Infundibular Pulmonary Stenosis Workup

  • Author: Poothirikovil Venugopalan, MBBS, MD, FRCP(Glasg), FRCPCH; Chief Editor: Stuart Berger, MD   more...
 
Updated: Jun 23, 2010
 

Laboratory Studies

  • Blood investigations are helpful in acute-stage management when an infant presents with cyanosis or heart failure.
Next

Imaging Studies

  • Chest radiography
    • Heart size is usually within reference ranges but, at times, may be slightly enlarged. Pulmonary vasculature is reduced in patients with cyanosis or in those with cardiac failure. (see image below)Chest radiograph of a 2-year-old boy with severe pChest radiograph of a 2-year-old boy with severe pulmonary stenosis (infundibular). Note the mild cardiomegaly, reduced pulmonary vascularity, and absence of poststenotic dilatation of pulmonary artery.
    • Cardiomegaly or dilatation of RV may be evident in severe cases and becomes more marked with TR or cardiac failure.
    • Pulmonary vascularity is usually normal, except in severe cases with right-to-left shunt across the atrial or ventricular septa.
    • In infants with severe or critical PS, cardiomegaly with a huge cardiac silhouette is the rule. Pulmonary vascular markings are also reduced.
    • Poststenotic dilation of the main PA seen in PVS is not a feature.
  • Echo-Doppler studies
    • Noninvasive echo-Doppler studies play a major role in demonstrating the presence, magnitude, and site of the obstruction. They also help find associated cardiac anomalies.
    • Echo-Doppler studies can be very useful in evaluating RV size and function and pulmonary valve anatomy.[2]
      • The projections used to obtain these views are the standard and high-parasternal short axis and the subcostal sagittal views. The ventricular cavity and tricuspid valve can also be easily assessed.
      • A subcostal oblique view is especially helpful to visualize hypertrophy of the RV outflow tract (RVOT).
      • Contract echocardiography may detect the presence of right-to-left shunting at the atrial or ventricular level.
    • In mild obstruction, cardiac chambers are normal. Their only abnormality may be the hypertrophied infundibulum with a turbulent flow across it. High flow velocity is confirmed with pulsed wave and continuous wave Doppler studies.
    • In moderate-to-severe obstruction, the RV is dilated and hypertrophied, and the right atrium may also be dilated, with the atrial septum bulging toward the left atrium. In cases of dynamic obstruction that characterize the infundibular hypertrophy, a late-peaking Doppler signal is recorded across the RVOT.
    • Echo-Doppler can be used to quantify the pressure drop across the stenosed infundibulum. The peak velocity measured across the RVOT is used to calculate the pressure gradient, using the modified Bernoulli equation, p = 4V2 (p is the peak instantaneous pressure gradient in mm Hg across the obstructed infundibulum, whereas V is peak flow velocity in m/sec distal to the obstructive orifice).
      • The technique is as accurate as cardiac catheter data in prediction of pressure gradients across the RVOT.
      • Doppler studies measure the actual instantaneous pressure gradient, which is about 10% more than the peak-to-peak gradient measured using cardiac catheterization.[3]
    • Do not allow for possible energy losses caused by the elongated obstruction or the presence of narrowing at more than a single level in patients with infundibular obstruction.
Previous
Next

Other Tests

  • Electrocardiography
    • With mild stenosis, ECG findings are usually within reference ranges. Occasionally, a rightward shift of the main QRS frontal axis may be present.
    • Moderate-to-severe cases show right-axis deviation and RV hypertrophy, proportional to severity.
    • Except in the newborn period, the height of the R wave in right chest leads provides an assessment of the RV pressure.
    • Upright T waves and QRS in right chest leads and incomplete right bundle-branch block may be present but do not necessarily indicate severity of obstruction. Tall p waves suggest RA enlargement (p pulmonale).
    • In infants with maximal obstruction bordering on pulmonary atresia, the evidence for RV hypertrophy may be less convincing, and LV dominance is rarely observed.
    • The abrupt transition in the pattern of the QRS complex in the mid-precordial leads, a pattern often found with tetralogy of Fallot, is not seen.
Previous
Next

