Is the death of the stethoscope near? Why do we even listen to the heart anyway now that we have portable echocardiography? Is it a waste of time?
When I was in training to become a cardiologist, I was fortunate enough to be taught by physicians who practiced medicine when physical examination skills were essential in diagnosis. We had multiple physical exam lectures and even a dedicated exam on the topic. W. Proctor Harvey (legendary cardiac auscultation expert) was the idol of our program director.
I personally studied and practiced quite hard to learn the details of heart sounds and heart murmurs. I recall as a medical student thinking “I can never go into cardiology since hearing loss runs in my family and I will not be able to examine the heart adequately later in my career.” Then I realized how very few clinicians actually have good cardiac physical exam skills, at least compared to the physicians of old.
The era where the stethoscope is used as the primary means to diagnose heart disease has passed in cardiology now that we have echocardiography and other diagnostic testing as well as markedly less robust cardiac physical exam experience during medical training and the fast pace of medicine.
The Golden Age of Medicine
Sir William Osler once said “Mitral stenosis may be concealed under a quarter of a dollar. It is the most difficult of all heart diseases to diagnose.” Personally, despite good physical exam training and an expensive electronic stethoscope, have never heard a classic murmur of mitral stenosis, yet it is quite simple to diagnose nowadays with echocardiography.
No longer will you see a patient taken directly for aortic valve replacement when the cardiologist heard an aortic regurgitation murmur with an S3 heart sound and new onset heart failure. Now that patient will get a transthoracic echocardiogram, coronary angiogram with hemodynamic assessment, an aortogram and maybe even a transesophageal echocardiogram as well!
No longer do we have the skill to estimate the ejection fraction simply by palpating the PMI (point of maximal impulse/intensity). One skilled attending cardiologist that I worked with and an amazing ability to do just that.
I recall my mentor telling me stories of diagnosing Chagas Disease (which causes a dilated cardiomyopathy) during mission trips to Africa simply by listening for paradoxically split S2 heart sound indicating a left bundle branch block since they had no other diagnostic testing.
In the 19th century in Europe, syphilis was widespread and there were no antibiotics to treat this infectious disease. Syphilitic aortitis was common and caused quite severe aortic regurgitation. Physicians described a vast array of physical exam findings from the high stroke volume present in this valvular disorder. When was the last time you detected on physical examination severe aortic regurgitation causing one of these?
Corrigan's pulse: A rapid and forceful distension of the arterial pulse with a quick collapse.
De Musset's sign: Bobbing of the head with each heartbeat (like a bird walking).
Muller's sign: Visible pulsations of the uvula.
Quincke's sign: Capillary pulsations seen on light compression of the nail bed.
Traube's sign: Systolic and diastolic sounds heard over the femoral artery ("pistol shots").
Duroziez's sign: Gradual pressure over the femoral artery leads to a systolic and diastolic bruit.
Hill's sign: Popliteal systolic blood pressure exceeding brachial systolic blood pressure by 60 mmHg or greater (most sensitive sign for aortic regurgitation).
Shelly's sign: Pulsation of the cervix.
Rosenbach's sign: Hepatic pulsations.
Becker's sign: Visible pulsation of the retinal arterioles.
Gerhardt's sign (aka Sailer's sign): Pulsation of the spleen in the presence of splenomegaly.
Mayne's sign: A decrease in diastolic blood pressure of 15 mmHg when the arm is held above the head (very non-specific).
Landolfi's sign: Systolic contraction and diastolic dilation of the pupil.
I can honestly say that in my 6 years of academic internal medicine and cardiology training and my time in practice, I have seen very few of these findings despite an intense radar to locate them! Perhaps we surgically fix the valves quickly now before the disease progresses...
Look at these guys...THIS is the emphasis that used to be placed on cardiac auscultation:
Should We Throw Out the Stethoscope?
Does that mean that it is worthless to even listen to the heart? Of course not! A stethoscope is cheaper and more readily available then a full echocardiographic examination, however as I will discuss below, cardiac physical examination is markedly less accurate to make the correct diagnosis, especially in mitral and aortic valve regurgitation.
