Distinct U Wave Changes in Patients With Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT)

Abstract

SUMMARYAlthough catecholaminergic polymorphic ventricular tachycardia (CPVT) is associated with fatal ventricular arrhythmias and sudden death, the ECG findings are not fully understood. In this paper, we report on alterations in the U-wave.Seven patients from 6 families with CPVT in which bidirectional tachycardia and polymorphic VT were induced by exercise or isoproterenol infusion visited our hospitals. VT was not inducible by programmed electrical stimulation. A novel gene mutation of the ryanodine receptor 2 (RyR2) was confirmed in 2 families.In one of these patients, U-wave alternans was observed following ventricular pacing at 160 beats/min. In the other patient, U-wave alternans was observed during the recovery phase after the exercise stress test, which was terminated because of polymorphic VT. In both cases, leads V 3 -V 5 were the leads showing alternans most clearly. In the third patient, a negative U-wave became positive following a pause from sinus arrest and a change in T-wave was also noted.Since such findings were not found in the other subjects who underwent electrophysiologic study, isoproterenol infusion or exercise stress testing, the phenomenon seems to be relevant to the underlying pathogenesis of CPVT. The genesis and significance of Uwave alteration need to be determined. (Int Heart J 2006; 47: 381-389)

Catecholaminergic Polymorphic Ventricular Tachycardia

“…11 In addition, a prominent U-wave is observed in a subset of patients and may also be related to altered intracellular calcium handling. 12 It is, however, unknown if the presence of a prominent U-wave has any clinical relevance. Supraventricular dysrhythmias such as atrial fibrillation and sick sinus syndrome are present in 16-26% of the patients 1,5, 9 and may provoke ventricular arrhythmias in some patients.…”

Exercise induced a rare cardiac arrest: A case with catecholaminergic polymorphic ventricular tachycardia

“…1:10000 sıklıkla görülür. Elektrokardiyogramda normalden daha düşük istirahat kalp hızı ve U dalgası gözlenebilir (3,4) . Bidireksiyonel ventriküler taşikardili hastalarda ayı-rıcı tanıda digoksin zehirlenmesi, bitkisel kurtboğan zehirlenmesi ve LQTS-7 (Anderson-Tawil sendromu) yer almalıdır.…”

Catecholaminergic Polymorphic Ventricular Tachycardia in 2012

“…In some patients' resting ECGs prominent U-waves have been observed. 33,34 Ventricular arrhythmias tend to initiate at an individually fixed and reproducible threshold, usually between 110 and 135 beats per minute. 30 Typically ventricular arrhythmias evolve from single isolated ventricular premature beats (VPB) to bigeminy, couplets and non-sustained polymorphic or bidirectional VT (Figure 3B-D).…”