Sublingual Administration Of Nitroglycerin Research Articles

Computed tomography angiography assessment of Adamkiewicz artery with sublingual nitroglycerin administration.

Identification of the Adamkiewicz artery before aortic surgery is important for preventing postoperative complications due to spinal cord ischemia. The Adamkiewicz artery is difficult to identify due to its small diameter. Nitroglycerin has a vasodilatory effect and is used clinically to improve visualization of blood vessels on coronary computed tomography (CT) angiography. We investigated whether the vasodilatory effect of nitroglycerin could improve the ability to visualize the Adamkiewicz artery. We extracted 33 cases wherein contrast-enhanced CT images were taken before and after aortic aneurysm surgery. Nitroglycerin was administered for coronary artery evaluation on the preoperative CT. However, no nitroglycerin was administered before the postoperative CT. Aortic contrast-to-noise ratio, CT value, image noise, and diameter of the Adamkiewicz artery and anterior spinal artery were measured. The depiction of the Adamkiewicz artery was graded into four grades and evaluated. These measurements were performed by two independent reviewers. In nitroglycerin-administered cases, the contrast-to-noise ratio and CT values were significantly higher (P < 0.001, P < 0.001, respectively); the Adamkiewicz artery and anterior spinal artery diameters were dilated (P = 0.005, P = 0.001, respectively). The Adamkiewicz artery score also improved significantly (P < 0.001). No significant difference was found in image noise. Nitroglycerin contributed to improving the Adamkiewicz artery's visualization.

The Impact of Nitroglycerin on the Evaluation of Coronary Stenosis in Coronary-CT: Preliminary Study in 131 Patients.

The sublingual administration of short-acting nitroglycerin (NTG) before coronary computed tomography (CCT) improves the visualization of coronary arteries, causing vasodilatation. The aim of this study was to evaluate whether and how nitroglycerin can influence the concordance between radiologists and cardiologists in the evaluation of vessel stenosis measured in CCT by the former and during the following coronarography by the latter. We conducted a retrospective analysis of 131 patients who underwent CCT for cardiac symptoms in 2022, followed by coronarography performed six months later because of significant stenosis revealed by the CCT. First, the patients were divided into two groups: an NTG group who received sublingual nitroglycerin before CCT and a non-NTG group who did not because of contraindications. Second, 254 stenoses were measured by two radiologists after CCT and by two interventional cardiologists during the next coronarography; moreover, stenoses were classified on the basis of their location and plaque pattern (calcific, mixed and lipidic). Third, the strength of agreement was evaluated between the two radiologists, between the two cardiologists and finally between the radiologists and cardiologists in order to evaluate whether and how the interdisciplinary discrepancy in stenosis evaluation could change with or without the use of nitroglycerin before CCT and in relation to the different plaque pattern. In the NTG group, the use of nitroglycerine reduced the agreement between radiologists and cardiologists in calcific stenosis but did not change the concordance in the case of mixed or lipidic plaques on the same vessels. The use of sublingual nitroglycerin before CCT may lead to a radiological overestimation of calcific stenosis.

Improving the visualisation of perforator arteries for anterolateral thigh flaps harvest in CT angiography via sublingual glyceryl trinitrate

To investigate the improvement of image quality and visualisation of the anterolateral thigh (ALT) flap perforators on computed tomography angiography (CTA) after administration of sublingual glyceryl trinitrate (GTN). Sixty patients with oral lesions received thigh CTA examinations were divided randomly into two groups after administration of sublingual GTN (GTN group) or without administration of sublingual GTN (non-GTN group). Two radiologists calculated the signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and assessed the image quality of each vessel. Besides, the grade of thigh artery, the lumen diameter of deep femoral artery, lateral circumflex femoral artery (LCFA), the descending branch of LCFA and its proximal and distal perforators, and the number and type of visible perforators were evaluated quantitatively. The SNR and CNR were not significantly different between the two groups (p>0.05). The image quality of CTA in the GTN group was significantly better than that in the non-GTN group (p<0.01). The lumen diameters of the deep femoral artery, LCFA, the descending branch of LCFA and its perforators were significantly larger in the GTN group than those in the non-GTN group (p<0.01). Compared with the non-GTN group, the number of visible perforators and the number of visible septocutaneous perforators were significantly more in the GTN group, and the qualitative grade of visible perforators was significantly higher (p<0.001). The administration of sublingual GTN in preoperative thigh CTA can improve the image quality and visualisation of perforator vessels, thus could help surgeons to select the optimum ALT flaps.

