How to display Subscribe data in HTML which is continuous change every second in Angular 4

i m working BLE native library in ionic. I m try to display heartbeat on screen. Here,i m able to get heartrate value on console.log() which is continuously change. what i want is to show heartrate value in html page live. <p>{{ heartrate }}</p> Where heartrate:number = 0; global variable.

This is my code

this.ble.startNotification("EB:53:D1:0A:A0:78", "180D", "2A37").subscribe((buffer)=>{

  this.getHeartRateNotifications(buffer);

  console.log(buffer);

},(err)=>{
  console.log('aa',JSON.stringify(err))
})

getHeartRateNotifications(buffer){
  console.log(buffer);
  console.log('array : ', String.fromCharCode.apply(null, new Uint8Array(buffer)));
  const value = new DataView(buffer);

  console.log("I am value: ", JSON.stringify(value));

  const flags = value.getUint8(0);

  console.log('FLAGS', flags);


 if(this.session.isEven(flags)){

   this.heartRate = value.getUint8(1);
   console.log('HEART RATE 8 bit: ', this.heartRate);

 }else if(this.session.isOdd(flags)){
   this.heartRate = value.getUint16(2);
   console.log('HEART RATE 16 bit: ', this.heartRate);
 }
}