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S’ha conegut que durant una angioplàstia coronària transluminal percutània (PTCA), intervenció que té l’objectiu de “desbloquejar” l’obstrucció auricular, en alguns pacients produeix una oclusió accidental en les aurícules coronàries. Actualment s’està investigant però no existeixen estudis específics previs. Per aquest motiu, en aquest projecte s’estudia si és possible detectar aquesta oclusió a partir de senyals elèctrics del cor (ECG) mitjançant l’ús del electrocardiògraf. Amb aquesta finalitat, a partir dels registres del senyal ECG de 64 pacients, que s’han sotmès a la PTCA de l’Hospital de Sant Pau i Santa Creu, es realitza el preprocessament i el processament amb l’objectiu de caracteritzar les alteracions elèctriques, manifestades en el ECG i en les senyals R-R, i amb el propòsit d’estudiar la variabilitat del ritme cardíac i, en conseqüència, el comportament del sistema nerviós autònom.

The hemodynamic response of the kidney to acute arterial occlusion is poorly understood. The purpose of the present study was to determine intrarenal hemodynamic changes in intact and isolated kidneys following arterial occlusion., The relative roles of metabolic, myogenic and tissue pressure influences on the post-occlusion response were evaluated. The [illegible] of the kidney to occlusion was found to be complex depending on the interaction of a variety of physical and humoral forces. Increases in renal resistance appeared to be due in part to adrenergic agents and were enhanced by extending time of occlusion and lowering the arterial pressure., The combined effects of pre-venous dilation and [illegible] tissue pressure resulted in a decreased resistance following shorter periods of occlusion. Pre-venous dilation was accounted for by depressed vascular sensitivity to [illegible] agents and the presence of vasodilator substances. Changes in venous [illegible] resistance were found to be of primary importance in both the autoregulatory phenomenon and the post=occlusion hyperemic response to short (fifteen second) occlusion periods.

Both an increase and a decrease in total renal vascular resistance, following a period of total renal artery occlusion, have been reported from this laboratory. The duration of the occlusive period and height of the perfusion pressure were found to prescribe consistently the hemodynamic response. The present study, using adult mongrel dogs, indicates that, following a period of partial occlusion, in a critical range of renal artery pressure (40% to 50% of control), intrarenal hemodynamic changes mimicked those seen after total obstruction of blood flow. Reactive hyperemia was not observed.

Rheoencephalography, the monitoring of cerebral blood flow by impedance methods, has been used successfully in clinical medicine in Europe and Russia but not in the United States. Three cases are presented to demonstrate the potential value of this method in the diagnosis of cerebrovascular pathology. These cases also demonstrate that the method appears to monitor intracranial circulation in humans. The first case of the subclavian steal syndrome second to any extravascular occlusion disease is presented.

Clot dissolution using fibrinolytic agents is a promising approach to the treatment of thromboembolic disease, particularly peripheral venous and arterial occlusion. In their present state of development, these agents are not recommended for general use in thrombosis or embolism in the cerebral or coronary circulations. Dosage units are still not standardized. The commercially available "fibrinolysins" are, in reality, combinations of plasmin (or fibrinolysin) and an activator of plasminogen (or profibrinolysin). Physicians must know the limitations of these preparations and the factors that alter doasage requirements.

The mechanism of renal autoregulation is unclear. The subject of the present investigation is the mechanism of autoregulation of blood flow in the intact kidney. The left kidney of the anesthetized dog was exposed via a flank approach. Renal venous outflow was measured during control periods and following separate elevations of renal artery pressure, renal vein pressure, and ureteral pressure., Extravascular pressure (tissue pressure) was estimated by obtaining values of, 1.deep vein pressure, 2.needle pressure and, 3.large vein pressure and ureteral pressure elevations resulting in significant decreases in renal blood flow., Results are in agreement with previously reported studies regarding the important role of extravascular pressure in autoregulation. Increases in renal artery pressure result in elevation of extravascular pressure which [compresses] the renal vasculature. Increases in renal vein and ureteral pressures do not decrease renal blood flow until approximating or exceeding resting tissue pressure. Results from carotid artery occlusion experiments indicate that extrarenal humoral influences may be superimposed in the autoregulatory phenomenon.

A method for screening large populations for asymptomatic but potentially incapacitating cerebrovascular disease has obvious application in aviation medicine. Rheoencephalography (REG), a simple, rapid and innocuous method of studying the cranial circulation, was investigated for this purpose. A standardized, repeatable method involving tracing during brief arterial compressions was developed and is fully described. A 95% predictive accuracy in diagnosis and localization of carotid occlusive disease is demonstrated in patients with cerebrovascular insufficiency., A significant number of asymptomatic, medically certified normal airmen are found to be potential stroke candidates by the same method. Individual extra- and intra-cranial arterial circulatory components are demonstrated for the first time. Previously reported difficulties in REG diagnosis are elucidated. The potential value of REG screening of normal populations for cerebrovascular anomalies and early disease is demonstrated.

A case is reported of chronic massive thromboembolic occlusion of major pulmonary arterial branches successfully treated with embolectomy and endarterectomy. The historic features, physical signs and pathophysiologic alterations which form the basis for the diagnosis of this disorder are reviewed.