This is a complicated topic. To summarize, I think "narrow complex" refers to a narrow QRS complex, and a wide QRS complex, a wide one.
The concern about a wide complex is that is could be V-tach. And V-tach could be a problem. But having a wide complex does not mean that you necessarily have V-tach, even if your wide complex appears regular. Even if you do have V-tach, it does not mean you are necessarily in danger.
If you have wide complex, an electrophysiologist has to look at your ECG to interpret whether you might have v-tach or something else. A doctor also need to help you decide how to handle this.
sorry, I forgot to add the definition of what a wide complex is:
Wide complex tachycardia (QRS > 120 ms)
Wide complex tachy-arrhythmias originate from impulses in the ventricles and hence affect the width of the QRS wave, hence the name wide (QRS > 120 ms by EKG). It can be further classified according to its rhythm as either regular or irregular.
. NARROW COMPLEX (QRS less than 120 ms)
Narrow complex tach-arrhythmias originate from impulses in the atrium but do not affect the width of the QRS wave. It can be further classified according to its rhythm as either regular or irregular.
- Regular narrow complex tachycardia
Sinus tachycardia
Paroxysmal supraventricular tachycardia: These are paroxysmal; i.e., characterized by an abrupt onset and abrupt termination. They are caused by an accessory pathway in the conduction system between atria and ventricles. This maybe dual AV node (AVNRT) which is present in many people or an accessory pathway (AVRT e.g. Wolf-Parkinson-White syndrome).
Atrial tachycardia: P wave rate 120 ms by EKG). It can be further classified according to its rhythm as either regular or irregular.
* Regular wide complex tachycardia would be V-Tach
* Irregular wide complex tachycardia would be V-Fib
1 single wide complex beat would be a PVC(premature ventricular contraction)
Without any other info it is really hard to tell you anything more than what i have already. Have you had any kind of testing/moitoring done?