FIG. 30:  The excess mortality in SERVE-HF appeared to be due to sudden death that occurred outside the hospital.^[17]  This was assumed to be arrhythmic, but we will have to wait for more data to be published to confirm this.  The cause of the increased cardiovascular mortality was not really established.^[15]  The possibilities include the possibility that

• CSR is a compensatory mechanism in heart failure and therefore trying to reverse that actually does harm;
• ASV induces a decrease in cardiac output from a decrease in preload due to the relatively high pressures that that particular device generates;
• ASV induces hyperventilation (again, because of the relatively high inspiratory pressures that this device generates), and hypocapnia, alkalosis, and hypokalemia, which would increase the risk of cardiac arrhythmias.

However, until we see more data, this is all speculation.