Changes in heart rate under the influence of nitroglycerin in patients with stable angina pectoris of functional classes III and IV in combination with hypertension

Background. For many years, nitroglycerin has been the primary treatment for coronary pain in patients with angina pectoris, but its effect on heart rate is not fully understood.&#x0D; Aim. To study the change in heart rate under the influence of nitroglycerin in patients with stable angina pectoris of functional classes III and IV in combination with hypertension.&#x0D; Material and methods. The study included 122 men aged 40 to 65 years (mean age 58.425.8 years) with stable exertional angina of functional classes III and IV in combination with hypertension. A rhythmocardiographic study was performed with simultaneous recording of an electrocardiogram initially and 5 minutes after sublingual administration of nitroglycerin. The number of ventricular and supraventricular extrasystoles was assessed in each vegetative test (background, Valsalva, Ashner, active orthostatic and with physical activity) initially and after taking nitroglycerin. To evaluate the compared values, the mean value, standard error of the mean, maximum, minimum, frequencies, Wilcoxon criteria, Pearson's 2 were calculated.&#x0D; Results. Under the influence of sublingual intake of nitroglycerin, the number of supraventricular extrasystoles decreased in approximately 7% of patients in the background sample, in the rest, an increase prevailed in 7.49.0% of patients, depending on vegetative test. At the same time, the number of ventricular extrasystoles decreased in the background (in 13.9% of patients) and orthostatic (in 9.8%) samples, in the rest, their growth prevailed in 917% of patients, depending on vegetative test.&#x0D; Conclusion. Sublingual use of nitroglycerin leads to an increase in the number of supraventricular extrasystoles, as well as a variable effect on ventricular extrasystoles, depending on the vegetative test performed.

Pill or pump? Nitroglycerin 0.5 mg tablet vs 0.8 mg spray: Effect on proximal vessel diameters at Coronary CT Angiography (CCTA)

IntroductionThe administration of sublingual Nitroglycerin (NTG) prior to CT coronary angiography (CCTA) can be perfomed using pump spray or tablets. Choice of method seems to be based on local preference, rather than published guidelines. This retrospective analysis tested whether proximal coronary diameters differed dependent on the sublingual administration of 0.5 mg Nitroglycerin (NTG) tablets or 0.8 mg NTG spray. Methods287 ECG-gated CCTA studies with optimal image quality and Agatston scores<400 were included in this retrospective analysis. 143 of the patients were dosed with NTG tablets at a dose of 0.5 mg prior to CCTA. 144 patients received 2 puffs of 0.4 mg NTG spray for a total dose of 8 mg.All were scanned on a second-generation Dual Source CT. Diameters of proximal segments of Left Main (LM), Right (RCA), Left Anterior (LAD) and circumflex (CX) coronary arteries were measured using semi-automatic electronic callipers by two blinded readers. Results were summarised as the mean of maximum and minimum diameters. Sex-specific analysis of diameters was carried out using repeated-measures ANOVA for each vessel. Agreement between readers was examined with Bland-Altman analysis and intra-class-correlation coefficient (ICC). ResultsNo significant differences in coronary diameters were found except in the RCA for women and LM for men. In both cases, diameters were smaller in the spray group (11 and 9%, respectively). Reader agreement was excellent, with ICC>0.96 for all vessels, and no significant bias, except in CX (0.03 mm). ConclusionsWe found no evidence for the systematic superiority of either administration method in proximal coronary vessels. Implications for practiceChoosing between tablet or spray NTG prior to CCTA can be guided by practical, economical and hygienic considerations alone.

