We usually blame cardiac murmurs on the “turbulence” caused by blood flowing past an irregular valve surface but, believe it or not, how the murmur is created has been a matter of controversy. 1-4
For sure, murmurs are generated by disturbance of laminar blood flow (ie, turbulence) but over the years many have argued that turbulence per se fails to produce adequate acoustic force to be audible at the chest wall.2 Although challenged by some,1 the concept of “vortex shedding” borrowed from fluid dynamics is fascinating and has been proposed as a potential explanation.
Per this theory, just as a boulder causes a stream to separate and generate vortices, valves (particularly when abnormal) also create vortices. As the vortices are shed near the valve, they leave in their place relatively calm wakes which are then rapidly filled by flowing blood, creating the sound of a murmur.
Two important variables in this theory are velocity and viscosity. When the velocity of blood flow increases substantially as in high cardiac output states (eg, fever, pregnancy), vortex shedding and the intensity of the murmur also increase. Similar phenomenon may be expected when the blood viscosity is lowered (eg, in anemia).
- Sabbah HN, Stein PD. Turbulent blood flow in humans: Its primary role in the production of ejection murmurs. Circ Res 1976;38: 513-24. https://www.ncbi.nlm.nih.gov/pubmed/1269101
- Alpert MA, Systolic murmurs. In Walker HK, Hall WD, Hurst JW. Clinical methods: The history, physical, and laboratory examinations. 3rd ed. Butterworths, Boston, 1990. https://www.ncbi.nlm.nih.gov/books/NBK345/
- Bruns D. A general theory of the causes of murmurs in the cardiovascular system. Am J Med 1959;27:360-74. http://www.amjmed.com/article/0002-9343(59)90002-6/fulltext
- Guntheroth WG. Innocent murmurs: A suspect diagnosis in non-pregnant adults. Am J Cardiol 2009;104:735-7. https://www.ncbi.nlm.nih.gov/pubmed/19699354
The data on the performance of capillary refill time (CRT) in adults is quite limited and what’s available does not suggest that the commonly cited 2 seconds cutoff is useful in assessing peripheral perfusion in critically ill adults1,2.
For example, a large study involving 1000 healthy adults reported that 45% of participants had a CRT > 2 seconds3. Age also affects CRT with its 95 percentile upper limits reaching 4.5 seconds among healthy adults >60 y old3.
Among patients with septic shock, a baseline median CRT of 5 seconds has been reported. Values <5.0 seconds within 6 hours of treatment of septic shock has also been highly associated with successful resuscitation even before normalization of lactate levels4.
For these reasons, if CRT is used as a measure of peripheral perfusion in critically ill adults, a cut off of 5 seconds, not 2 seconds, may be more appropriate. But just like many other diagnostic tests, CRT should never be interpreted in isolation from other clinical parameters.
- Lima A, Bakker J. Clinical Assessment of peripheral circulation. Critical Care 2015:21: 226-31. https://www.ncbi.nlm.nih.gov/pubmed/25827585
- Lewin J, Maconochie I. Capillary refill time in adults. Emerg Med J 2008;25:325-6. https://www.ncbi.nlm.nih.gov/pubmed/18499809
- Anderson B, Kelly AM, Kerr D, et al. Impact of patient and environmental factors on capillary refill time in adults. Am J Emerg Med 2008;26:62-65. https://www.ncbi.nlm.nih.gov/pubmed/18082783
- Hernandez G, Pedreros C, Veas E, et al. Evolution of peripheral vs metabolic perfusion parameters during septic shock resuscitation. A clinical-physiologic study. J Crit Care 2012;27:283-288. https://www.ncbi.nlm.nih.gov/pubmed/21798706
Yes! That’s because any urinary tract infection (UTI) in men has the potential for prostatic involvement1 —-as high as 83% by one report2.
To make the matters more confusing, patients with acute bacterial prostatitis (ABP) often present with symptoms just like those of UTI such as urinary frequency, dysuria, malaise, fever, and myalgias3. In the elderly, atypical presentation is not uncommon (eg, confusion, incontinence, fall)4. Under these circumstances, bacteriuria and pyuria may also be related to ABP and the prostate exam should be an important part of your evaluation.
