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PubMed1996

Coronary flow reserve and oesophageal dysfunction in syndrome X.

The relative prevalence of abnormalities of coronary flow reserve and oesophageal function was ascertained in 32 syndrome X patients with typical angina chest pain, a positive exercise test, and normal coronary arteries. Coronary flow reserve in response to a hyperaemic dose of papaverine was measured using an intracoronary Doppler catheter positioned in the left anterior descending coronary artery. An abnormal coronary flow reserve was defined as being < 3.0. Patients were investigated for oesophageal dysfunction by manometry and 24-hour pH monitoring. Thirteen patients had an impaired coronary flow reserve (group 1) and 19 patients had a normal flow reserve (group 2). Eight of the 13 group 1 patients (62%) and 13 of the 19 group 2 patients (68%, p = NS) had evidence of oesophageal dysfunction on either manometry or pH studies. Therefore, a total of 26 (81%) syndrome X patients had either an abnormality of coronary flow reserve or oesophageal dysfunction suggesting that chest pain in these patients may be due to myocardial ischaemia or oesophageal dysfunction, thus confirming the heterogeneous nature of this syndrome. The prevalence of oesophageal abnormalities was independent of any abnormalities of coronary flow reserve.

Adult↗
PubMed1999

Antianginal and anti-ischemic effects of nisoldipine and ramipril in patients with syndrome X.

BACKGROUND: Syndrome X is defined as typical angina pectoris, positive treadmill exercise test, negative intravenous ergonovine test, and angiographically normal coronary arteries. HYPOTHESIS: In the present study, we investigated the anti-ischemic and antianginal effects of nisoldipine and ramipril in patients with syndrome X. METHODS: After 2 weeks of the first wash-out period, 18 patients (7 men, 11 women, age 46 +/- 10 years) were given nisoldipine (NIS) 5 mg twice daily for 4 weeks, and after 2 weeks of the second wash-out period, the same patients were given ramipril (RAM) 2.5 mg once daily for 4 weeks. A treadmill exercise test with modified Bruce protocol was performed at the end of each period. RESULTS: The time to angina in exercise (607 +/- 115 s-650 +/- 117 s, p = 0.006, vs. 630 +/- 114 s-660 +/- 123 s, p = 0.02), total exercise time (612 +/- 110 s-656 +/- 114 s, p = 0.0008, vs. 630 +/- 114 s-660 +/- 123 s, p = 0.02), and maximum MET value (11.09 +/- 2.08-11.86 +/- 2.04, p = 0.0016, vs. 11.42 +/- 2.09-12.2 +/- 2.26, p = 0.01) were increased significantly with both therapy modalities. The time to 1 mm ST-segment depression (123 +/- 93 s-220 +/- 172 s, p = 0.002) was increased significantly with NIS therapy. The time to ST-segment recovery (434 +/- 268 s-330 +/- 233 s, p = 0.016 vs. 443 +/- 289 s-370 +/- 278 s, p = 0.012), the frequency of anginal attacks per week (1.27 +/- 1.4-0 +/- 0.38, p = 0.005, vs. 1 +/- 1.32-0.33 +/- 0.59, p = 0.028), and the need for sublingual nitroglycerin (1.16 +/- 1.29-0.11 +/- 0.32, p = 0.005, vs. 0.94 +/- 1.16-0.27 +/- 0.57, p = 0.012) were decreased significantly with both drugs. CONCLUSION: We observed that 10 mg daily NIS and 2.5 mg daily RAM have similar anti-ischemic and antianginal effects in patients with syndrome X.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1995

Syndrome X in women is associated with oestrogen deficiency.

This study was undertaken to ascertain whether gynaecological history or a reduction in ovarian hormones are triggers of angina in menopausal women with a positive exercise test and normal coronary arteries. The majority of patients with angina pectoris, a positive exercise test and normal coronary arteries are female, suggesting that the female gender may be important in the aetiology. We studied the gynaecological features of 107 women (age 53 +/- 9 years) with syndrome X, taken from a population of 134 patients including 27 males. Cardiological investigations were undertaken and detailed gynaecological history obtained from all the female patients. Menopausal status was confirmed by plasma levels of oestradiol-17 beta < or = 100 pmol.l-1. In 95 of the 107 female patients, chest pain began either during the perimenopausal period (32) or after the menopause (63). Of the 63 menopausal patients, 43 had undergone hysterectomy at an average of 8 +/- 6 years prior to the onset of chest pain. The incidence of hysterectomy in the study population (40%) was four times greater than that of an age-matched population. These findings confirm that the majority of patients with syndrome X are women in whom the chest pain began after the onset of menopause. Ovarian hormone deficiency may, therefore, play a role in the onset of syndrome X in female patients.