Nitroglycerin improves the visibility of fibula-free flap perforators on computed tomography angiography in patients with oral or maxillofacial lesion

PurposeTo investigate the improvement of image quality and visualization of fibula-free flap (FFF) perforators on computed tomography angiography (CTA) after administration of sublingual nitroglycerin (NTG) tablets. MethodsA total of 60 patients with oral or maxillofacial lesions before CTA of the lower extremity were randomly divided into two groups (NTG group and non-NTG group). The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR), overall image quality and grading of vessels were evaluated and compared. The lumen diameters of the major arteries and the proximal and distal peroneal perforators were measured. The number of visible perforators in muscular clearance and muscular layer was also counted and compared between the two groups. ResultsThe CNR of posterior tibial artery and overall image quality of CTA images in the NTG group was significantly higher than that in the non-NTG group (p < 0.05), although the SNR and CNR of other arteries did not show significant differences (p > 0.05). The lumen diameters of the peroneal artery and its perforators, anterior tibial artery, and posterior tibial artery were significantly larger in the NTG group (p < 0.001), while no significant difference prevailed in the diameter of the popliteal artery between the two groups (p = 0.298). Compared with the non-NTG group, a significant increase in the number of visible perforators was noted in the NTG group (p < 0.001). ConclusionsThe administration of sublingual NTG in CTA of the lower extremity can improve the image quality and visualization of perforators, which aids to surgeons select the optimum FFF.

Post-partum myocardial ischemia due to intramuscular methylergonovine-induced coronary vasospasm: case report

BackgroundMethylergonovine is a vasoconstrictive agent historically used as a provocative agent in the lab for coronary vasospasm; it is also a first line uterotonic agent for management of postpartum hemorrhage.Case PresentationA 29-year-old female with history of smoking and idiopathic thrombocytopenia received intramuscular methylergonovine after delivery of twins for intrauterine hemorrhage management. Subsequently, she had episodes of chest pain with high sensitivity Troponin I elevation to 1509 ng/L with accompanying septal T wave inversions, decreased left ventricular ejection fraction to 49% and basal septal wall hypokinesis. Computed tomography (CT) coronary angiogram showed patent coronary arteries and no coronary arterial dissection. The patient was conservatively managed with aspirin and metoprolol, and on follow up had fully recovered left ventricular function with resolution of wall motion abnormalities. Given this, coronary vasospasm due to intramuscular methylergonovine is the most likely cause of patient’s chest pain and associated myocardial ischemia.ConclusionsIntramuscular, intrauterine, intravenous, and even oral methylergonovine can rarely cause coronary vasospasm leading to myocardial ischemia. Cardiologists caring for postpartum patients should be aware of these potential lethal complications; prompt identification and administration of sublingual nitroglycerin can prevent severe complications of arrythmias, heart block, or cardiac arrest.

The first study to evaluate non-invasive haemodynamic profile changes in reaction to nitroglycerin in patients with HFmrEF in comparison to HFpEF and HFrEF

Abstract Introduction According to 2021 guidelines for management of heart failure (HF) there are 3 types of HF – with reduced (HFrEF; ≤40%), mildly reduced (HFmrEF; 41–49%) and preserved (HFpEF; ≥50%) left ventricle ejection fraction (LVEF). The middle group – HFmrEF – is the least known and requires further research. The aim of the study was to assess clinical and hemodynamic profile of patients with HFmrEF at rest and after sublingual administration of 0.4 mg of nitroglycerin (NTG). Material and methods The hemodynamic profile was assessed on the last day of hospitalization due to acute decompensated heart failure. The control groups for patients with HFmrEF were groups of HFpEF and HFrEF, while there was no control group on healthy subjects. The clinical profile of patients was assessed by data from medical interview, results of laboratory tests and measured echocardiographic parameters, while the hemodynamic profile – at rest and after administration of 0.4mg of NTG – was assessed by electrical cardiometry (EC) using the ICON® device. Results Overall, 15 consecutive patients from each type of HF were included into the study and most of them were men (N=32; 71%). Diabetes was significantly more frequent in the HFpEF group. The HFrEF group had significantly higher left ventricle end-diastolic dimension (LVDD; p=0.0003) and lower right ventricle systolic function (TAPSE; p=0.0026). The analysis of the hemodynamic profile at rest showed significant differences between HFmrEF and HFrEF in systolic time ratio (STR; p=0.0202) and pre-ejection period (PEP; p=0.0487). In comparison to HFrEF group, patients with HFmrEF were significantly different in the change of stroke volume and stroke volume index (SV/SI; p=0.0134/0.0223), cardiac output and cardiac index (CO/CI; p=0.005/0.0079), systemic vascular resistance and its' indexed values (SVR/SVRI; p=0.0339/0.0294), the cardiac power index (CPI; p=0.0489) and corrected flow time (FTC; p=0.0369). The change in the following parameters: SV, SI, CO, CI, FTC, SVR, SVRI and CPI after NTG administration, in the HFmrEF group had and an opposite direction in comparison to patients with HFpEF (p=NS) and HFrEF (p&amp;lt;0.05) (Fig. 1). The principal component analysis showed that the HFmrEF group is less heterogenetic and located within the two others (Fig. 2). Conclusions Clinical profile of patients with HFmrEF based on medical interview, laboratory and echographic findings showed that they are a mid-filed group. Patients with HFmrEF significantly differs from HFrEF in the changes of hemodynamic profile after sublingual NTG administration, considering EC parameters of the blood flow (SV, SI, CO, CI, SVR, SVRI) and heart muscle contractility (CPI, FTC). The reaction to NTG showed that HFmrEF is the intermediate and more homogeneous group that is comprised in the other two groups. The median reaction to NTG in the HFmrEF group was opposite to the reaction in HFpEF and HFrEF patients. Funding Acknowledgement Type of funding sources: None.

