Intra-arterial Nitroglycerin Research Articles

Intra-Arterial Nitroglycerin Injection in Upper Extremity Buerger's Disease for Faster Ulcer Recovery: A Case Report

AbstractThromboangiitis obliterans (TAO), also known as Buerger's disease, is a challenging nonatherosclerotic vascular disorder predominantly affecting smokers. Current management of TAO lacks standard guidelines, with smoking cessation as the only cornerstone. We present the case of a 28-year-old smoker with TAO manifesting as necrotic finger ulcers. Regardless of initial debridement, conventional therapy failed to improve his condition. Angiography confirmed the diagnosis of TAO and intra-arterial nitroglycerin injection was administered, leading to immediate vasodilation and improved perfusion. Combined with oral vasodilators and anticoagulants, the patient showed significant ulcer healing within 2 weeks. TAO's etiology remains unclear; however, it is linked to smoking and immune responses. Diagnosis relies on clinical criteria and angiographic findings. While smoking cessation remains crucial, various pharmacological interventions like vasodilators show considerable potential for enhancing therapeutic outcomes. Our case highlights the potential of intra-arterial nitroglycerin in TAO management. However, further studies are warranted due to limited sample size. Advancements in understanding TAO's biology and diagnostic techniques offer hope for improved management strategies in the future.

Incidence and Prognostic Factors of Radial Artery Occlusion in Transradial Coronary Catheterization.

Background/Objectives: Radial artery occlusion (RAO) is the most common complication of transradial coronary catheterization. In this study, we aimed to evaluate the incidence of RAO and identify the risk factors that predispose patients to it. Methods: We conducted an investigator-initiated, prospective, multicenter, open-label study involving 1357 patients who underwent cardiac catheterization via the transradial route for angiography and/or a percutaneous coronary intervention (PCI). Univariate and multivariate logistic regression analyses were performed to identify potential predictors of RAO occurrence. Additionally, a subgroup analysis only for patients undergoing PCIs was performed. Results: The incidence of RAO was 9.5% overall, 10.6% in the angiography-only group and 6.2% in the PCI group. Independent predictors of RAO were as follows: (i) the female gender (aOR = 1.72 (1.05-2.83)), (ii) access site cross-over (aOR = 4.33 (1.02-18.39)), (iii) increased total time of the sheath in the artery (aOR = 1.01 (1.00-1.02)), (iv) radial artery spasms (aOR = 2.47 (1.40-4.36)), (v) the presence of a hematoma (aOR = 2.28 (1.28-4.06)), (vi) post-catheterization dabigatran use (aOR = 5.15 (1.29-20.55)), (vii) manual hemostasis (aOR = 1.94 (1.01-3.72)) and (viii) numbness at radial artery ultrasound (aOR = 8.25 (1.70-40)). Contrariwise, two variables were independently associated with increased odds for radial artery patency (RAP): (i) PCI performance (aOR = 0.19 (0.06-0.63)), and (ii) a higher dosage of intravenous heparin per patient weight (aOR = 0.98 (0.96-0.99)), particularly, a dosage of >50 IU/kg (aOR = 0.56 (0.31-1.00)). In the PCI subgroup, independent predictors of RAO were as follows: (i) radial artery spasms (aOR = 4.48 (1.42-14.16)), (ii) the use of intra-arterial nitroglycerin as a vasodilator (aOR = 7.40 (1.67-32.79)) and (iii) the presence of symptoms at echo (aOR = 3.80 (1.46-9.87)), either pain (aOR = 2.93 (1.05-8.15)) or numbness (aOR = 4.66 (1.17-18.57)). On the other hand, the use of intra-arterial verapamil as a vasodilator (aOR = 0.17 (0.04-0.76)) was independently associated with a greater frequency of RAP. Conclusions: The incidence of RAO in an unselected, all-comers European population after transradial coronary catheterization for angiography and/or PCIs is similar to that reported in the international literature. Several RAO prognostic factors have been confirmed, and new ones are described. The female gender, radial artery trauma and manual hemostasis are the strongest predictors of RAO. Our results could help in the future identification of patients at higher risk of RAO, for whom less invasive diagnostic procedures maybe preferred, if possible.

