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- [Effect of verapamil and nitroglycerin on transplanted lung function in canines]. [English Abstract, Journal Article]
- Zhong Nan Da Xue Xue Bao Yi Xue Ban 2014 Aug; 39(8):802-6.
To investigate the protective effect of combined administration of verapamil and nitroglycerin on the function of canine transplanted lungs.Twenty orthotopic left lung transplantations were performed in 40 canines, which were randomly divided into 4 groups. In group I (control), the donor lungs were perfused and preserved with LPD solution, while group II with LPD solution plus verapamil 0.1 g/L, group III with LPD solution plus nitroglycerin 0.1g/L, and group IV with LPD solution plus verapamil 0.1 g/L and nitroglycerin 0.1 g/L. Hemodynamics and graft gas exchange were assessed 0, 2 and 4 h after the operation. The lung grafts were harvested to measure the wet/dry weight ratio, malondialdehyde (MDA) contents and superoxide dismutase (SOD) activity.Compared with group I, II and III, the mean pulmonary artery pressure (MPAP), pulmonary vascular resistance index (PVRI), partial pressure of oxygen in arterial blood (PaO2), dynamic compliance (Cdyn) and alveolar-arterial oxygen tension volume [P(A- a)O2] in group IV were improved significantly (P<0.05). No significant difference in the partial pressure of carbondioxide (PaCO2) and peak inspiratory pressure (PIP) was observed in the 4 groups (P>0.05). In group IV, the wet/dry weight ratio and MDA contents were lower than those in the other 3 groups, and the SOD activity was significantly higher than that of the other 3 groups (P<0.05).Verapamil and nitroglycerin in LPD solution can protect the respiratory function of canine lung grafts by attenuating pulmonary edema and oxidative stress.
- Combined coronary lumen and vessel wall magnetic resonance imaging with i-T2prep: influence of nitroglycerin. [JOURNAL ARTICLE]
- Int J Cardiovasc Imaging 2014 Sep 9.
It has been shown that sublingual nitroglycerin (NTG) improves image quality of coronary lumen magnetic resonance angiography. Our aim was to investigate the influence of NTG on coronary lumen and vessel wall image quality using a combined, single sequence approach (i-T2prep), which is able to image both within the known time frame of action of NTG. Ten healthy volunteers underwent right coronary artery lumen and vessel wall imaging using the i-T2prep sequence before and after administration of NTG. Image quality was assessed qualitatively and quantitatively. Diameter, length and wall thickness were also measured using dedicated semi-automatic software. NTG induced coronary vasodilatation (lumen diameter increased from 2.16 ± 0.32 to 2.52 ± 0.59 mm; p = 0.036). As a result, visualized lumen length (9.8 ± 2.6 to 11.4 ± 3.3 cm; p = 0.025) and qualitative lumen image quality (median 3 (interquartile range 2-3.25) vs. median 3 (interquartile range 3-4); p = 0.046) both improved. Vessel wall imaging also demonstrated a significant improvement in vessel wall sharpness after NTG (24.8 vs. 27.3 %; p = 0.036). This study demonstrates the benefits of NTG for coronary lumen and vessel wall imaging using a combined sequence, i-T2prep. The methodology described here has great potential for future pathophysiological studies.
- The impact of decreases in air temperature and increases in ozone on markers of endothelial function in individuals having type-2 diabetes. [JOURNAL ARTICLE]
- Environ Res 2014 Sep 5.:331-338.
