Cardio Exam

The First Heart Sound



  • The first heart sound (S1) indicates closure of the mitral and tricuspid valves.
  • S1 is normally heard best over the apex.
    • Causes of a Soft S1

    • Mitral regurgitation
    • Ventricular septal defect
    • First degree heart block
    • Left bundle branch block
    • Myocardial depression
    • Causes of a Loud S1

    • Mitral stenosis
    • Hyperdynamic circulation - exercise, infection, hyperthyroidism, pregnancy
Want more info like this?
  • Your electronic clinical medicine handbook
  • Guides to help pass your exams
  • Tools every medical student needs
  • Quick diagrams to have the answers, fast
  • Quizzes to test your knowledge


 Barnard S. Thoracic Incisions. Surgery. 2004; 22(5): 105-107. Bergan JJ, Schmid-Schonbein GW, Smith PD, Nicolaides AN, Boisseau MR. Mechanisms of Disease: Chronic Venous Disease. The New England Journal of Medicine. 2006 Aug; 355(5): 488-498. Betul A. Hatipoglu. Cushing’s Syndrome. Journal of Surgical Oncology. 2012 Oct; 106(5): 565-571.
Butler R, Radhakrishnan R. Dementia. Clinical Evidence. 2012; 9.
 Campbell DB. Thoracic Incisions. Operative Techniques in General Surgery. 2008; 10(2): 77-86. Cheng TO. Grading Murmurs Must Always Indicate the Grading System Used. International Journal of Cardiology. 2009 Jun; 135(2): 143-145. Clark A, Cleland JG. Causes and Treatment of Oedema in Patients with Heart Failure. Nature Reviews Cardiology. 2013 Mar; 10: 156-170. Cotter L. History and Examination of the Cardiovascular System. Medicine. 38(7): 344 - 347. Daniel P Judge, Harry C Dietz, Marfan's syndrome, The Lancet, Volume 366, Issue 9501, 3-9 December 2005, Pages 1965-1976 Del Guidice P. Cutaneous Complications of Intravenous Drug Use. The British Journal of Dermatology. 2004;150(1) . Dihingia P, Pegu AK, Chaliha MS, Baruah KD, Kar S, Pramod GR, Kakati S. Takayasu’s Disease–Spectrum of Manifestations A Case Series. Official Journal of Association of Physicians of India, Assam Chapter.:31. Dornhurst AC. Pulsus Paradoxus. Intensive Care Medicine. 1986; 12: 387-388. Drasner MH, Rame JE, Stevenson LW, Dries DL. Prognostic importance of elevated jugular venous pressure and a third heart sound in patients with heart failure. N Engl J Med. 2001; 345: 574–581. Farrior III JB, Silverman ME. A consideration of the differences between a Janeway's lesion and an Osler's node in infectious endocarditis. Chest. 1976 Aug 1;70(2):239-43. Fowler NO. Adolph RJ. Fourth Sound Gallop or Split First Sound?. The American Journal of Cardiology. 1972 Sept; 30: 441-444. Fuller GN, Hargreaves MR, King DM. Scratch Test in Clinical Examination of the Liver. Lancet. 1988; 331(5878): 181. Getzen JH, Dimond EG. Saga of the Fourth Heart Sound. The American Journal of Cardiology. 1968 Nov; 22(5): 608-613. Gillam PM, Deliyannis AA, Mounsey JP. The Left Parasternal Heave. British Heart Journal. 1964; 26: 726. Gray IR. Paradoxical splitting of the second heart sound. British heart journal. 1956 Jan;18(1):21. Grey JE, Enoch S, Harding KG. ABC of Wound Healing: Venous and Arterial Ulcers. British Medical Journal. 2006 Feb; 332: 347-350. Gunson TH, Oliver GF. Osler's nodes and Janeway lesions. Australasian Journal of Dermatology. 2007 Nov;48(4):251-5. Gupta K, Dhawan A, Abel C, Talley N, Attia J. A Re-evaluation of the Scratch Test for Locating the Liver Edge. BMC gastroenterology. 2013; 13: 35.