Although the sensitivity of prostate tenderness on digital rectal exam varies widely for ABP (9%-100%), a painful exam should raise suspicion for ABP, and by itself may be an independent predictor for clinical and bacteriologic failure of therapy1. Along with tenderness, fluctuance of prostate, particularly in the setting of voiding difficulties and longer duration of symptoms, may also suggest the presence of prostatic abscess5,6.
But be gentle when performing a prostate exam and don’t massage it because you could potentially cause bacteremia and worsening of sepsis!1,7
- Etienne M, Chavanet P, Sibert L, et al. Acute bacterial prostatitis: heterogeneity in diagnostic criteria and management. Retrospective multicentric analysis of 371 patients diagnosed with acute prostatitis. BMC Infectious Diseases 2008;8:12. https://bmcinfectdis.biomedcentral.com/track/pdf/10.1186/1471-2334-8-12?site=bmcinfectdis.biomedcentral.com
- Ulleryd P, Zackrisson B, Aus G, et al. Prostatic involvement in men with febrile urinary tract infection as measured by serum prostate-specific antigen and transrectal ultrasonography. BJU Int 1999;84:470-4. http://onlinelibrary.wiley.com/doi/10.1046/j.1464-410x.1999.00164.x/pdf
- Krieger JN, Nyberg L, Nickel JC. NIH consensus definition and classification. JAMA 1999;282:236-37. http://jamanetwork.com/journals/jama/article-abstract/1030245
- Harper M, Fowlis. Management of urinary tract infections in men. Trends in Urology Gynaecology & Sexual Health. January/February 2007. http://onlinelibrary.wiley.com/doi/10.1002/tre.8/pdf
- Lee DS, Choe HS, Kim HY, et al. Acute bacterial prostatitis and abscess formation. BMC Urology 2016;16:38. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4936164/
- Oliveira P, Andrade JA, Porto HC, et al. Diagnosis and treatment of prostatic abscess. International Braz J Urol 2003;29: 30-34. http://www.scielo.br/pdf/ibju/v29n1/v29n1a06.pdf
- Lipsky BA, Byren I, Hoey CT. Treatment of bacterial prostatitis. Clin Infect Dis 2010; 50:1641-52. https://oup.silverchair-cdn.com/oup/backfile/Content_public/Journal/cid/50/12/10.1086/652861/2/50-12-1641.pdf?Expires=1501276981&Signature=X5SLG2Pq5IpbsjDigES70~Nk6g5onrPwhrFClIAFIvdFiEyCsc1~2aWN9LpR~56DlGqxjmZuIX33JtOn-tURGG0puEwnulZDEDXFjFt6fXucSgtKMDOmGXSKoMvgtPZe86nduJMNDuaifEZXITpDXjSLXAJXVamJ-bbSUMEqSysnCCMxZx~5MaAb6WEikqG5Vi~Xnp58fXABG7BJS~ZFRn2~BTlVEEvmIIDDaY5cJjgUcN7SNOhs0rOS71WzlNtlXSqnXffZEdFSJ~iDcbyRL-wh-9OZqZ2fwojdk8Be89DsKJg8rIh8dlLc5O7v92yL~cZ6iieiP8xTGOU-21tVeA__&Key-Pair-Id=APKAIUCZBIA4LVPAVW3Q
Even in this age of high-tech medicine, physical exam is still a great starting point for assessing the severity of aortic stenosis (AS) even if you are not a skilled cardiologist like most.
Start out by listening over the right clavicle. If you don’t hear a systolic murmur, you can be pretty confident that your patient doesn’t have moderate to severe AS (>98% sensitivity, LR 0.10)1.
If you hear a systolic murmur look for combination of findings that may increase the likelihood of moderate to severe AS: slow carotid artery upstroke, reduced carotid artery volume, maximal murmur intensity at the second right intercostal space, and reduced intensity of the second heart sound. The presence of 3 or 4 of these signs increases the likelihood of moderate to severe AS (LR 40), with less than 3 not helping much1.