Adult↗
PubMed2002

Dipyridamole body surface potential mapping: noninvasive differentiation of syndrome X from coronary artery disease.

Up to 20% to 30% of patients with angina and abnormal stress test have normal coronary arteries at angiography or syndrome X (Sy X). We tested whether body surface potential mapping (BSPM) with intravenous dipyridamole could differentiate patients with Sy X from patients with coronary artery disease (CAD). We compared the effects of intravenous dipyridamole (0.28 mg/kg over 4 min) on BSPM in 17 healthy volunteers (controls) and in 2 groups of patients with angina and abnormal ergometric tests who were referred for angiography: 27 patients with obstructive disease (> or =70% diameter stenosis) in the CAD group, and 17 patients with Sy X. Control subjects were easily differentiated from patients with CAD or Sy X by markedly smaller baseline BSPM DeltaST-T < or = LSD departure areas (P <.001), but the Sy X and CAD groups had similar ST-T departure areas. The average potential integral difference after dipyridamole (APID) differentiated Sy X and CAD patients: the mean APID increased in patients with Sy X and trended negative in the CAD group. The APID(20%-40%) (integrated over 20% to 40% of the ST-T interval) mean value was 0.59 +/- 0.67 microVs in the Sy X group and -0.18 +/- 0.59 microVs in the CAD group (P <.01). At a threshold APID(20%-40%) > 0.17 microVs, the sensitivity and specificity for Sy X was 71% and 78%, respectively; the area under the receiver operating characteristic curve was 0.79 (95% CI 0.64, 0.93). Dipyridamole BSPM is a promising noninvasive diagnostic modality to differentiate patients with Sy X from those with CAD.

Body Surface Potential Mapping↗
PubMed1994

Insulin resistance syndrome as a feature of cardiological syndrome X in non-obese men.

OBJECTIVE: To assess the features of the insulin resistance syndrome in patients presenting with cardiological syndrome X, who experience angina despite angiographically normal coronary arteries. PATIENTS AND METHODS: 14 Non-obese male patients with syndrome X and 38 symptom free, apparently healthy, male volunteers were studied. Insulin sensitivity (inversely related to insulin resistance) was measured by minimal modelling analysis of glucose and insulin concentrations during an intravenous glucose tolerance test. Serum lipids, lipoproteins, and apolipoproteins were also measured. RESULTS: Insulin sensitivity was 31% lower in the men with syndrome X (p < 0.05) and fasting insulin concentration was 30% higher (p < 0.05). The patient group also had 64% higher mean triglycerides (p < 0.001) and 20% lower mean high density lipoprotein cholesterol concentration (p < 0.01). Systolic blood pressure was also 10% higher in the syndrome X group (p < 0.01). There were no differences in total cholesterol, low density lipoprotein cholesterol or lipoprotein (a). CONCLUSION: These findings show that non-obese male patients with anginal chest pain but normal coronary arteries (syndrome X) are insulin resistant, hyperinsulinaemic, and have higher concentrations of triglycerides and lower high density lipoprotein cholesterol than healthy men. The insulin resistance syndrome may predispose to a spectrum of arterial disease capable of causing myocardial ischaemia.

Adult↗
PubMed1993

Exercise-induced diastolic abnormalities assessed by handgrip-apexcardiographic test in syndrome X.

It has been shown recently that the handgrip-apexcardiographic test (HAT) represents a new mode of stress test, which shows a high sensitivity in identifying coronary patients by assessing exercise-induced ischemic left ventricular diastolic abnormalities. To assess the prevalence of left ventricular diastolic abnormalities and the usefulness of HAT as a diagnostic tool in patients with syndrome X (angina pectoris in the presence of normal coronary arteries), HAT was obtained in 275 clinically normal subjects and in 9 patients who presented with typical chest pain and who were subsequently found to have a positive treadmill ECG test and no coronary artery disease by angiography. As diastolic indices served: the relative A wave to total height (A/H) and to diastolic amplitude (A/D) of the apex tracing, the total apexcardiographic relaxation time (TART), TART corrected for the duration of diastole (TARTI) and the diastolic amplitude time index [DATI = TARTI/(A/D)]. Positivity of HAT was defined by the presence of at least one of the following recently introduced criteria: (1) A/H during or after handgrip > 21%, (2) TART during handgrip > TART at rest > 143 ms or/and TARTI during handgrip < 0.14 or (3) DATI during handgrip < 0.27. At rest, in 6/9 (67%) patients all variables were within normal limits, whereas in 3/9 (33%) patients an abnormal A/H or TARTI was observed. During and after handgrip, however, all patients showed abnormal changes in at least two diastolic variables, DATI and A/H being most frequently abnormal (67 and 56%, respectively). Further, using the above-mentioned positivity criteria, all patients had a positive HAT result.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed2000