Abstract 15619: Smoking Towards Prinzmetal

Background: Vasospastic (Prinzmetal) angina is a result of coronary vasospasm leading to myocardial ischemia. It is defined by nitrate responsive angina, transient ischemic ECG changes, and coronary vasospasm. In this report, we highlight coronary angiographic findings of Prinzmetal angina and underscore tobacco use as a known risk factor. Case Presentation: A 62-year-old male with hypertension and tobacco use presented with acute substernal chest pain. Laboratory testing revealed elevated troponin to 17.4 mg/mL and ECG with new T-wave inversions in the lateral leads. Coronary angiogram revealed non-obstructive coronary artery disease (CAD) (Figure 1). He was discharged on medical therapy and instructed to stop smoking. Four days later, he returned with one day of chest pain that improved with sublingual nitroglycerin. Repeat troponin was elevated to 46.9 ng/mL and ECG revealed ST depressions in V2-V6. Repeat coronary angiogram revealed 99% narrowing in the proximal left circumflex (LCx) (Figure 2). Intra-arterial nitroglycerin administration led to resolution of the LCx narrowing (Figure 3). Conclusion: Prinzmetal angina can be precipitated by tobacco use. Clinicians ought to maintain a high degree of suspicion for Prinzmetal angina as an etiology of cardiac ischemia in patients who have non-obstructive CAD and concomitant tobacco use.

The efficacy of nitroglycerin to prevent radial artery spasm and occlusion during and after transradial catheterization: A systematic review and meta-analysis of randomized controlled trials.

Radial artery spasm (RAS) is the most common cause of transradial access site crossover and is a common intra-procedural complication. RAS incidence can lead to radial artery occlusion (RAO) postprocedure, preventing the radial artery as a future access site. We evaluated the efficacy of nitroglycerin preventing RAS and RAO during transradial catheterization discussing the different routes of administration, including topical, subcutaneous, and intra-arterial. A systematic review and meta-analysis included all relevant articles until April 23, 2022. We searched six databases Google Scholar, Web of Science, SCOPUS, EMBASE, PubMed (MEDLINE), and CENTRAL. We registered our review protocol in PROSPERO with ID: CRD42022330356. We included 11 trials with 5814 patients. Compared to placebo, the pooled analysis favored subcutaneous nitroglycerin in preventing RAS (risk ratio [RR]: 0.57 with 95% confidence interval [CI] [0.43-0.77], p = .0003) and RAO (RR: 0.39 with 95% CI [0.16-0.98], p = .05). In contrast to the intra-arterial nitroglycerin that showed nonstatistically significant results in preventing RAS and RAO (RR: 0.8 with 95% CI [0.63-1.02], p = .07)- (RR: 0.78 with 95% CI [0.6-1.01], p = .06)), respectively. Also, topical nitroglycerin did not prevent RAS (RR: 0.73 with 95% CI [0.42-1.24], p = .24). Compared with placebo, subcutaneous nitroglycerin during transradial catheterization reduced the incidence of RAS and RAO. Meanwhile, Intra-arterial and topical nitroglycerin did not show statistically significant outcomes. Subcutaneous nitroglycerin may be a practical and cost-effective technique to facilitate transradial catheterization; however, more RCTs are needed to evaluate the subcutaneous versus intra-arterial nitroglycerin administration.

Abstract No. 466 Quantitative assessment of the effect of intra-arterial nitroglycerin on hepatocellular carcinoma perfusion using two-dimensional digital subtraction angiography

To evaluate the effects of intra-arterial nitroglycerin on hepatocellular carcinoma perfusion using 2-D perfusion angiography Two-dimensional (2D) perfusion angiograms obtained during planning arteriography for radioembolization of HCCs from September 2019 to February 2020 were retrospectively reviewed. Inclusion criteria included LIRADS-5 lesions and angiographically identifiable tumor and background parenchyma. Exclusion criteria included treated lesions and motion-degraded studies. Tumor and background liver parenchyma 2D perfusion data before and after the administration of intra-arterial nitroglycerin were processed and the area under the curve (AUC) of the time-density curve was calculated. Relative perfusion of HCC to background liver was compared at the 2 time points using a 2-tailed unpaired t-test. Twenty-four arteriograms were reviewed. Twelve were excluded from the analysis due to prior treatment (n = 5), motion degradation (n = 2), and no identifiable background liver (n = 5). Twelve HCCs in 12 patients were included in the final analysis. Mean patient age was 71.7 ± 9.7 years. Ten patients had cirrhosis. Mean maximum tumor dimension was 4.9 ± 2.0 cm. Seven tumors were in the right lobe and 5 in the left lobe. Contrast injection duration was 5 seconds. Mean intra-arterial nitroglycerin dose was 279 ± 69 micrograms. The arteriograms were then analyzed using 2D perfusion software. The ratio of the AUC of HCC to background liver was 2.18 ± 1.11 before intra-arterial nitroglycerin and 3.14 ±1.70 after nitroglycerin administration (P < 0.05). Intra-arterial nitroglycerin significantly increases perfusion to hepatocellular carcinoma when compared to background liver. Further research is needed to determine if nitroglycerin increases the permeability of HCC tumors and thereby increases intra-tumoral dose delivery.

