She returns for a follow-up visit for palpitations, and a 12-lead ECG is obtained ... 90° (positive QRS complex in leads I and aVF). The QT/QTc intervals are normal (280/440 msec).

Most people are unaware they have the condition until they go for a routine electrocardiogram (ECG). Without an ECG, people may only notice symptoms when the condition progresses to second- or ...

ECG markers and their association with stroke ... CAST trials showed increased sudden death with few antiarrhythmics QT interval prolongation 4–6% 1.5-fold increase Myocardial infarction ...