-diastolic pressure > 20 mmHg. Cardiopulmonary bypass time was 73.1 +/- 21.7 min. The mean number of grafts per patient was 3.2. At least one internal mammary artery was used in all cases and 16 patients (14.9%) had bilateral internal mammary artery grafts (1.2 arterial grafts/patient). Endarterectomies were performed in 23 (21.5%) patients. RESULTS: Perioperative mortality was 2.8% (respiratory-1; cardiac-2). Forty one (38.3%) patients required inotropes, but for longer than 24 h in only 12 (11.2%), and two (1.9%) needed intra-aortic counterpulsation. The incidence of myocardial infarction was 2.8%. Two (1.9%) patients had reintervention for haemorrhage and another five (4.6%) for sternal complications. The incidences of supraventricular arrhythmias, renal failure and cerebrovascular accident were 16.8%, 3.6% and 2.8%, respectively. The mean time of hospital stay was 9.3 +/- 6.4 days. CONCLUSION: These results appear to demonstrate that non-cardioplegic methods afford good myocardial protection and operating conditions with excellent applicability, even in patients with severe left ventricular dysfunction.

Mediastinitis after aorto-coronary bypass surgery.

OBJECTIVES: To identify risk factors in 60 cases of mediastinitis amongst 2512 patients (2.3%) subjected to isolated coronary bypass surgery from March 1988 through December 1995, treated by a closed irrigation/drainage system. PATIENTS AND METHODS: The mean age of the 60 patients was 56.9 +/- 6.8 years (45-81 years) and 55 (91.6%) were male. Early mediastinal reexploration was performed in all cases immediately after the diagnosis of mediastinitis, with debridement of necrosed tissues, followed by implantation of a closed-circuit irrigation system of the mediastinum constituted by irrigation catheter and drain, closure of the sternum and skin, and specific systemic antibiotic therapy. The mean interval between the original surgery and reexploration was 9.4 days (range 6-14 days). No patient required more extensive procedures, namely omental or muscular flaps. Twenty potential risk factors in patients with mediastinitis, including diabetes mellitus, obesity, coexistence of peripheral vascular disease, decreased LV function, use of inotropes, mediastinal blood drainage and utilization of double IMA, were compared with the group without mediastinitis. RESULTS: Mean cardiopulmonary bypass time was 74.1 +/- 8.1 min, anesthetic time 3.5 +/- 0.8 h and postoperative mechanical ventilation 18 +/- 3 h. A total of 23 patients (38.3%) received one IMA and 35 (58.3%) two IMAs. In the postoperative period, 7 of the 60 patients (11.6%) had required inotropes because of low output. Mediastinal blood loss was 1112cc +/- 452cc and 9 patients (15%) were transfused. Cultures were positive in 40 cases (66.6%) and the most frequent infecting agent was the Staph. epidermidis in 25 cases (62.5%), followed by Candida albicans and Enterobacter and Serratia species (7.5% each); 1 patient (1.7%) died and 9 (15%) had renal failure. The irrigation/drainage was maintained for a mean of 9.1 days (5-83 days). Patients with mediastinitis had a significantly higher prevalence of diabetes (41.6% vs. 18.8%; P < 0.01), obesity (48.3% vs. 15.2%; P < 0.001), peripheral vascular disease (11.6% vs. 4.0%; P < 0.05), but a lower incidence of poor LV function (18.3% vs. 32.7%; P < 0.05). A double IMA was used more frequently in patients who had mediastinitis (58.3% vs. 23.5%; P < 0.001) CONCLUSIONS: Diabetes mellitus, obesity, co-existence of peripheral vascular disease and use of double IMA are risk factors for mediastinitis after coronary artery surgery. The efficacy of the closed method of treatment with a mediastinal irrigation/drainage system was increased with early diagnosis and reintervention.

Meralgia paresthetica after aortic valve surgery.

We report a case of meralgia paresthetica, a rare neurological complication, following aortic valvuloplasty. Although this complication was previously described after coronary artery bypass surgery, we believe this is the first case described after a valve procedure and hypothesize on its etiology.

[Revascularization of the left coronary system with both internal mammary arteries in disease of the left main artery]. / Revascularização do sistema coronário esquerdo com dupla artéria mamária interna na doença do tronco comum.

