Effects Of Sublingual Nitroglycerin Research Articles

Positive effect of sublingual nitroglycerin on performance of non-contrast enhanced magnetic resonance coronary angiography

Background Cardiac magnetic resonance imaging (CMR) is increasingly proposed for non-invasive detection of relevant coronary artery disease (CAD), currently using an integrated assessment of myocardial perfusion, viability and function. Magnetic resonance coronary artery imaging (MRCA) is still experimental. Currently, it is not proven if sublingual nitroglycerin (slNitro) should be given to enhance performance of MRCA. Methods 15 volunteers, 9 (60%) of them male, mean age 37.2 years (±11) without known CAD underwent MRCA, without and with slNitro. slNitro dosage was adjusted according to blood pressure (systolic blood pressure (BP) >180 mmHg =>1.6 mg glyceroltrinitrat, BP 140-179 mmHg =>1.2 mg, BP 100-139 mmHg =>0.8 mg, BP 90-100mmHg =>0.4mg). All volunteers were examined in supine position using a GE Signa HDxt 1.5 Tesla scanner, equipped with EchoSpeed gradients, and a dedicated 8-element phased array cardiac coil (GE Healthcare, Milwaukee, Wisconsin). For imaging of the coronary arteries a commercially available whole heart 3D navigator gated multislab steady state free precession sequence (3D HEART, based on 3D FatSat FIESTA) without the administration of contrast medium was employed. This sequence is designed for free breathing cardiac MR angiography, using a navigator echo pulse that detects motion of the diaphragm. We used an abdominal belt in all vol to reduce motion of the diaphragm. Post processing was perfomed with cvi 42 5.0 (Circle, Calgary, Canada). Vessel diameter was measured before and after slNitro. Image quality was graded visually before and after slNitro on a 4-point scale: 1 = non-assessable with severe image artifacts, poor vessel contrast; 2 = assessable with

Central Aortic Blood Pressure and Management of Hypertension

See related article, pp 1138–1145 Hypertension, a condition of elevated arterial blood pressure (BP) conventionally diagnosed by brachial cuff sphygmomanometry, is associated with increased risk of cardiovascular mortality and morbidity and end-organ damage. However, the marked differences in pulse pressure between the central aorta and peripheral limbs1 suggest that effects of peak values of arterial BP (eg, systolic BP) on centrally located organs (heart, brain, kidney) may not be accurately assessed using peripheral measurements. Our early studies2 showed substantial difference in the effects of sublingual nitroglycerin on peripheral and central (carotid) pulse pressures: in some cases, central systolic BP decreasing ≤20 mm Hg with little or no effect on brachial or radial systolic BP. There were, however, marked changes in the pulse wave form.2 The relationship between central aortic and radial pressure waves, quantified in terms of a mathematical transfer function, has been validated to be applicable across a large range of physiological pressures.3 The use of this noninvasive technique (and other variations, including other forms of analysis of the radial pulse or direct registration of the carotid pulse) has facilitated a large number of studies highlighting the differential effects of antihypertensive therapy on central aortic systolic BP for similar values of brachial cuff systolic BP.4 A seminal study by McEniery et al5 in >10 000 subjects demonstrated a substantial overlap of central and brachial BP between categories of hypertension. Approximately 32% of men and 10% of women who would be considered to have normal brachial systolic BP (and therefore, not treated) would be classified as having stage 1 hypertension based on equivalent central aortic systolic BP. Indeed, the implications of these findings suggested a possible sign of a paradigm shift in the management and treatment of hypertension as a significant cardiovascular risk.6 Subsequent studies …

SCCT guidelines for performance of coronary computed tomographic angiography: A report of the Society of Cardiovascular Computed Tomography Guidelines Committee

The increasing use of coronary computed tomographicangiographic (CTA) requires the establishment of standardsmeant to ensure reliable practice methods and qualityoutcomes. The Society of Cardiovascular ComputedTomography Guidelines Committee was formed to developrecommendations for acquiring, interpreting, and reportingof these studies in a standardized fashion. Indications andcontraindications for specific services or procedures are notincludedinthescopeofthese documents.Theserecommen-dations were produced as an educational tool for practi-tioners to improve the diagnostic care of patients, in theinterest of developing systematic standards of practice forcoronary CTA based on the best available data. Because ofthe highly variable nature of individual medical cases, anapproach to scan performance that differs from these guide-lines may represent an appropriate variation based on alegitimate assessment of an individual patient’s needs.

