ABSTRACT
<p><b>OBJECTIVE</b>To evaluate factors for predicting ventricular arrhythmia, the clinical effect of drugs on patients with catecholaminergic polymorphic ventricular tachycardia (CPVT), and their long-term outcomes.</p><p><b>METHODS</b>Six 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.</p><p><b>RESULTS</b>Syncope 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.</p><p><b>CONCLUSIONS</b>Bifid 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.</p>
Subject(s)
Adolescent , Adult , Child , Female , Humans , Male , Adrenergic beta-Antagonists , Therapeutic Uses , Electrocardiography , Electrocardiography, Ambulatory , Tachycardia, Ventricular , Drug Therapy , Treatment OutcomeABSTRACT
<p><b>OBJECTIVE</b>To describe the clinical features of 6 patients with catecholaminergic polymorphic ventricular tachycardia.</p><p><b>METHODS</b>Clinical data including signs and symptoms, electrocardiograms, Holter monitoring electrocardiograms and echocardiography was analyzed. Definite diagnosis was made based on the mutations of RYR2 and CASQ2.</p><p><b>RESULTS</b>From July 2002 to March 2010, 6 consecutive patients referred to our center because of syncope [4 males, mean age (13.0 ± 4.2) years] were diagnosed with CPVT by clinical evaluation and genetic testing. Their electrocardiograms showed T waves with notch or bimodal and tall U waves in right chest leads. There was no J wave, no ST-segment deviation, no prolongation or shortening of QT interval. We captured the so-called "bidirectional and(or) polymorphic ventricular tachycardia (bVT and pVT)" in 2 out of 6 patients by ECG, in 5 out of 6 patients by 24-hours Holter monitor, in 3 out of 6 patients by exercise test. All patients received β blockers and no syncope occurred during the 3 months follow-up after discharge from hospital.</p><p><b>CONCLUSIONS</b>CPVT is an inherited cardiac channelopathy characterized by syncope and(or) sudden death relatived to motion. The ECG shows T wave alteration and tall U wave in right chest leads. The mode of its onset is bVT and(or) pVT, and can be captured by Holter easily. β blocker is a safe and effective remedy for suppressing its attack.</p>