Estrogen-induced improvement in coronary flow responses during atrial pacing in relation to endothelin-1 levels in postmenopausal women without coronary disease

Figures & data

Figure 1 Schematic presentation of the study protocol indicating time-points when coronary sinus samples and recordings of coronary blood flow (CBF) and diameter were taken.

Figure 2 Representative coronary blood flow (CBF) of left anterior descending artery of a postmenopausal woman in the treated group at the two atrial pacing (AP) protocols before (upper panel) and after estrogen administration (low panel).

Abbreviations: AP, aortic pressure; ECG, electrocardiogram.

Table 1 Clinical characteristics of the study population

Parameters	Treated group (n = 18)	Controls (n = 6)	p
Age (years)	55.6 ± 3.7	56.2 ± 3.2	NS
Time since menopause (years)	5.7 ± 2.8	5.4 ± 3.1	NS
Body mass index (kgr/m^2)	27.2 ± 1.1	27.1 ± 1.1	NS
Office systolic blood pressure (mmHg)	142 ± 10	141 ± 10	NS
Office diastolic blood pressure (mmHg)	88 ± 4	89 ± 4	NS
Heart rate (bpm)	72 ± 8	72 ± 8	NS
Total cholesterol (mg/dl)	228 ± 25	230 ± 20	NS
LDL cholesterol (mg/dl)	150 ± 40	145 ± 36	NS
HDL cholesterol (mg/dl)	43 ± 14	45 ± 14	NS
Serum estradiol levels (pg/ml)	40 ± 14	38 ± 14	NS
Coronary sinus estradiol levels (pg/ml)	39 ± 12	39 ± 13	NS
Coronary sinus ET-1 levels (mol/L)	1.60 ± 0.48	1.64 ± 0.29	NS

Abbreviations: ET-1, endothelin-1; HDL, high-density lipoprotein; LDL, low-density lipoprotein.

Figure 3 Plot of coronary artery diameter at baseline-1, peak-1, recovery-1, and baseline-2, peak-2, recovery-2 of the first and second atrial pacing (AP) protocol, respectively. Upper panel: For the treated group before (solid line) and after estrogen administration (dotted line). Low panel: For the control group before (solid line) and after saline administration (dotted line).

Figure 4 Plot of coronary blood flow (CBF) at baseline-1, peak-1, recovery-1 and baseline-2, peak-2, recovery-2 of the first and second atrial pacing (AP) protocol, respectively. Upper panel: For the treated group before (solid line) and after estrogen administration (dotted line). Low panel: For the control group before (solid line) and after saline administration (dotted line).

Table 2 Coronary artery responses at first atrial pacing protocol in the treated group (n = 18)

	Baseline-1	Peak-1	Recovery-1
Aortic pressure (mmHg)	145/90	155/88	142/88
Heart rate (bpm)	75 ± 5	160 ± 3*	78 ± 6
Coronary artery diameter (mm)	3.47 ± 0.42	3.02 ± 0.41*	3.28 ± 0.49*
Average peak velocity (cm/sec)	27.94 ± 3.31	47.61 ± 5.00*	35.44 ± 4.98*
Coronary blood flow (mL/min)	82.28 ± 30.14	106.44 ± 43.51*	89.51 ± 38.86*

* Notes: p < 0.05 vs (baseline-1).

Table 3 Coronary artery responses at second atrial pacing protocol in the treated group (n = 18)

	Baseline-2	Pacing-2	Recovery-2
Aortic pressure (mmHg)	141/87	153/85	142/88
Heart rate (bpm)	77 ± 4	160 ± 4*	80 ± 5
Coronary artery diameter (mm)	3.49 ± 0.41	3.32 ± 0.41*	3.44 ± 0.40*
Average peak velocity (cm/sec)	28.61 ± 2.70	53.77 ± 6.55*	34.37 ± 4.02*
Coronary blood flow (mL/min)	84.82 ± 28.95	145.01 ± 54.42*	95.58 ± 35.01*

* Notes: p < 0.05 vs (baseline-2).

Figure 5 Graphs of correlations of coronary blood flow (CBF) or degree of constriction, and levels of endothelin before and after estrogen infusion when atrial pacing (AP) is incorporated.