When considered individually, many of the signs we often attribute to significant AS2 may not be as helpful in part because most of us are not skilled cardiologists and over the years the cause of AS has changed from primarily rheumatic heart disease-related to that advancing age and valve degeneration3.
So it may not be surprising that murmur intensity (eg grade 3/6 or above) may have a poor sensitivity and is an unreliable predictor of the severity of AS when patients with left ventricular failure are also studied3. Remember also that the absence of the 2nd sound may not distinguish between moderate and severe AS4.
- Etchells E, Glenns V, Shadowitz S, et al. A bedside clinical prediction rule for detecting moderate or severe aortic stenosis. J Gen Intern Med 1998;13:699-704. https://link.springer.com/article/10.1046/j.1525-1497.1998.00207.x
- Etchells EE, Bell C. Robb KV. Does this patient have an abnormal systolic murmur? JAMA 1997;277:564-71. https://www.ncbi.nlm.nih.gov/pubmed/10376577
- Das P, Pocock C, Chambers J. The patient with a systolic murmur: severe aortic stenosis may be missed during cardiovascular examination. Q J Med 2000;93:685-8. https://oup.silverchair-cdn.com/oup/backfile/Content_public/Journal/qjmed/93/10/10.1093_qjmed_93.10.685/1/930685.pdf?Expires=1500852139&Signature=TwyO6Z4fUfbPc1yiA~2xZC7jOjed0juH604DshdvRYy~VqeNQ57Sv1yE-LNsImthgQogkawMruBPdXn6PvVCVmdvXxE9QsMzQYhZ13JqXDTQhRiPBcsIBKDdROr~xbz0gp0nv-zEmjCp1M8-CXjrlVnjVtwJ6q2nIPTRW5h-CUOnDAmf8vCeJHRi2M9Dt3a4vGALDJQPaETvxKDfoADamBDtZHzzoCIH3OyXT3–jHRtv9AJI2uHlzN79Vzkh~oIrR-rI5mkHle3Yz0R3qIBY0l4P3PssMng~v-IXMNKS~Ghjav8YFTigHN23aEA5yUYllsC7hR25L6h9PA0SZP3QA__&Key-Pair-Id=APKAIUCZBIA4LVPAVW3Q
- Aronow WS, Kronzon I. Prevalence and severity of valvular aortic stenosis determined by Doppler echocardiography and its association with echocardiographic and electrocardiographic left ventricular hypertrophy and physical signs of aortic stenosis in elderly patients. Am J Cardiol 1991;67:776-7. https://www.ncbi.nlm.nih.gov/pubmed/1826070
Mitral regurgitation (MR) murmur can radiate to several places on the chest wall as well as the spine and….ready for this…. the top of the head!
Classically, MR is thought to have 4 patterns of radiation1,2.
- Axilla and the inferior angle of the left scapula (typical)
- Left sternal border, base of the heart and into the neck
- Cervical and lumbar spine (down to sacrum)
- Right of the sternum (associated with a “giant left atrium”)
Less well-known and perhaps most intriguing is the radiation of MR to the top of the head. Original reports involved patients who often had ruptured chordae tendineae due to subacute bacterial endocarditis and/or rheumatic heart disease2. It was posited that “the flail portion of the mitral valve folds back into the left atrial cavity forming a hood which deflects the regurgitant stream against the atrial wall”. In the setting of a flail anterior leaflet, if the jet stream is sufficiently high energy and comes in contact with the spine, the murmur may be transmitted by bone conduction to the top of the skull2!
I suggest you explain to your patient what you are doing before you auscultate the top of their heads!
