Direct cardiac stimulation mas conducted in the open chest. In normal animals, auricular stimulation a t frequencies faster than the spontaneous rate caused little change in vascular pressures or cardiac output. Comparable ventricular stimulation in the same animals caused falls in cardiac output and blood pressure, with elevations in venous pressure. In contrast, ventricular stimulation in ani...

Direct cardiac stimulation was conducted in the open chest. In normal animals, auricular stimulation at frequencies faster than the spontaneous rate caused little change in vascular pressures or cardiac output. Comparable ventricular stimulation in the same animals caused falls in cardiac output and blood pressure, with elevations in venous pressure. In contrast, ventricular stimulation in anim...

A study has been conducted immediately and up to 18 (lays after the surgical production of complete heart block in dogs. Immediately after surgery cardiac output, coronary flow, and mean arterial pressure were reduced in rough proportion to the degree of bradveardia. In time, these measures began to return toward preoperative levels. Paralleling the diminished left ventricular work was a dimini...

A pacing system requiring only a single lead was used to establish atrial synchronised pacing in eight patients with complete atrioventricular block and cardiogenic shock following acute myocardial infarction. Spontaneous atrial activity was sensed through electrodes positioned on the pacing lead and used to trigger ventricular demand pacing. A normal atrioventricular relation could be establis...

TOKES Adams attacks with loss of consciousness due to a sudden decline in cardiac output usually occurs in patients with complete heart block. The precipitating event is ventricular asystole, ventricular flutter-fibrillation or a combination of both arrhythmias. Ventricular fibrillation may follow a period of asystole, or ventricular fibrillation may precede a period of asystole. Infrequently t...

The exponential output size problem is to determine whether the size of output trees of a tree transducer grows exponentially in the size of input trees. In this paper the complexity of this problem is studied. It is shown to be NL-complete for total top-down tree transducers , DEXPTIME-complete for general top-down tree transducers, and P-complete for bottom-up tree transducers.