Hello and thanks for the query
I can understand your concern because it is ultimately the patient who gets confused.
Both defibrillation and pace maker are the treatment of choice for atrial fibrillation and few doctors advocate for defibrillation while a few of them are of opinion of going for pace maker and each of them has it's own advantages.

 Cardioversion (also termed defibrillation): This technique uses electrical current to "shock" the heart back to normal sinus rhythm with an electrical current. This is sometimes called DC cardioversion. Prior to cardioversion, many patients undergo a sonogram of the heart to determine if any clots are present.
Cardioversion works very well; more than 90% of people convert to sinus rhythm. It is most successful if the atrial fibrillation is new (that is, hours, days, or a few weeks). For many, however, this is not a permanent solution because the arrhythmia often comes back.
Cardioversion increases the risk of stroke and thus usually requires pretreatment with an anticoagulant medication.

Pacemaker: A pacemaker is an electronic device that prevents slow heartbeats and may reduce the likelihood of atrial fibrillation in a small number of patients. The artificial pacemaker takes the place of the "natural pacemaker XXXXXXX the SA node, supplying electrical impulses to keep the heart beating in a normal rhythm when the SA node no longer can.
The pacemaker is usually implanted in both the right atrium and right ventricle. The goal is to override the patient's own atrial fibrillation electric impulses with a new atrial electrical pacemaker. A minority of patients are offered this technique currently. This is a more complex technique and device, and no long-term data regarding success are available yet.

Since I can't advise  without knowing anything about you,the best would be to go for a third opinion and follow that, because both the methods are good and it is a question of selecting one out of two.
Best of luck
Thanks

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