The axis is normal between 0° and +90° (positive QRS complex in leads I and aVF). The QT/QTc intervals are prolonged (420/480 msec) but are normal when the prolonged QRS complex interval is ...

However, when adjusting for the prolonged QRS complex of 0.20 sec and subtracting 100 msec (the QRS width beyond the normal value) from the measured QT interval, the QT interval is actually 340 msec.

It’s well known that the benefits of CRT—established in patients with heart failure, reduced LVEF, and a prolonged QRS duration—are dependent on the characteristics of a patient’s QRS complex, ...

No significant differences observed in overall HF risk among patients with moderately prolonged QRS intervals who receive cardiac resynchronization therapy.

Additionally, subjects with reduced ejection fraction consistently exhibited increased AI ECG heart ages, along with prolonged QRS durations (the time taken for the heart's electrical signal to ...