OBJECTIVETo evaluate factors for predicting ventricular arrhythmia, the clinical effect of drugs on patients with catecholaminergic polymorphic ventricular tachycardia (CPVT), and their long-term outcomes.

METHODSSix patients diagnosed with CPVT underwent a series of electrocardiograms and 24-hour Holter monitoring. β-blockers were recommended for all patients, while some patients were also prescribed propafenone and 1 patient underwent catheter-based renal sympathetic denervation (RDN). The characteristics of electrocardiogram, arrhythmia and long-term outcomes were monitored.

RESULTSSyncope episodes did not occur any longer in 1 patient on β-blocker, but recurred in 3 other patients and 2 patients died (one due to his cessation of metoprolol for 3 months). Inverted and/or bifid T waves and abnormal U wave were observed in the precordial leads. T wave alternans was observed in 4 patients in the precordial leads. These abnormal electrocardiogram features disappeared or diminished with β-blocker treatment. All spontaneous episodes of ventricular tachycardia occurred prior to sinus tachycardia and frequent polymorphic premature ventricular contractions.

CONCLUSIONSBifid and/or inverted T waves, T wave alternans and abnormal U waves together with sinus tachycardia and frequent premature ventricular contractions are indicator for predicting ventricular arrhythmia and assessing the effect of β-blockers. Compliance with β-blocker treatment is a strong indicator of outcome.