is qrs duration 74 ms normal
When the duration of the QRS is> 120 msec, this happens in case of electrolyte abnormality, like Hyperkalemia—tall T wave, wide QRS. Tricyclic antidepressants like Amitriptyline, Imipramine, and Phenothiazines also cause broad QRS complexes. The QRS complex shows ventricular depolarization — the signal spreads through the ventricles, causing them to contract. This is the most critical part: if the QRS is wide or abnormal, the ventricles aren’t conducting electricity properly. QRS duration is the time interval from the onset to the end of the QRS complex. A short QRS complex is desirable as it proves that the ventricles are depolarized rapidly, which in turn implies that the conduction system functions properly. Medscape: QRS Duration Is an Insensitive Marker of Left Ventricular Dyssynchrony in Patients With End-Stage Heart Failure QRS Duration Is an Insensitive Marker of Left Ventricular Dyssynchrony in Patients With End-Stage Heart Failure
Atrial Overdrive Pacing Inducing QRS Complexes of Varying Duration in a Patient with Recurrent Syncope. What is the Mechanism? Medscape: Prevalence of Mechanical Dyssynchrony in Heart Failure Patients With Different QRS Durations Prevalence of Mechanical Dyssynchrony in Heart Failure Patients With Different QRS Durations Healio: CRT may be harmful in patients with RBBB, very wide QRS duration CRT may be harmful in patients with RBBB, very wide QRS duration
QRS Interval • LITFL • ECG Library Basics