Sublingual Nitroglycerin Administration to Relieve Radial Artery Vasospasm and Retrieve Wedged Catheter: A Consideration in Neuroangiography

Background Radial artery spasm is a common hinderance during transradial approaches for neuroangiography. Ways of alleviation have been described, including patient sedation, local lidocaine, or even prophylactic administration of intra‐arterial vasodilators. Methods We present a case of a wedged catheter attributable to radial artery spasm, which failed all conventional methods to relieve spasm. Results The catheter was ultimately removed after administration of sublingual nitroglycerin. Conclusion To our knowledge, this is the first time sublingual nitrogen has been reported as an effective means to alleviate radial artery spasm during a transradial approach for neuroangiography.

Modulation of Arterial Stiffness Gradient by Acute Administration of Nitroglycerin.

Background: Physiologically, the aorta is less stiff than peripheral conductive arteries, creating an arterial stiffness gradient, protecting microcirculation from high pulsatile pressure. However, the pharmacological manipulation of arterial stiffness gradient has not been thoroughly investigated. We hypothesized that acute administration of nitroglycerin (NTG) may alter the arterial stiffness gradient through a more significant effect on the regional stiffness of medium-sized muscular arteries, as measured by pulse wave velocity (PWV). The aim of this study was to examine the differential impact of NTG on regional stiffness, and arterial stiffness gradient as measured by the aortic-brachial PWV ratio (AB-PWV ratio) and aortic-femoral PWV ratio (AF-PWV ratio).Methods: In 93 subjects (age: 61 years, men: 67%, chronic kidney disease [CKD]: 41%), aortic, brachial, and femoral stiffnesses were determined by cf-PWV, carotid-radial (cr-PWV), and femoral-dorsalis pedis artery (fp-PWV) PWVs, respectively. The measurements were repeated 5 min after the sublingual administration of NTG (0.4 mg). The AB-PWV and AF-PWV ratios were obtained by dividing cf-PWV by cr-PWV or fp-PWV, respectively. The central pulse wave profile was determined by radial artery tonometry through the generalized transfer function.Results: At baseline, cf-PWV, cr-PWV, and fp-PWV were 12.12 ± 3.36, 9.51 ± 1.81, and 9.71 ± 1.89 m/s, respectively. After the administration of NTG, there was a significant reduction in cr-PWV of 0.86 ± 1.27 m/s (p < 0.001) and fp-PWV of 1.12 ± 1.74 m/s (p < 0.001), without any significant changes in cf-PWV (p = 0.928), leading to a significant increase in the AB-PWV ratio (1.30 ± 0.39 vs. 1.42 ± 0.46; p = 0.001) and AF-PWV ratio (1.38 ± 0.47 vs. 1.56 ± 0.53; p = 0.001). There was a significant correlation between changes in the AF-PWV ratio and changes in the timing of wave reflection (r = 0.289; p = 0.042) and the amplitude of the heart rate-adjusted augmented pressure (r = − 0.467; p < 0.001).Conclusion: This study shows that acute administration of NTG reduces PWV of muscular arteries (brachial and femoral) without modifying aortic PWV. This results in an unfavorable profile of AB-PWV and AF-PWV ratios, which could lead to higher pulse pressure transmission into the microcirculation.

