problem interfacing regarding iteration of for loop at interval of 1ms for800ms

Hi! I am doing a ecg project .In which I want 800 sensor reading at interval of 1ms for 800ms.After that I want to give delay of 800ms ,again want 800 sensor reading at interval of 1ms for 800ms and so on.But I am not getting desired output
Here is my code that I am writing on arduino ide but not getting the desired output.So please help me how can I get desired output.

Hereis code-

#include <EEPROM.h>

unsigned long previousMillis=0;

void setup() {
// initialize the serial communication:
Serial.begin(115200);
pinMode(10, INPUT); // Setup for leads off detection LO +
pinMode(11, INPUT); // Setup for leads off detection LO
}
unsigned long currentMillis;
void loop()
{
int t,i;
if((digitalRead(10)==1)||(digitalRead(11)==1))
{
Serial.println("!");
}else
{ for(i=0;i<800;i++)
{currentMillis=micros();
if(currentMillis-previousMillis>=1000)
{
previousMillis=currentMillis;
t=float(currentMillis)/1000;
Serial.print(t);
Serial.print(",");
Serial.println(analogRead(A0));}}}
delay(800);

}

hg63370:
delay(800);

You're telling the processor to nothing but twiddle its fingers for 800ms. If this is not really your intent check out several things at the same time.

what are you getting if not the "desired" output? The only thing that I see is you delcare 't' as an int and then compute '(float)CurrentMillis / 1000' but that just turns it back into an int. You should declare 't' as a float is that is what you want or at least an unsigned long.