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Two Cases of Alkaptonuria

1957; BMJ; Volume: 2; Issue: 5048 Linguagem: Inglês

10.1136/bmj.2.5048.794

0959-8138

A. W. McKENZIE, Jesse Owen, J. H. R. Ramsay,

Peroxisome Proliferator-Activated Receptors

COMPLICATION OF DIGITALIS THERAPY BDITALJOIRL increased dosage of digitalis is required for uncontrolled auricular fibrillation, such treatment may be disastrous in the presence of the toxic arrhythmia.Even electrocardiographic analysis may be difficult.Well-defined P waves are helpful, and should be sought in all leads.Oesophageal leads may be necessary (Brown, 1936).Our patients were thought to have auricular fibrillation in the first instance.Cuttings from appropriate leads showing P waves were selected for the figures.An isoelectric interval between successive P waves helps to differentiate paroxysmal auricular tachycardia with auriculo-ventricular block from auricular flutter.Such electrocardiographic diagnoses as "impure flutter" and "impure fibrillation" should be regarded with suspicion, especially if the patient is receiving digitalis.It is doubtful if they have any fundamental meaning, and they may conceal the serious disturbance of auricular rhythm under review.In our cases the auricular rate varied between 195 and 230 a minute.Our cases were receiving digitalis when they developed paroxysmal auricular tachycardia with auriculo-ventricular block.The response to potassium treatment supports the view that digitalis was the causative agent (Cases 1, 2, and 3; Lown and Levine, 1955).An excessive dose of the drug may cause the arrhythmia, but it is important to realize that it may occur when the heart muscle is sensitized to digitalis by potassium loss (Lown, Salzberg, Enselberg, and Weston, 1951).Thus in intractable heart failure prolonged diuresis may render a therapeutic dose of digitalis a toxic dose, and thereby cause paroxysmal auricular tachycardia with auriculo-ventricular block.Prompt treatment is essential in paroxysmal auricular tachycardia with auriculo-ventricular block due'to digitalis toxicity.The drug, of course, must be stopped, and diuresis, paracentesis, and other measures aimed at diminishing the load