AN: why has no-one written about one Tony Stark having heart surgery? It's the obvious solution to ... stuff! Well, maybe not, but anyway, here's a moderately well researched and accurate heart surgery for you. Writers; write! I don't know why there aren't more stories where this is a feature, so have at it.

Be inspired.

Warnings: graphic description of surgery, medical jargon and so on.

Proof that Tony Stark has a Heart.

His head felt strange.

The usual, faint sound of his heart beating was missing, replaced by a disconcerting thrum. His head lolled slightly to the side; it was difficult to focus his eyes, but the heart-lung machine keeping him going was big, bulky and blinking. Surgical nurses, his anaesthetist, the surgeons were standing around, sterile scrubs, masks and hats making them unrecognisable, despite the close working relationship of the past week. For now they were silent, letting him get his bearings and get used to the frankly bizarre feeling of not breathing. An injection or seven into his spine, at the base of his neck and into nerves of his chest had paralyzed him safely from the shoulder blades down, leaving his hands able to move without dislodging or interfering with the heart-lung machine.

He couldn't feel anything either, but he knew what he would see when he looked down and it was not something he was looking forwards to. He closed his eyes for a long minute, longing for a shot of something that wasn't delivered in a needle, before mentally shaking himself and signalling his readiness to his team with a small nod and a hand gesture.

A nurse gently lifted his head with a wedge of foam so he could see. His chest was wide open; the central section of his ribcage was pulled back with shining steel to reveal his heart, which hadn't beaten on its own since Afghanistan and was still now, with the arc reactor gone. The reactor casing was untouched and safely bedded in the bone of his sternum, modifying it was his job, the titanium shone painfully bright in the surgical lights and he had to blink repeatedly to get used to the brightness. Pink was smeared on the metal in places and the sight of a surgeon gently dabbing blood away from the surface of his heart made him want to throw up. Phantom shivers raced up his spine and he closed his eyes for a moment.

"Mr Stark? Are you in any pain, sir?" The anaesthetist, he made the universal A-OK symbol with his left hand, before running through a round of finger-to-thumb exercises to check that he had full movement. The anaesthetist gave the rest of the team the go ahead once Tony had touched his forefinger to the tips of each of the anaesthetists' fingers and the surgeons began moving again.

"The shrapnel was removed fully, Mr Stark. All seven fragments have been retrieved and no further splintering has occurred. Damage to the Sinoatrial node is as predicted, sir, the electrodes were surrounded by necrotic tissue." He recognised the voice, SHEILD's specialist, a man with clearance and skill. Tony gave him a thumbs up then typed 'as planned?' Into the keyboard under his right hand. The man agreed and called for the silicone microcircuits they had collaborated to design. The hope was that the more advanced sensors and electrodes would allow Tony's heart to function more stably and compensate for the metabolic needs of his body. "As we removed the electro-magnet, there was some unusual tissue growth due to leeched copper which also had to be removed. It did not affect the procedure."

The surgeon would handle attaching the silicone sheets, but only Tony could do the fine work needed to connect the wires into the reactor housing; work that could only be done while he was on heart-bypass. He could freak out about what he could see later, right now there was Work. He activated JARVIS's sensors and projectors, bringing up a hologram of the housing, rotating and zooming to check for disruption. There had been inch-wide circular saws involved in opening his chest, after all. The inspection complete, he made the hand gesture for his fine pliers and then a soldering laser and got to work. Having tools in his hands made everything easier; the distanced, utterly focused headspace was a relief and he slipped into it easily.

The angle was awkward and some of the muscles in his shoulders had been paralyzed, but he hadn't willingly spent an entire day training the nurse at his right hand for nothing and she strapped his shoulder up at the best angle. He knew Pepper and at least two of the Avengers were watching from the gallery, one of the benefits of having surgery in your own home, but he didn't look up; he needed focus now, not comfort.

They had pre-prepared the titanium contacts with beads of solder, so he was able to focus on the intricate circuitry locating the right contact on the miniature circuit. There was a total of twenty seven wires, each one approximating the thickness of a human hair and he was forced to rely almost entirely on JARVIS's scans and the hologram, using it like a microscope, to read the code that identified them. He had to partially rewire the microprocessor about halfway through the procedure, its hundreds of pins subtly in the wrong places to allow the new circuitry to function.

By the time the surgeon had finished implanting the electrodes on the heart and the sensors of the nerves that supplied it, Tony was nearly finished. JARVIS's diagnostics were coming out green and he was nearly ready for the new reactor. He twisted his wrist into one final awkward position and the last contact was made.

