Left ventricular false aneurysm after previous repair of acquired ventricular septal defect.

We report a novel case of a 69-year-old woman who was treated surgically for a postinfarction inferior ventricular septal defect and presented 3 years postoperatively with a large left ventricular false aneurysm. This was successfully repaired.

Oesophageal epiphrenic diverticulum: an unusual presentation and review.

Epiphrenic pulsion diverticula are rare and often asymptomatic. We describe a case presenting in an unusual fashion, and review the controversy over the management of this condition with regard to the requirement for myotomy and antireflux surgery. We believe that both procedures are necessary, but believe that both procedures are necessary, but optimal management strategies are unlikely to be resolved as the rarity of the condition precludes largescale prospective studies.

Adult congenital lobar emphysema in pregnancy.

A young woman presented with left sided chest pain. Chest radiography revealed a hyperexpanded left upper lobe and the rare diagnosis of congenital lobar emphysema was made. She was then found to be pregnant. Thoracotomy and left upper lobectomy were performed during the pregnancy without adverse effects to the mother or fetus. The implications of pregnancy on the surgical management of this rare condition are discussed.

Spontaneous rupture of a congenital diaphragmatic eventration.

A 51-year-old man presented as an emergency with acute intestinal obstruction following herniation of abdominal contents into the left hemithorax through a spontaneous rupture of his eventrated left hemidiaphragm. He underwent a left thoracotomy with reduction of the herniated abdominal contents, repair of the diaphragmatic rupture and plication of the diaphragm. He made an uneventful recovery and remains asymptomatic. This is the first reported case of spontaneous rupture of an eventration of the diaphragm.

Anions, membrane resistance and ventricular fibrillation.

Clinical success in prevention of sudden cardiac death has been poor. New approaches to prevention of ventricular fibrillation (VF), one of the main causes of sudden cardiac death, are clearly needed. In the present article we have reviewed some of our own data which support the notion that VF may be prevented by manipulation of chloride homeostasis. Our studies have revealed a novel approach to VF suppression via alteration of sarcolemmal membrane resistance.

Anion manipulation, a novel antiarrhythmic approach: mechanism of action.

We recently reported that modulation of anion homeostasis by substitution of extracellular chloride by nitrate prevents ischaemia- and reperfusion-induced ventricular fibrillation (VF) in rat and rabbit in vitro by an unknown mechanism independent of haemodynamic changes but related to widening of QT interval (Ridley and Curtis 1991). In the present study we have examined three possible explanations for the mechanism: modification of membrane anion permeability, alteration of cyclic nucleotide homeostasis and alteration of intracellular pH. In isolated Langerdorff-perfused rat heart (n = 12/group), substitution of chloride in modified Krebs perfusion solution by anion surrogates (methylsulphate, bromide, nitrate or iodide) inhibited left regional ischaemia- and reperfusion-induced arrhythmias only when the membrane permeability of the surrogate was greater than that of chloride (e.g., nitrate, bromide, iodide); the least permeant anion, methylsulphate, was proarrhythmic during ischaemia. Rank order of arrhythmia susceptibility correlated with the relative permeability of each anion, with near abolition of both ischaemia- and reperfusion-induced VF (P < 0.05) by the most permeant anions (iodide and nitrate). Arrhythmia suppression occurring in the iodide and nitrate groups was accompanied by significant widening of QT interval at 90% repolarization, with effects substantially more marked during ischaemia than before ischaemia. In separate studies using the same model we determined cardiac cyclic (c) AMP and cGMP content and their molar ratios by radioimmunoassay of biopsies before, during and after ischaemia. There was no meaningful relation between cyclic nucleotide content and rank order of arrhythmia susceptibility ruling out changes in the former as a contributory mechanism to the latter. In further studies we measured intracellular pH in the isolated perfused rat heart by phosphorus NMR spectroscopy. Nitrate caused a slight intracellular acidosis which was exacerbated when hearts were made globally ischaemic, indicating that its antiarrhythmic activity was not a consequence of alkalinisation (e.g., via inhibition of chloride-bicarbonate exchange). To test for inherent adverse effects on cardiac contractile function we analysed Starling curves in isolated rat hearts perfused under conditions equivalent to those used for arrhythmia studies. There was no relationship between perfusion anion composition and systolic (developed pressure at constant intraventricular volume, and pressure-volume slope) or diastolic function (end-diastolic pressure at constant intraventricular volume). In conclusion, alteration of membrane permeability is a mechanism which may be sufficient to explain modulation of arrhythmias by manipulation of extracellular anion content, appears to be devoid of deleterious effects on contractile function, and may represent a focus for future antiarrhythmic drug development.

