A wide QRS complex is more than 2.5 mm (100 msec) at standard settings. This can be caused by ventricular rhythms / pacing or abnormal conduction e.g. bundle branch blocks, hyperkalemia, sodium channel blockade, pre-excitation or hypothermia.
The QRS must be more than 3 mm (120 msec) to diagnose a complete bundle branch block.See also: QRS complex
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This ECG is from a man in his 60s who presented with abdominal pain dyspnoea and altered level of consciousness, in shock.
This ECG shows wide complex tachycardia with concordant ST elevation in V4-6, due to LAD occlusion. The rhythm was likely sinus tachycardia with RBBB and then LAFB mid way through the trace.
This ECG is from a woman in her 60s who presented from a nursing home with altered mental status, hypotension, hypoxia and bradycardia. This was the repeat ECG after placement of a transvenous pacemaker.
This ECG shows a very wide ventricular paced rhythm with widespread excessive discordant ST elevation. The cause was hyperkalemia.
This ECG is from a woman in her 40s who presented with chest pain that had been waxing and waning over the past 24 hours. She had a history of renal failure on dialysis, hypertension, diabetes and a normal catheterisation a year ago. This was her initial ECG.
This ECG shows sinus tachycardia with nonspecific intraventricular delay, tall QRS and widespread PR segment depression. The ST segments are all discordant apart from V4 and V1. These changes were dynamic over serial ECGs. The cath was again normal. Echo showed a trace of pericardial effusion. The diagnosis was myopericarditis.