Left ventricular flow from apex to base during systole and isovolumic relaxation in a patient with hypertrophic cardiomyopathy and midventricular obstruction

The occurrence of a left ventricular anterograde flow velocity (maximal: 3·9m . s−1) is demonstrated in a 32-year-old patient with hypertrophic cardioinyopathy and midveniricular obstruction, beginning at early systole and persisting throughout the isovolumic relaxation. Cardiac catheterization with simultaneous dual high fidelity pressure measurements in the apical and basal chambers confirmed the presence of the Doppler maximal instantaneous pressure gradient of 60 mmHg. Contrast left ventricular angiography excluded apical dyskinesia. In the two intracavity compartments, isovolumic relaxation time and the time constant of pressure decay (τ) were abnormal whereby τ was more delayed in the apical than in the basal portion. The presence of an apical high pressure zone during systole with impeded and delayed emptying through the midventricular obstacle and the late onset and prolongation of relaxation are thought to be the cause of the intraventricular flow from apex to base lasting from early systole throughout isovolumic relaxatio

Simultaneous determination of the stroke volume and the left ventricular residual fraction with the fiberoptic- and thermodilution method

Simultaneous measurements of the concentration of dye by a fiberoptic catheter and of the temperature by a thermistor catheter were obtained in dogs. No significant difference for cardiac output and stroke volume was found. The slightly but significant higher residual fraction by thermodilution than by fiberoptic technique is caused by cold transfer between ventricular myocardium and cavity. It becomes evident after the fifth bea

Early results after mitral valvuloplasty for pure mitral regurgitation

In this study we present the results of 105 consecutive patients with pure mitral regurgitation who underwent surgical treatment. In all patients mitral regurgitation was associated with mitral valve prolapse: 54 patients underwent mitral valvuloplasty and 51 patients mitral valve replacement. Clinical assessment and echocardiography were used as follow-up criteria at one year after surgery. After mitral valvuloplasty, NYH A decreased from 2.7±0.8 to 1.1±0.7 (P<0.01) and workload capacity increased from 65±28% to 96±25% (P<0.001); left endsystolic atrial dimension and enddiastolic dimension decreased from 6.2±0.8 to 4.8±1.2 cm (P<0.001) and from 7.2±1.3 to 5.9±0.8 cm (P<0.01); ventricular contraction fraction did not change significantly. After mitral valve replacement, clinical and echocardiographic improvement was significant but less remarkable than after valvuloplasty; ventricular contraction fraction fell from 39±7% to 29±8% in contrast to patients undergoing mitral valvuloplasty in whom no significant change occurred. Complications were rare in both groups though only a minority of patients undergoing mitral valvuloplasty received anticoagulants. We conclude that mitral valvuloplasty in patients with pure mitral regurgitation associated with mitral valve prolapse gives excellent results, particularly regarding left ventricular function when compared with the patients after mitral valve replacemen

Potential role of coronary vasoconstriction in ischaemic heart disease: effect of exercise

Coronary vasomotion plays an important role in the regulation of coronary perfusion at rest and during exercise. Normal coronary arteries show coronary vasodilation of the proximal (+20%) and distal (+40%) vessel segments during supine bicycle exercise. However, patients with coronary artery disease show exercise-induced vasoconstriction of the stenotic vessel segments. The exact mechanism of exercise-induced stenosis narrowing is not clear but might be related to a passive collapse of the disease-free vessel wall (Venturi mechanism), elevated plasma levels of circulating catecholamines, an insufficient production of the endothelium-derived vesorelaxing factor or increased platelet aggregation due to turbulent blood flow with release of thromboxane A2 and serotonin. Various vasoactive drugs, such as nitroglycerin and calcium antagonists, prevent exercise-induced stenosis vasoconstriction. An additive effect on coronary vasodilation of the stenotic vessel segment was observed after combination of nitroglycerin with diltiazem. Thus, exercise-induced stenosis narrowing plays an important role in the pathophysiology of myocardial ischaemia during dynamic exercise. The antianginal effect of vasoactive substances can be explained—besides the effect on pre- and afterload—by a direct action on coronary stenosis vasomotio

Platelet inhibitors versus anticoagulants for prevention of aorto-coronary bypass graft occlusion