Although the longterm patency of the internal mammary artery (IMA) has been clearly demonstred, some doubts have been cast as to the perioperative adequacy of its flow. Hence, the sole use of these conduits in patients with left main disease (LMD) has been cautioned. To clarify the significance of this problem in our own population, we have considered in this study, 110 patients with significant LMD subjected to isolated myocardial revascularization from November 1992 trough November 1994. These patients were retrospectively divided into two Groups based on the type of revascularization of the left coronary territory: Group I-35 patients (mean age 51.8 +/- 6.0 years) in whom both the left anterior artery and branches of the circunflex artery were grafted with the left and right IMAs, respectively; and Group II-85 patients (mean age 63.9 +/- 7.7 years) in whom the anterior descending artery received the left IMA and the circunflex system received saphenous vein grafts. No patient in Group I received venous grafts in the left coronary system and in four patients of Group II the rigth IMA was anastomosed to the right coronary artery. The operative mortality was 0% in Group I and 3.5% in Group II (p = NS). The rate of perioperative myocardial infarction was 2.9% and 2.3%, respectively. The incidence of other complications was also similar in the two groups with regards to the need for inotropes (8.6% in the Group I and 7.0% in group II), and the prevalence of arrhythmias (22.8% and 23.5%) but was marginally higher in Group I with regards to reoperation for haemorrhage (8.6% and 3.5%) and sternal dehiscence (5.7% and 2.3%). The mean time of hospital admission was 8.3 days for both groups. The use of both IMAs as the sole conduits for revascularization of the left coronary system in patients with LMD did not increased surgical risk. Also, the hypothesis of insufficient blood flow to the myocardium does not appear to be supported by this study.

[Coronary surgery in patients 70 years and older]. / Cirurgia coronária depois dos 70 anos.

Previous reports on coronary artery bypass grafting in elderly patients have not usually addressed the current era of aggressive percutaneous angioplasty. To investigate this important subgroup of patients, we analyzed our recent coronary artery bypass grafting experience with patients 70 years of age or older-From May 1988 to August 1993, 158 consecutive patients in this age range (mean age 73.0 years) underwent surgical revascularization at our institution. Overall operative mortality was 4.4% (7/158), with 71.4% (5/7) of deaths due to cardiac causes. Postoperative morbidity occurred in 50.6% (80/158) of patients but was of a serious nature in only 12.0% (19/158). Surgical priority was significantly correlated with operative mortality: 1.6% (2/122) for elective cases and 17.2% (5/29) for urgent or emergency cases (p < 0.01). Univariate analysis isolated the need for postoperative inotropic support or mechanical assistance, perioperative myocardial infarction and reoperation for bleeding as significant risk factors for operative mortality (p < 0.01). Of the patients discharged from the hospital, 144 (95.4%) were followed up for a mean of 23 months (3-62). During the follow-up period there were 3 deaths, all from non cardiac causes, and 92.3% of the patients were in Canadian Cardiovascular Society class I (CCS). These results indicate that, although with somewhat higher morbidity and mortality rates, elderly patients have a very acceptable operative risk in the current era of high-risk coronary artery bypass grafting, particularly if elective revascularization is possible.

[Coronary revascularization with the double internal mammary artery]. / Revascularização coronária com dupla artéria mamária interna.

From January 1989 through December 1991, 730 patients (mean age 60.4 years) underwent coronary revascularization. In 124 patients (17%), with a mean age of 51.8 +/- 7.9 years, both internal mammary arteries (IMA) were used. Of these, 19 (15%) had diabetes mellitus and 11 (9%) were obese, and 72 (58%) had history of myocardial infarction. Fifty three (45%) patients were in class III and 17 (14%) were in class IV (Canadian Cardiovascular Society), and 27 (22%) had moderate to severe left ventricular dysfunction. Ten (8.1%) patients had left main stem coronary artery disease and 5 (4.0%) had a left ventricular aneurysm. The total number of distal anastomoses performed was 382 (3.1/patient). In 87 (70%) patients one or more saphenous vein grafts (1.2/patient) were used in addition to both mammary arteries. Hence, 279 distal anastomoses were constructed using arterial conduits (2.3/patient). In one patient the right gastroepiploic artery was also used. The venous grafts were predominantly (71%) constructed to the right coronary artery. The left IMA was used as a free graft in 3 (2.3%) patients and as a pedicled graft in the remainder patients, predominantly to the territory of the left anterior descending artery and its diagonal branches (92%). The right IMA was used as a free graft in 100 (81%) patients, mainly to the territory of the circumflex coronary artery and as a pedicled graft in 24 patients, in 21 to the territory of right coronary artery. Thirty nine (31%) patients required endarterectomy of the right coronary artery. Mean cardiopulmonary bypass time and mean duration of aortic cross-clamping were 78.6 minutes and 29.6 minutes, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)