Quantitative Assessment of the Hemodynamic Effects of Intra-Arterial Nitroglycerin on Hepatocellular Carcinoma using Two-Dimensional Perfusion Angiography

PurposeTo determine the hemodynamic effects of intra-arterial nitroglycerin on hepatocellular carcinoma (HCC) using 2-dimensional (2D) perfusion angiography. Materials and MethodsTwo-dimensional perfusion angiograms obtained prior to radioembolization from September 2019 to February 2020 were retrospectively reviewed. The inclusion criteria were the presence of Liver Imaging Reporting and Data System-5 tumors and angiographically distinguishable tumor and background liver. The exclusion criteria were previously treated tumors and motion-degraded studies. Thirteen patients with 2D perfusion angiograms obtained before and 2 minutes ± 1 after the administration of intra-arterial nitroglycerin were analyzed. The mean patient age was 72 years ± 9 and 11 of 13 (85%) had cirrhosis. The mean maximum tumor dimension was 4.6 cm ± 2.1. Eight tumors were in the right lobe and 5 were in the left lobe. The tumor and background liver 2D perfusion data were processed and the areas under the time-density curves were calculated. The relative perfusion of HCC to background liver was compared before and after nitroglycerin administration using a 2-tailed paired t-test. ResultsThe mean rate of contrast administration was 1.4 mL/s ± 0.7 and the mean volume administered was 7.1 mL ± 3.3. The mean nitroglycerin dose was 281 μg ± 69. Ten of 13 patients (77%) demonstrated a relative increase in tumor perfusion. The mean HCC to background liver area under the curve ratio was 1.94 ± 0.76 before and 2.40 ± 0.89 after nitroglycerin administration (P < .05). ConclusionsIntra-arterial nitroglycerin increases previously untreated HCC perfusion relative to background liver as measured by 2D perfusion angiography, but this effect is variable among patients and should be validated with 3-dimensional imaging techniques.

3:00 PM Abstract No. 182 Effect of intra-arterial nitroglycerin and verapamil administration during radial artery access on systemic blood pressure and its correlation with timing of moderate sedation administration

3:00 PM Abstract No. 182 Effect of intra-arterial nitroglycerin and verapamil administration during radial artery access on systemic blood pressure and its correlation with timing of moderate sedation administration

Abstract No. 414 Transradial embolization: a preliminary single-center experience

To report a single-center experience using transradial approach to perform embolization procedures. In this IRB-approved, HIPPA compliant study, the informed consent was waived. Consecutive patients underwent transradial embolization were retrospectively reviewed from January 2017 to September 2019. Procedure details, medications, and complications were reported. Thirty-two patients underwent transradial embolization. All (100%) underwent US-guided access, and received intraarterial nitroglycerin (200-1000 μg (416.6)), as well as heparin (3000-6000 IU (3458)). None required crossover to transfemoral access. There were 14 (44%) fibroid embolization, 7 (22%) radioembolization, 5 (16%) hepatic mapping, and 3 (9%) chemoembolization. The remaining three were embolization of angiomyolipoma, renal cell carcinoma, and splenic artery aneurysm. There was one (3%) minor hematoma, and one (3%) asymptomatic, nonocclusive radial artery thrombus. None required further management. Transradial embolization is safe and feasible in our preliminary experience.

Fatal Vasospasm of the Coronary Arteries in a Patient Undergoing Distal Bypass Surgery and Endovascular Therapy for Threatened Lower Limbs Due to Acute Exacerbation of Peripheral Arterial Disease.

A 79-year-old man with a heavy smoking history presented with threatened lower limbs due to acute exacerbation of peripheral artery disease (PAD). He underwent emergent distal bypass surgery for the right leg and external iliac stenting for the left leg. Fatal coronary artery spasm (CAS) with ST segment changes on electrocardiography was observed 28 h after the procedures, resulting in cardiac arrest. Coronary angiography showed widespread CAS with improvement after intra-arterial nitroglycerin infusion. We should keep in mind that CAS may occur more frequently than expected in PAD patients, especially those who have not stopped smoking prior to revascularization.

