ADS1298: Pace detection and Low pass filter cut-off frequency

Hi All,
I want to use ADS1298 for ECG application with following requirements;

• 5 electrodes (7 lead) ECG.
• Pace detection for 0.1ms to 2ms pulse width.

Question regarding ADS1298;

1. What is the Max possible sampling rate which can be supported by ADS1298's SPI with Gain of 12 and 4 channel of ECG signals?
2. If 32KSPS sampling rate is selected then the digital filter will have LP cutoff at 0.262*fDR Hz = 8.3KHz ?
3. Anyway possible to disable this sinc decimation filter?
4. 8.3KHz will not be able to detect 0.1ms Pace pulse, so how this will be addressed?  Datasheet claims ADS1298 supports systems meeting IEC60601-2-27!!

Best regards,

BM