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A new exercise test was used to assess the effects of coronary angioplasty in 22 patients. Twenty five angioplasty procedures were performed and the exercise maximal ST segment/heart rate slope was measured before and after operation on 23 occasions; in two patients treated for unstable angina the slope was measured only after the two procedures. Successful angioplasty (23 of the 25 procedures) resulted in a significant reduction of the maximal ST/HR slope, usually falling by the equivalent of single vessel disease according to previously published criteria. When angioplasty produced little angiographic change (two of the 25 procedures) the maximal ST/HR slope was not significantly altered. A second, and successful, angioplasty for these two patients led to a significant reduction of the maximal ST/HR slope. Twelve patients were restudied by coronary angiography and exercise testing approximately six months after angioplasty. Of these, six had experienced recurrent chest pain, and the exercise test successfully identified the three who had restenoses and the three who did not. Thus the maximal ST/HR slope was useful as a non-invasive and accurate method for following the progress of individual patients after coronary angioplasty. [ABSTRACT FROM PUBLISHER]

The incidence of systemic embolism has been assessed in 461 patients having mitral valve replacement with the pericardial xenograft. No patient received long-term anticoagulant therapy. The bulk of the patients received six weeks' postoperative treatment with warfarin (322 patients) or dipyridamole (71 patients).No case of valve thrombosis has been encountered. Embolism was recognised in 9 patients of whom 7 had chronic atrial arrhythmias. No patient has died from the effects of embolism and only 2 patients have any residual clinical deficit. The majority of the episodes occurred within the first 6 postoperative weeks.The linearised rate of embolism is 0·55% per annum and is very similar to the rates reported after closed mitral valvotomy, open mitral commissurotomy and mitral valve repair. This rate of embolism is significantly lower than that reported after mitral valve replacement with porcine heterografts (2·9–5·3% per annum) even in patients having long-term anticoagulation where there is an additional haemorrhagic risk associated with the anticoagulant treatment. [ABSTRACT FROM PUBLISHER]

The fate of 1001 pericardial xenograft valves was analysed during a maximum follow-up period of 13 years. Two basic types of pericardial valves have been implanted. Between 1971 and 1975. 213 patients received ‘hospital made’ valves (single replacement). Between 1976 and 1983, 601 patients received 788 pericardial valves manufactured by Shiley Inc. (474 Standard and 314 Low profile valves) for both single and multiple replacement.There were 27 instances of valve dysfunction between 13 and 92 months after operation, 20 with ‘hospital made’ and 7 with Shiley valves. The actuarial freedom from valve failure at 8 years is 94·0 ±4·6% for aortic and 98·8± 1·2% for mitral replacement in patients with Shiley valves. In patients with ‘hospital made’ valves the actuarial freedom from valve failure at 12 years of follow-up is 86·7 ±7·6% for aortic and 84·7± 14·1% for mitral replacement. The linearised rate of valve dysfunction was 0·31% per annum for Shiley valves and 1·27% per annum for ‘hospital made’ valves.This analysis demonstrates that the pericardial xenograft has a low risk of valve failure and a predictable behaviour over a period of 13 years. The Shiley made valves have shown improved durability when compared with the ‘hospital made’ valves. [ABSTRACT FROM PUBLISHER]

Comments on various topics related to medicine in Great Britain. Prevalence of strongylodiasis in ex-prisoners; Cardiac pacemakers as prophylaxis of surgical wound sepsis; Use of antibiotic therapy for appendicectomy.

Because epoprostenol (prostacyclin) is a prostaglandin that causes vasodilatation and inhibits platelet function it may be of benefit during coronary artery angioplasty. The safety and capacity of intracoronary epoprostenol to dilate coronary arteries were assessed in 16 patients undergoing routine coronary angiography. The view that best displayed the left epicardial coronary arteries was selected as a control for each patient. Intracoronary epoprostenol was then given and the angiogram was repeated in the chosen view. The procedure was repeated twice: once with a higher dose of epoprostenol and once after intracoronary isosorbide dinitrate. Angiograms were coded and analysed by an observer who was unaware of the treatment. The calibre of the arteries was measured from traced projections of the angiograms. The blood pressure, heart rate, and electrocardiogram were recorded throughout. The first two patients were given epoprostenol infusions of 2.5 and 5.0 ng/kg per minute to assess safety, and there were no untoward reactions. The next ten patients had epoprostenol infusions of 5.0 and 7.5 ng/kg per minute followed by intracoronary isosorbide dinitrate. No haemodynamic disturbances occurred and coronary luminal calibre did not change with epoprostenol (mean (SD) luminal diameter: 2.85 (0.62) mm control, 2.80 (0.61) mm at 5.0 ng/kg, and 2.80 (0.54) mm at 7.5 ng/kg), but it did increase significantly with isosorbide dinitrate (to 3.17 (0.36) mm). The last four patients had epoprostenol infusions of 7.5 and 10 ng/kg followed by intracoronary isosorbide dinitrate and two of them became hypotensive (one after epoprostenol and one after isosorbide dinitrate). Coronary luminal calibre did not change significantly (3.5 (0.45) mm control, 2.96 (0.81) mm at 7.5 ng/kg, 3.45 (0.96) mm at 10 ng/kg, and 3.20 (0.61) mm with isosorbide dinitrate). Eight patients developed tall T waves on the electrocardiogram during epoprostenol infusion but none had arrhythmias. The results indicate that clinically tolerable doses of intracoronary epoprostenol do not significantly dilate the epicardial coronary arteries. This route of administration is therefore unlikely to be of use during coronary angioplasty, although the antiplatelet action of intravenous epoprostenol might help to prevent restenosis. [ABSTRACT FROM PUBLISHER]