Vascular Endothelial Function Assessed by Flow-Mediated Vasodilatation in Young Adults Born Very Preterm or With Extremely Low Birthweight: A Regional Cohort Study.

Background: Preterm birth and low birthweight have been associated with increased risk of cardiovascular disease in young adults. Endothelial dysfunction is established as an early marker for development of atherosclerotic cardiovascular disease. Previous studies of endothelial function in young adults born very preterm or with extremely low birthweight have, however, shown diverging results.Objective: We aimed to evaluate the risk of cardiovascular disease as measured by vascular endothelial function in young adults born very preterm (<29 weeks of gestation) or with extremely low birthweight (<1,000 g), compared with term-born controls.Methods: This study included 50 young adults born very preterm or with extremely low birthweight and 49 term-born controls born in Norway in the periods 1982–1985, 1991–1992, and 1999–2000 at mean age 28 (±6) years. The endothelial function was assessed by ultrasound measured flow-mediated dilatation (FMD) of the right brachial artery. The arterial diameter was measured at baseline, after release of 5 min of occlusion, and after sublingual administration of nitroglycerine. FMD was reported as absolute and percentage diameter change from baseline and relative to nitroglycerine-induced dilatation.Results: The participants were mainly normal weight non-smokers, without hypertension, diabetes, or established cardiovascular disease. The cases and controls had mean blood pressure 112/71 (SD 12/9) and 112/69 (SD 11/8) mmHg, body mass index 24.0 (SD 4.2) and 24.4 (SD 4.5) kg/m2, and HbA1c 32.7 (SD 2.5) and 33.0 (SD 2.6) mmol/mol, respectively. For both groups, 4 (8%) were smokers. Mean FMD for the adults born very preterm or with extremely low birthweight was 0.17 mm (95% CI 0.14, 0.21) vs. 0.24 mm (95% CI 0.20, 0.28) for the controls (p = 0.01), corresponding to a percentage increase of 5.4% (95% CI 4.2, 6.6) and 7.6% (95% CI 6.2, 8.9), respectively (p = 0.02). The FMD relative to maximal nitroglycerine-induced dilatation was 20% and 31%, respectively (p = 0.001).Conclusions: Young adults born very preterm or with extremely low birthweight have significantly lower FMD compared with the term-born controls suggesting an increased risk of cardiovascular disease.

Spinal nociceptive sensitization and plasma palmitoylethanolamide levels during experimentally induced migraine attacks.

Migraine pathophysiology has been suggested to include dysregulation of the endocannabinoid system (ES). We simultaneously evaluated plasma anandamide (AEA) and palmitoylethanolamide (PEA) levels and spinal sensitization in a validated human model of migraine based on systemic nitroglycerin (NTG) administration. Twenty-four subjects with episodic migraine (MIG) and 19 healthy controls (HC) underwent blood sampling and investigation of nociceptive withdrawal reflex thresholds (RTh: single-stimulus threshold; TST: temporal summation threshold) before and 30 (T30), 60 (T60), and 120 (T120) minutes after sublingual NTG administration (0.9 mg). At baseline, the MIG and HC groups were comparable for plasma AEA (P = 0.822) and PEA (P = 0.182) levels, and for RTh (P = 0.142) and TST values (P = 0.150). Anandamide levels increased after NTG administration (P = 0.022) in both groups, without differences between them (P = 0.779). By contrast, after NTG administration, PEA levels increased in the MIG group at T120 (P = 0.004), while remaining stable in the HC group. Nitroglycerin administration induced central sensitization in the MIG group, which was recorded as reductions in RTh (P = 0.046) at T30 and T120, and in TST (P = 0.001) at all time points. In the HC group, we observed increases in RTh (P = 0.001) and TST (P = 0.008), which suggest the occurrence of habituation. We found no significant correlations between the ES and neurophysiological parameters. Our findings suggest a role for PEA in the ictal phase of episodic migraine. The ES does not seem to be directly involved in the modulation of NTG-induced central sensitization, which suggests that the observed PEA increase and spinal sensitization are parallel, probably unrelated, phenomena.