Endothelial activation in patients with cardiac syndrome X.

BACKGROUND: The presence of endothelial dysfunction with increased endothelin-1 plasma concentrations in patients with cardiac syndrome X is still under debate. The aim of the present study was to evaluate the presence of endothelial dysfunction in patients with cardiac syndrome X. METHODS AND RESULTS: ++Endothelin-1 levels were evaluated with a sensitive radioimmunoassay with previous purification through reverse phase HPLC in 24 patients (3 men and 21 women, mean age 54+/-7 years) with typical angina, instrumental evidence of ischemia, and normal coronary angiograms both under baseline conditions and after oral glucose load (75 g D-glucose). We also measured plasma nitrite-plus-nitrate levels, a sharp index of endothelial nitric oxide production, and circulating concentrations of the soluble fraction of the endothelial adhesion molecule vascular cell adhesion molecule-1, a well-recognized marker of early endothelial dysfunction. Fourteen healthy subjects (1 man and 13 women, mean age 47+/-15 years) served as controls. There were no significant differences in baseline plasma endothelin-1 concentrations between patients and control subjects (0.55+/-0.34 versus 0.48+/-0.22 pg/mL, P=0.503). Plasma nitrite-plus-nitrate and soluble vascular cell adhesion molecule-1 concentrations were also similar between the 2 groups. After glucose ingestion, circulating endothelin-1 concentrations were significantly higher in patients with cardiac syndrome X than in control subjects (P<0.03 at 60, 90, and 120 minutes). CONCLUSIONS: Our findings show that no basal endothelial damage is present in patients with cardiac syndrome X. Nevertheless, increased responsiveness of endothelin-1 to glucose loading suggests that patients with cardiac syndrome X present an increased susceptibility to releasing endothelin-1 under stressful circumstances.

Chromatography, High Pressure Liquid↗
PubMedDate not supplied

[Left ventricular diastolic behavior in patients with syndrome X during isometric exercise assessed by Doppler flowmeter].

Left ventricular (LV) diastolic filling during isometric exercise was evaluated in patients with syndrome X using pulsed Doppler echocardiography. The handgrip exercise was performed by 12 normal subjects (group N), 14 patients with syndrome X (group X), and 20 patients with effort angina, who were divided into 13 patients with single vessel disease (group SVD) and seven patients with multiple vessel disease (group MVD). The transmitral inflow patterns before and at the end of exercise were recorded using Doppler flowmetry, to measure the peak velocity of early diastolic flow (E) and the peak velocity of atrial contraction flow (A). The A/E ratio and the % change in A/E (% A/E) at the end of exercise compared with those before were calculated. 1. Group N: E, A, and A/E did not change significantly. 2. Group X: E decreased, A increased, and A/E increased. 3. Group SVD: E did not change significantly. A increased, and A/E increased. 4. Group MVD: E decreased, A increased, and A/E increased. 5. % A/E in group X and group MVD were larger than in group SVD. 6. Systolic blood pressure (SBP) and heart rate (HR) increased during exercise to the same extent in each group. The impairment of LV diastolic filling in group X was more severe than in group SVD, possibly due to more extensive ischemic areas in group X than in group SVD. The extension of ischemic areas in syndrome X may be similar to that in group MVD.

Adult↗
PubMedDate not supplied

Increased levels of soluble adhesion molecules E-selectin and P-selectin in patients with cardiac syndrome X.