Haber R, Khoury R, Kechichian E, Tomb R. Splinter hemorrhages of the nails: a systematic review of clinical features and associated conditions. International journal of dermatology. 2016 Dec;55(12):1304-10.
 Hass PL. Differentiation and Diagnosis of Jaundice. AACN Clinical Issues. 1999; 10(4): 433-441. Henkind SJ, Benis AM, Teichholz LE. The Paradox of Pulsus Paradoxus. American Heart Journal/ 1987; 114: 198-203. Holleman DR, Simel DL. Does the Clinical Examination Predict Airflow Limitation?. JAMA. 1995 Jan; 273(4): 313-319. Jansson L, Lavstedt S, Frithiof L, Theobald H. Relationship between oral health and mortality in cardiovascular diseases. Journal of Clinical Periodontology. 2001 Aug; 28(8): 762-768.
Jebb S. Obesity: causes and consequences. Women's Health Medicine. 2004;1:38-41.
 Kalantar J, Talley N. Unexplained weight loss. Current Therapeutics. 1998; 39: 37-43.
Keren R, Tereschuk M, Luan X. Evaluation of a Novel Method for Grading Heart Murmur Intensity. Arch Pedtr Adolesc Med. 2005. 159(4): 329-334.
 Khare N, Puri V, Venkateshwaran N. Trophic Ulcers - Practical Management Guidelines. Indian Journal of Plastic Surgery. 2012; 45(2): 340-351. Kidd HR. Examination of the Mouth. Canadian Family Physician. 1976 May; 22: 59-62. Kirby B, MacLeod K. Clinical examination of the heart. Medicine. 2006 Apr; 34(4): 123-128. Lear SA, James PT, Ko GT, Kumanyika S. Appropriateness of waist circumference and waist-to-hip ratio cutoffs for different ethnic groups. Eur J Clin Nutr. 2010;64:42-61. Leatham A. Auscultation of the heart. Lancet. 1958; 2: 702-708 757-765. Lee WH, Fisher J. Right Ventricular Diastolic Disorders.Archives of Internal Medicine. 1983 Feb; 143: 332-337. Lembo NJ, Dell’Italia LJ, Crawford MH, O’Rourke RA. Bedside Diagnosis of Systolic Murmurs. The New England Journal of Medicine. 1988; 318(24): 1572-1578. Loeys BL, Dietz HC, Braverman AC, Callewaert BL, De Backer J, Devereux RB, Hilhorst-Hofstee Y, Jondeau G, Faivre L, Milewicz DM, Pyeritz RE. The revised Ghent nosology for the Marfan syndrome. Journal of medical genetics. 2010 Jul 1;47(7):476-85. Lucy Flanders, Robert Tulloh, Cardiac problems in Down syndrome, Paediatrics and Child Health, Volume 21, Issue 1, January 2011, Pages 25-31
Malnick SDH, Knobler H. The medical complications of obesity. QJM : monthly journal of the Association of Physicians. 2006;99:565-579.
Margolies A, Wolferth CC. The opening snap (claquement d'ouverture de la mitrale) in mitral stenosis, its characteristics, mechanism of production and diagnostic importance. American Heart Journal. 1932 Apr 1;7(4):443-70.