Effects of sublingual nitroglycerin on working conditions of the heart and arterial system: analysis using wave intensity

The effects of nitroglycerin (NTG) on the vascular system are well known. However, the effects of NTG on the heart are still obscure, because these effects are modified by those on the vascular system, and vice versa. Therefore, to evaluate the hemodynamic effects of NTG, it is important to understand the interaction between the heart and the vascular system. Wave intensity (WI) is a new hemodynamic index that provides information about working conditions of the heart interacting with the arterial system. The purpose of this study was to evaluate the interactive effects of NTG on the cardiovascular system in normal subjects using wave intensity. We simultaneously measured carotid arterial blood flow velocity and diameter change using a specially designed ultrasonic system, and calculated the WI and the stiffness parameter β. Measurements were made in 13 normal subjects (9 men and 4 women, aged 47 ± 10 years) in the supine position before and after sublingual NTG. The maximum value of WI (W 1) and the mid-systolic expansion wave (X) increased (W 1 from 9.1 ± 4.3 to 12.3 ± 5.5 × 10(3) mmHg m/s(3), P < 0.001; X from 105 ± 185 to 345 ± 370 mmHg m/s(3), P < 0.05). β increased (from 10.5 ± 3.8 to 14.1 ± 3.8, P < 0.001). The pressure contours changed considerably. NTG increased W 1 and the mid-systolic expansion wave, which suggests enhanced cardiac power during the initial ejection and mid-systolic unloading. These results are new findings about the effects of NTG that can be added to the widely known late systolic unloading and preload reduction. NTG also increased arterial stiffness, which reduces the Windkessel function. By using an echo-Doppler system, WI can be obtained noninvasively. WI has the clinical potential to provide quantitative and detailed information about working conditions of the heart interacting with the arterial system.

Effects of sublingual nitroglycerin on human uterine contractility during the active phase of labor

Nitroglycerin is administered intravenously in acute obstetric emergencies to relax the uterus. However, complications (eg, hypotension, acute uterine bleeding) are frequent, which prompted a search for alternative routes of administration. We hypothesized that the sublingual administration of nitroglycerin would reduce uterine tone and contractility with few complications. Intrauterine pressure was measured in 12 women who were actively laboring (>4 cm dilatation, regular contractions) with epidural analgesia and who were alert and responsive throughout the study. In a double-blind fashion, subjects were randomized to receive either placebo or sublingual nitroglycerin (3 doses, 800 μg each) 10 minutes apart. The obstetric anesthesiologist continuously monitored maternal blood pressure and fetal heart rate. Cervical dilatation was assessed at the beginning and the end of the protocol. The area under the intrauterine pressure curve (integral) was used to estimate uterine contractility. Intrauterine pressure was analyzed before the randomization code was broken. Nitroglycerin did not alter the intrauterine pressure integral after the first dose (placebo, 3147 mm Hg · s [95% CI, 2206-4088] vs nitroglycerin, 4146 mm Hg · s [95% CI, 2451-5841]; P =.22), second dose (placebo, 3123 mm Hg · s [95% CI, 2447-3799] vs nitroglycerin, 3611 mm Hg · s [95% CI, 2723-4499]; P =.28), or third dose (placebo, 3303 mm Hg · s [95% CI, 2616-3990] vs nitroglycerin, 3810 mm Hg · s [95% CI, 2306-5314]; P =.45). Cervical dilation, basal uterine tone, duration and frequency of uterine contractions, or fetal heart rhythm remained unaffected. Maternal mean arterial pressure decreased significantly after nitroglycerin was administered. All women were delivered vaginally without intervention. Three doses of sublingual nitroglycerin (800 μg per dose) reduce neither uterine activity nor tone, despite lowering maternal blood pressure. If a clinical option, sublingual nitroglycerin will require a higher dose, which would place mother and fetus at risk for complication. (Am J Obstet Gynecol 2002;187:235-8.)