The role of endothelial dysfunction and platelet activation in patients with cardiac syndrome X is controversial. The aim of this study was to investigate the plasma levels of circulating E- and P-selectin molecules in patients with syndrome X. The study included 21 patients with cardiac syndrome X (11 men and 10 women, mean age = 56 +/- 5 years) and 20 patients with significant coronary artery disease who had stable angina pectoris (11 men and 9 women, mean age = 60 +/- 8 years). Twenty-two age- and sex-matched subjects (12 men and 10 women, mean age = 58 +/- 8 years) undergoing diagnosis of atypical chest pain in whom coronary arteries were found normal and exercise test had no signs of ischemia served as the control group. Syndrome X was defined as presence of typical chest pain on exertion or at rest with positive exercise test and angiographically normal epicardial coronary arteries with no evidence of coronary spasm after intracoronary infusion of ergonovine maleate. The mean plasma concentrations of P-selectin were significantly elevated both in patients with coronary artery disease and syndrome X as compared with control subjects (49.15 +/-7.47 and 42.80 +/- 8.93 vs 22.63 +/-6.47 ng/mL, p < 0.001). Similarly, both patients with coronary artery disease and syndrome X had higher plasma concentrations of E-selectin than the control group (78.85 +/- 16.69 and 68.38 +/- 15.30 vs 36.43 +/- 4.72 ng/mL, p < 0.001). In conclusion, patients with syndrome X had increased plasma concentrations of soluble adhesion molecules, E-selectin and P-selectin, reflecting an ongoing chronic inflammation involved with endothelial dysfunction and enhanced platelet activation/damage in this setting.

Coronary Disease↗
PubMed1996

17-beta-Estradiol therapy lessens angina in postmenopausal women with syndrome X.

OBJECTIVES: We sought to investigate the hypothesis that estrogen replacement therapy ameliorates symptoms in postmenopausal women with syndrome X. BACKGROUND: Syndrome X (angina pectoris, positive findings on exercise electrocardiography and normal results on coronary angiography) frequently occurs in menopausal women. This observation, in conjunction with the known vasoactive properties of estrogens, suggests that estrogen depletion may contribute to the pathogenesis of syndrome X in some women. METHODS: Twenty-five postmenopausal patients with syndrome X completed a double-blind, placebo-controlled study of the effect of 17-beta-estradiol cutaneous patches (100 micrograms/24 h) on the frequency of chest pain and on exercise tolerance. Patients were randomly assigned to receive either placebo or 17-beta-estradiol patches for 8 weeks and were then crossed over to the other treatment. RESULTS: During the placebo phase, patients had a mean of 7.3 episodes of chest pain/10 days. A reduction to 3.7 episodes/10 days was observed during the 17-beta-estradiol phase (p < 0.05). No significant differences were observed between the effects of 17-beta-estradiol and placebo on exercise duration or the results of other cardiologic investigations. CONCLUSIONS: Estrogen replacement reduces the frequency of chest pain and may be a useful new therapeutic option for treating postmenopausal women with syndrome X.

Cross-Over Studies↗
PubMed1996

The effect of transcutaneous electrical nerve stimulation on coronary and systemic haemodynamics in syndrome X.

BACKGROUND: Neurostimulation techniques have been shown to be beneficial in patients with angina and syndrome X but the mechanism remains unclear. We examined the effect of transcutaneous electrical nerve stimulation (TENS) on coronary artery blood flow in a group of patients with syndrome X. METHODS: Coronary blood flows were measured in 11 patients with angiographically normal coronary arteries, positive results from exercise tests and angina (syndrome X) using intracoronary Doppler catheters combined with quantitative coronary angiography. RESULTS: The mean coronary flow velocity did not increase in any patient during TENS therapy; in fact, there was a fall from 5.2 +/- 2.8 to 4.3 +/- 1.9 cm/s (P = 0.02) and the coronary blood flow index fell from 47 +/- 22 to 38 +/- 16 cm/s per mm2 (P = 0.007). This was associated with a fall in the rate x pressure product from 0.92 +/- 0.22 to 0.83 +/- 0.18 mmHg/min (P = 0.038). The coronary vascular resistance rose from 2.4 +/- 1.1 to 3.0 +/- 1.6 mmHg/cm per s per mm2 (P = 0.041). There were no major changes in the epicardial coronary artery diameter during TENS and there was no significant effect on the response to the cold-pressor test. CONCLUSIONS: In this group of patients with syndrome X, TENS produced a small but significant fall in coronary artery blood flow associated with a reduction in the rate x pressure product. TENS had no significant effect on coronary vasomotion during sympathetic stimulation by the cold-pressor test. Thus, TENS is unlikely to have a direct effect on coronary artery vasomotion or haemodynamics in syndrome X but reduces the rate x pressure product and thus myocardial oxygen consumption.