Two hundred and forty percutaneous transluminal coronary angioplasty procedures were performed in three centres over a two year period. Acute occlusion of the vessel undergoing angioplasty was seen on 20 (8%) occasions. The cause of occlusion was determined angiographically and in some cases confirmed at the time of emergency open heart surgery. The mechanism of coronary occlusion was arterial dissection in six cases, persisting coronary arterial spasm in seven, and coronary thrombosis in four. In three patients the mechanism could not be determined. Immediate reintroduction of a balloon dilatation catheter was attempted in 10 patients and resulted in restoration of adequate coronary flow in six. The remaining 14 patients underwent open heart surgery as an emergency procedure. [ABSTRACT FROM PUBLISHER]

The article presents a case study of a 74 year old man who developed numerous intracerebral haemorrhages following a thrombolytic treatment of acute myocardial infarction.

Acute kidney injury (AKI) affects up to 50% of cardiac surgery patients. The definition of AKI is based on changes in serum creatinine relative to a baseline measurement or a decrease in urine output. These monitoring methods lead to a delayed diagnosis. Monitoring the partial pressure of oxygen in urine (PuO 2 ) may provide a method to assess the patient's AKI risk status dynamically. This study aimed to assess the predictive capability of two machine learning algorithms for AKI in cardiac surgery patients. One algorithm incorporated a feature derived from PuO 2 monitoring, while the other algorithm solely relied on preoperative risk factors. The hypothesis was that the model incorporating PuO 2 information would exhibit a higher area under the receiver operator characteristic curve (AUROC). An automated forward variable selection method was used to identify the best preoperative features. The AUROC for individual features derived from the PuO 2 monitor was used to pick the single best PuO 2 -based feature. The AUROC for the preoperative plus PuO 2 model vs. the preoperative-only model was 0.78 vs. 0.66 ( p -value < 0.01). In summary, a model that includes an intraoperative PuO 2 feature better predicts AKI than one that only includes preoperative patient data.

Background: Transcatheter aortic valve implantation (TAVI) is now routinely performed in patients with aortic stenosis with low mortality and complication rates. Although periprocedural risks have been substantially minimized, procedure- and contrast-induced acute kidney injury (AKI) remains a major concern. AKI remains a frequent complication of contrast-guided interventional procedures and is associated with a significantly adverse prognosis. We review the currently available clinical data related to AKI, with emphasis on contrast-induced nephropathy (CIN), and discuss a novel, integrated approach aiming to minimize AKI risk in high-risk patients. A stepwise algorithm is also proposed for the management of these complex patients.

Strain analysis allows for global and regional analysis of myocardial function and has been shown to be an independent predictor of outcomes after cardiac surgery. Strain imaging offers advantages over traditional EF measurements in that it is relatively angle independent, it is less dependent upon loading conditions, it is reproducible, it does not rely on geometric assumptions, and it can detect subclinical systolic dysfunction. Limitations of strain analysis include high temporal resolution requirements, a strong dependence on image quality, and inter-vendor variability. In addition, there is a paucity of data on the intraoperative applications of strain. The ASE has defined a global longitudinal strain of -20% measured by transthoracic echocardiography to be considered normal, with less negative values considered abnormal. Presently, there are no published guidelines on the normal values of strain with transesophageal echocardiography (TEE). However, multiple studies have shown that a reduction in intraoperative strain assessed with TEE has been shown to be an independent predictor of complications during cardiac surgery. Accordingly, further incorporation of intraoperative strain analysis with TEE could aid in prognostication for patients undergoing cardiac surgery. As perioperative strain analysis continues to advance, an understanding of these concepts is imperative for perioperative echocardiographers. It is the authors' goal to show that strain imaging can provide a reliable and objective measure that can be performed in real time to aid in decision-making and perioperative risk stratification., (Published by Elsevier Inc.)