- Chatterjee K. Physical examination. In Topol EJ, ed. Textbook of cardiovascular medicine, 2007, pp 193-224. Lippincott, Williams &Wilkins. Philadelphia. https://books.google.com/books?id=35zSLWyEWbcC&pg=PA219&lpg=PA219&dq=top+of+the+head+mitral+regurgitation+murmur&source=bl&ots=56Erim4eNM&sig=82TrOiU52ojmhVBMG7G2jMULxVo&hl=en&sa=X&ved=0ahUKEwit8_WnmorVAhVGyj4KHcwUC_8Q6AEIRzAF#v=onepage&q=top%20of%20the%20head%20mitral%20regurgitation%20murmur&f=false
- Merendino KA, Hessel EA. The “murmur on top of the head” in acquired mitral insufficiency: Pathological and clinical significance. JAMA 1967;199:892-896. http://jamanetwork.com/journals/jama/article-abstract/663746
Skin atrophy is a common feature of Cushing’s syndrome (CS), a hypercortisol state, with multiple studies reporting radiographic evidence of reduced skin thickness in this condition1,2.
Measurement of skin thickness on the dorsal aspect of the 2nd or 3rd proximal phalanges on the non-dominant hand by using ECG calipers to pinch together a fold of skin has also been reported to assess skin atrophy in CS, with thickness less than 18 mm correlating strongly with CS3,4; the minimal subcutaneous fat at this location allows for a more accurate measurement of skin thickness.
However, caution should be exercised in interpreting the results of this study. Specifically, some overlap was observed between normal controls and patients with CS. In addition, the study population was limited to women of reproductive age presenting with oligomenorrhea and hirsutism for at least 2 years, a subset of patients that may account for only 40% of cases with CS5,6. Further studies are clearly needed to determine the clinical utility of the skin-fold test in patients suspected of CS.
- Sheppard RH, Meema HE. Skin thickness in endocrine disease. A roentgenographic study. Ann Intern Med 1967;66:531-9.
- Ferguson JK, Donald RA, Weston TS, et al. Skin thickness in patients with acromegaly and Cushing’s syndrome and response to treatment. Clin Endocrinol (Oxf) 1983;18:347-53.
- Corenblum B, Kwan T, Gee S, et al. Bedside assessment of skin-fold thickness: A useful measurement for distinguishing Cushing’s disease from other causes of hirsutism and oligomenorrhea. Arch Intern Med. 1994;154:777-781.
- Loriaux DL. Diagnosis and differential diagnosis of Cushing’s syndrome. N Engl J Med 2017;376:1451-9.
- Lindholm J, Juul S, Jorgensen JOL, et al: Incidence and late prognosis of Cushing’s syndrome: a population-based study. J Clin Endocrinol Metab 2001;86:117–123.
- Lado-Abeal J, Rodriguez-Arnao J, Newell-Price JD, et al. Menstrual abnormalities in women with Cushing’s disease are correlated with hypercortisolemia rather than raised circulating androgen levels. J Clin Endocrinol Metab. 1998;83:3083-8.
Contributed by Sagar Raju, Medical Student, Harvard Medical School
Carnett’s sign (described by British surgeon J.B. Carnett in 1926) is a physical exam finding that helps differentiate abdominal wall from intra-abdominal sources of pain.
The test is considered positive when, upon locating the tender abdominal spot, the patient’s pain worsens on tensing of the abdominal wall muscles by lifting the head and shoulders from the bed or by raising both legs with straight knees. Conversely, if the pain decreases with this maneuver, an intra-abdominal source is more likely1,2.
A positive Carnett’s sign should broaden the differential of abdominal pain to include: hernias, irritation of intercostal nerve roots, rectus sheath hematomas, myofascial pain, anterior cutaneous nerve entrapment (latter also discussed in another pearl).
In the appropriate clinical setting, local corticosteroids or anesthetic injections, or the application of hot or cold packs may be therapeutic. 2,3
- Carnett JB. Intercostal neuralgia as a cause of abdominal pain and tenderness. J Surg Gynecol Obstet 1926; 42:625-632.
- Bundrick JB, Litin SC. Clinical pearls in general internal medicine. Mayo Clin Proceedings 2011;86: 70–74. https://mayoclinic.pure.elsevier.com/en/publications/clinical-pearls-in-general-internal-medicine-2
- Suleiman S , Johnston DE. The abdominal wall: an overlooked source of pain. Am Fam Physician 2001; 64: 431-8. https://www.ncbi.nlm.nih.gov/pubmed/11515832
Contributed by Brad Lander MD, Mass General Hospital, Boston, MA.