 McLoughlin MJ, Colapinto RF, Hobbs BB. Abdominal Bruits: Clinical and Angiographic Correlation. JAMA. 1975 Jun; 232(12): 1238-1242. McLoughlin MJ, Colapinto RJ, Hobbs BB. Abdominal bruits. Clinical and angiographic correlation. JAMA. 1975 Jun 23;232(12):1238-42. McMullen SM, Ward P. Cyanosis. The American Journal of Medicine. 2013; 126(3): 210-212. Merrigan JM, Hamdan A, Lynm C, Livingston EH. Varicose Veins. JAMA. 2012; 308(24): 2638. Morgan T. Turner syndrome: diagnosis and management. American family physician. 2007 Aug 1;76(3). N Assy, G Jacob, G Spira and Y Edoute. Diagnostic approach to patients with cholestatic jaundice. WJG, 1999 June; 5(3):252-262 Nancy J Roizen, David Patterson, Down's syndrome, The Lancet, Volume 361, Issue 9365, 12 April 2003, Pages 1281-1289 O'Rahilly R, The normal cardiac apex and apex beat: A critical review of recent data. American Heart Journal. 1952 Jul; 44(1): 23-34. O’Neill TW, Smith M, Barry M, Graham IM. Diagnostic Value of the Apex Beat. Lancet. 1989 Feb; 334(8661): 499. O’Sullivan OC. On the Nature of High Arched Palate. British Medical Journal. 1934 May; 1(3826): 800. Parker F. Xanthomas and Hyperlipidaemias. Journal of the American Academy of Dermatology. 1985 Jul; 13(1): 1-30. Parmet S. Pericarditis. JAMA. 2003; 289: 1194. Pedersen SD. Metabolic complications of obesity. Best practice & research.Clinical endocrinology & metabolism. 2013;27:179. Perloff JK. Cardiac Auscultation. Disease-a-Month. 1980 Jun; 26(9): 1-47. Phillips JH, Burch GE. Selected Clues in Cardiac Auscultation. American Heart Journal. 1962 Jan; 63(1): 1-8. Pickett CA, Jackson JL, Hemann BA, Atwood JA. Carotid Artery Examination, an Important Tool in Patient Evaluation. Southern Medical Journal. 2011 Jul; 104(7): 526-532. Pozo AL, Godfrey EM, Bowles KM. Splenomegaly: Investigation, Diagnosis and Management. Blood Reviews. 2009 May; 23(3): 105-111. Shively BK. Infective Endocarditis. Current Treatment Options in Cardiovascular Medicine. 2001; 3: 25-35. Smith J. Compartment Syndrome. JAAPA. 2013 Sept; 26(9): 48-49. Sybert VP, McCauley E. Turner's Syndrome. The New England journal of medicine. 2004; 351(12): 1227-38. Teasdale G, Jennett B. Assessment of Coma and Impaired Consciousness: a practical scale. Lancet. 1974 July; 304(7872): 81-84. Timmis AJ. The Third Heart Sound. British Medical Journal. 1987. 294: 326-327. Tracy CM, Epstein AE, Darbar D, DiMarco JP, Dunbar SB, Estes M. 2012 ACCF/AHA/HRS Focused Update of the 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities: A Report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Journal of the American College of Cardiology. 2012; 60(14): 1297-1313. Troughton RW, Asher CR, Klein AL. Pericarditis. The Lancet. 2004; 363: 717-727. Tuy T, Peacock WF. Fluid Overload Assessment and Management in Heart Failure Patients. Semin Nephrol. 2012;32:112-120. Uzun G, Mutluoglu M. Dependent Rubor. The New England Journal of Medicine. 2011 Jun; 364(26). Woodgate P1, Jardine LA. Neonatal jaundice: phototherapy. BMJ Clin Evid. 2015 May 22;2015. pii: 0319.
Wright SM, Aronne LJ. Causes of obesity. Abdom Imaging. 2012;37:730-732.
 Yasney J. The value of optimising dentition before cardiac surgery. Journal of Cardiothoracic and Vascular Anaesthesia. 2007 Aug; 21(4): 587-591. Yernault JC, Bohadana AB. Chest Percussion. Eur Respir J. 1995; 8: 1756-1760. Zulkowski K, Ratliff CR. Managing Venous and Neuropathic Ulcers. Nursing. 2004 Aug; 24(8): 68.