Several studies have reported an association between air pollution and endothelial dysfunction, especially in individuals having diabetes. However, very few studies have examined the impact of air temperature on endothelial function. The objective of this analysis was to investigate short-term effects of temperature and ozone on endothelial function in individuals having diabetes. Moreover, we investigated interactive effects between air temperature and air pollution on markers of endothelial function. Between November 2004 and December 2005 flow-mediated dilatation (FMD), nitroglycerin-mediated dilatation (NTGMD) and several blood markers representing endothelial function were measured using brachial artery ultrasound on four consecutive days in 22 individuals with type-2 diabetes mellitus in Chapel Hill, North Carolina (USA). Daily measurements of meteorological parameters, ozone and particulate matter with an aerodynamic diameter ≤2.5µm (PM2.5) were obtained from fixed monitoring sites. We used additive mixed-models adjusting for time trend, day of the week, relative humidity and barometric pressure to assess temperature and ozone associations with endothelial function. A 1°C decrease in the 24-h temperature average was associated with a decrease in mean FMD on the same day (-2.2% (95%-confidence interval:[-4.7;0.3%])) and with a delay of one and four days. A temperature decrement also led to an immediate (-1.7%[-3.3;-0.04]) decrease in NTGMD. Moreover, we observed an immediate (-14.6%[-26.3;-2.9%]) and a one day delayed (-13.5%[-27.0; 0.04%]) decrease in FMD in association with a 0.01ppm increase in the maximum 8-h moving average of ozone. Temperature effects on FMD strengthened when PM2.5 and ozone concentrations were high. The associations were similar during winter and summer. We detected an association between temperature decreases and ozone increases on endothelial dysfunction in individuals having diabetes. We conclude that endothelial dysfunction might be a possible mechanism explaining cardiovascular events in association with environmental stimuli.
- Topical Nitroglycerin Ointment for Treatment of Acute Hypertension in Hospitalized Inpatients. [JOURNAL ARTICLE]
- J Cardiovasc Pharmacol Ther 2014 Sep 4.
Hypertension in the hospital setting is common; however, guidelines provide limited guidance specific to the inpatient setting. Acute antihypertensive treatment options can be limited in this setting by monitoring requirements of intravenous medications and patients' inability to take oral medications. A possible treatment choice used to treat acute hypertension is nitroglycerin ointment. Nitroglycerin is not approved by the Food and Drug Administration for this condition, and limited evidence exists to support this indication.To evaluate the statistical and clinical effectiveness of nitroglycerin ointment as a treatment option for acute hypertension based on a 20 mm Hg or greater reduction in systolic blood pressure.A retrospective chart review at a large tertiary community teaching hospital was performed on all adult noncardiac inpatients with an episode of acute hypertension that resulted in the administration of nitroglycerin ointment.Seventy-two patients met inclusion criteria with a total of 112 applications of nitroglycerin ointment. Of the 112 applications, systolic blood pressure decreased 20 mm Hg or more in 42% of occurrences with a median decrease of 16 mm Hg.Study results suggest possible efficacy of nitroglycerin ointment for the treatment of acute hypertension in noncardiac hospitalized patients.
- Prognostic impact of chronic nitrate therapy in patients with vasospastic angina: multicentre registry study of the Japanese coronary spasm association. [JOURNAL ARTICLE]
- Eur Heart J 2014 Sep 4.
Although nitrates are widely used as a concomitant therapy with calcium channel blockers (CCBs) for vasospastic angina (VSA), their prognostic contribution remains unclear. The present study aimed to examine the prognostic impact of chronic nitrate therapy in patients with VSA.A total of 1429 VSA patients (median 66 years; male/female, 1090/339) were enrolled. The primary endpoint was defined as major adverse cardiac events (MACE). The propensity score matching and multivariable Cox proportional hazard model were used to adjust for selection bias for treatment and potential confounding factors. Among the study patients, 695 (49%) were treated with nitrates, including conventional nitrates [e.g. nitroglycerin (GTN), isosorbide mono- and dinitrate] in 551 and nicorandil in 306. Calcium channel blockers were used in >90% of patients. During the median follow-up period of 32 months, 85 patients (5.9%) reached the primary endpoint. Propensity score-matched analysis demonstrated that the cumulative incidence of MACE was comparable between the patients with and those without nitrates [11 vs. 8% at 5 years; hazard ratio (HR): 1.28; 95% confidence interval (CI): 0.72-2.28, P = 0.40]. Although nicorandil itself had a neutral prognostic effect on VSA (HR: 0.80; 95% CI: 0.28-2.27, P = 0.67), multivariable Cox model revealed the potential harm of concomitant use of conventional nitrates and nicorandil (HR: 2.14; 95% CI: 1.02-4.47; P = 0.044), particularly when GTN and nicorandil were simultaneously administered.Chronic nitrate therapy did not improve the long-term prognosis of VSA patients when combined with CCBs. Furthermore, the VSA patients with multiple nitrates would have increased risk for cardiac events.