Procedures

  • Cardiac catheterization
    • Cardiac catheterization is not essential for diagnosis or to assess severity.
      • The procedure is sometimes undertaken before surgical intervention and in infants for whom other associated lesions must be evaluated.
      • Occasional reports of balloon dilatation of RVOT are available, but results are not encouraging. The procedure is not recommended in patients with infundibular pulmonary stenosis (IPS).
    • Resting peak systolic pressures in the RV of more than 30-35 mm Hg, as well as pressure gradients across the stenotic infundibulum of more than 10-15 mm Hg, are considered abnormal.
    • In mild IPS, PA pressure is normal. In severe IPS, a marked reduction of mean PA pressure and obliteration of the usual pulsatile configuration of the pressure tracing are present.
    • Presence of IPS may be suggested by the withdrawal pressure tracing. In some cases of combined valvar and discrete infundibular stenosis, 2 pressure gradients may be encountered; the first at the valve and the second at the infundibular level.
      • Pressure gradients may be encountered at more than one level, making it difficult to assess the severity of all but the most proximal stenoses.
      • In severe valvar stenosis with diffuse infundibular narrowing, a characteristic infundibular pressure pulse pattern is frequently observed.
      • End-diastolic pressure in the RV may be normal or elevated with severe obstruction or RV failure.
    • The degree of RV hypertension is the main indicator of severity. Mild stenosis is present when the proximal systolic pressure is less than 60 mm Hg. With moderate stenosis, this pressure may be as high as 100 mm Hg; above this level, the stenosis is considered severe. Other hemodynamic findings in severe stenosis include the following:
      • RV end-diastolic and RA a wave pressures are elevated.
      • A high v wave in the right atrium indicates TR.
      • A right-to-left shunt at the atrial or ventricular level should be sought in all patients with cyanosis.
      • A left heart catheterization is indicated in all patients with subvalvular stenosis that may be a component of a hypertrophic cardiomyopathy.
  • Angiocardiography
    • Right ventriculography in right anterior oblique projection demonstrates obstruction at the infundibular level.
    • The best all-purpose projection for evaluation of the pulmonary outflow tract and PAs is an anteroposterior projection with a 45° head-up tilt.
    • When taken along with the lateral projection, a good view is obtained of all the important structures.
    • This projection makes distinguishing the hourglass variant from bottle-shaped sinuses possible.
    • A 4-chamber axial oblique projection may occasionally be preferred to visualize the PA bifurcation.
    • Left-sided angiocardiography is indicated when a VSD or a left-sided obstruction is present.
      • The long-axis oblique projection is the most useful and is the best tool to accurately diagnose this lesion.
      • Always perform biplane angiocardiography when evidence of a significant intraventricular pressure gradient has been found during cardiac catheterization.
      • Anterior projection reveals filling defects within the RV between the outflow and inflow areas.
Previous
Next

Histologic Findings

  • Isolated infundibular stenosis of the PA is a mass of muscle-fibrous tissue that creates an obstacle to blood flow in the RV.
  • Morphogenetic regularities of compensatory and adaptive reactions in isolated infundibular stenosis are similar to those in hypertrophic cardiomyopathy.
  • Some have suggested that abnormalities in the structure of the hypertrophied myocardium in isolated stenosis of the RV infundibulum are caused by a fundamental error in the cardiac morphogenesis and do not reflect an increased degree of cardiac hypertrophy.
Previous
Proceed to Treatment & Management
 
 
Contributor Information and Disclosures
Author

Poothirikovil Venugopalan, MBBS, MD, FRCP(Glasg), FRCPCH,  Consulting Staff, Department of Child Health, University Hospital of North Tees and Hartlepool, UK

Poothirikovil Venugopalan, MBBS, MD, FRCP(Glasg), FRCPCH, is a member of the following medical societies: British Cardiac Society, Paediatrician with Cardiology Expertise Special Interest Group, Royal College of Paediatrics and Child Health, and Royal College of Physicians and Surgeons of Glasgow

Disclosure: Nothing to disclose.

Specialty Editor Board

Jeffrey Allen Towbin, MD, MSc, FAAP, FACC, FAHA  Professor, Departments of Pediatrics (Cardiology), Cardiovascular Sciences, and Molecular and Human Genetics, Baylor College of Medicine; Chief of Pediatric Cardiology, Foundation Chair in Pediatric Cardiac Research, Texas Children's Hospital

Jeffrey Allen Towbin, MD, MSc, FAAP, FACC, FAHA is a member of the following medical societies: American Academy of Pediatrics, American Association for the Advancement of Science, American College of Cardiology, American College of Sports Medicine, American Heart Association, American Medical Association, American Society of Human Genetics, Cardiac Electrophysiology Society, New York Academy of Sciences, Society for Pediatric Research, Texas Medical Association, and Texas Pediatric Society

Disclosure: Nothing to disclose.

