Sudden cardiac death recorded during ambulatory electrocardiographic monitoring

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Abstract
Two case reports of sudden cardiac death are detailed here. Holter monitoring plays an important role in documenting arrhythmias leading to sudden cardiac death. In addition, the importance of the Lown grading concept should not be underestimated. Our two case reports and a subsequent review of the literature demonstrate both points. A total of 57 patients with sudden cardiac death during Hotter monitoring have been reported. In this population bradyarrhythmias can be found in about 15%. Such arrhythmias can mainly be seen in elderly patients and are predictors of a very poor outcome for these individuals. Ventricular tachyarrhythmias in Holter recordings are the most common documented rhythm disturbances leading to sudden cardiac death. In patients with manifest cardiac diseases they are nearly always preceded by ventricular arrhythmias of the Lown grade III‐V which usually occur 3–5 h prior to the terminal event. Short coupled ventricular premature beats, so called R on T extrasystoles, were observed in more than one‐third of Holter recordings of patients suffering sudden death due to ventricular tachyarrhythmias; the importance of this phenomenon becomes obvious with this high incidence. The clinical value of these warning arrhythmias is, of course, limited because the arrhythmias were detected only after the fatal event by re‐evaluation of the Holter monitoring recordings. Nevertheless, these high‐grade ventricular arrhythmias demonstrate a marked degree of electrical instability within the heart. Furthermore, the high incidence of serious rhythm disturbances in the setting of sudden cardiac death underlines the importance of the Lown grading concept of ventricular arrhythmias (Lown and Wolf, 1971). Polymorphous ventricular tachycardia, commonly called torsade de pointes, must be considered as the cause of sudden cardiac death in approximately 20–25% of patients. This special kind of ventricular arrhythmia may play a dominant role in the origin of sudden death in patients treated with antiarrhythmic agents. (Denes et al, 1981; Hust et al, 1983; Keren et al., 1981). Clinical recognition is of enormous importance because therapy of torsade de pointes differs from therapy of other forms of ventricular tachyarrhthmias.