467 Effects of sublingual nitroglycerin (NTG) on human uterine contractility during active phase of labor

467 Effects of sublingual nitroglycerin (NTG) on human uterine contractility during active phase of labor

Sublingual Nitroglycerin Delays Arterial Wave Reflections Despite Increased Aortic “Stiffness” in Patients with Hypertension: A Doppler Echocardiography Study

Venodilatation with consequent reduction in left ventricular filling and end-diastolic wall stress is an important mechanism for the beneficial effects of nitroglycerin in ischemic heart disease and in left ventricular failure. The effects of sublingual nitroglycerin on arterial pulsatile hemodynamics are less well defined. Doppler echocardiography and the calibrated subclavian artery pulse tracing were used to assess hemodynamics in subjects with sustained arterial hypertension (n = 25) before and 5 to 10 minutes after sublingual deposition of 0.5 mg glyceryl trinitrate. Aortic characteristic impedance was calculated by averaging the modulus of the input impedance (ratio of pressure to flow) at high frequencies and by calculating the ratio of pressure and flow increments during upstroke. The pressure wave was split into forward and backward components, and the reflection coefficient (the ratio of backward to forward pressures) was calculated. Parameters of the arterial bed were estimated by using 2- and 3-element Windkessel models. Nitroglycerin delayed the return of arterial wave reflections by 17% (P =.02) and increased aortic characteristic impedance by 20% (P =.01), but it did not influence total arterial compliance. Mean arterial pressure decreased 7% (P =.0001), but pulse pressure did not change. Stroke volume and the acceleration time of aortic root flow decreased by 13% (P =.0001) and 8% (P =.01), respectively. Cardiac output decreased 7% (P =.01), despite an increase in heart rate of 10% (P =.0001). Peripheral resistance tended to decrease (4%, P =.06). Thus, in subjects with sustained hypertension, sublingual nitroglycerin dilates peripheral, predominantly muscular arteries with a subsequent delayed return of reflected pressure waves. Reflex activation of the sympathetic nervous system with consequent increased acceleration of left ventricular ejection seems to counteract the effect of reduced mean arterial pressure (distending pressure) with respect to the “stiffness” of the aorta. (J Am Soc Echocardiogr 2000;13:1100-8.)

Acute Effects of Sublingual Nitroglycerin on Hepatic Blood Flow in Healthy Volunteers

Duplex sonography was used to assess the effects on hepatic blood flow after administering 0.6 mg nitroglycerin (NTG) sublingually to ten healthy volunteers. The study was a randomized, placebo-controlled, cross-over study in which subjects were studied on three separate occasions. Each visit involved administering either placebo or NTG followed by estimation of blood flow through a particular branch of the hepatic artery, portal vein, and hepatic vein every minute for 15 minutes after NTG and placebo administration. Two hours later, subjects were crossed over to the other treatment and the same vessel branch was again examined for 15 minutes. Total blood flow increased 7% in the portal vein and 27% in the hepatic vein during NTG treatment, but did not change significantly in the hepatic artery. Vascular resistance was increased in the hepatic artery and decreased in the portal and hepatic veins after NTG. Qualitatively, flow changed dramatically in the hepatic vein after NTG with the disappearance of normal retrograde flow. The results indicate that nitroglycerin effects hepatic blood flow through the portal and hepatic veins with a decrease in vascular resistance in the portal and hepatic veins and an increase in resistance in the hepatic artery.

Effects of sublingual nitroglycerin on the gas exchange response to exercise in stable angina pectoris

To quantitate changes in gas exchange variables that occur after administration of sublingual nitroglycerin in patients with stable angina pectoris, a randomized double-blind 2-period crossover study was performed with continuous expired gas exchange chalysis and progressive exercise using individualized ramp treadmill protocols. Significant reductions in minute ventilation and respiratory rate were observed at 5 minutes of exercise during nitroglycerin therapy. Gas exchange variables i.e., minute ventilation, carbon dioxide production and oxygen uptake were significantly increased at the onset of angina after nitroglycerin administration. When techniques for optimizing the assessment of cardiopulmonary function were used, significant improvements in gas exchange variables were demonstrated in stable angina pectoris after administration of sublingual nitroglycerin.