He carefully put his instruments down and his assistant nurse guided his arms back to the bed gently. Now that he wasn't holding familiar steel handles, his fingers began to tremble faintly and his arms ached with exhaustion; his blood oxygen levels had been flirting with too low for four hours as the bypass machine struggled to keep up with the expenditure of a metabolically active body. Normally a patient would be cooled right down if they were on bypass, but Tony had never been normal, so why start now?

He let his eyes fall shut and lay limply.

"-Stark? Mr Stark?" The surgeon was talking, but he couldn't muster the energy to respond.

"TONY, open your eyes, I KNOW you're awake!" Pepper? When had Pepper got her hands on an intercom? He blinked his eyes open slowly, looking up into the gallery where half the Avengers team were watching. Mrs Potts was indeed in possession of the intercom. She was ruffled; they all were, even Steve.

His blood O2 was creeping back up as he rested and his head cleared a little. He sent Pepper a faint smile and paid attention to his surgeon. The man had a brand new arc reactor in hand, its triangular central piece glowing brilliantly, but its edges dark.

He needed to seal the hole leading from the housing to the electrodes on his heart, but he was too tired. Tony shifted a trembling hand to his keyboard and told JARVIS to show the nurse how, instead. It wasn't something that could go wrong. She was a little nervous, but packed the baseplate with antibiotic and covered it with sealant all the same. He ran one last diagnostic over it before nodding to the surgeon.

They would put him back to sleep now, chill his body down to 28 degrees, and put his chest back together, but he had to stay awake until the anaesthetic went in. There could to be adjustments to be made to the algorithms that JARVIS just wasn't up to. He so wanted to go to sleep though...

The shock of the reactor sliding into the housing was stronger than he was expecting and he jerked in a way that wasn't supposed to be possible, given the amount of sedative in his spine. The clamps rattled and something slipped, alarms blared loudly, covering the schlick of the reactor settling firmly in place and the housing locking it down.

Tony's mouth opened slightly and his eyes went wide, even as gray and black faded across his vision, covering Steve and Clint and the rest of his hangers on. The alarms faded out of awareness, unless it was awareness full-stop fading, and then there was silence, for a long, long time.

XXXXXXXXX

Being Tony Stark's colleagues was bad enough, but being his friends was terrible. There was always the threat that he would be caught without his armour, or that the arc reactor would run out of juice or that he would just fall over and die when the shrapnel got tired of hanging around.

That was why they were here in the first place; Tony had brushed of the first attack as nothing but by the time he couldn't stand up suddenly without losing blood flow to his brain, couldn't use the stairs in his own home anymore, the other Avengers had stepped in, with Pepper at the vanguard.

There had been scans and blood tests and Bruce with a needle and cannula, and finally, a heart surgeon. Three weeks of meticulous planning, a padlock on the alcohol cabinet and Pepper living in the room next to Natasha had come to this;

Clint was leaning on the rail by the window, looking down intently at Tony, eyes flicking distrustfully at the few staff he didn't recognise.

Steve sat pensively with his elbows on his knees, unable to look at the gaping hole in the middle of his friend's chest.

Bruce was far upstairs, equipping JARVIS and a clean-room with the things Tony would need when they got him back. It was a job that had been done many times over the past week, but no one begrudged him the final check.

Natasha was... somewhere. The others had no idea where, but she had seen Tony go under the anaesthetic and then vanished with only a faint not to Clint.

Thor was with Loki, far, far away, at the other end of the bifrost, stressing in his own way. Pepper got messages from him ever few days, but he would arrive soon.

Pepper herself was pacing. The first few hours had been easy, it was a long but routine process to get Tony onto bypass and the surgeons had been reassuringly coordinated. Then they had woken Tony up.

The look of muzzy confusion had been horrible to see; even waking up hung-over didn't make him so blankly unfocused. He had paled when he saw the state of his chest and a monitor just out of his view had spiked. Pepper's hands still hurt from the fierce grip she'd had on the railing, which she'd only been able to relax from when he'd taken up his tools as if he was just working on his suit.

She broke out her CEO voice to keep him awake long enough to start up the reactor and she was just about ready to cry in relief when it went in, properly wired and glowing brilliantly as energy flowed into the edging ring. She hadn't immediately cottoned on to what the screaming alarms and sudden gush of red from the wound meant, but she knew what that look on Tony's face was; he was passing out.

"JARVIS!" She barked, if Tony couldn't then JARVIS was the next best thing to start up the reactor.

"Yes, Mrs Potts. Reactor core is online, booting processor." The artificial voice could have been announcing the weather for all the intonation in its British accent.

The doctors were swarming, moving as quickly as possible to repair the tear that had caused the problem in the first place, even as JARVIS restarted Tony's heart.