P0677CONTRAST-ENHANCED ULTRASOUND TO ASSESS RENAL MICROCIRCULATION IN PATIENTS WITH CHRONIC KIDNEY DISEASE

Abstract Background and Aims Vascular factors such as capillary rarefaction, increased vascular stiffness and reduced vasodilatation due to endothelial dysfunction probably play an important role in the pathophysiology of chronic kidney disease (CKD). However, our understanding of the underlying mechanisms is hampered by the lack of non-invasive techniques to quantify renal microvasculature in humans. The aim of this study was to assess whether contrast-enhanced ultrasonography (CEUS) can identify (1) differences in renal microcirculation and (2) the degree of nitroglycerin-induced vasodilatation (NIV) as a measure of renal flow reserve between CKD-patients and age-matched healthy volunteers. Method All participants underwent CEUS under standardized conditions. Sonovue© (0.015 ml/kg/min) was perfused as contrast agent until a steady state was obtained, followed by four destruction-refilling sequences. Outcome measure of CEUS was the mean (change in) perfusion index (PI) of the outer renal cortex (see figure for an example). In a subgroup of participants, CEUS was repeated before and five minutes after the sublingual administration of nitroglycerin (0.2mg). Renal resistive index (RRI) as a measure of vascular stiffness was also measured at each time point with Doppler ultrasound. Results A total of 38 healthy volunteers (aged 50±8 years, eGFR 95±13 ml/min/1.73 m, 69% women) and 18 CKD stage 2-3 patients (aged 55±15 years, eGFR 64±32 ml/min/1.73m, 56% women) were included. Renal PI was significantly lower in CKD patients (1304±762 vs 2989 ±2503 arbitrary units, p=0.034), whereas RRI did not differ (0.66± 0.07 vs 0.63± 0.04), p=0.10). PI was lower in CKD due to vascular nephropathy (n=3) or interstitial nephritis (n=4) than CKD due to diabetes (n=4) or other causes (7). In continuous analysis, PI correlated with eGFR (spearman’s r=0.54, p=0.005) but not with blood pressure. Renal PI did not change after nitroglycerin in both groups; RRI decreased in healthy (from 0.64±0.03 to 0.61±0.02, p=0.01) but not in CKD patients. Conclusion In this study, contrast-enhanced ultrasound identified important alterations in renal microperfusion in patients with moderate CKD. Whether a low perfusion index predicts renal function decline needs further study. Sublingual nitroglycerin seems to have limited potential as a new test of renal flow reserve.

Diabetes Attenuates the Increase in Estrogen‐Mediated Endothelial Function

BackgroundApparently healthy premenopausal women are protected against cardiovascular disease (CVD) compared to men; and estrogen has been thought to play a key role. In the presence of diabetes; however, this overall sex‐dependent cardiovascular protection is lost. The increase in vascular function throughout the menstrual cycle in healthy premenopausal women has been established. The present investigation sought to test the hypothesis that the increase in vascular function from menses to the late follicular phase of the menstrual cycle is lost in premenopausal women with type 1 diabetes (T1D).MethodsPremenopausal women with a clinical diagnosis of T1D (n=22, HbA1c=8.2±1.7%, age=26±8 years, BMI=26.9±5.4 kg/m2) and seemingly healthy, age‐ and sex‐matched controls (n=10, HbA1c=5.2±0.3%, age=26±9 years, BMI=23.3±4.1 kg/m2) were recruited to participate. Flow mediated dilation (FMD), a measure of endothelial function, was assessed during the menses (cycle day=4±1) and late follicular phases (cycle day=13±1) of the menstrual cycle to represent periods of low and high concentrations of estrogen, respectively. Visit 1 (menses) was confirmed by a positive hemolytic urological multistix test and visit 2 (late follicular) was scheduled based on indications from an ovulation prediction kit. A small venous blood sample was collected at each visit to measure concentrations of estrogen. Endothelial independent vasodilation was determined by administration of sublingual nitroglycerin after each FMD test.ResultsThe increase in estrogen from menses to the follicular phase was similar (p=0.73) in both groups (Δ estrogen: T1D=78.3±92.6 vs Controls=85.6±30.0 pg/mL). Baseline brachial artery diameter was similar between T1D and controls (p=0.25) and was not different between visit 1 and visit 2 (p=0.76). Fasting blood glucose was higher (p&lt;0.01) in women with T1D compared to controls at both visits; however, the change within groups was similar (p=0.49) across time. A near significant interaction (p=0.07) for endothelial function was observed such that FMD increased from the menses to follicular phase in controls (ΔFMD=1.151±1.603%), whereas no change was observed in patients with T1D (ΔFMD=−0.633±2.126%). Endothelial independent vasodilation was not different between groups (p=0.82). Additionally, the endothelial independent response was similar across the menstrual cycle (p=0.97).ConclusionThese data suggest that the presence of diabetes may attenuate the beneficial effects of estrogen on endothelial function in premenopausal women. The loss of estrogen’s cardiovascular protective effect on the vasculature in diabetes may explain the increased risk of CVD observed in women with T1D.Support or Funding Information1RO1HL137087‐01A1.

