Follow-Up and Risk Assessment in Patients with Myocardial Infarction Using Artificial Neural Networks

Table 1

Detailed description of input variables used in this study.

Methods	Parameters	Units	Description
ECG parameters	QT interval	ms	Measure of the time between the start of the Q wave and the end of the T wave
	QTc interval	ms	Heart rate corrected QT interval
	PR interval	ms	Measure of time from the beginning of the upslope of the P wave to the beginning of the QRS wave
	QRS complex	ms	Complex of Q wave, R wave, and S wave
	P wave	ms	The P wave is the first positive deflection on the ECG
Time domain analysis	Average HR	bpm	Average heart rate during 24 hours
	SDNN	ms	Standard deviation of NN intervals
	RMSSD	ms	Square root of the mean squared differences of successive NN intervals
	pNN50	%	Proportion of interval differences of successive NN intervals greater than 50 ms
HRV statistics	LFnu-RRI	%	LF power in normalized units
	HFnu-RRI	%	HF power in normalized units
	VLF-RRI	ms^2	Power in very low frequency range
	PSD-RRI	ms^2	Total power
	LF/HF-RRI		Ratio LF [ms^2]/HF [ms^2]
	BRS	ms/mmHg	Change in interbeat interval (IBI) in milliseconds per unit change in BP