The commission is due to make a decision by Nov. 23. Neither company could be reached for comment Wednesday morning.
Both saw shares spike about 1.5% Tuesday, with Abbott hitting $39.81 per share and St. Jude reaching $79.75 per share.
Abbott Laboratories agreed to acquire St. Jude Medical Inc. for approximately $33 billion in cash, stock and debt back in April this year. The deal comprised of $46.75 in cash and 0.8708 shares, for a total consideration of approximately $85 per share of Abbott common stock, plus the total liabilities of St. Jude of approximately $9 billion will be assumed.
St. Jude has been facing criticism from Muddy Waters Capital since August, when the research firm wrote that its devices could be hacked by outsiders.
Separately, St. Jude announced on Oct. 11 that its implantable cardioverter defibrillator, or ICD, and its cardiac re-synchronization therapy devices made before May 23, 2015, could deposit lithium in patients as the battery depletes.
The company said only 0.21% of devices were affected, but advised doctors and patients to make sure they were aware of the battery life of its devices. At the time, analysts said the device failures likely wouldn't impact the deal.
Meanwhile Abbott is having legal struggles of its own, with its $7.9 billion acquisition of Alere (ALR) being stalled thanks to multiple lawsuits. The deal was announced in February.