Heterotopic heart transplantation and recipient heart operation in ischemic heart disease.

The role of heterotopic heart transplantation in coronary heart disease has not been defined. Between 1983 and 1988, 28 patients with end-stage ischemic heart disease were managed by heterotopic heart transplantation and adjunctive operation on the recipient heart: coronary artery bypass grafts and aneurysmectomy, 20; coronary artery bypass grafts, 5; and aneurysmectomy, 3. Indications were feasibility of operative procedures to the recipient heart and small donor size (61% of the donors were less than 15 years). The 1-year and 5-year actuarial survival was 79% and 63%. Of the 22 patients who survived to 2-year follow-up, all of whom had been severely limited (New York Heart Association grade III/IV) preoperatively, 20 were in grades I or II at 2-year follow-up (p less than 0.001). In 14 of 22 patients (64%), the recipient heart augmented the donor cardiac output substantially, and in 4 the recipient heart supported the patient when the donor heart failed to eject. In conclusion, this series demonstrates the efficacy of heterotopic transplantation combined with operation to the recipient heart in the management of patients with end-stage ischemic heart disease.

Anion manipulation: a new antiarrhythmic approach. Action of substitution of chloride with nitrate on ischemia- and reperfusion-induced ventricular fibrillation and contractile function.

The role of anions in the initiation of ischemia- and reperfusion-induced arrhythmias is unknown. We examined the antiarrhythmic effects of isotonic substitution of extracellular Cl- with NO3- by using the rat Langendorff preparation (n = 12 per group). During 30 minutes of regional ischemia, the incidence of ventricular fibrillation (VF) was reduced from 50% in hearts perfused with control solution (containing a Cl-:NO3- ratio of 100:0) to 25%, 0% (p less than 0.05), 0% (p less than 0.05), and 0% (p less than 0.05) by perfusion with solution containing Cl-:NO3- ratios of 75:25, 50:50, 25:75, and 0:100, respectively. The incidence of reperfusion-induced VF was also reduced from 58% to 25%, 8% (p less than 0.05), 8% (p less than 0.05), and 0% (p less than 0.05), respectively. Similar effects were produced in hearts reperfused after briefer durations of ischemia (10 or 15 minutes). Substitution of NO3- for Cl- also facilitated spontaneous termination of VF. Heart rate and occluded zone size were not affected by anion manipulation. Coronary flow was affected by NO3-, but changes did not correlate with arrhythmias. During ischemia, electrocardiographic changes indicative of class III activity (widening of the ventricular complex) were produced by anion substitution. These changes occurred selectively in the ischemic tissue with no significant influence before ischemia onset. However, the relation between this effect and arrhythmia reduction was not linear and a cause-effect relation is therefore unlikely. In separate groups of hearts (n = 12 per group), switching from 100:0 to 0:100 Cl-:NO3- solution or vice versa 10 seconds after coronary occlusion or just before reperfusion demonstrated that 1) protection against ischemia-induced VF resulted partly from an action in the ischemic zone and partly from an action in the nonischemic zone, and 2) protection against reperfusion-induced VF resulted principally from an action occurring during reperfusion and within the reperfused tissue. To assess whether benefit was offset by deleterious effects on contractile function in nonischemic tissue, we constructed Starling curves in isolated rate hearts. The 0:100 Cl-:NO3- solution had no effect on compliance or contractility at physiological end-diastolic pressures but reduced the slope of the peak systolic pressure-volume relation by approximately 20% as end-diastolic pressure was increased above 10 mm Hg. In conclusion, anions appear to play a hitherto unrecognized role in arrhythmogenesis in ischemia and reperfusion. Manipulation of anion homeostasis may represent a novel target for antiarrhythmic drug development.