Mary L Windle, PharmD  Adjunct Associate Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Nothing to disclose.

Hugh D Allen, MD  Professor, Department of Pediatrics, Division of Pediatric Cardiology and Department of Internal Medicine, Ohio State University College of Medicine

Hugh D Allen, MD is a member of the following medical societies: American Academy of Pediatrics, American College of Cardiology, American Heart Association, American Pediatric Society, American Society of Echocardiography, Society for Pediatric Research, Society of Pediatric Echocardiography, and Western Society for Pediatric Research

Disclosure: Nothing to disclose.

Gilbert Z Herzberg, MD  Assistant Professor, Department of Pediatrics, Section of Pediatric Cardiology, New York Medical College; Consulting Staff, Department of Pediatrics, Sound Shore Medical Center

Gilbert Z Herzberg, MD is a member of the following medical societies: American Academy of Pediatrics

Disclosure: Nothing to disclose.

Chief Editor

Stuart Berger, MD  Professor of Pediatrics, Division of Cardiology, Medical College of Wisconsin; Chief of Pediatric Cardiology, Medical Director of Pediatric Heart Transplant Program, Medical Director of The Heart Center, Children's Hospital of Wisconsin

Stuart Berger, MD is a member of the following medical societies: American Academy of Pediatrics, American College of Cardiology, American College of Chest Physicians, American Heart Association, and Society for Cardiac Angiography and Interventions

Disclosure: Nothing to disclose.

References

  1. Marton T, Hajdu J, Papp C, et al. Pulmonary stenosis and reactive right ventricular hypertrophy in the recipient fetus as a consequence of twin-to-twin transfusion. Prenat Diagn. Jun 2001;21(6):452-6. [Medline].

  2. Joy MV, Subramonium R, Venkitachalam CG, Balakrishnan KG. Two dimensional and Doppler echocardiographic evaluation of double chambered right ventricle. Indian Heart J. May-Jun 1992;44(3):159-63. [Medline].

  3. Nakajima T, Arakaki Y, Kamiya T, et al. Doppler echocardiographic estimates of pressure gradients in various types of stenoses: usefulness and limitations [in Japanese]. J Cardiol. Sep 1989;19(3):851-8. [Medline].

  4. Schrope DP. Primary pulmonic infundibular stenosis in 12 cats: natural history and the effects of balloon valvuloplasty. J Vet Cardiol. Jun 2008;10(1):33-43. [Medline].

  5. Sahin T, Bildirici U, Kandemir C, Celikyurt U, Ural D, Komsuoglu B. Infective endocarditis in the setting of infundibular-valvular pulmonary stenosis with incomplete cor triatriatum dextrum and patent foramen ovale. Int J Cardiol. Jul 21 2008;127(3):e129-31. [Medline].

  6. Matsuo S, Sato Y, Higashida R, Shiraishi S, Asai T, Nakae I, et al. A giant main pulmonary artery aneurysm associated with infundibular pulmonary stenosis. Cardiovasc Revasc Med. Jul-Sep 2008;9(3):188-9. [Medline].

  7. Alekian BG, Petrosian IuS, Podzolkov VP, et al. Catheter therapy of congenital cardiovascular defects [in Russian]. Vestn Rentgenol Radiol. Mar-Apr 1995;(2):16-26. [Medline].

  8. Alipour MS, Shadkhoo G, Tarbiat C. Congenital pulmonary valvular and infundibular stenosis complicating Ebstein's anomaly of the tricuspid valve. A case report. Jpn Heart J. Nov 1980;21(6):883-90. [Medline].

  9. Bhandari S, Dev V, Shrivastava S, Bhatia ML. Echocardiographic demonstration of pulmonary valve vegetation in a child with infundibular pulmonic stenosis and closed VSD. Indian Heart J. Sep-Oct 1986;38(5):425-8. [Medline].