Potentially adverse effects of sublingual nitroglycerin during consumption of alcohol

Potentially adverse effects of sublingual nitroglycerin during consumption of alcohol

Effects of Nitroglycerin on Myocardial Excursions and Velocities in the Early Hours of Acute Myocardial Infarction

The effects of sublingual nitroglycerin on septal and left ventricular wall motion were determined by echocardiography in the early hours of acute myocardial infarction (MI) in 20 patients admitted via a mobile coronary care unit. Left ventricular and septal echoes were obtained in 11 patients with acute anterior MI and in 9 with acute inferior MI before and after administration of 500 micrograms sublingual nitroglycerin. In the group with acute anterior MI, nitroglycerin did not significantly affect the B-C excursion, posterior wall excursion, and mean posterior wall velocity. Nitroglycerin significantly increased (P less than 0.01), however, the systolic septal excursion, systolic septal velocity, diastolic septal excursion, and diastolic septal velocity. In the group with acute inferior MI, nitroglycerin significantly increased the B-C excursion (P less than 0.01); posterior wall excursion (P less than 0.01); mean posterior wall velocity (P less than 0.01); systolic septal excursion (P less than 0.01); diastolic septal excursion (P less than 0.05), and diastolic septal velocity (P = 0.01) but did not affect the systolic septal velocity. All measurements were obtained by use of a method of labeling and describing specific points of the wall motion that has been described recently.

New transdermal and transmucosal nitroglycerin delivery systems in patients with ischaemic heart disease

The efficacy of a transdermal (Nitroderm-TTS) and a transmucosal (Trinitrolong) nitroglycerin (NG) formulation has been compared with sublingual NG in 9 patients with ischaemic heart disease and stable angina pectoris. The duration and the degree of anti-ischaemic effect were assessed in terms of similar, individually adjusted work loads performed prior to and repeatedly after drug application in comparison with placebo. The anti-ischaemic effect of nitroderm appeared in 0.5-3 h after administration, reached a maximum in about 3.8 h and persisted for 7.9 h. The maximal nitroderm effect was significantly lower than that of sublingual NG or Trinitrolong. The effect of Trinitrolong was less variable and lasted for 4.6 h. It was evident in all patients 0.5 h after drug administration. Plasma NG levels were monitored in 9 patients after sublingual NG and trinitrolong and in 4 following Nitroderm. The relative bioavailability of Nitroderm and Trinitrolong according to the pharmacokinetic data was 29% and 256%, respectively, of sublingual NG tablets. A therapeutic NG level in blood (0.5 ng/ml) after Trinitrolong appeared much earlier (2 min) than after Nitroderm (1 h). A significant reduction in the effect of sublingual NG was observed during Nitroderm application. Thus, the transdermal NG formulation did not exhibit an antianginal effect lasting for 24 h; transmucosal NG had a relatively short, but more pronounced and stable antianginal effect.

Coronary vasomotion in angina at rest and effect of sublingual nitroglycerin on coronary blood flow

Coronary vasomotion in angina at rest and effect of sublingual nitroglycerin on coronary blood flow

Effect of sublingual nitroglycerin and long-acting nitrate preparations on esophageal motility

The effect of nitroglycerin and long-acting nitrates in normal humans is unknown. Therefore, we studied the effect of commonly used clinical doses of nitrate preparations on the esophagus in normal subjects. Three minutes after administration of sublingual nitroglycerin 0.6 mg, a significant reduction in lower esophageal sphincter pressure occurred (19.0 ± 2.6 to 12.7 ± 2.2 mmHg (P < 0.01). This effect was transient, and no effect was seen on amplitude, duration of esophageal contractions or peristaltic wave velocity measured 6 min after nitroglycerin administration. Neither nitroglycerin ointment, 1.5 in. applied to the forearm, nor 20 mg oral isosorbide dinitrate, resulted in a major change in any measured parameter of esophageal motility. In addition, pretreatment with long-acting nitrates did not alter lower esophageal sphincter response to intravenous pentagastrin.