Blood Flow Velocity↗
PubMed2005

Abnormal cortical pain processing in patients with cardiac syndrome X.

AIMS: Previous studies suggested that an enhanced pain sensitivity is present in patients with cardiac syndrome X (SX). We investigated whether SX patients present abnormalities in the electrical cerebral signals generated by pain stimuli. METHODS AND RESULTS: Cortical laser evoked potentials (LEPs) were recorded in 16 SX patients, in 10 patients with refractory angina due to obstructive coronary artery disease (CAD) and in 13 healthy controls. LEPs were recorded during stimulation of chest and right hand dorsum. Three sequences of painful stimuli were applied at each site. Subjective pain rating was assessed by a 0-100 mm visual analogic scale (VAS). Basal LEPs did not differ among groups and there were no differences for most LEP components across the repetitions of stimuli. However, the amplitude of the N2/P2 LEP component, specifically reflecting cortical pain processing, decreased across the three sequences of stimuli in controls and CAD patients, but not in SX patients. Compared with the first sequence, the N2/P2 amplitude during the third sequence of stimuli in the three groups was 77+/-16, 56+/-24, and 99+/-34%, respectively, for chest (P=0.001), and 63+/-31, 72+/-17, and 98+/-46%, respectively, for right hand (P=0.03) stimulation. The changes in VAS pain score across the three sequences paralleled those of N2/P2 amplitude. CONCLUSION: Our data show that in SX patients, central handling of painful stimuli is characterized by inadequate habituation, which might play a role in determining the peculiar clinical characteristics of anginal chest pain of these patients.

Cerebral Cortex↗
PubMed1994

Left ventricular dysfunction during exercise in patients with angina pectoris and angiographically normal coronary arteries (syndrome X)

Left ventricular function during exercise and recovery was investigated in patients with angina pectoris, ST segment depression during exercise and angiographically normal coronary arteries (syndrome X) using a continuous left ventricular function monitor with cadmium telluride detector (CdTe-VEST). Fourteen patients with syndrome X and 14 patients with atypical chest pain without ST segment depression during exercise and normal coronary arteries (control group) performed supine ergometric exercise after administration of 740-925 MBq of technetium-99m labelled red blood cells, and left ventricular function was monitored every 20 s using CdTe-VEST. Left ventricular ejection fraction (EF) response was impaired (< or = 5% increase from rest to peak exercise) in 11 or 14 patients with syndrome X but in none of the control patients. Resting EF was similar in the two groups (62.1% +/- 6.7% in patients with syndrome X, 61.9% +/- 6.2% in controls); however, EF increase from rest to peak exercise was lower in syndrome X (-3.1 +/- 9.5% vs 14.7% +/- 7.4%, P < 0.001). After cessation of exercise, all patients showed rapid EF increase over baseline and this EF overshoot was lower (19.3% +/- 8.3% vs 26.4% +/- 7.3%, P < 0.001) with the time to EF overshoot longer (114 +/- 43 s vs 74 +/- 43 s, P < 0.05) in patients with syndrome X. Thus, in patients with syndrome X, left ventricular dysfunction was frequently observed during exercise in spite of normal epicardial coronary arteries.

Adult↗
PubMed1999

Magnetic resonance contrast enhancement with gadolinium-DTPA in patients with angina and angiographically normal coronary arteries: effect of chronic beta-blockade.