A modified model of global ischaemia: application to the study of syncytial mechanisms of arrhythmogenesis.

OBJECTIVE: The aim was to develop a simple modified global ischaemia preparation to study the relation between ischaemic zone size and the incidence of ischaemia induced and reperfusion induced arrhythmias, to test the hypothesis that arrhythmias are initiated by flow of injury current between the ischaemic zone and the uninvolved myocardium. The new model was used to examine whether injury current suppression is involved in the mechanism of action of a new antiarrhythmic intervention, substitution of chloride anion by nitrate. METHODS: Isolated perfused (Langendorff mode) rat hearts (n = 12 per group) were subjected to 30 min global or regional ischaemia. Ventricular arrhythmia incidence during ischaemia and during reperfusion were related to the size of the involved region. The modified model of global ischaemia employed right intra-atrial superfusion to maintain normal sinus rate and 1:1 atrioventricular (AV) conduction. RESULTS: Sham ligation, low left coronary ligation, high left coronary ligation, and global ischaemia produced, as a percentage of total ventricular weight, 0%, 21.0(SEM 0.8)%, 47.0(1.0)%, and 100% regions of ischaemia (occluded zones). Heart rates were similar in each group and AV block did not occur. The incidences of ischaemia induced ventricular fibrillation (VF) were 0, 17, 75, and 17% with increasing occluded zone sizes. Incidences of reperfusion induced VF were 0, 8, 92, and 92% respectively. The antiarrhythmic action of substitution of extracellular chloride by nitrate, previously shown using models of regional ischaemia, was confirmed in the modified global ischaemia model. CONCLUSIONS: These findings strongly support the theory that current of injury between ischaemia and adjacent non-ischaemic zones is necessary for initiation of ischaemia induced VF, since susceptibility was maximal when ischaemic and uninvolved regions were equivalent in size (and the scope for injury current was maximal) whereas susceptibility was negligible when scope was minimal. In contrast, reperfusion induced VF appears to depend only on the presence and amount of reperfused tissue, indicating that flow of injury current between involved and uninvolved tissue is unnecessary for its initiation. Discrimination of the mechanism of action of antiarrhythmic interventions may be possible since drugs effective solely via amelioration of flow of injury current (or incrementation of collateral flow) will not influence arrhythmias in this model. Modification of injury current and collateral flow do not appear to contribute to the antiarrhythmic action of substitution of extracellular chloride by nitrate.

Thoracoscopic debridement and pleural irrigation in the management of empyema thoracis.

As a sequel to a paper reporting good results obtained in 12 patients with empyema thoracis treated by thoracoscopic debridement and irrigation in our department, subsequent experience with a further 18 patients is reported. Drainage of pus and irrigation resulted in resolution of pyrexia with improvement in general condition in all patients. Overall, complete resolution was obtained by this technique alone in 60% (18/30). Of the 12 patients in whom complete resolution was not obtained, secondary surgical measures resulted in resolution of empyema in 8. Four patients died; all were elderly and severely debilitated, 3 with advanced malignancy. Their deaths were not related to the technique, which was well tolerated in all cases. Thoracoscopic debridement and irrigation used routinely as a first-line measure in empyema thoracis is a safe and relatively atraumatic procedure, does not exclude the use of any subsequent surgical measure, and provides valuable time to improve the condition of debilitated patients so that they may tolerate more aggressive surgical procedures.

Primary sarcoma of the lung: potential dangers of immunocytochemistry.

