[Acquired systemic arteriovenous fistulas. Experience of 33 cases]. / Fístulas arteriovenosas sistémicas adquiridas. Experiencia de 33 casos.

We analyzed 33 cases of Acquired Systemic Arteriovenous Fistulas (FAVSA) seen in the INC-ICH between 1945 and 1981. The most frequent causes were traumatic (gunshot and knife wounds) and iatrogenic (surgery). The most affected vessels were femoral, carotid, axillary and subclavian. The FAVSA produced a hyperkinetic hemodynamic syndrome of high output that frequently resulted in fistular cardiopathy. Fistular cardiopathy and heart failure became evident from 4 days to 31 years after the initial insult and was related to the magnitude of the arteriovenous shunt. The latter depended on the distensibility of the communicating ring (the development of perifistular fibrosis did not allow dilatation of the fistular opening). Heart failure was a result of the magnitude of the shunt, even when the patient was young with a healthy heart. A detailed traumatic or surgical history was extremely important in the diagnosis. Relevant physical signs included: bounding pulses, a wide pulse pressure, the presence of a continuous murmur and thrill, a positive Nicoladoni-Branham's sign with a decrease in the heart rate and an increase in systemic blood pressure when the FAVSA was compressed. The existence of the condition became suspicious when heart failure appeared otherwise unexplained by an obvious cardiac lesion. Other important signs included the development of distal venous insufficiency and the presence of a palpable pulsatile mass. Fistular cardiopathy was observed in 60% of the cases studied, although the ECG was normal in 33%; 73% had cardiomegaly which improved with correction of the FAVSA. The treatment is necessarily surgical and required the appropriate technique.

[Measurement of tricuspid transvalvular flow by M-mode echocardiography and its application in the calculation of the A-V shunt in interatrial communication]. / Medición del flujo transvalvular tricúspideo por ecocardiografía modo-M y su aplicación en el cálculo del cortocircuito A-V en la comunicación interauricular.

Previous studies have demonstrated that it is possible to measure the cardiac output by M-mode echocardiography (M-echo), using the echogram of the mitral (MV) or aortic valves. In this communication we pretend to demonstrate the possibility of calculating the right cardiac output by the echocardiographic image of the tricuspid valve (TV). We studied patients with atrial septal defects (ASD) because the anatomic and physiologic conditions allowed us to obtain a complete record of the TV. The study was done in a prospective form with 12 patients with isolated ASD, without pulmonary hypertension, cases with ostiumprimum were excluded. The measure of stroke volume of the MV and TV was made using Rasmussen's formula and mechanic planimetric measure of the diastolic opening area of both valves. For the TV area calculation it was considered that the area of the posterior valve was similar to the septal valve and the area of the last one was multiplicated by 2, in this form we obtained the value of the whole TV. For confirmation of the reliability of this method, we studied 8 healthy subjects for the comparison of the mitral and tricuspid flows. The velocity of the transvalvular flow was obtained by measuring the D-E slope. The correlation between MV and TV flows was good in healthy subjects (r = 0.957). Similar results were obtained with the areas of MV and TV in the same group (r = 0.971). In patients with ASD, the comparison between Rasmussen's method and the planimetric method showed that the value of TV increased higher than the MV values. The difference is most important between the areas. The correlation of the cardiac output calculated by the Fick method and M-echo was not significative. The defective output determined by catheterization and M-echo showed a significative correlation (r = 0.793). It is possible the quantitation of the right ventricle output by M-echo, this technic is useful because it shows the hemodynamic conditions of patients with ASD, and it is possible the measure the TV flow, and probably it will be useful in patients with other congenital heart disease with left right shunts.

[Echocardiographic study of chronic aortic insufficiency. Hemodynamic, angiographic and total clinical correlates. II. Evaluation of left ventricular function]. / Estudio ecocardiográfico de la insuficiencia aortica crónica. Correlacion hemodinámica, angiográfica y clínica integral. Segunda parte: evaluación de la funcion ventricular izquierda.

An important point in the evolution of chronic aortic insufficiency (CAI) is the degree of disturbance of left ventricular performance (LVP), from which the surgical risk and the prognosis depend. Is possible by M mode Echocardiography (M-Echo) to evaluate the different elements that regulate the LVP, with the known measurements and by ratios of integral appraisal that are described here. We studied 14 patients with pure CAI at the National Institute of Cardiology, all of them had left catherization, ventriculography aortography, M-Echo, Chest X ray and EKG. The end systolic diameter (ESD) of the left ventricle (LV) and the fractional shortening (FS) showed good correlation with the end diastolic pressure (EDP) of the LV (r = 0.86 and -0.74 respectively). The percentage of aortic regurgitation (%AR) did not show significative correlation with the parameters of LV function. The ratios of integral appraisal showed good correlation with the EDP of the LV, the left atrium diameter over ejection fraction ratio (LAD/EF) was r = 0.764; the E point-septum separation over the fractional shortening ratio (E-S/FE) was r = 0.776, and for the ESD over the normalized velocity of the posterior wall of the LV ratio (ESD/NVPW) was r = 0.85. The relationship of the ESD/NVPW ratio with the EF was good (r = 0.95), with the mean velocity of circunferential shortening (r = -0.94) and with the cardiothoracic index (r = 0.88). We did not find a relationship between the functional class (NYHA) and the LVP, evaluated hemodynamic and echocardiographic methods used here. The M-Echo is an useful procedure for the sequential study of CAI, that permits recognition of the initiation and severity of the LV dysfunction, and it is of great help to signal the right moment for the surgical treatment.

[New echocardiographic (M-mode) index for evaluation of left ventricular end-diastolic pressure in chronic aortic regurgitation (author's transl)]. / Nuevo índice for ecocardiografía modo-m para la evaluación de la presión diastólica final del ventrículo izquierdo en la insuficiencia aórtica crónica.

The clinical evaluation of the best time for the surgical treatment of chronic aortic insufficiency is difficult to be assessed. Several invasive and non invasive procedures had been used, but there is no definitive solution yet. At the National Institute of Cardiology Ignacio Chávez, 13 patients wih pure, chronic and isolated cortic regurgitation (AR) were studied by echocardiography M mode (Echo M) to determine the state of left ventricular performance and the correlation with the valves of the end diastolic pressure of left ventricle (LVEDP). Besides catheterism of the left side, aortography and ventriculography were performed to all the patients. Catheterism, X-nay and electrocardiogram were done within a period no longer than 24 hours after the Echo M record. The function of the left ventricle (LV) was evaluated by measures and calculations published by other authors. With the purpose of integrating the functional characteristics of the LV in one expression, the indices left ventricle and systolic diameter divided by left ventricular normalized velocity of posterior wall (LVESD/LVPWNV) was created. It showed good correlation with LVEDP (r = 0.92). The index also had good correlation with the cardiothoracic ratio (r = 0.86) and the mean velocity of circumferential shortening of the LV by Echo M (r = 0.91). We consider important the LVESD/LVPWNV index proposed here, to determine the LVEDP of these patients; together with the whole clinical information, it makes easier the identification of the most appropriate time for surgical treatment making possible to evade the phase of myocardial damage which is risky to patients with chronic aortic insufficiency.