Efficiently Triggering Autovacuum Analyze?

We have a performance problem accessing one of our tables, I think because the statistics are out of date.  The table is fairly large, on the order of 100M rows or so. 

The general structure of the table is as follows:Column | Type | Modifiers
-------------------+--------------------------+------------------------------------------------
id | bigint | not null default nextval('foo_id_seq'::regclass)
record_id | text |
account_id | bigint | not null

With indexes:

    "foo_pkey" PRIMARY KEY, btree (id)

This table is almost always queried using a combination of (account_id, record_id) and is generally pretty fast.  However, under certain loads, the query becomes slower and slower as time goes on.  The workload that causes this to happen is when data for a new account_id is being inserted into the table.  This will happen in rapid succession and may insert millions of rows over the course of several hours.

The pattern that I notice when this happens is that the CPU on DB will be pegged much higher than usual, and the query to lookup records for the (account_id, record_id) combo will steadily rise from <1ms to more then 2 or 3 seconds over time. 

The fix I have employed to restore the speed of the query after I notice it is happening is to manually issue a VACUUM ANALYZE on the table.  After the analyze is done, the query returns to its normal speed.

I am looking for suggestions for how to tune, or perhaps automatically detect this pattern, so that I don't have to manually intervene whenever this happens.

Here are my autovacuum settings:

We're using 9.4.4 (RDS)