XXXXXX

The patient's BP was dropping more quickly than they could compensate for, so they had no choice but to clamp off either side of the broken venous connection to the bypass machine. The pump would keep blood pressure up for now, but there would be no flow, no fresh blood getting to the brain, no oxygen.

"We're going to have to run without coolant. Becker, keep the flow low once you have his BP back up."

Starks brain had minutes.

"Ventilate, 90 percent." He ordered without looking, fingers tight around the leaking connection.

It was the fastest suture job he had ever done, but do it he did, closing over the hole he had cut himself to hook up the bypass tubing in one minute and ten seconds. The perfusion expert running the bypass was counting steadily and he wasted no time in moving on to the aorta; his surgical assistant had already clamped the artery and removed the bypass tube and he bent to sewing.

"Clamps off," He ordered as he divested himself of the special sutures used to close blood vessels. "Paddles." Before the nurse was even part way through passing over the paddles Stark had designed, the AI interrupted;

"That will not be necessary, Mr Ross." JARVIS commented blandly, having already started Tony's heart with power from the arc reactor, fine tuned through the most precise and intricate pacemaker ever designed. The strong beep of the heart monitor filled the room, closely followed by the gentle rush of 90% oxygen into the man's lungs. The release of tension was palpable but the team paused for only a bare half-second.

"Hang two pints of whole blood, push the protamine sulphate." People started moving again and the anaesthetist read out Stark's stats with a pleased note in his voice.

"Right, double check those sutures, Tompkins, lets get him closed up."

XXXXXX

The next time he was aware, it was to the horrible weight of something tick and cold down his throat and the rush of air into his lungs. His mind was swimming, distorted and unable to articulate its own ideas to itself. It was not like being drunk, it wasn't like anything, but he could hear again, even if the words didn't make any sense.

Pepper was there, that brisk, slightly drawled tone was absurdly welcome, and he fell asleep again.

Next, he woke to quiet and the dark behind his eyelids was complete. Boring. He thought, not remembering to be surprised that it made sense.

The third time, he opened his eyes. Pepper was still there, and Bruce too. He felt very heavy, his thoughts were slow, and more sleep was appealing, but the tube down his throat was very uncomfortable. He groped for it blindly, wanting it gone, but someone grabbed his hand before he could get rid of it.

"Hey, hey, Tony," Pepper's voice was soft and as welcome as ever, and she leaned over so he could see her clearly; he was flat out on his back, covered in wired and tubes, and she was wearing a surgical mask.

He gripped her hand tightly, fighting the gagging sensation of the ventilator. "It's alright, Tony, Bruce will be back soon and you can go back to a mask." He glared at her for a moment; he didn't want reminding about being on oxygen, the entire business was frankly humiliating. She didn't seem to notice.

There was that unpleasant rubber-glove sound as Bruce returned with his pet nurse and Tony turned his scowl to her, their pre-op relationship was not a good one; evil, catheter wielding woman. Bruce he greeted rather more genially, despite the gloves.

"Nothing wrong with your recognition then?" he commented flippantly as he reached down to tilt the top of the bed up. "Excuse us, Pepper," Tony flipped him the bird a little sloppily, distracted by the movement. His chest felt like someone had stamped on it. He lifted a hand to the MIII arc reactor, blinking slowly and trying to remember how the calibration had gone. No more shrapnel rusting away. There had been... things he was supposed to do... His eyes widened in alarm; something had gone wrong, he hadn't done any tuning at all, all he could remember was blacking out, Pepper shouting at him... no, that was before, then the reactor and blood. Well, more blood.

"Tony, calm down, it's fine, you're fine. Concentrate on me for a second." He swung his eyes towards Bruce, who was looking thoroughly scrubbed. "Try not to throw up, ok? Your throat wouldn't like you. Keep swallowing and you'll be fine, there's juice for after."

He jerked his head down minutely, trying not to cringe. Bruce was quick with the tape, at least, and pulled the mask smoothly away from his face. Evil-nurse helped him sit forwards with the motion and dear god he wanted to throw up. He swallowed frantically, half around the tube as it slid out, eyes screwed shut, and then it was gone and he was laid back on the bed and told to 'breathe'.

The first one was hard, the ribs they had broken to get at his heart screaming at him loudly, until he remembered to breathe with his stomach more than his chest. Four or five breaths in, he opened his eyes again and gave Pepper a dazed look. Bruce was fiddling with something by his bed that beeped and buzzed and made Tony's whole body feel floaty. A straw was offered and he took a sip; apple, nothing fancy, but it cleared the taste of pipe from his mouth.

"Hey Pep'." He rasped. She was back gripping his hand again, his other was plastered over the reactor, enjoying the thrum and warmth. "'did it."

"Yeah, Tony. Yeah you did."

He felt the cold plastic of a mask settling over his face and smirked sleepily behind it.