[Clinical polymorphisms and approaches of arrhythmias treatment in a family with δKPQ1505-1507 deletion in SCN5A gene].

BACKGROUND: The aim of the study was to analyze spectrum of manifestation and treatment response in large family with rhythm disturbances caused by p.delKPQ1505-1507 mutation in SCN5A gene. PATIENTS AND METHODS: We had under our observation 18 members of large Iranian family with various combination of inherited arrhythmic syndromes. Careful cardiological examination, genetic councelling and venous blood sampling for molecular genetic study were performed for family members. Mutation screening in SCN5A gene was performed using bidirectional Sanger sequencing. RESULTS: Here by we show the observation of Iranian family with known mutation p.delKPQ 1505-1507 in SCN5A gene, who display not only LQ-TS phenotype but also some of the carriers of this mutation have had LQ-TS and Brugada syndrome (combine phenotype), interestingly. CONCLUSION: The overlapping phenotype associated with high risk of sudden cardiac death may require complex approaches to antiarrhythmic therapy, surgical treatment and prevention of sudden cardiac death in the family.

Heart rate variability: does it change after RF ablation of reentrant supraventricular tachycardia?

BACKGROUND: Following RF ablation of reentrant supraventricular tachycardia, inappropriate sinus tachycardia may occur. Local parasympathetic denervation is a possible mechanism for these rhythm disturbances. The purpose of this study was to determine the incidence of sinus tachycardia and to determine the relation between endocardial lesions at different ablation sites and alterations in autonomic tone in several different groups of patients with supraventricular tachycardia, using techniques of heart rate variability analysis. METHODS: The subjects of this study were 75 patients (48 women, 27 men) with a mean age of 39.99 (SD = 13.39). They underwent RF ablation of AV nodal slow pathways (40 cases), posteroseptal APs (23 cases), left lateral and right free wall APs (12 cases) because of symptomatic tachycardias. The mean sinus rate and time domain (standard deviation of RR intervals and root mean square of differences of adjacent RR intervals) and frequency domain (low frequency, high frequency and low frequency/high frequency ratio) analyses of heart rate variability were obtained by use of 24 hour Holter monitoring before and 1 month after ablation compared with pre-ablation values. RESULTS: Analysis of 24 hour ambulatory Holter-monitors, performed 1 month after RF ablation, showed no significant changes in time and frequency domain parameters of heart rate variability in different groups. A significant increase in mean heart rate was noted after RF ablation at AV nodal slow pathway group and left freewall/right free wall accessory pathways group. Patients undergoing RF ablation of right or left posteroseptal accessory pathways had no significant increase in the mean heart rate. CONCLUSION: In summary, an increase in sinus tachycardia may be initiated by RF ablation of atrioventricular reentrant tachycardia (AVNRT) and right free wall or left free wall accessory pathways. This finding shows that the modifications of heart rate are not directly related to the posteroseptal region or to the accessory pathways.