Benjamín Elencwajg

Spinal Cord Stimulation for Severely Ischemic Limbs

Severe atherosclerosis of the lower limbs causes rest pain, skin ulcerations and gangrene. In such situations and when standard surgical treatment had failed or it is impossible to employ, spinal cord stimulation (SCS) seems to he of value. Since April 1985, we have used this technique on 19 patients. The results have been beneficial in 70.6% of the cases and have shown some evidence of increasing cutaneous flow. However, randomized series are required before accepting it as having a special place in the fight against atherosclerotic disease.

Efficacy of flecainide in the management of ventricular arrhythmias: comparative study with amiodarone.

The effects on ventricular arrhythmias of a new class IA drug, flecainide, were compared with those of amiodarone in 10 patients with frequent, chronic, and stable ventricular ectopic beats (VEBs). The study consisted of an initial 1-week, placebo-controlled, baseline period followed by two 12-day, randomized, crossover, double-blind treatment periods with incremental dosage and 1 month of placebo between drug periods. Frequent VEBs, which were present in all 10 patients during both placebo control periods (30 or more VEBs/hour every hour, during 24-hour Holter monitoring), were markedly suppressed (reduction greater than 80%) in nine patients with both drugs (p less than 0.01). There was almost total abolition of the VEBs in six patients with flecainide, and the satisfactory results with a minimal dose in three demonstrate its fast onset of action. Side effects from either agent were infrequent and no discontinuation was necessary. We conclude from our study that flecainide is a highly effective antiarrhythmic agent.

Ambulatory electrocardiographic findings in out-of-hospital cardiac arrest secondary to coronary artery disease.

Abstract Sudden death is a frequent cause of mortality worldwide, affecting people with either known or unknown heart disease. Coronary artery disease is its most common etiology. 1 The causal mechanisms of sudden death have become better understood with the study of animal models 2 and patients resuscitated from cardiac arrest. 3,4 Patients in whom an electrocardiographic recording is available at the time of death offer valuable information, but are scarce. 5–18 We present data from 8 patients with coronary artery disease in whom out-of-hospital cardiac arrest was documented by ambulatory electrocardiographic recording.

Antiarrhythmic Effect of Tiapamil in Patients with Acute Myocardial Infarction

The efficacy of intravenously administered tiapamil in treating premature ventricular contractions (PVCs) in the acute phase of acute myocardial infarction was evaluated in 20 patients using 24-hour continuous ECG monitoring (Holter). All patients presented frequent and/or complex ventricular arrhythmias (Lown classification II-V). Tiapamil reduced the number of PVCs to a statistically highly significant degree (p less than 0.01), i.e. 82-85% in the 4th hour of treatment. The number of PVCs increased again after therapy was discontinued. Where supraventricular ectopic beats were present in addition to PVCs, tiapamil reduced them by 93% in the 3rd and 4th hours of treatment. These results suggest that tiapamil could be an effective antiarrhythmic agent in acute myocardial infarction.

Electrophysiological Activation and Times of Propagation in the Ventricular Muscle Band. First Study in Humans

Del analisis de la descripcion anatomica de la banda muscular de Torrent Guasp y de la consecuente investigacion electrofisiologica en pacientes realizada por nosotros en anteriores estudios, se desprende la necesidad de una interpretacion aclaratoria en algunos puntos fundamentales. De los tres giros que realiza la bandeleta descendente en relacion a la ascendente, los dos primeros pasan sucesivamente por delante y detras de la segunda constituyendo la lazada basal (Figura 2). El ultimo paso, luego de doblez de la gran banda que la convierte en el segmento descendente vuelve a ser posterior a la bandeleta ascendente, siendo de esta manera fallida la disposicion helicoidal en este espacio de la lazada apexiana. Esta situacion anatomica espacial de las bandeletas musculares guarda correlacion importante con la funcion cardiaca.(4) En la zona basal ventricular del corazon se produce el movimiento de estrechamiento ventricular. Se condiciona esto con la activacion consecutiva de los segmentos derecho e izquierdo de la lazada basal para producir la fase de estrechamiento (contraccion sistolica). La continuacion de esta fase, en el proceso de estimulacion de la bandeleta descendente (axial), junto a la propagacion concomitante (radial) hacia la bandeleta ascendente, hallada en nuestras investigaciones (2-3) (Figura 3), determina un movimiento helicoide de torsion con el consiguiente acortamiento del eje vertical del ventriculo izquierdo (expulsion). El apex cardiaco, constituido por la disposicion de las fibras subepicardicas que se hacen subendocardicas en su giro, constituyen un apex libre con un fondo de saco para soportar la presion intraventricular que ejerce el corazon en su impulsion por el acortamiento ventricular. El movimiento subsiguiente con la contraccion de la bandeleta ascendente, su envaramiento y el alargamiento ventricular determina en consecuencia un mecanismo activo durante la fase isovolumetrica diastolica. Esta situacion mantiene a la cavidad en una situacion isovolumetrica pero con disminucion de la presion intraventricular (destorsion y fase de succcion activa) para luego dar paso al lleno ventricular con la apertura ariculoventricular (fase de ensanchamiento). Estos movimientos de acortamiento (descenso de la base) y alargamiento del ventriculo izquierdo (ascenso de la base) guardan correlacion con el principio de accion y reaccion de Newton

Electrophysiological Bases of Torsion and Suction in the Continuous Cardiac Band Model

Objective: Torrent Guasp concept, that postulates that the ventricles are formed by a continuous muscle band, provides the basis for two aspects of left ventricular dynamics: The torsion mechanism and the rapid early diastolic filling by the suction effect. We investigated the electrophysiological basis of this mechanism, by electroanatomical left ventricular endoepicardial mapping (EEM) in five patients, during radiofrequency ablation. Results: The apical loop is activated by a simultaneous depolarization of the distal descending and proximal ascending band segments. At the point of crossing of both bands a radial activation spreads from the descending to the ascending band. From this point, begins a simultaneous and opposing activation of the proximal and distal ascending band. The activation of the distal ascending band segment is the latest. Conclusions: The activation sequence of the continuous band provides an electrophysiological basis for the ventricular torsion and suction mechanism.