Left ventricular function during spontaneous angina pectoris: Effect of sublingual nitroglycerin

Global and regional left ventricular function was assessed at rest, during spontaneous angina pectoris and after nitroglycerin therapy in 14 patients with ischemic heart disease. Cardiac output, left ventricular pressure and left ventricular volume were measured when patients experienced spontaneous angina pectoris during cardiac catheterization. In every patient control measurements had already been made; further measurements were made after nitroglycerin had relieved pain. Subsequent coronary angiography showed significant two or three vessel disease in all 14 patients. The S-T segment was depressed in every patient during pain (average 0.26 + 0.04 mV; mean + standard error of the mean [SEM]). During spontaneous angina, there was a significant increase in left ventricular end-diastolic pressure (17 ± 2 to 35 ± 2 mm Hg, p < 0.001), left ventricular end-diastolic volume (77 ± 6 to 88 ± 8 ml/m 2, p < 0.005) and left ventricular end-systolic volume (35 ± 4 to 52 ± 7 ml/m 2, p < 0.001). Concomitantly stroke index decreased from 42 ± 2 to 36 ± 3 ml/beat per m 2 (p < 0.01) and ejection fraction from 56 ± 4 to 44 ± 4 percent (p < 0.001). Assessment of regional left ventricular performance during spontaneous angina revealed either development of new areas or extension of already existing areas of abnormal wall motion in all patients. Nitroglycerin restored global and regional left ventricular function to a normal state. In six individual patients there was an excellent correlation between the S-T depression (V 5) and left ventricular end-diastolic pressure during spontaneous angina (correlation coefficient [r] = 0.88 to 0.96) and after nitroglycerin therapy (r = 0.76 to 0.84). For the group, there was a good correlation between change in S-T depression and changes in left ventricular end-diastolic pressure (r = 0.87) and left ventricular end-diastolic volume (r = 0.78). Thus, these data indicate marked systolic and diastolic dysfunction of the left ventricle during spontaneous angina pectoris, characterized by decreases in stroke index and ejection fraction and increases in left ventricular end-systolic and end-diastolic volumes and left ventricular filling pressure.

Effect of sublingual nitroglycerin on left ventricular function at rest and during spontaneous angina pectoris: Assessment with a radionuclide approach

Left ventricular function and size were assessed with equilibrium radionuclide angiography at rest and after administration of 0.6 mg of sublingual nitroglycerin in 12 patients with a history of previous myocardial infarction. Spontaneous angina developed in five patients and seven patients had no pain at the time of study. Sequential ejection fractions and end-diastolic and end-systolic volumes were developed by summing multiple R-R intervals to produce a composite time-activity curve. Volumes were calculated with a nongeometric method that utilizes counts at end-diastole and end-systole and is corrected for total heartbeats and plasma radioactivity. In the patients without acute ischemia, peak increase in ejection fraction occurred 6 to 8 minutes after ingestion of nitroglycerin and was associated with an equal decrease in end-diastolic and end-systolic volumes with no change in stroke volume. End-diastolic and end-systolic volumes, stroke volume, heart rate and systolic blood pressure all returned to baseline levels by 1 hour after nitroglycerin. In the patients with spontaneous angina, ejection fraction and stroke volume decreased before pain occurred. End-diastolic volume increased slightly (7 percent), but end-systolic volume increased markedly (38 percent), thus explaining the decrease in stroke volume. After nitroglycerin, end-diastolic volume and end-systolic volume and systolic blood pressure decreased and stroke volume and ejection fraction increased. Improvement in function occurred before relief of pain. It is concluded that the action of nitroglycerin on the left ventricle in patients without acute ischemia is to increase ejection fraction by an equal decrease in end-diastolic and end-systolic volumes with little change in stroke volume. A reduction in left ventricular function during acute ischemia precedes complaints of pain and is associated with an increase in end-systolic and end-diastolic volumes and a decrease in ejection fraction and stroke volume. In these patients, nitroglycerin appeared to contribute to relief of pain by decreasing end-diastolic volume and systolic blood pressure.

