Understanding, and thereby being able to manage, the risk of stroke in AF, has in the past often been difficult and frustrating. From an attitude prevalent in the medical community not so many years ago --- that AF is an annoying but essentially harmless disturbance --- we have seen a progression of alarm that pronounces that AF is a very common prelude to stroke and must be treated in the most aggressive fashion. Mr. Larsen helps us understand that the AF population is very heterogeneous in terms of stroke risk and that sub-groups of this population should be treated differently: some more and some less aggressively. On the critical issue of anti-coagulation as prophylaxis against stroke, he has concisely summarized the most extensive recent studies, all of which suggest that for AF patients without identified stroke risk factors (congestive heart failure, hypertension, advanced age, diabetes or a prior history of stroke) anticoagulation with coumarin is not indicated, while for those with stroke risk factors it often is.

Mr. Larsen guides the AF patient, and his physician, through the basics of blood clotting and how this is affected by the various anti-platelet and anti-coagulant drugs. He makes a particularly valuable contribution in his discussion of "natural", non-pharmaceutical approaches to stroke prevention, which actually has relevance to the general, and not just the AF, population.

Those interested in AF and stroke would be hard put to find a more valuable reference on the subject than Mr. Larsen's outstanding little book.