Intra-arterial nitroglycerin as directed acute treatment in experimental ischemic stroke

BackgroundNitroglycerin (also known as glyceryl trinitrate (GTN)), a vasodilator best known for treatment of ischemic heart disease, has also been investigated for its potential therapeutic benefit in ischemic stroke. The...

Post-procedural/pre-hemostasis intra-arterial nitroglycerin after transradial catheterization: A gender based analysis.

We analyzed the effect of nitroglycerin on radial artery occlusion (RAO) in women undergoing transradial catheterization. A total of 1706 patients undergoing transradial catheterization were randomized to receive either 500μg intra-arterial nitroglycerin or placebo at the end of the radial procedure. We explored the gender-based analysis between women (n=539) and men (n=1167). The primary outcome was the incidence of RAO as confirmed by absence of antegrade flow at one day after the transradial procedure evaluated by duplex ultrasound of the radial artery. The use of nitroglycerin, as compared with placebo, did not significantly reduce the risk of RAO in women patients [odds ratio, 0.69; 95% confidence interval (CI), 0.38 to 1.26; P=0.147]. The risk of RAO was higher in women age <60years as compared with women age ≥60years [5.6% vs. 3.5%; odds ratio, 2.16; 95% CI, 1.18 to 3.94; P=0.008]. In women age <60years (n=237), both counter puncture technique and a duration of hemostasis ≥4h were associated with a similar enhanced risk of developing RAO (odds ratio, 3.51; 95% CI, 1.59 to 7.72; P<0.001). The administration of nitroglycerin at the end of a transradial catheterization in women did not reduce the risk of RAO as determined by ultrasound one day after the radial procedure. Age <60years was associated with a higher risk of RAO compared with age ≥60years in women. Further strategies to reduce RAO in women are needed.

The use of nitroglycerin for treatment of progressive moyamoya disease: A prospective pilot study of safety and efficacy

No proven medical therapy exists for the treatment of moyamoya disease. Case reports have suggested that calcium channel blockers may be beneficial, potentially improving cerebral blood flow through a vasodilatory effect. The first objective of this pilot study was to prospectively evaluate whether intraarterial nitroglycerin, a potent vasodilator, could improve angiographic cerebral circulation in moyamoya patients. The second objective was to monitor the safety profile of transdermal nitroglycerin in our cohort of patients. Intraarterial nitroglycerin was infused in five patients with moyamoya disease at escalating doses. Angiography was performed before and after the nitroglycerin infusion. Pre- and post-infusion angiograms were compared for angiographic improvement. The contralateral side was used as an internal control in patients with unilateral moyamoya disease. The patients were then placed on a transdermal nitroglycerin patch and followed with serial neurological exams, blood pressure measurements, and either follow-up angiography or single photon emission computed tomography scans. All five patients had evidence of angiographic improvement after nitroglycerin infusion in the affected arteries, but no change was identified in the control arteries of patients with unilateral disease. No patient had adverse effects from either intraarterial or transdermal nitroglycerin. This small pilot study demonstrates angiographic improvement after intraarterial nitroglycerin in affected moyamoya arteries, but not in control arteries in the same patients, if present. There were no complications associated with transdermal nitroglycerin in these patients.

Use of intra-arterial nitroglycerin during uterine artery embolization for severe postpartum hemorrhage with uterine artery vasospasm

ObjectiveUterine artery embolization (UAE) is a standard method for treating postpartum hemorrhage (PPH), although uterine artery vasospasm during UAE may lead to failure of hemostasis. Here, we report our experience with a case of PPH in which the bleeding was successfully controlled by intra-arterial administration of nitroglycerin during the second UAE. Case reportA 30-year-old woman experienced PPH following a successful cesarean section, and a UAE was performed. However, 6 hours later, vaginal bleeding restarted; the reason for unsuccessful embolization during the first UAE was vasoconstriction due to hypovolemic shock. We performed a second UAE, but uterine bleeding continued. After intra-arterial administration of nitroglycerin, hemostasis was confirmed, and there was no reperfusion of the uterine artery. After these two UAE procedures, no recurrence of bleeding was observed. ConclusionThus, use of intra-arterial nitroglycerin was effective for controlling uterine artery vasospasm during UAE. However, larger studies are required to confirm these findings.