BACKGROUND: The syndrome of angina and normal coronary arteries (syndrome X) comprises a heterogeneous group of patients with typical chest pain, a positive exercise test, angiographically smooth coronary arteries and no evidence of spasm. Magnetic resonance imaging (MRI) has been used to detect areas of myocardial ischemia and/or recent necrosis both in animal and human studies. Most of these studies have been conducted after intravenous administration of the paramagnetic contrast medium gadolinium-DTPA (Gd-DTPA), that is considered a sensitive marker of extracellular, probably ischemic in origin, edema. On the basis of these data, we used MRI to evaluate the possibility of myocardial Gd-DTPA deposition at rest in patients with syndrome X, and to assess the effects of oral treatment with atenolol. METHODS: We have studied 24 patients with syndrome X, 10 patients with coronary artery disease and 10 age-matched control subjects. The protocol was similar in all study subjects. Exercise testing and MRI were undertaken off therapy after coronary arteriography. Following MRI, patients underwent a 10 day treatment period with atenolol and repeated exercise stress test and MRI while on therapy. RESULTS: In all patients with syndrome X and coronary artery disease were observed effort diagnostic ST-segment changes that were associated with angina in 9 (37%) and 7 (70%) patients, respectively. Of 24 patients with syndrome X, 16 (66.6%) showed areas of myocardial enhancement after Gd-DTPA in comparison to the precontrast imaging. In 4 out of 10 patients with coronary artery disease (40%), Gd-DTPA accumulation was documented. Finally, focal Gd-DTPA myocardial enhancement was not observed in any normal control subject. After beta-blockade, 22 (92%) patients with syndrome X and 2 (20%) with coronary artery disease did not show any ischemic ST-segment changes on effort; 14 syndrome X patients (88%) and 2 coronary artery disease patients (50%) showed complete disappearance of the previously Gd-DTPA enhanced areas on MRI. CONCLUSIONS: Patients with syndrome X often exhibit regional accumulation of Gd-DTPA on MRI. The agent is believed to trace interstitial water accumulation as occurs during ischemia and its accumulation is reduced or abolished by treatment with atenolol, probably by different mechanisms. It is likely that an overactivation of the sympathetic outflow to the cardiovascular system can induce most of the abnormalities observed in syndrome X patients. In this context, beta-blockers probably represent the mainstay of the medical treatment of this condition.

Adrenergic beta-Antagonists↗
PubMed1997

[The onset of syndrome X in old age].

There is evidence that angina-like chest pain associated with normal coronary angiography (syndrome X) may appear in adult patients. We have reviewed the clinical documentation of all the patient aged 65 or more admitted to our hospital because of recent onset typical or atypical angina, who underwent an exercise tolerance test and coronary angiography. Exclusion criteria were ischaemic or valvular heart disease and significant arterial hypertension. The selection lead to a series of 11 patients (6 females, 5 males) aged 65-72 years (mean 69). The bicycle ergometric test was positive in 7 and negative or not diagnostic in 2 patients each. Thallium-201 scintigraphy (performed in 6 patients) revealed reversible perfusion defects in 4 and was equivocal in 2 patients. At coronary angiography 6 patients showed non obstructive lesions (range: 20-40%) and only 5 had normal findings: 2 of these patients showed gastro-intestinal disease which could be considered as possible trigger of chest pain. Thus only 3 patients fulfilled the criteria for a diagnosis of syndrome X. These were 2 females and 1 male and were followed-up for a minimum of 2 years. All were in good condition, with normal left ventricular function free of major cardiac events, although occasional chest pain was still present. We conclude that syndrome X may appear also in the elderly with the same clinical features already described in younger patients. The overall prognosis is good and symptoms are partially insensitive to standard therapy. The low incidence in the older age may be explained, in our series, also by the restricted criteria adapted to select the study population.

Age of Onset↗
PubMed2001

Comparison of ischemic patterns in myocardial bridge and syndrome X: evaluation by dobutamine stress echocardiography and stress thallium-201 SPECT.

BACKGROUND AND PURPOSE: Ischemic patterns in patients with syndrome X are thought to differ from those in patients with myocardial bridge, because the mechanisms of coronary flow reduction in these two diseases are different. The aim of this study was to compare the ischemic patterns in patients with syndrome X and those with myocardial bridge through the use of dobutamine stress echocardiography (DSE) and stress thallium-201 single-photon emission computed tomography (SPECT). METHODS: Twenty-six patients with typical angina and stress-induced ST-segment depression were enrolled. All patients underwent coronary angiography, DSE, and stress thallium-201 SPECT within 7 days after enrollment. RESULTS: Of the 26 patients enrolled, 10 had myocardial bridge of the left anterior descending artery and 16 had syndrome X. Among patients with myocardial bridge, myocardial dyssynergy was found by DSE in five patients and reversible or fixed thallium-201 perfusion defects were found in four. Seven patients with myocardial bridge had reverse redistribution patterns on thallium-201 scintigraphy. In the 16 patients with syndrome X, myocardial dyssynergy was found by DSE in only one patient (p = 0.018 vs myocardial bridge group) and reversible or fixed thallium-201 perfusion defects were found in nine (p > 0.05 vs myocardial bridge group). Four patients with syndrome X had reverse redistribution patterns on thallium-201 scintigraphy. The resting left ventricular end-diastolic pressure was higher in patients with myocardial bridge than in those with syndrome X (17 +/- 4 vs 12 +/- 5 mm Hg, p = 0.02). CONCLUSIONS: The most common ischemic patterns in patients with syndrome X were chest pain and stress-induced ST-segment depression, followed by myocardial perfusion defects. Dobutamine-induced dyssynergy was rare. Left ventricular end-diastolic pressure elevation and dobutamine-induced wall motion abnormalities were more common in patients with myocardial bridge than in those with syndrome X.