- Noninvasive assessment of endothelial function and vascular parameters in patients with familial and non-familial hypercholesterolemia. [JOURNAL ARTICLE]
- Pol Arch Med Wewn 2014 Sep 3.
INTRODUCTION Endothelial dysfunction is one of the markers of atherosclerosis. OBJECTIVE The purpose of study was to evaluate endothelial function assessed by flow-mediated dilation (FMD) and arterial stiffness parameters in the brachial artery in groups of patients with genetically confirmed familial hypercholesterolemia (FH) and non-familial hypercholesterolemia (NFH). PATIENTS AND METHODS Endothelial function and arterial stiffness were evaluated in a group of 60 individuals (mean age 41.9±7.7 years) without documented cardiovascular events and clinical symptoms of cardiovascular diseases. The study was performed in 21 patients with elevated low-density lipoprotein (LDL) cholesterol plasma levels and genetically confirmed FH, in 19 patients with elevated LDL and without mutations causing FH and in 20 healthy controls. High-resolution ultrasound was applied to determine FMD and nitroglycerin-induced endothelium-independent dilatation (EID) in the brachial artery. In addition, echo-tracking methods and photoplethysmography technique were used for assessment of the arterial stiffness parameters. RESULTS FMD was significantly lower in patients with FH (11.0±9.9% vs 21.0±14.3%, P<0.01) and NFH (14.2±10.1% vs 21.0±14.3%, P<0.05) as compared with controls. Arterial stiffness parameters did not differ between all groups. CONCLUSIONS Reduced FMD may suggest endothelial dysfunction. Lack of significant differences in arterial stiffness parameters may indicate that process of vascular remodeling may not be advanced in younger patients with elevated LDL. Lack of significant differences in FMD and vascular stiffness parameters may indicate that mutation causing FH itself is not the main determinant of endothelial dysfunction and vascular remodeling in the younger patients with hypercholesterolemia.
- A novel approach to reduce radial artery occlusion after trans-radial catheterization: Post-procedural/pre-hemostasis intra-arterial nitroglycerin. [JOURNAL ARTICLE]
- Catheter Cardiovasc Interv 2014 Sep 1.
Objective oTo evaluate whether administration of nitroglycerin through the sheath at the end of a trans-radial procedure might preserve the patency of the radial artery. Background Despite the increasing acceptance of trans-radial approach, radial artery occlusion (RAO) continues to be a vexing problem of trans-radial access and limits utility of the radial artery as an access site in the future. Methods We conducted a multi-center, prospective, randomized, placebo-controlled, operator-blinded trial and enrolled 1706 patients who underwent trans-radial catheterization in three experienced radial centers. Patients were randomized to receive either 500 µg nitroglycerin (n=853) or placebo (n=853), given intra-arterially through the sheath at the end of the radial procedure. The primary outcome was the incidence of RAO as confirmed by absence of antegrade flow at one day after the trans-radial procedure evaluated by duplex ultrasound of the radial artery. Results The use of nitroglycerin, as compared with placebo, reduced the risk of the primary outcome (8.3% vs. 11.7%; odds ratio, 0.62; 95% confidence interval [CI], 0.44 to 0.87; P=0.006). From a multivariable analysis, duration of hemostasis was a predictor of RAO (odds ratio, 3.21; 95% CI, 1.73 to 5.96; P<0.001). There were no significant differences between the groups with respect to the sheath size (P=0.311), number of puncture attempts (P=0.941), duration of hemostasis (P=0.379) and procedural time (P=0.095). Conclusion The administration of nitroglycerin at the end of a trans-radial catheterization, reduced the incidence of RAO, examined one day after the radial procedure by ultrasound. Post procedural/pre-hemostasis pharmacologic regimens may represent a novel target for further investigation to reduce RAO. © 2014 Wiley Periodicals, Inc.
- Malignant multivessel coronary spasm complicated by myocardial infarction, transient complete heart block, ventricular fibrillation, cardiogenic shock and ischemic stroke. [Journal Article]
- Oman Med J 2014 Jul; 29(4):296-8.
