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Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a lethal autosomal dominant heritable arrhythmia syndrome. Patients diagnosed with CPVT are at high risk of life-threatening ventricular arrhythmias if untreated. Beta-blockers or a combination with calcium channel blockers/flecainide are cornerstone in China, but the the efficacy for prevention of arrhythmic events in CPVT is unkown. This study aimed to evaluate treatment efficacy by exercise-stress tests.
A retrospective analysis of all exercise-stress test data during following-up for 20 CPVT probands (12 male, 60.0%) diagnosed in the Department of Cardiology, of Beijing Tsinghua Changgung Hospital and Peking University People's Hospital between September 2006 and March 2016.
Followed changing lifestyle, all patients received enduring largest dose beta-blockers, four patients combination with calcium channel blockers, and one combination with flecainide. Exercise-stress tests after medication showed increasing maximum workload (p<0.05), improving ventricular arrhythmia score significantly (p<0.05) and non-sustained ventricular tachycardia (NSVT) were suppressed in 14 patients (14/20,70.0%). However the threshold of ventricular arrhythmia had a lower trend and bigeminal/frequent VPBs decreased significantly (137.3±19.6 vs.122.5±13.5, p<0.05). ICD implantation was recommended in five patients who experienced NSVT despite optimal medical management and changed lifestyle, only one receving dual chamber pacemaker. During the follow up of 44.7±66.6 months, emotion stress induced sudden cardiac death associated with noncompliance occurred in two patient and the remaining 18 patients would not experience syncope.
Conventional therapy beta-blockers is incompletely effective in preventing arrhythmic events in patients with CPVT, combination with calcium channel blockers or flecainide is needed.