The effects of sublingual nitroglycerin administration in coronary computed tomography angiography

PurposeThe purpose of our study was to compare coronary luminal diameters in patients undergoing coronary computed tomography angiography (CCTA) performed with different sublingual nitroglycerin (NTG) spray regimens. Materials and methodsWe retrospectively reviewed CCTA studies performed in two historical groups (Group 1, single dose nitroglycerin 2 min prior to CCTA, and Group 2, single dose 10 min prior), and a current protocol group (Group 3, single dose at 2 and 10 min prior). Thirty patients were evaluated per group. Two blinded readers measured coronary luminal diameters with comparison of diameter measurements. A third blinded reader assessed image quality of coronary artery segments. ResultsSignificant group-level differences in median luminal diameters were identified. Higher median diameters (95% CI) across all segments of 0.40 mm (0.20, 0.60) for Group 2 versus 1 and 0.50 mm (0.30, 0.70) for Group 3 versus 1 were recorded (both P < 0.001). No significant differences in median luminal diameters were found between Groups 2 and 3. No significant differences in image quality were found among the groups apart from higher image quality for the distal LAD for both Groups 2 and 3 compared to Group 1. ConclusionSublingual nitroglycerin spray administered as a single dose at 10 minute dilates coronary arteries more than when only administered at 2 min prior to CCTA. Combined two doses at 10 and 2 min prior to CCTA do not yield further dilatation of coronary arteries.

75-Year-Old Man With Chest Pain and Dyspnea

75-Year-Old Man With Chest Pain and Dyspnea

ENDOTHELIAL FUNCTION IS ASSOCIATED WITH TRIPLE SIGNAL IN FIBROMUSCULAR DYSPLASIA

Objective: Triple signal (TS) is a subclinical lesion were found in the common carotid artery of individuals with renal fibromuscular dysplasia (FMD), However, the mechanisms underlying this alteration in FMD patients are still unknown and might involve endothelial and/or smooth muscle cell dysfunction. We aimed at investigated whether FMD or triple signal, is associated with systemic vascular dysfunction. Design and method: The MEDYA study is a case-control, cross-sectional study, enrolling 47 individuals with renal FMD,47 matched individuals with essential hypertension (HT) and 50 healthy controls (C). All individuals underwent an assessment of endothelium-dependent dilation (EDD) of the brachial artery by the flow-mediated dilation technique and endothelium-independent dilation (EID) by sublingual administration of glyceryl trinitrate 150 mcg. EDD and EID were allometrically corrected for baseline diameter. Triple signal score was also computed in the common carotid arteries bilaterally, based on B-mode and RF images. A cut-off of 8 was used to discriminate TS carriers. Results: FMD, but not HT, showed impaired EID in comparison to controls (p = 0.003). FMD (but not TS) was among the determinants of EID_corr in a multiple linear regression model (beta = −0.03, p = 0.005). TS prevalence (FMD 48.9%, HT 31.9%, C 16.0%) was higher in FMD than in C (p < 0.001), but tended to be increased in HT as well (p = 0.07). In a multiple logistic regression model adjusted for confounders, FMD (OR 4.54, CL95% 1.56–13.23) but not HT, was independently associated with TS. In the FMD subgroup, TS was associated with older age, higher peak shear stress and lower EDD. EDD was still reduced in FMD patients with TS after correction for confounders (1.14 ± 3.59 vs 3.55 ± 4.18, p = 0035). In the HT subgroup, TS was independently associated only with older age and hypercholesterolemia. Conclusions: FMD is characterized by impaired smooth muscle cell function and increased TS prevalence, subclinical alterations independent from each other. TS might have a different pathophysiological significance in FMD and HT. Indeed, among FMD patients TS is associated with impaired endothelial function. Conversely, in HT TS seems to be associated only with classical CV risk factors.