The effects of the antiaggregant substance ticlopidine and of the anticoagulant acenocoumarol on patency rates of aorto-coronary bypass grafts were compared in a prospective randomized trial. Ticlopidine, 250 mg b.i.d. was administered orally from the first postoperative day till angiography, while anticoagulation with acenocoumarol was initiated on the second to third postoperative day. Side-effects of ticlopidine were rare and patient management with the standard dosage of this drug was easier than oral anticoagulation. From an initial group of 166 randomized patients 149 completed the trial by coronary angiography three months postoperatively. The 78 patients in the ticlopidine group showed a compliance of 85%. The average prothrombin time in the 71 patients receiving acenocoumarol was 26.9%. Detailed statistical analysis of the two study groups revealed no reason to doubt the correctness of randomization. Coronary angiography showed an average patency rate per patient of 84% with ticlopidine and of 82% with acenocoumarol. This and various other measures of graft occlusion did not reveal any substantial difference in graft patency of patients receiving ticlopidine or acenocoumarol. It is concluded that ticlopidine may well be used instead of anticoagulants forprevention of postoperative occlusion of aorto-coronary bypass graft

Acute recurrent haemorrhage of an intracranial meningioma

Meningioma-associated haemorrhages are rare. To our knowledge this is the first report of a patient with an acute two-stage haemorrhage of a benign intracranial meningioma (World Health Organization grade I) verified by cranial CT scan and histopathological examination. Early surgery with complete tumour removal led to a good outcome for the patient

Collision sellar lesions: experience with eight cases and review of the literature

The concomitant presence of a pituitary adenoma with a second sellar lesion in patients operated upon for pituitary adenoma is an uncommon entity. Although rare, quite a great variety of lesions have been indentified coexisting with pituitary adenomas. In fact, most combinations have been described before, but an overview with information on the frequency of combined pathologies in a large series has not been published. We present a series of eight collision sellar lesions indentified among 548 transsphenoidally resected pituitary adenomas in two Neurosurgical Departments. The histological studies confirmed a case of sarcoidosis within a non-functioning pituitary adenoma, a case of intrasellar schwannoma coexisting with growth hormone (GH) secreting adenoma, two Rathke’s cleft cysts combined with pituitary adenomas, three gangliocytomas associated with GH-secreting adenomas, and a case of a double pituitary adenoma. The pertinent literature is discussed with emphasis on pathogenetic theories of dual sellar lesions. Although there is no direct evidence to confirm the pathogenetic relationship of collision sellar lesions, the number of cases presented in literature makes the theory of an incidental occurrence rather doubtful. Suggested hypotheses about a common embryonic origin or a potential interaction between pituitary adenomas and the immune system are presented

Methodology of calculation of construction and hydrodynamic parameters of a foam layer apparatus for mass-transfer processes

Промислова реалізація методу стабілізації газорідинного шару дозволяє значно розширити галузь застосування пінних апаратів і відкриває нові можливості інтенсифікації технологічних процесів з одночасним створенням маловідходних технологій. У статті встановлені основні параметри, що впливають на гідродинаміку пінних апаратів, розглянуті основні конструкції та режими роботи пінних апаратів. Виявлено зв'язок гідродинамічних параметрів. Розглянуто гідродинамічні закономірності пінного шару. Вказані фактори, що впливають на процес масообміну, як в газовій, так і в рідкій фазах. Проведений аналіз ряду досліджень показав, що перспективним напрямком інтенсифікації процесу масообміну є розробка апаратів з трифазним псевдозрідженим шаром зрошуваної насадки складних форм із сітчастих матеріалів. Отже, необхідне проведення спеціальних досліджень гідродинамічних режимів роботи апарату з сітчастою насадкою і визначенням параметрів, що впливають на швидкість переходу насадки з одного режиму в інший.Industrial implementation of the stabilization method of the gas-liquid layer can significantly expand the field of use of foaming apparatus and opens up new opportunities for intensifying technological processes with the simultaneous creation of low-waste technologies. The article establishes the basic parameters influencing the hydrodynamics of foam apparatus, considers the basic constructions and operating modes of foam apparatus. The connection of hydrodynamic parameters is revealed. The hydrodynamic laws of the foam layer are considered. The indicated factors affecting the process of mass transfer, both in the gas and in the liquid phases. The conducted analysis of a number of studies showed that the perspective direction of intensification of the mass transfer process is the development of apparatuses with a three-phase fluidized bed of an irrigated nozzle of complex forms with mesh materials