Adult↗
PubMed1995

Effect of epinephrine infusion on chest pain in syndrome X in the absence of signs of myocardial ischemia.

Eight female patients (aged 51 to 65 years) with New York Heart Association class II angina pectoris, normal coronary angiograms, normal hyperventilation, and abnormal exercise stress tests (chest pain and ST depression), and 5 sex- and age-matched controls participated in this study. Epinephrine was given intravenously to both patients and controls at 5-minute intervals in doses of 0.1, 0.2, 0.3, 0.4, and 0.6 nmol/kg/min. After rest (15 minutes), the alpha-adrenoceptor antagonist phentolamine or placebo was administered intravenously to patients in a double-blind, crossover study on 2 separate occasions in doses of 250 micrograms/min for 5 minutes and 500 micrograms/min for the next 10 minutes; the epinephrine infusion was repeated. Blood pressure, heart rate, and electrocardiogram were monitored continuously and pain was estimated on the Borg CR-10 scale. On a third occasion, chest pain was induced in patients using the same epinephrine protocol during echocardiographic monitoring. In the control group, all patients received the maximal epinephrine dose. No chest discomfort or pain developed. In the patient group, the maximal tolerable epinephrine dose (0.39 +/- 0.19 nmol/kg/min) decreased diastolic pressure (-14 +/- 9 mm Hg, p < 0.01) and increased heart rate (+24 +/- 10 beats/min, p < 0.01), not statistically different from the control group. Pulse pressure increased in the patient group (27 +/- 17 mm Hg, p < 0.01) but not in the controls. Left ventricular ejection fraction at baseline was within reference limits (58% to 75%) and did not change during epinephrine infusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1996

High prevalence of the thallium-201 reverse redistribution phenomenon in patients with syndrome X.

OBJECTIVE: To evaluate the stress-myocardial perfusion pattern in patients with angina, positive exercise test and angiographically smooth coronary arteries (syndrome X). DESIGN: Prospective study. PATIENTS AND METHODS: Twenty-five consecutive patients (seven males, mean age 54 +/- 8 years) with typical angina, positive exercise test, normal coronary arteries and no inducible spasm, underwent stress-redistribution thallium-201 myocardial perfusion scintigraphy. Thirty-two consecutive patients (14 males, mean age 49 +/- 7 years) with atypical chest pain and negative exercise test, undergoing stress-redistribution thallium scan, served as controls. RESULTS: Exercise was discontinued for angina and/or ST-segment depression after 12 +/- 3 min. Thallium stress images revealed 40 hypoperfused segments in 27 patients (77%); after 4 h, 16 of these segments had completely normalized, 10 remained unchanged, six exhibited partial reperfusion and eight worsened. Twenty-four patients (69%) exhibited thallium reverse redistribution in 33 segments. Thirty-four patients (97%) had at least one hypoperfused segment in one of the two scintigraphic phases. Of the 24 patients with reverse redistribution, eight also underwent stress-rest 99m Tc-MIBI SPECT: six exhibited reduced tracer uptake that was present at rest, but not on stress images, in the same segments showing thallium reverse redistribution. Thallium stress images revealed four hypoperfused segments in three controls (9%); at redistribution, one segment normalized, two remained unchanged and one exhibited partial reperfusion. Additionally, there were four new underperfused segments appearing on redistribution in four patients (13%). Overall, there were seven controls (22%) with at least one hypoperfused myocardial segment in one of the two scintigraphic phases. CONCLUSIONS: Our study confirms that perfusion abnormalities are present in most syndrome X patients. Additionally, the data show that reverse redistribution (a perfusion defect that develops or becomes more evident on delayed imaging) is a common finding in these patients. The mechanisms of the phenomenon remain obscure: we suggest that it is due to inhomogeneous perfusion, and the hyperaemic response induced by exercise masks resting underperfusion of certain areas.

Adult↗