Mechanisms of changes in functional mitral regurgitation by preload alterations

BackgroundThis study aimed to investigate the mechanisms of acute changes in functional mitral regurgitation (FMR) by preload alterations. MethodsTwenty-two consecutive patients with left ventricular ejection fraction <40% and at least mild FMR underwent transthoracic echocardiography. Passive leg lifting and sublingual administration of nitroglycerin were performed to alter preload. Mitral regurgitant volume (MRV) was assessed using the Doppler method. ResultsMRV changed in parallel with preload alterations. MRV correlated better with tenting height (TH) than with mitral annular area (MAA) at baseline, whereas the difference in the correlate coefficients was not statistically significant (R=0.69 and R=0.40, respectively; p=0.19). On the other hand, changes in MRV between each sequential stage correlated better with those in MAA than with those in TH (R=0.68 and R=0.44, respectively; p=0.043). Multiple regression analysis revealed that baseline TH was the independent determinant of baseline MRV (R=0.69, p=0.0004), whereas changes in MAA with preload alteration were the independent determinant of the changes in MRV (R=0.68, p<0.0001). Changes in left atrial (LA) volume were the independent determinant of the changes in MAA (R=0.30, p=0.0063). ConclusionsAcute changes in FMR with preload alterations resulted from the transverse changes in MAA rather than the longitudinal changes in tethering–tenting of mitral geometry, and mitral annular deformation was determined by changes in LA volume. Preload reduction might help heart failure treatment through the reduction in FMR resulting from the decrease in LA and mitral annular size.

Effects of Sublingual Glyceryl Trinitrate Administration on the Quality of Preprocedure CT Angiography Performed to Plan Prostate Artery Embolization

PurposeTo determine the effects of sublingual glyceryl trinitrate (GTN) on the quality of planning computed tomography (CT) angiography performed prior to prostate artery embolization (PAE). Materials and MethodsA retrospective cohort study was performed on patients who had previously undergone CT angiography before a procedure for PAE at our institution. Early CT angiography studies for PAE at our single center had initially been performed without GTN. These were compared to subsequent CT angiography studies that had been performed with GTN, after a previously implemented change in practice. Prostate arteries were examined by 2 blinded observers for peak enhancement (Hounsfield units [HU]) and lumen diameter. In addition, assessors’ interpretation of the prostate artery origin from CT angiography was compared with the true anatomy demonstrated at the time of procedure. ResultsA total of 16 patients, corresponding to 32 prostate arteries, were examined on CT angiography. Mean diameter of the prostate artery was found to be significantly greater in those receiving GTN (2.2 mm vs. 1.6 mm, P < .001). Peak prostate artery enhancement was also greater in the GTN group (218 HU vs 173 HU, P = 0.042). Observers correctly identified the prostate artery origin more frequently in the GTN group; however, this difference was not statistically significant (56% vs 25%, odds ratio = 3.9, P = .149). ConclusionsThe administration of sublingual GTN immediately prior to CT angiography is associated with a significant increase in prostate artery diameter and peak opacification. This was not associated with a statistically significant increase in the ability of observers to correctly identify the origin of the prostate artery.

‘Have you had Viagra within the past 24 hours?’

Rapid drug-induced vasodilation is essential in treating coronary medical emergencies. Through oral or sublingual administration of glyceryl trinitrate (GTN), changes occur in cyclic guanosine monophosphate (cGMP) levels, as well as a reduction in blood pressure. Patients who require GTN treatment may also take vasodilatory medication for other medical conditions, including erectile dysfunction (ED). Current guidance in the UK contraindicates GTN use alongside sildenafil (commercially known as Viagra) and other related drugs, owing to the likelihood of life-threatening hypotension. Therefore, it is essential that paramedics and emergency responders establish whether patients have taken sildenafil within the past 24 hours before administering GTN. This article identifies the action mechanisms of both drugs, and provides an evidence-based explanation for co-administration outcomes; a dramatic drop in blood pressure which can potentially be fatal. This article also reflects on the challenges faced by paramedics when considering administration of GTN to determine whether sildenafil has been taken within the past 24 hours.