Officials of Symbion Inc. announced sales of $1.25 million for the quarter ending Sept. 30, a 58 percent increase over $792,000 in sales in the third quarter of 1987.

Sales of the company's total artificial heart and acute ventricular assist device are 43 percent ahead of last year. In the first nine months of this year, 44 artificial hearts and 34 ventricular assist devices were implanted at various hospitals in the world, company officials said.Company sales in the first nine months of 1988 totaled $4.03 million, an 11 percent increase over the same period a year ago. The net loss for the nine months was $662,000 in 1988 compared to $1.5 million a year ago.

The company's newly acquired subsidiary, Symbion Medical of Canada Ltd., continues its progress with the Mitroflow pericardial tissue heart valve, company officials said.