A case is presented of a successfully resected primary pulmonary sarcoma in a 27-year-old man, followed by an eight-year disease-free follow-up. Details of the histological findings are presented, and the factors associated with good prognosis discussed. Immunocytochemical stains were carried out this year when the case was reviewed, and not at the time of resection. Had the immunostains been available at the time, the results would have suggested that the tumour might be a secondary deposit, and so have caused needless anxiety to the patient and his physicians.

The metabolic consequences of a "washed" cardiopulmonary bypass pump-priming fluid in children undergoing cardiac operations.

The substrate load of the pump-priming fluid, especially glucose and lactate, has a major influence on the metabolic response of children during cardiac operations and may be detrimental neurologically. It is possible to cleanse the priming fluid of these excess substrates by ultrafiltration followed by the addition of a balanced electrolyte solution. We have used this technique in the bypass management of nine children over 1 year of age and weighing less than 18 kg who were studied from induction of anesthesia to 6 hours postoperatively. Frequent blood samples were taken for measurement of electrolytes, intermediary metabolites, and stress-related hormones. Throughout the study period electrolyte concentrations were maintained within the physiologic range and changes in blood glucose and lactate were minimized compared with those of matched historical controls from previous studies. During the period of cardiopulmonary bypass mean serum glucose concentrations varied between 4.4 and 7.7 mmol/L and peaked at 10.7 mmol/L just before skin closure. The mean serum lactate concentration did not exceed 2.3 mmol/L during the period studied. Thus ultrafiltration of the priming fluid and replacement with a balanced electrolyte solution results in the delivery to the patient of a reasonably physiologic substrate load, which is reflected in improved control of mean plasma intermediary metabolite concentrations. The method may form the basis of further clinical studies to determine specific aspects of the metabolic stress response in children.

Protein C deficiency associated with massive cerebral thrombosis following open heart surgery.

We describe a case of massive cerebral venous thrombosis following open heart surgery in a patient with a reduced level of Protein C (40% of mean level). Protein C deficiency is an inherited disorder which in the homozygous form may result in massive fatal venous thrombosis in the newborn. A Protein C level below 55% is highly suggestive of heterozygous deficiency and has been associated with a tendency to venous thrombosis although its clinical penetrance is variable. This is the first reported case of massive venous thrombosis in a patient following open heart surgery associated with Protein C deficiency.

Comparative evaluation of cefotaxime and cephamandole in the prevention of post-operative infective complications following emergency abdominal surgery.

In previous published work we described 57 patients undergoing emergency abdominal surgery, prospectively randomised to receive either cefotaxime or cephamandole as a single-antibiotic, three-dose, peri-operative prophylaxis against post-operative infective complications. This earlier work suggested that cefotaxime might be more effective than cephamandole in preventing wound sepsis in emergency abdominal surgery. We describe here our findings in a further 63 patients undergoing emergency abdominal surgery who were similarly allocated into either a cefotaxime or cephamandole antibiotic group. Infective complications occurred in 12/32 (37 per cent) of the cefotaxime group and 15/31 (48 per cent) of the cephamandole group. Wound infections occurred in 5/32 (16 per cent) of the cefotaxime group and 9/31 (29 per cent) of the cephamandole group. The organisms cultured and their sensitivities are discussed in detail. The total of 120 patients studied in the two series showed wound infection to occur in 13 per cent of the 62 patients receiving cefotaxime and 30 per cent of the 58 patients receiving cephamandole. This difference reaches statistical significance (p less than 0.05). Possible mechanisms to explain this finding are discussed. Again we found the regime of 4 g of cefotaxime given peri-operatively to be a simple, safe and effective single agent as prophylaxis for emergency abdominal surgery.

Rupture of a pseudoaneurysm of a saphenous vein coronary arterial bypass graft presenting with superior caval venous obstruction.

We describe the first reported case of rupture of a pseudoaneurysm of a sapheneous vein coronary arterial bypass graft presenting with acute superior caval venous obstruction. The patient was successfully treated by urgent surgical excision of the graft.