Safety of early endovascular catheterization and intervention through extracranial-intracranial bypass grafts

The goal of this study was to demonstrate feasibility and evaluate technical aspects of early endovascular access through extracranial-intracranial (EC-IC) bypass grafts. Patients undergoing endovascular interventions through the graft in the acute postoperative period following EC-IC bypass are presented. Results, complications, and technical nuances are reviewed. Fourteen endovascular procedures were performed in 5 patients after EC-IC bypass for ruptured aneurysms in 4 patients and posterior circulation ischemia in 1 patient. In 2 patients, a saphenous vein graft (SVG) was used to bypass the common carotid artery (CCA) to the middle cerebral artery (MCA). One patient underwent a superficial temporal artery (STA)-MCA bypass, and in 2 other patients the STA stump was connected to the intracranial circulation via an interposition SVG. The interval from surgery to endovascular intervention spanned 2-18 days; the indication was intracranial vasospasm in all patients. One case involved angioplasty of the proximal anastomosis on postoperative Day 14. All other interventions entailed proximal access through the bypass conduit for intraarterial infusion of vasodilators. Significant vasospasm of the STA itself was encountered in 2 patients during endovascular manipulation, and it was treated with intraarterial nitroglycerin. There were no cases of anastomotic disruption. Endovascular catheterization and intervention involving a recent EC-IC bypass is feasible. The main limitation in this series was catheter-induced vasospasm involving the STA. A vein graft may be the more appropriate option in patients with subarachnoid hemorrhage who may require subsequent endovascular intervention for vasospasm.

Successful management of contrast medium extravasation injury through stellate ganglion block and intra-arterial nitroglycerin

We describe the successful management of extravasation injury to the left hand by contrast medium with stellate ganglion block and intra-arterial nitroglycerin in a patient which befell during contrast-enhanced imaging. The incidence of contrast-medium extravasation injury is increasing because of the convenience and availability of contrast-enhanced imaging and ease of injection access. Extravasation of contrast medium may results in severe pain, erythema, cyanosis, and edema or even skin necrosis, which is largely related to the ionization, osmolarity, and volume of the contrast medium. The conservative treatment is often adequate in small amount extravasation, but if the extravasation is overwhelming further energetic management is mandatory. A 29-year-old man was brought to our emergency because of diffuse abdominal pain and he was arranged to receive intravenous contrast media enhanced abdominal computed tomography for diagnosis. Ruptured appendicitis with abscess formation was suspected; then the patient underwent emergent appendectomy and drainage of the abscess. However, severe swelling and cyanotic change that radiated from the intravenous catheter insertion site in every direction over the entire dorsum of the left hand were noted after the surgery. Contrast-medium extravasation injury was highly contemplated and a left stellate ganglion block was performed immediately for relief of symptoms. The consulting surgeon ruled out compartment syndrome, but advised emergent left upper limb arteriography, which revealed signs of vasospasm with high intravascular pressure of the left distal ulnar and radial arteries; thus nitroglycerin was injected into left distal ulnar and radial arteries for relief of vasospasm. The clinical symptoms were improved after the above managements and the patient was discharged 7 days later without any sequela.

Evaluation and Management of Peripheral Vascular Injury. Part 1. Western Trauma Association/Critical Decisions in Trauma

This is a position article from members of the Western Trauma Association (WTA). Because there are no prospective randomized trials on the evaluation and management of peripheral vascular trauma, the algorithm (Fig. 1) is based on the expert opinion of WTA members and published observational studies. It may not be applicable at all hospitals caring for injured patients. The algorithm contains letters that correspond to lettered text that is intentionally concise. This Part I algorithm emphasizes evaluation, diagnosis, and need for operation versus a therapeutic procedure performed in interventional radiology, while a Part II algorithm (2011) will focus on operative techniques. Peripheral vascular injures defined as axillobrachial and branches in the upper extremity and femoropopliteal and branches in the lower extremity account for 40% to 75% of all vascular injuries treated in civilian trauma centers.1–4 With the exception of the axillary artery, the long tracks of named arteries and veins in the extremities make them particularly susceptible to either penetrating or blunt trauma. This fact coupled with the smaller diameter of many of these vessels (as compared with those in the thorax or abdomen) and the ability of the patient and others to control external hemorrhage with compression contribute to a low incidence of death in the field.