  10. Brown JW, Ruzmetov M, Rodefeld MD, et al. Valved bovine jugular vein conduits for right ventricular outflow tract reconstruction in children: an attractive alternative to pulmonary homograft. Ann Thorac Surg. Sep 2006;82(3):909-16. [Medline].

  11. Carlson KM, Neish SR, Justino H, et al. Use of cutting balloon for palliative treatment in tetralogy of Fallot. Catheter Cardiovasc Interv. Apr 2005;64(4):507-12. [Medline].

  12. Caspi J, Coles JG, Benson LN, et al. Management of neonatal critical pulmonic stenosis in the balloon valvotomy era. Ann Thorac Surg. Feb 1990;49(2):273-8. [Medline].

  13. Conte S, Jashari R, Eyskens B, et al. Homograft valve insertion for pulmonary regurgitation late after valveless repair of right ventricular outflow tract obstruction. Eur J Cardiothorac Surg. Feb 1999;15(2):143-9. [Medline].

  14. Daskalopoulos DA, Pieroni DR, Gingell RL, et al. Closed transventricular pulmonary valvotomy in infants. J Thorac Cardiovasc Surg. Aug 1982;84(2):187-91. [Medline].

  15. Delhaas T, Prinzen FW. Sequelae of DDD pacing in patients with pulmonary infundibular stenosis [letter]. Am J Cardiol. Nov 1 1999;84(9):1142. [Medline].

  16. Fawzy ME, Awad M, Galal O, et al. Long-term results of pulmonary balloon valvulotomy in adult patients. J Heart Valve Dis. Nov 2001;10(6):812-8. [Medline].

  17. Freed MD, Heymann MA, Lewis AB, et al. Prostaglandin E1 infants with ductus arteriosus-dependent congenital heart disease. Circulation. Nov 1981;64(5):899-905. [Medline].

  18. Galal O, Kalloghlian A, Pittappilly BM, Dzimiri N. Phentolamine improves clinical outcome after balloon valvoplasty in neonates with severe pulmonary stenosis. Cardiol Young. Mar 1999;9(2):127-8. [Medline].

  19. Gibbs JL, Uzun O, Blackburn ME, et al. Right ventricular outflow stent implantation: an alternative to palliative surgical relief of infundibular pulmonary stenosis. Heart. Feb 1997;77(2):176-9. [Medline]. [Full Text].

  20. Glen S, Burns J, Bloomfield P. Prevalence and development of additional cardiac abnormalities in 1448 patients with congenital ventricular septal defects. Heart. Nov 2004;90(11):1321-5. [Medline]. [Full Text].

  21. Goebel N, Gander MP. [Echinococcus of the heart. Infundibular pulmonary stenosis due to a large solitary cyst of the ventricular septum (author's transl)]. Rofo. Jan 1977;126(1):11-4. [Medline].

  22. Gupta D, Saxena A, Kothari SS, Juneja R. Factors influencing late course of residual valvular and infundibular gradients following pulmonary valve balloon dilatation. Int J Cardiol. Jul 2001;79(2-3):143-9. [Medline].

  23. Harinck E, Becker AE, Groot AC, et al. The left ventricle in congenital isolated pulmonary valve stenosis. A morphological study. Br Heart J. Apr 1977;39(4):429-35. [Medline].

  24. Houston AB, Simpson IA, Sheldon CD, et al. Doppler ultrasound in the estimation of the severity of pulmonary infundibular stenosis in infants and children. Br Heart J. Apr 1986;55(4):381-4. [Medline].

  25. Ilbawi M, Cua C, DeLeon S, et al. Repair of complete atrioventricular septal defect with tetralogy of Fallot. Ann Thorac Surg. Sep 1990;50(3):407-12. [Medline].

  26. Imafuku T, Ogihara T, Kudo H, et al. Kartagener's syndrome associated with infundibular pulmonic stenosis, chronic renal failure and azoospermia: a report of a case. Jpn J Med. May 1986;25(2):195-8. [Medline].

  27. Isomura T, Hisatomi K, Hirano A, et al. Ruptured aneurysms of the sinus of Valsalva. J Cardiovasc Surg (Torino). Apr 1994;35(2):135-8. [Medline].