Multivessel coronary spasm resulting to cardiogenic shock and malignant ventricular arrhythmias though rare has been reported in the literature. The disease seems to be more prevalent in Asians. There have been isolated reports of coronary spasm in patients with reactive airway disease. We report the first case of spontaneous multivessel spasm in a male patient with bronchial asthma of Arab ethnicity resulting in acute myocardial infarction complicated by cardiogenic shock, recurrent ventricular arrhythmias, and transient complete heart block. Literature review of similar cases suggests a strong association with bronchial asthma and a more malignant course in patients with reactive airway disease. The role of intracoronary nitroglycerin in proving the diagnosis even in patients in shock on maximal inotropic supports and intra-aortic balloon pump is highlighted and the importance of considering multivessel coronary spasm as a cause for acute coronary syndrome even in patients with conventional risk factors for atherosclerotic coronary artery disease is reinforced in the discussion of this case.
- Nitroglycerin tolerance in caveolin-1 deficient mice. [Journal Article]
- PLoS One 2014; 9(8):e104101.
Nitrate tolerance developed after persistent nitroglycerin (GTN) exposure limits its clinical utility. Previously, we have shown that the vasodilatory action of GTN is dependent on endothelial nitric oxide synthase (eNOS/NOS3) activity. Caveolin-1 (Cav-1) is known to interact with NOS3 on the cytoplasmic side of cholesterol-enriched plasma membrane microdomains (caveolae) and to inhibit NOS3 activity. Loss of Cav-1 expression results in NOS3 hyperactivation and uncoupling, converting NOS3 into a source of superoxide radicals, peroxynitrite, and oxidative stress. Therefore, we hypothesized that nitrate tolerance induced by persistent GTN treatment results from NOS3 dysfunction and vascular toxicity. Exposure to GTN for 48-72 h resulted in nitrosation and depletion (>50%) of Cav-1, NOS3 uncoupling as measured by an increase in peroxynitrite production (>100%), and endothelial toxicity in cultured cells. In the Cav-1 deficient mice, NOS3 dysfunction was accompanied by GTN tolerance (>50% dilation inhibition at low GTN concentrations). In conclusion, GTN tolerance results from Cav-1 modification and depletion by GTN that causes persistent NOS3 activation and uncoupling, preventing it from participating in GTN-medicated vasodilation.
- Advanced Clinical Interventions Performed by Emergency Medical Responder Firefighters prior to Ambulance Arrival. [JOURNAL ARTICLE]
- Prehosp Emerg Care 2014 Aug 25.
Abstract Introduction. Data on the clinical interventions performed by emergency medical responder firefighters (EMRFs) are limited outside the context of cardiac arrest. We sought to understand the broader medical role of firefighters by examining fire-ambulance arrival order and documenting specific interventions provided by firefighters with advanced EMR training. Methods. A secondary analysis was conducted using electronic patient care records from a single ambulance service and two municipal fire departments that partner to provide emergency response in two suburbs of Minneapolis, Minnesota. Firefighters in both municipalities are dispatched to all medical calls, regardless of severity, and receive training in the following advanced EMR skills: intravenous line placement, administration of oral nitroglycerin and aspirin, placement of supraglottic airways, administration of albuterol via nebulizer, and injections of intramuscular glucagon and epinephrine. Time stamps for unit arrival on scene were used to determine arrival order and to quantify fire lead time (i.e., the interval EMRFs were on scene before paramedics). Results. Fire and ambulance records were linked for 10,403 patient encounters that occurred over 2.5 years. EMRFs arrived first in 9,001 calls (88%) with an average fire lead time of 4.5 minutes. In the two communities, firefighters performed at least one of the six advanced training interventions in 688 patient encounters (7.6%) when they reached the patient first, the most frequent being intravenous line placement (n = 340; 3.8%) and administration of oral nitroglycerin or aspirin (n = 303; 3.4%). EMRFs arrived first to 96 cases of cardiac arrest and performed chest compressions in 78%, automated external defibrillator use in 44%, supraglottic airway placement in 32%, and intravenous line starts in 18%. A modest positive association was observed between increasing fire lead time and use of cardiac arrest interventions by EMRFs. Conclusions. EMRFs performed advanced EMR training interventions in a small fraction of the patients they were able to reach before paramedics, and further study of the clinical significance of these interventions in the hands of this responder group is needed. EMRF training in these communities should continue to emphasize the fervent and consistent application of BLS resuscitation interventions in victims of cardiac arrest.