Cardiol Res

Cardiology Research, ISSN 1923-2829 print, 1923-2837 online, Open Access

Article copyright, the authors; Journal compilation copyright, Cardiol Res and Elmer Press Inc

Journal website https://cr.elmerpub.com

Original Article

Volume 16, Number 1, February 2025, pages 64-71

Correlations Between Endothelial Function and Right Ventricular Performance in Primary Hypertension

Figure 1. Flow-mediated dilation (FMD) measurement. The baseline diameter (D0) of the artery was measured under resting conditions. Subsequently, a cuff was inflated to 50 mm Hg above systolic pressure for 5 min to induce reactive hyperemia. Following cuff release, the post-occlusion diameter (D1) was measured 60 s later.

Figure 2. Tei index measurement. Tei index = (a - b)/b = (ICT + IRT)/ET. ET: ejection time; IRT: isovolumetric relaxation time; ICT: isovolumetric contraction time; Tei index: myocardial performance index.

**Table 1.** Comparison of General Clinical Data Between Groups
Parameters	FMD ≥ 6% group (n = 20)	FMD < 6% group (n = 14)	P value
*P < 0.05. BMI: body mass index; FMD: flow-mediated dilation; HDL-C: high-density lipoprotein cholesterol; hs-CRP: high-sensitivity C-reactive protein; LDL-C: low-density lipoprotein cholesterol; PWD: platelet distribution width; RDW: red cell distribution width; TC: total cholesterol; WBC: white blood cell count.
Age (years)	44.29 ± 11.44	56.60 ± 8.59	0.001*
Gender (male)	7	6	0.643
Heart rate (bpm)	71.36 ± 9.61	72.70 ± 11.78	0.727
BMI (kg/m²)	29.71 ± 4.99	27.32 ± 5.76	0.218
TC (mmol/L)	4.98 ± 1.01	5.28 ± 0.88	0.364
WBC (× 10⁹/L)	6.07 ± 1.76	6.03 ± 1.64	0.261
PWD (fL)	11.8 (11.08, 12.63)	12.45 (11.25, 13.38)	0.192
hs-CRP (mg/L)	1.88 (1.24, 7.15)	1.83 (0.74, 3.05)	0.306
HDL-C (mmol/L)	1.20 (1.04, 1.50)	1.36 (1.01, 1.61)	0.473
LDL-C (mmol/L)	2.93 (2.73, 3.13)	3.03 (2.85, 3.84)	0.245
Homocysteine (µmol/L)	11.6 (11.35, 19.48)	12.4 (10.40, 15.40)	0.904
RDW (%)	12.6 (12.48, 13.23)	12.7 (12.43, 13.73)	0.959

Table 1. Comparison of General Clinical Data Between Groups

Parameters

FMD ≥ 6% group (n = 20)

FMD < 6% group (n = 14)

P value

*P < 0.05. BMI: body mass index; FMD: flow-mediated dilation; HDL-C: high-density lipoprotein cholesterol; hs-CRP: high-sensitivity C-reactive protein; LDL-C: low-density lipoprotein cholesterol; PWD: platelet distribution width; RDW: red cell distribution width; TC: total cholesterol; WBC: white blood cell count.

Age (years)

44.29 ± 11.44

56.60 ± 8.59

0.001*

Gender (male)

0.643

Heart rate (bpm)

71.36 ± 9.61

72.70 ± 11.78

0.727

BMI (kg/m²)

29.71 ± 4.99

27.32 ± 5.76

0.218

TC (mmol/L)

4.98 ± 1.01

5.28 ± 0.88

0.364

WBC (× 10⁹/L)

6.07 ± 1.76

6.03 ± 1.64

0.261

PWD (fL)

11.8 (11.08, 12.63)

12.45 (11.25, 13.38)

0.192

hs-CRP (mg/L)

1.88 (1.24, 7.15)

1.83 (0.74, 3.05)

0.306

HDL-C (mmol/L)

1.20 (1.04, 1.50)

1.36 (1.01, 1.61)

0.473

LDL-C (mmol/L)

2.93 (2.73, 3.13)

3.03 (2.85, 3.84)

0.245

Homocysteine (µmol/L)

11.6 (11.35, 19.48)

12.4 (10.40, 15.40)

0.904

RDW (%)

12.6 (12.48, 13.23)

12.7 (12.43, 13.73)