Effect of Sublingual Nitroglycerin in Emergency Treatment of Severe Pulmonary Edema

Abstract Twenty-two patients with clinical signs of pulmonary edema (orthopnea, cyanosis, profuse sweating and pulmonary rales∗) were studied and separated into two groups. In seven patients (Group A), hemodynamic studies were performed. Pulmonary arterial pressure and cardiac output were measured during the emergency condition of severe pulmonary edema. Within 10 minutes after sublingual administration of nitroglycerin, 1.6 mg, left ventricular filling pressure decreased from 33 ± 10 (mean ± 1 standard deviation) to 24 ± 8 mm Hg, and cardiac output increased significantly from 3.3 ± 0.8 to 3.7 ± 0.8 liters/min. In one patient with recent myocardial infarction, left ventricular filling pressure decreased from 50 to 27 mm Hg within 5 minutes. Orthopnea and pulmonary rales disappeared rapidly. In 15 patients (Group B), the clinical course was observed and documented. These patients received one to six doses of 0.8 to 2.4 mg of nitroglycerin sublingually at intervals of 5 to 10 minutes. Five minutes after administration, the first evidence of clinical improvement was observed in seven of these patients. After 15 to 20 minutes, pulmonary rales disappeared or decreased in 11 and dyspnea decreased in 14. The elevated arterial blood pressure and heart rate decreased significantly. Only one patient with terminal pulmonary edema remained refractory to therapy. Thus, sublingual nitroglycerin had beneficial effects in the emergency treatment of classic pulmonary edema. Elevated left ventricular filling pressure decreased and cardiac output increased within 5 minutes. These hemodynamic changes produced immediate clinical improvement.

Effect of sublingual nitroglycerin in emergency treatment of severe pulmonary edema

Effect of sublingual nitroglycerin in emergency treatment of severe pulmonary edema

Effect of sublingual nitroglycerin in emergency treatment of severe pulmonary edema

Twenty-two patients with clinical signs of pulmonary edema (orthopnea, cyanosis, profuse sweating and pulmonary rales∗) were studied and separated into two groups. In seven patients (Group A), hemodynamic studies were performed. Pulmonary arterial pressure and cardiac output were measured during the emergency condition of severe pulmonary edema. Within 10 minutes after sublingual administration of nitroglycerin, 1.6 mg, left ventricular filling pressure decreased from 33 ± 10 (mean ± 1 standard deviation) to 24 ± 8 mm Hg, and cardiac output increased significantly from 3.3 ± 0.8 to 3.7 ± 0.8 liters/min. In one patient with recent myocardial infarction, left ventricular filling pressure decreased from 50 to 27 mm Hg within 5 minutes. Orthopnea and pulmonary rales disappeared rapidly. In 15 patients (Group B), the clinical course was observed and documented. These patients received one to six doses of 0.8 to 2.4 mg of nitroglycerin sublingually at intervals of 5 to 10 minutes. Five minutes after administration, the first evidence of clinical improvement was observed in seven of these patients. After 15 to 20 minutes, pulmonary rales disappeared or decreased in 11 and dyspnea decreased in 14. The elevated arterial blood pressure and heart rate decreased significantly. Only one patient with terminal pulmonary edema remained refractory to therapy. Thus, sublingual nitroglycerin had beneficial effects in the emergency treatment of classic pulmonary edema. Elevated left ventricular filling pressure decreased and cardiac output increased within 5 minutes. These hemodynamic changes produced immediate clinical improvement.

Effects of sublingual nitroglycerin on resting pulmonary gas exchange and hemodynamics in man.

Simultaneous hemodynamic, ventilation and blood gas measurements were performed in 19 males during cardiac catheterization for evaluation of chest pain syndrome before and 3 to 5 min after 0.4 mg sublingual nitroglycerin. Pulmonary arterial pressures and total pulmonary vascular resistance fell (P less than 0.001 for both), and mean systemic arterial pressure decreased (P less than 0.05). However, peripheral vascular resistance, cardiac output, and mixed venous PO2 did not change. Total and tidal ventilation, PCO2, pH, and base excess remained unchanged. However, the arterial PO2 decreased from a mean of 80 +/- 3 (SEM) to 72 +/- 2 mm Hg (P less than 0.001) and mean venous admixture increased from 8.8 +/- 1% to 12.6 +/- 1.5% (P less than 0.001). The alveolar arterial PO2 difference increased (P less than 0.001) and the dead space tidal volume ratio rose (P less than 0.05). We conclude that the decrease in arterial PO2 following sublingual nitroglycerin is caused by redistribution of pulmonary blood flow with imbalance in ventilation-perfusion relationships or shunting.