La pérdida patrimonial desapareció, de ahí que dudemos.

De ahí que is a set expression meaning something like hence, which is why, or from that it follows that.

It links the first idea to the second:

• La pérdida patrimonial desapareció = the patrimonial/financial loss disappeared
• de ahí que dudemos = hence / which is why we doubt

It is a fairly formal connector, more common in written or careful speech than in everyday conversation.

Because de ahí que normally introduces a consequence that is presented through the subjunctive.

So after de ahí que, Spanish usually uses the subjunctive:

• de ahí que dudemos
• de ahí que sea importante
• de ahí que no quieran venir

This is one of those expressions you largely have to learn as a pattern:

• de ahí que + subjunctive

If you said de ahí que dudamos, it would sound wrong to most speakers.

Desapareció is the preterite of desaparecer.

It means:

• it disappeared
• it vanished
• it ceased to exist

The preterite is used because the sentence presents the disappearance as a completed event.

Dudemos is the present subjunctive, first person plural of dudar.

So it means we doubt.

The subject nosotros is not stated because Spanish often leaves subject pronouns out when the verb ending already makes the subject clear.

Pérdida patrimonial is a fairly formal expression. Its exact meaning depends on context, but it often refers to:

• a loss of assets
• a financial loss
• a loss affecting someone’s estate or property
• in legal/tax contexts, a capital loss or patrimonial loss

A learner should notice that this is not very everyday vocabulary. It sounds more legal, financial, or administrative than casual.

It is common enough to understand and use, but it sounds more formal or written than everyday alternatives.

In more neutral or conversational Spanish, you might often hear:

• por eso dudamos
• así que dudamos
• por eso tenemos dudas

So de ahí que dudemos is correct, but it has a more polished or formal feel.

Yes, but you would normally need a different connector.

For example:

• La pérdida patrimonial desapareció, por eso dudamos.
• La pérdida patrimonial desapareció, así que dudamos.

With those connectors, the indicative is normal.

But with de ahí que, the normal structure is:

• de ahí que + subjunctive

So the issue is not the meaning of doubt itself; it is the grammar required by the connector.

The comma separates the main statement from the consequence introduced by de ahí que.

That punctuation is very natural here:

• La pérdida patrimonial desapareció, de ahí que dudemos.

It helps show that the second part is a conclusion or result drawn from the first part.

In standard modern Spanish, yes, normally it does.

You should learn it as a fixed rule:

• de ahí que + subjunctive

Examples:

• De ahí que sea necesario actuar.
• De ahí que no lo acepten.
• De ahí que dudemos.

For a learner, that is the safest and most useful rule.

Yes, a learner might notice that the logic is not immediately obvious without context.

Literally, it says:

• The patrimonial loss disappeared; hence we doubt.

Since dudar needs an understood object or idea, the sentence really means something like:

• ...hence we have doubts
• ...hence we are doubtful
• ...hence we doubt that things are as they seemed

So grammatically the sentence is fine, but semantically it feels a bit incomplete unless the surrounding context makes clear what is being doubted.

Yes. Spanish, like English, can use dudar without explicitly naming the object of doubt if the context already makes it clear.

For example:

• No estoy seguro; dudo.
• De ahí que dudemos.

Still, in many real situations, speakers often make the content of the doubt explicit:

• De ahí que dudemos de su versión.
• De ahí que dudemos que sea cierto.

So the sentence is grammatical as it stands, but context matters a lot.