Objective To investigate the relationship between QRS duration (QRSd)

R-wave amplitude

heart rate variability (HRV)

and cardiac function in patients with heart failure (HF).

Methods

2

Total 152 patients with heart failure (HF) diagnosed at Puyang Oilfield General Hospital from March 2021 to May 2024 were selected and divided into Grade Ⅱ group (

n

=55)

Grade Ⅲ group (

n

=47)

and Grade Ⅳ group (

n

=50) according to cardiac function classification. All patients underwent cardiac ultrasound exam

ination

and the cardiac function indicators of the three groups were compared. Electrocardiogram examination was performed

and QRSd and the sum of R-wave amplitudes (∑R) were compared among the three groups. Dynamic electrocardiogram examination was performed

and HRV time-domain indicators were compared among the three groups of patients.

Results

2

There was no significant difference in the distribution of primary disease types among the three groups of heart failure patients (

P

>

0.05)

indicating comparability. The LVEDD and LVESD of the Grade Ⅱ group were significantly lower than those of the Grade Ⅲ and Ⅳ groups (

P

<

0.05)

and the Grade Ⅲ group was significantly lower than the Grade Ⅳ group (

P

<

0.05); The LVEF of the Grade Ⅱ group was significantly higher than that of the Grade Ⅲ and Ⅳ groups (

P

<

0.05)

and the Grade Ⅲ group was higher than the Grade Ⅳ group (

P

<

0.05). The QRSd levels in the Ⅱ and Ⅲ groups were significantly lower than those in the IV group (

P

<

0.05)

while there was no significant difference between the Ⅱ and Ⅲ groups (

P

>

0.05). The ∑R of the Grade Ⅱ group was significantly higher than that of the Grade Ⅲ and Ⅳ groups (

P

<

0.05)

and the Grade Ⅲ group was significantly higher than the Grade Ⅳ group (

P

<

0.05). The standard deviation of the average RR interval every 5 minutes in the Class Ⅱ group was significantly higher than that in the Class Ⅲ and Ⅳ groups (

P

<

0.05)

and the Class Ⅲ group was higher than the Class Ⅳ group (

P

<

0.05). The root mean square of successive normal RR interval differences and the percentage of adjacent RR intervals differing by

>

50 ms (PNN50) in the Class Ⅱ group were significantly lower than those in the Class Ⅲ and Ⅳ groups. Pearson correlation analysis showed that LVEDD (0.467

P

<

0.05)

LVESD (0.493

P

<

0.05) were positively correlated with QRSd

while LVEF (-0.426

P

<

0.05) was negatively correlated with QRSd. LVEDD (-0.431

P

<

0.05) and LVESD (-0.447

P

<

0.05) were negatively correlated with ∑R

while LVEF (0.432

P

<

0.05) was positively correlated with ∑R. All HRV indicators were not correlated with QRSd and ∑R.

Conclusions

2

QRSd and ∑R on electrocardiogram in HF patients are significantly correlated with cardiac function

but not with HRV.