  28. Jackson F. The heart at high altitude. Br Heart J. May 1968;30(3):291-4. [Medline].

  29. Keith A. Malformation of the heart. Lancet. 1909;2:359.

  30. Khikmatov AA. Changes in intracardiac hemodynamics during of the natural course of isolated stenoses of pulmonary artery and the right ventricular outflow tract [in Russian]. Ter Arkh. 2001;73(9):73-6. [Medline].

  31. Kirklin JW, Blackstone EH, Jonas RA, et al. Morphologic and surgical determinants of outcome events after repair of tetralogy of Fallot and pulmonary stenosis. A two-institution study. J Thorac Cardiovasc Surg. Apr 1992;103(4):706-23. [Medline].

  32. Krabill KA, Wang Y, Einzig S, Moller JH. Rest and exercise hemodynamics in pulmonary stenosis: comparison of children and adults. Am J Cardiol. Aug 1 1985;56(4):360-5. [Medline].

  33. Kraiem S, Hmem M, Longo S, et al. Double chamber right ventricle. About 3 cases [in French]. Tunis Med. May 2006;84(5):316-20. [Medline].

  34. Kronik G, Fitscha P, Slany J, Mösslacher H. [Echocardiographic diagnosis of subpulmonic obstruction in hypertrophic cardiomyopathy (a case report) (author's transl)]. Z Kardiol. Jun 1979;68(6):415-8. [Medline].

  35. Latsis AT, Iagmanis MIa, Kreile IE, Trushelis E. Correction of a partially patent atrioventricular canal with a common atrium, infundibular and valvular stenosis of the pulmonary artery and a single (left) superior vena cava [in Russian]. Grud Serdechnososudistaia Khir. Feb 1991;(2):53-5. [Medline].

  36. Levin DL, Heymann MA, Rudolph AM. Morphological development of the pulmonary vascular bed in experimental pulmonic stenosis. Circulation. Jan 1979;59(1):179-82. [Medline].

  37. Lucas RV, Varco RL, Lillehei CW, et al. Anomalous muscle bundle of the right ventricle. Hemodynamic consequences and surgical considerations. Circulation. Mar 1962;25:443-55. [Medline].

  38. Mantri RR, Bajaj R, Shrivastava S. Multiple anomalies of caval veins in a patient with pulmonic stenosis. Int J Cardiol. Sep 1994;46(2):172-4. [Medline].

  39. McQuinn TC, Miga DE, Mjaatvedt CH, et al. Cardiopulmonary malformations in the inv/inv mouse. Anat Rec. May 1 2001;263(1):62-71. [Medline].

  40. Mehan VK, Meier B. Interventional cardiology: state of the art. Presse Med. Feb 19 1994;23(7):339-44. [Medline].

  41. Mori F, Tsuboi H, Ohmi M, et al. Noonans syndrome associated with atrial septal defect, ventricular septal defect and infundibular pulmonary stenosis--a case report [in Japanese]. Nippon Kyobu Geka Gakkai Zasshi. Jun 1983;31(6):936-9. [Medline].

  42. Moura C, Carrico A, Baptista MJ, et al. Balloon pulmonary valvotomy performed in the first year of life. Rev Port Cardiol. Jan 2004;23(1):55-63. [Medline].

  43. Patel R, Astley R. Right ventricular obstruction due to anomalous muscle bands. Br Heart J. Sep 1973;35(9):890-3. [Medline].

  44. Pogrebniak VV, Tereshchenko VP, Zin'kovskii MF, Zurnadzhi IuN, Chumak OS. [Morphogenetic patterns of isolated infundibular stenosis of the pulmonary artery]. Vrach Delo. Sep 1989;44-6. [Medline].

  45. Pongiglione G, Freedom RM, Cook D, Rowe RD. Mechanism of acquired right ventricular outflow tract obstruction in patients with ventricular septal defect: an angiocardiographic study. Am J Cardiol. Oct 1982;50(4):776-80. [Medline].

  46. Qureshi SA, Parsons JM, Tynan M. Percutaneous transcatheter myectomy of subvalvar pulmonary stenosis in tetralogy of Fallot: a new palliative technique with an atherectomy catheter. Br Heart J. Aug 1990;64(2):163-5. [Medline].

  47. Rao PS. Transcatheter management of cyanotic congenital heart defects: a review. Clin Cardiol. Jul 1992;15(7):483-96. [Medline].

