But all that suddenly came to a halt this spring, in Washington DC where I now live.
Stepping out of the car on to the pavement outside my own house, I became uncontrollably giddy for what seemed an eternity and then (apparently) crashed down on to the concrete - giving myself a black eye and a face so dramatically bloody that it looked as though I had been in the ring with Mike Tyson for at least a few seconds.
I was forced to consult a doctor, whose conclusion was that my collapse was due to a drug I have to take - and we agreed that I should go into hospital for a couple of days for the apparently medically delicate process of switching from the offending medicine to an alternative.
The natural choice was the Georgetown University Medical Centre, where all but a tiny minority of patients are funded by private insurance. This is a massive institution that prides itself on being one of the best private teaching hospitals in the US and therefore, according to American belief, almost certainly one of the best in the world: a truly Thatcherite dream.
The only problem was that it didn't quite turn out like that: the two days I was told I would have to be in hospital turned into 12, and I am still reeling from the experience.
My treatment began much as it was to go on - with a mistake. A young, macho doctor came to give me a physical examination under the impression, I later discovered, that I was somebody else.
But the die was cast, and my fate was to be stuck with Dr M for the rest of my stay. Though clearly barely out of medical school himself, he pompously led around a posse of medical students while expounding to them on all the conditions from which I, the specimen in front of them, could be suffering. (Showing off like this is called "roundsmanship", I was later told.)
Because of my curiosity value as a real, live patient with a mechanically ticking heart valve, I quickly became used to a parade of medical students queuing up to listen to my chest through their stethoscopes. The questions never stopped, but were always the same. What colour was my sputum? Did I feel dizzy?
Within a few hours I was desperate to see a doctor or even medical student who looked older than about 11 - but no one seemed to be in charge.
Even my own doctor, an older man whom I would have welcomed with open arms, was not informed of what was happening for several days and then (as I discovered later) was not kept in the picture by the ambitious 11- year-olds.
What had, in fact, happened was that I was more ill than anyone had supposed. A chest X-ray showed that I had pneumonia. I was badly dehydrated. Most baffling and serious of all, blood tests showed that my red and white blood cells were dramatically abnormal. My condition was so poor, I was told, that it was astonishing that I had managed to walk into the hospital.
So after an 11-year-old had stabbed and punctured the back of my hand countless times in a finally successful effort to find a vein, I was quickly put on drips for antibiotics, saline solution - and lots of blood.
This was all bad enough, but it was the attitude of Dr M and his posse that was already beginning to make me feel more and more wretchedly ill. The feelings of patients seemed to come last in just about anyone's considerations. Yes, I heard a voice telling me, the blood condition could be leukaemia (from which my father died); and, yes, it was certainly possible that an alternative cause was internal bleeding from cancer of the colon. Looking at a picture of my two small children, I quickly became resigned to the notion that I was not long for this world. I was visited by two clergy from my church, who each gave me Holy Communion at my bedside; a (genuinely) kind nurse said that she would pray for me.
But this was not all. Besides having to digest the new likelihood that I was going to die soon, I was discovering the disadvantages of sharing a supposedly luxurious two-man room; I would so much have preferred a good, old, British-style open ward, where relationships with other patients can be either as close or as remote as the individual chooses.
My first roommate was an apparently hyper-cheerful man of about my own age, so relentlessly talkative that I suspected he was on something (legal or otherwise). He had come into the hospital bleeding, and as he was questioned by the parade of 11-year olds he recounted his symptoms again and again with enthusiastic exactitude: his orange-black stools, his thrush, his gonorrhoea, the vast number of drugs (including AZT) that he had tried.
Slowly, it dawned on me that this man was in the advanced stages of Aids.
Now I have met my fair share of Aids sufferers and do not think I am unduly hypochondriacal about casual contact; but here I was sharing a bathroom, toilet and washbasin with a man who was bleeding, and suffering from a variety of secondary infectious venereal diseases as well as Aids. I was uncomfortable about it all, and quietly told one of the nurses.
I pointed out that none of them would have dreamed of going near this poor man without their obligatory disposable gloves. During this conversation my dinner arrived - at ten to five - and while I was attempting to eat it, my roommate was behind a curtain having a biopsy apparently taken from his backside, a highly audible process of snipping and snapping.