0.959

**Table 2.** Comparison of Echocardiographic Parameters Between Groups
Parameter	FMD ≥ 6% group (n = 20)	FMD < 6% group (n = 14)	P value
*P < 0.05. a’₁: late diastolic velocity of the interventricular septal mitral annulus; a’₂: late diastolic velocity of the lateral wall mitral annulus; A peak: late diastolic peak velocity; E peak: early diastolic peak velocity; EDV: end-diastolic volume; e’₁: early diastolic velocity of the interventricular septal mitral annulus; e’₂: early diastolic velocity of the lateral wall mitral annulus; FMD: flow-mediated dilation; ICT: isovolumic contraction time; ICT₁: isovolumic contraction time of the interventricular septal mitral annulus; ICT₂: isovolumic contraction time of the lateral wall mitral annulus; ICT, RV: isovolumic contraction time of the free wall tricuspid annulus; IRT: isovolumic relaxation time; IRT₁: isovolumic relaxation time of the interventricular septal mitral annulus; IRT₂: isovolumic relaxation time of the lateral wall mitral annulus; IRT, RV: isovolumic relaxation time of the free wall tricuspid annulus; LVEF: left ventricular ejection fraction; LVPW: left ventricular posterior wall; RV a’: late diastolic velocity of the free wall tricuspid annulus; RV e’: early diastolic velocity of the free wall tricuspid annulus; RV: right ventricle; s’₁: peak systolic velocity of the interventricular septal mitral annulus; s’₂: peak systolic velocity of the lateral wall mitral annulus; s’ RV: peak systolic velocity of the free wall tricuspid annulus; TAPSE: tricuspid annular plane systolic excursion; Tei: myocardial performance index.
Aortic sinus diameter (mm)	33.21 ± 4.34	30.90 ± 2.69	0.064
Left atrium (mm)	33.29 ± 2.59	32.45 ± 3.25	0.430
Left ventricle (mm)	48.57 ± 5.80	48.90 ± 3.40	0.837
EDV (mL)	113.36 ± 28.25	110.60 ± 13.82	0.739
Cardiac output (L/min)	5.14 ± 1.33	5.00 ± 1.08	0.754
Stroke volume (mL)	72.71 ± 16.00	72.35 ± 7.96	0.938
E peak (cm/s)	89.00 ± 21.64	73.90 ± 17.92	0.034*
A peak (cm/s)	70.29 ± 21.26	78.25 ± 21.37	0.292
Pulmonary artery ejection time (ms)	311.71 ± 42.82	287.35 ± 32.92	0.070
Aortic ejection time (ms)	307.79 ± 26.18	315.70 ± 31.72	0.448
s’₁ (cm/s)	8.75 ± 1.21	7.61 ± 1.58	0.030*
e’₁ (cm/s)	8.50 ± 2.01	6.55 ± 1.61	0.003*
IRT₁ (ms)	87.57 ± 17.51	96.35 ± 12.60	0.098
ICT₁ (ms)	71.86 ± 10.34	77.65 ± 13.67	0.190
s’₂ (cm/s)	10.38 ± 2.23	9.64 ± 2.57	0.393
e’₂ (cm/s)	11.98 ± 1.86	9.21 ± 3.11	0.006*
IRT₂ (ms)	87.64 ± 19.97	92.00 ± 14.17	0.461
RV e’ (cm/s)	11.54 ± 2.35	8.67 ± 1.34	< 0.001*
RV a’ (cm/s)	14.58 ± 3.41	13.22 ± 2.82	0.213
IRT, RV (ms)	84.79 ± 18.99	91.70 ± 20.88	0.332
ICT, RV (ms)	64.50 ± 8.70	67.30 ± 11.03	0.434
LV Tei index	0.52 ± 0.07	0.55 ± 0.08	0.356
RV Tei index	0.48 ± 0.07	0.56 ± 0.12	0.031*
LVPW (mm)	10.00 (9.00, 10.00)	10.00 (9.00, 10.00)	0.823
LVEF (%)	68.0 (62.75, 73.00)	64.0 (63.00, 71.00)	0.290
TAPSE (cm)	2.34 (2.05, 2.54)	1.94 (1.77, 2.00)	0.002*
a’₁ (cm/s)	9.41 (8.20, 9.97)	9.56 (8.37, 9.74)	0.959
a’₂ (cm/s)	11.10 (9.17, 12.80)	9.58 (8.77, 13.60)	0.416
ICT₂ (ms)	72.0 (63.00, 78.00)	74.0 (64.00, 85.00)	0.416
RV s’ (cm/s)	13.6 (12.00, 14.95)	12.1 (11.40, 13.45)	0.066

Table 2. Comparison of Echocardiographic Parameters Between Groups

Parameter

FMD ≥ 6% group (n = 20)

FMD < 6% group (n = 14)

P value

*P < 0.05. a’₁: late diastolic velocity of the interventricular septal mitral annulus; a’₂: late diastolic velocity of the lateral wall mitral annulus; A peak: late diastolic peak velocity; E peak: early diastolic peak velocity; EDV: end-diastolic volume; e’₁: early diastolic velocity of the interventricular septal mitral annulus; e’₂: early diastolic velocity of the lateral wall mitral annulus; FMD: flow-mediated dilation; ICT: isovolumic contraction time; ICT₁: isovolumic contraction time of the interventricular septal mitral annulus; ICT₂: isovolumic contraction time of the lateral wall mitral annulus; ICT, RV: isovolumic contraction time of the free wall tricuspid annulus; IRT: isovolumic relaxation time; IRT₁: isovolumic relaxation time of the interventricular septal mitral annulus; IRT₂: isovolumic relaxation time of the lateral wall mitral annulus; IRT, RV: isovolumic relaxation time of the free wall tricuspid annulus; LVEF: left ventricular ejection fraction; LVPW: left ventricular posterior wall; RV a’: late diastolic velocity of the free wall tricuspid annulus; RV e’: early diastolic velocity of the free wall tricuspid annulus; RV: right ventricle; s’₁: peak systolic velocity of the interventricular septal mitral annulus; s’₂: peak systolic velocity of the lateral wall mitral annulus; s’ RV: peak systolic velocity of the free wall tricuspid annulus; TAPSE: tricuspid annular plane systolic excursion; Tei: myocardial performance index.