  48. Rao PS, Wilson AD, Thapar MK, Brais M. Balloon pulmonary valvuloplasty in the management of cyanotic congenital heart defects. Cathet Cardiovasc Diagn. Jan 1992;25(1):16-24. [Medline].

  49. Raut NB, Norton JB, Patil AA. Bourneville's tuberous sclerosis associated with double outlet right ventricle and infundibular pulmonary stenosis. J Assoc Physicians India. Jul 1992;40(7):469-70. [Medline].

  50. Rowland TW, Rosenthal A, Castaneda AR. Double-chamber right ventricle: experience with 17 cases. Am Heart J. Apr 1975;89(4):455-62. [Medline].

  51. Rummeny E, Hausen W, Lorbacher P, Willems D. Acquired infundibular pulmonary stenosis. Possible late complication following radiotherapy of Hodgkin disease [in German]. Z Kardiol. Oct 1984;73(10):641-5. [Medline].

  52. Shenoy AR, Padmakumar P, Subashchandra V. Right ventricular outflow tract stenting in tetrology of fallot with restrictive ventricular septal defect. J Invasive Cardiol. Jan 2006;18(1):E59-60. [Medline].

  53. Shimada Y, Yaku H, Kawata M, et al. Surgical repair of primary infundibular stenosis in a 72-year-old man. ANZ J Surg. Aug 2001;71(8):498-9. [Medline].

  54. Shishkov BV, Nikoliuk AP, Garibian VA, et al. Surgical tactics in critical stenosis and atresia of the pulmonary artery with intact interventricular septum in infants under 1 year of age [in Russian]. Grud Serdechnososudistaia Khir. Sep 1991;11-4. [Medline].

  55. Sholler GF, Colan SD, Sanders SP. Effect of isolated right ventricular outflow obstruction on left ventricular function in infants. Am J Cardiol. Oct 1 1988;62(10 Pt 1):778-84. [Medline].

  56. Simpson WF Jr, Sade RM, Crawford FA, et al. Double-chambered right ventricle. Ann Thorac Surg. Jul 1987;44(1):7-10. [Medline].

  57. Takahashi T, Sakakibara T, Nomura F, et al. A case report of isolated infundibular pulmonary stenosis with pouch of the infundibular chamber [in Japanese]. Nippon Kyobu Geka Gakkai Zasshi. Jun 1989;37(6):1197-201. [Medline].

  58. [Best Evidence] Tanner K, Sabrine N, Wren C. Cardiovascular malformations among preterm infants. Pediatrics. Dec 2005;116(6):e833-8. [Medline].

  59. Tereshchenko VP, Pogrebniak VV, Ishchenko VE, et al. The structure of isolated infundibular stenosis of the pulmonary artery [in Russian]. Vrach Delo. Jun 1990;(6):31-2. [Medline].

  60. Wu MH, Wu JM, Chang CI, et al. Implication of aneurysmal transformation in isolated perimembranous ventricular septal defect. Am J Cardiol. Sep 1 1993;72(7):596-601. [Medline].

  61. Yamagishi M, Nakamura Y, Kanazawa T, Kawada N. Extracardiac direct total cavopulmonary connection. Ann Thorac Surg. Dec 1997;64(6):1817-9; discussion 1819-20. [Medline].

  62. Yamamoto T, Habuchi Y, Morikawa J. Single coronary artery with infundibular pulmonary stenosis. Heart. Aug 1997;78(2):205-6. [Medline].

  63. Zacherl S, Feyertag C, Salzer-Muhar U, Wimmer M. Bacterial endocarditis in childhood [in German]. Klin Padiatr. Mar-Apr 1996;208(2):47-52. [Medline].

 
Previous
Next
 
Chest radiograph of a 2-year-old boy with severe pulmonary stenosis (infundibular). Note the mild cardiomegaly, reduced pulmonary vascularity, and absence of poststenotic dilatation of pulmonary artery.
 
 
 
All material on this website is protected by copyright, Copyright © 1994-2012 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.

DISCLAIMER: The content of this Website is not influenced by sponsors. The site is designed primarily for use by qualified physicians and other medical professionals. The information contained herein should NOT be used as a substitute for the advice of an appropriately qualified and licensed physician or other health care provider. The information provided here is for educational and informational purposes only. In no way should it be considered as offering medical advice. Please check with a physician if you suspect you are ill.