That afternoon I was wheelchaired down for a heart test, having been told by now that I could also be suffering from yet another life-threatening disease, endocarditis. Soon after I returned, the Aids patient (by chance) was moved to a room of his own.
His replacement was a clearly gravely ill black man in his eighties, who had spent all his working life asphalting driveways.
A white-coated 11-year-old came in and literally shouted a series of questions at this man. Had anyone ever told him he had cancer of the prostate? Cancer of the stomach? Cancer of the colon? No, the man croaked, he had never been told he had cancer of any kind.
He was a dear man, but not easy to be with: all he could do was sit up in his bed, clearly in much pain, continually bringing up bile which had quite the most putrid smell I have ever experienced.
My new roommate also had a hang-up, quaintly unexpected in someone so elderly, about the dark: he had to have the light on all night.
Was I already in Hades?
It certainly seemed so at the time; with hindsight it was all much more like a Fellini-esque farce.
An 11-year-old was sent to get some arterial blood from me, which apparently involved taking it from the underside of my wrist with a rather large needle. He poked, stabbed and prodded for what seemed like hours, a sweat forming on his forehead; then he simply gave up. This kind of thing happened a lot. In this case, nobody even bothered to return to get that arterial blood; it will be interesting to see if I get a bill.
In general, the nurses were excellent, but overworked and overburdened. They had little time to talk, and that was one of the great failings, I came to realise, of the US medical system: the hugely over-indulged and pampered American medical profession takes itself so seriously that basic humanity has become lost in all the long words, ingenious diagnoses and expensive technology.
I was longing for a straightforward, sensible, GP figure of fond British memory - but perhaps they don't actually exist any more? - who would be in charge, and supervise all this vague diffuseness of my treatment.
A nice young woman doctor, possibly 12 rather than 11 - looked in most days and even gave me her card, but when I asked a nurse what position she held, the nurse said that she had never seen her before.
The gastrointestinal ("GI") people came back and told me that the main problem was that my oesophagus was inflamed and bleeding - hence the hitherto- undetected loss of blood - and that they had meanwhile taken various biopsies from other bits of my insides. It was a relief that at least no one seemed to be mentioning leukaemia any more. The discrepancies in the white cells, meanwhile, seemed likely to be a result of the still extant pneumonia. Complicated, but not that complicated.
However, Dr M, perhaps with an eye already keenly honed for potential medical litigation by patients, was not finished with me yet. He and his eagle-eyed posse had spotted, after several X-rays had been taken to monitor the pneumonia, that there seemed to be a tiny spot on my chest which they thought should not be there. "We think it could be cancer," he told me simply.
I would need a fluoroscope (a kind of moving X-ray) taken of my chest, he said: the only problem was that this was a Saturday morning and the department was closed for the weekend except for emergencies. So I faced a weekend of further concentration of the mind on death, wills, farewells and so forth. But then there was an emergency and I was taken for my fluoroscope, where the radiologist said that as far as he could see there was nothing there to worry about ...
Physically, at least, my condition was supposedly improving; in other ways, I felt like a complete wreck as a result of the ministrations of Georgetown University Medical Centre ("At Georgetown, we never forget there's a human in every human body," trumpets a full-page ad in an August issue of LTS News and World Report - rather a good joke, I thought.)
Notwithstanding the fresh blood and manifold expensive drugs, I came out of the hospital feeling much more frail and ill than when I had gone in. I am still anaemic, and not yet back to full strength. Despite Georgetown's triumphant discharge of me, I have had further episodes of losing blood. My own doctor has been reassuring, saying that my condition certainly could be due to something terrible, but is much more likely to be because of more routine troubles, such as a troublesome oesophagus bleeding undetected, a bad bout of pneumonia, transfusions of new blood, and so on.
In about 10 days, after several calls, I finally received the results of my biopsy: there were no signs of cancer, in my colon or anywhere else.
I still cannot quite make sense of those 12 dreadful days in Georgetown Hospital. My heart surgery in London was a breeze in comparison. And the bill for the privilege of being at the receiving end of what is supposed to be one of America's best hospitals, of being jabbed and poked and stabbed by a procession of 11-year-olds who common sense dictated ought not to have been working in so unsupervised a way, now stands at more than $25,000 and is growing, with yet more indecipherable and baffling bills arriving by the day. Next time, I think, I'll go back to the good old NHSReuse content