Aortic sinus diameter (mm)

33.21 ± 4.34

30.90 ± 2.69

0.064

Left atrium (mm)

33.29 ± 2.59

32.45 ± 3.25

0.430

Left ventricle (mm)

48.57 ± 5.80

48.90 ± 3.40

0.837

EDV (mL)

113.36 ± 28.25

110.60 ± 13.82

0.739

Cardiac output (L/min)

5.14 ± 1.33

5.00 ± 1.08

0.754

Stroke volume (mL)

72.71 ± 16.00

72.35 ± 7.96

0.938

E peak (cm/s)

89.00 ± 21.64

73.90 ± 17.92

0.034*

A peak (cm/s)

70.29 ± 21.26

78.25 ± 21.37

0.292

Pulmonary artery ejection time (ms)

311.71 ± 42.82

287.35 ± 32.92

0.070

Aortic ejection time (ms)

307.79 ± 26.18

315.70 ± 31.72

0.448

s’₁ (cm/s)

8.75 ± 1.21

7.61 ± 1.58

0.030*

e’₁ (cm/s)

8.50 ± 2.01

6.55 ± 1.61

0.003*

IRT₁ (ms)

87.57 ± 17.51

96.35 ± 12.60

0.098

ICT₁ (ms)

71.86 ± 10.34

77.65 ± 13.67

0.190

s’₂ (cm/s)

10.38 ± 2.23

9.64 ± 2.57

0.393

e’₂ (cm/s)

11.98 ± 1.86

9.21 ± 3.11

0.006*

IRT₂ (ms)

87.64 ± 19.97

92.00 ± 14.17

0.461

RV e’ (cm/s)

11.54 ± 2.35

8.67 ± 1.34

< 0.001*

RV a’ (cm/s)

14.58 ± 3.41

13.22 ± 2.82

0.213

IRT, RV (ms)

84.79 ± 18.99

91.70 ± 20.88

0.332

ICT, RV (ms)

64.50 ± 8.70

67.30 ± 11.03

0.434

LV Tei index

0.52 ± 0.07

0.55 ± 0.08

0.356

RV Tei index

0.48 ± 0.07

0.56 ± 0.12

0.031*

LVPW (mm)

10.00 (9.00, 10.00)

0.823

LVEF (%)

68.0 (62.75, 73.00)

64.0 (63.00, 71.00)

0.290

TAPSE (cm)

2.34 (2.05, 2.54)

1.94 (1.77, 2.00)

0.002*

a’₁ (cm/s)

9.41 (8.20, 9.97)

9.56 (8.37, 9.74)

0.959

a’₂ (cm/s)

11.10 (9.17, 12.80)

9.58 (8.77, 13.60)

0.416

ICT₂ (ms)

72.0 (63.00, 78.00)

74.0 (64.00, 85.00)

0.416

RV s’ (cm/s)

13.6 (12.00, 14.95)

12.1 (11.40, 13.45)

0.066

**Table 3.** Correlation Factors of FMD
Variable	r	P value
E peak: early diastolic peak velocity; e’₁: early diastolic velocity of the interventricular septal mitral annulus; e’₂: early diastolic velocity of the lateral wall mitral annulus; e’ RV: early diastolic velocity of the free wall tricuspid annulus; FMD: flow-mediated dilation; RV Tei index: myocardial performance index of the right ventricle; S’₁: peak systolic velocity of the interventricular septal mitral annulus.
Age (years)	-0.536	0.001
E peak (cm/s)	0.365	0.034
S’₁ (cm/s)	0.372	0.030
e’₁ (cm/s)	0.488	0.003
e’₂ (cm/s)	0.465	0.006
e’ RV (cm/s)	0.624	< 0.001
RV Tei index	-0.370	0.030

Table 3. Correlation Factors of FMD

Variable

P value

E peak: early diastolic peak velocity; e’₁: early diastolic velocity of the interventricular septal mitral annulus; e’₂: early diastolic velocity of the lateral wall mitral annulus; e’ RV: early diastolic velocity of the free wall tricuspid annulus; FMD: flow-mediated dilation; RV Tei index: myocardial performance index of the right ventricle; S’₁: peak systolic velocity of the interventricular septal mitral annulus.

Age (years)

-0.536

0.001

E peak (cm/s)

0.365

0.034

S’₁ (cm/s)

0.372

0.030

e’₁ (cm/s)

0.488

0.003

e’₂ (cm/s)

0.465

0.006

e’ RV (cm/s)

0.624

< 0.001

RV Tei index

-0.370

0.030