widened QRS complex

Cardinal symptoms are cardiac (tachycardia, widened QRS complex) and neurological disturbances.

The COMPANION trial demonstrated that CRT improved survival in individuals with NYHA class III or IV heart failure with a widened QRS complex on an electrocardiogram.

It is contraindicated in patients who are on long-term benzodiazepines, those who have ingested a substance that lowers the seizure threshold, or in patients who have tachycardia, widened QRS complex on ECG, anticholinergic signs, or a history of seizures.

Electrocardiographic changes are characterized by slowed conduction, including prolonged P-R interval, widened QRS complex, shortened Q-T interval, shortened or absent S-T segments, and possibly abrupt sloping and early peaking of the proximal limb of T waves.