Competing interests: none declared

water, and swimming lead to abnormal remodelling of the left ventricle, but it does indicate that care should be taken when prescribing aqua exercises and swimming. (1) Decompensated heart failure is an absolute contraindication to immer-sion and swimming. (2) Patients with severe MI and/or CHF who tolerate sleeping in a flat posi-tion can bathe in a tub—that is, balneotherapeutic baths—in a half sitting position—that is, immersed no deeper than up to the xiphoid. (3) Therapeutic water exercises in a pool—for example, for orthopaedic reasons—can be allowed for patients with severe MI and severe CHF provided that they are in an upright position and immersed no deeper than the xiphoid. (4) Whether swimming is appropriate, and truly safe in the long term, in patients with severe MI and severe CHF needs to be investigated in a study of patients in a swimming programme and compared with non-swimming patients with CHF of similar aetiology and severity of disease