Use of a vascular reconstruction device to salvage acute ischemic occlusions refractory to traditional endovascular recanalization methods

Acute revascularization has been associated with improved stroke outcomes. The Prolyse in Acute Cerebral Thromboembolism (PROACT II) trial achieved recanalization rates of 66%. The Multi Mechanical Embolus Removal in Cerebral Ischemia (Multi MERCI) trial achieved recanalization in 70% of patients. However, these interventional tools are not always successful. The Enterprise vascular reconstruction device was recently introduced for treatment of cerebral aneurysms previously untreatable with endovascular techniques. The authors evaluated a multicenter experience using this stent as a salvage revascularization tool for acute stroke treatment. Four medical centers participated in a retrospective review of endovascularly treated patients with acute stroke for cases treated with the Enterprise stent after routine interventions had been unsuccessful. Data collected included preprocedure information, intraprocedure findings, and outcomes. Twenty patients with acute stroke (mean age 61.6 +/- 22 years) were treated with the Enterprise stent. Ten patients received intravenous recombinant tissue plasminogen activator before catheter intervention, without improvement. Intraarterial interventions attempted unsuccessfully before Enterprise deployment included the Merci retriever (12 patients), angioplasty (7 patients), glycoprotein IIb-IIIa inhibitor administration (12 patients), intraarterial nitroglycerin (1 patient), Wingspan stent deployment (3 patients), and Xpert stent deployment (1 patient). The mean preintervention National Institutes of Health Stroke Scale (NIHSS) score was 17 +/- 6 (median 17). All patients presented with a Thrombolysis in Myocardial Infarction (TIMI) score of 0 or 1. Revascularization was achieved in all patients (75% with a TIMI score of 3, 25% with a TIMI score of 2). Improvement (> or = 4 points on the NIHSS) was documented in 75% of patients. Mean NIHSS improvement from intervention to discharge was 8 +/- 7 points (median 9 points). These preliminary data suggest a potential benefit to the use of the Enterprise stent when routine intervention methods fail.

Postoperative Internal Thoracic Artery Spasm After Coronary Artery Bypass Grafting

Spasm of the left internal thoracic artery in the perioperative period represents a life-threatening complication after coronary artery bypass grafting. We present a case in which graft spasm was treated with the administration of intra-arterial nitroglycerin and verapamil. Although vasospasm is more often seen in radial artery grafts, this case demonstrates that left internal thoracic artery grafts are also prone to spasm.

Sympathetic activation markedly reduces endothelium-dependent, flow-mediated vasodilation

ObjectivesWe sought to evaluate whether increased sympathetic outflow may interfere with flow-mediated dilation (FMD). BackgroundEndothelial function, assessed as FMD, is frequently used as an intermediate end point in intervention studies. Many disease states with increased sympathetic tone are also characterized by endothelial dysfunction. MethodsSixteen healthy volunteers underwent FMD studies with and without concomitant sympathetic stimulation. Intra-arterial nitroglycerin (NTG) infusion was used to assess endothelium-independent vasodilation. Pathophysiologically relevant sympathetic stimulation was achieved by baroreceptor unloading, using a lower body negative pressure box. In a subset of eight volunteers, this protocol was repeated during loco-regional alpha-adrenergic blockade by intra-arterial infusion of phentolamine (PE). Reactive hyperemic flow was assessed with strain-gauge phlethysmography. ResultsOverall, FMD responses (8.3 ± 3.4%) were significantly attenuated by concomitant sympathetic stimulation (3.6 ± 3.4%, p < 0.01). Loco-regional alpha-adrenergic blockade had no effect on baseline FMD responses (10.7 ± 4.7%), whereas the attenuation by sympathetic stimulation was abolished completely during PE co-infusion (11.5 ± 3.3%). During intra-arterial NTG infusions, arterial diameters relative to baseline were not significantly different between the four possible stages. ConclusionsSympathetic stimulation, at a clinically relevant range, significantly impairs the FMD response by an alpha-adrenergic mechanism.

Reversible Vasospasm in Association With the Use of Heparin and Dihydroergotamine

A case of reversible vasospasm is reported in a 54-year-old man with a closed bimalleolar ankle fracture. On admission the patient had normal distal pulses and laboratory studies. He was a heavy smoker who continued to smoke in the hospital. Deep venous thrombosis (DVT) prophylaxis included dihydroergotamine and heparin (DHE-H). In the early postoperative period, marked spasm of all three arteries developed on the operative side. Smoking privileges and DHE-H were discontinued. The vasospasm resolved after intraarterial nitroglycerin. This case suggests an infrequent but potentially limb-threatening complication of DHE-H.