Diagnosis and Treatment of Cardiac Arrhythmias: New Trends [antikvár]

Editoriöl New Aspects to Diagnosis and Treatment of Arrhythmias Preventing sudden cardiac death continues to be a difficult problem despite all the advances that have taken place in the field of cardiology. The debate on the pros and cons of long-term antiarrhythmic treatment with regard to improving the prognosis was recently given new life. In the search for a rational approach to antiarrhythmic therapy, it turned out that there is no suitable risk marker that can reliably identify those patients who are genuinely at risk. This state of affairs makes it a matter of urgency to look for other diagnostic techniques with greater predictive power, in order that truly at-risk patients can be identified by means of individual risk stratification. Standard 24-h Holter monitoring does not suffice for this; in determining whether antiarrhythmic therapy is indicated, it is important to precisely quantify ventricular function, as this is clearly correlated with the appearance of complex ventricular arrhythmias and thus with prognosis. If antiarrhythmic therapy indeed does appear to be indicated on the basis of hemodynamic or prognostic factors, the central question then becomes the choice of the correct antiarrhythmic treatment. The side-effect profiles of the antiarrhythmic drugs must be taken into account, and attention must be paid not only to their negative inotropic effects, with the associated worsening of the hemodynamics, but also to their arrhythmogenic actions. The conventional classification of antiarrhythmic drugs, that of Vaughan-Williams from 1970, is being increasingly brought into question. This classification is basically concerned with actions and not with substances. Whether electrophysiological results obtained experimentally at the cellular level are relevant clinically is one critical question. For instance, recent studies carried out by Antoni 's group in Freiburg indicate that at increasing heart rates there is enhanced blockade of the binding sites for class I antiarrhythmic drugs on the sodium channels (Fig. 1). The saturation of this binding process is described as being a function of binding and dissociation dependent on the experimental stimulation frequency. These observations could explain exercise-dependent conduction delays and resulting proarrhythmic effects (Table 1). The results of the international symposium described here attempt to provide a rational basis for both diagnosis and treatment of arrhythmias. They show that recognizing and treating cardiac arrhythmias always represents a challenge to the physician, but also that this challenge, despite the many questions that remain to be answered, can be met with satisfactory results by individually tailoring diagnosis and treatment to the needs of the particular patient.