Lets start with aortic valve stenosis. This is the most easily heard on physical examination of the valvular heart diseases. Not only can it be accurately diagnosed with a stethoscope, but the severity can also be determined. Early systolic peaking is mild and late peaking is severe. A normal intensity S2 heart sound is mild and a soft or absent S2 heart sound is severe. Pulsus parvus et tardus is also helpful.
These exam findings were correlated with patient outcomes in a study where physicians used their physical exam skills to diagnose and categorize aortic stenosis murmurs1.
OK...so we have one valve disorder where physical exam is extremely helpful and accurate! How about the rest? While there is not extensive data on comparing cardiac auscultation to echocardiography, here is one intriguing study.
Only 11% of medical students and 33% of cardiology fellows accurately diagnosed mitral regurgitation on examination when it was known to be severe on echocardiography! Well...that speaks to two things: The difficulty in learning cardiac auscultation and the high prevalence of silent murmurs, especially in regurgitant valvular disease.
Portable Echocardiography - Quite Accurate!
Want to do an echocardiogram with your iPhone? Theres an App for that! With portable echocardiography down to the size of an iPhone, will we all be carrying one of these little gadgets in our pocket instead of a stethoscope one day? There is a distinct possibility that this may be in the near future. Sorry Litmann.
The American Society of Echocardiography in 2002 made a statement regarding portable echocardiography7:
“The newest introduction to echocardiography is a hand-carried ultrasound (HCU) device. It is a small echocardiographic machine and can obtain echocardiographic images and data. The American Society of Echocardiography believes that HCU will extend the concept of the complete physical examination, allowing more rapid assessment of cardiovascular anatomy, function and physiology”.
I guess some may ask if clinicians be trained well enough to do a portable echocardiogram accurately and how does it compare to physical examination? One interesting study took 4 cardiologists and 12 patients2. The had the physician use a stethoscope and report their diagnosis. They then performed a portable echocardiogram to try to make the correct diagnosis. There were 6 normal patients and 6 patients with known valvular or structural heart disease (HOCM and VSD).
Check out these results! Physical exam missed more than 50% of significant findings while the portable echocardiography missed only about 30%. Those missed by portable echo were confirmed present on a full transthoracic echo study.
Quite a few other studies did confirm that even non-cardiologists can be easily trained to perform portable echo3-6.
Portable echocardiography has also been utilized extensively in emergency rooms. See this nice review on ultrasound in emergency medicine. Chest pain patients for wall motion abnormalities for risk stratification and trauma patients can be quickly checked for hemopericardium causing cardiac tamponade. Cardiac filling pressures can be estimated to determine if the patient’s shortness of breath is related to congestive heart failure.
Pros and Cons of Cardiac Physical Examination
There are multiple benefits to actually using a stethoscope and examining a patient in my opinion. Certainly I find the cardiac physical exam including heart sounds and heart murmurs academically interesting and challenging as well. Here are the pros:
Physical contact...this creates a bond that psychologically reassures the patient...we should never lose that in medicine.
Exam findings in the outpatient setting can prompt further diagnostic testing.
Listening to the heart with a stethoscope is cheap, quick and readily available.
There are no echo parameters to detect an S3 heart sound, S4 heart sound, or to describe the intensity of heart sounds, so physical examination can detect some things that echo can't
What could the cons be to physical exam? Some may actually NOT prefer physical contact with the patient or physician...did you know that the stethoscope was first invented so physicians did not have to place their ear on the patient’s chest to hear the heart? Here are the cons:
Low sensitivity to detect clinically significant heart disease, especially valve regurgitation.
Difficult to truly become proficient in cardiac physical exam skills and with today’s residency work hour restrictions, clinical experience is more limited during training than ever.
Cardiac Physical Exam - Now What?
Cardiac auscultation is quite a challenging skillset to master. With the abundance of information to learn during medical training and the fast-paced, stressful setting of the current state of medicine, what percentage of students do you think graduate with the ability to identify subtle cardiac findings such as an aortic regurgitation murmur or an S3 or S4 heart sound? I would guess around 10%.
Should we just not listen to the heart and have every student and physician trained in portable echocardiography? Well...the day may come, but my heart is still for the cardiac physical exam! Looks like the American College of Cardiology and American Heart Association Agree with me in their 2006 Guidelines for Valvular Heart Disease8 where they stated:
“As valuable as echocardiography may be, the basic cardiovascular physical examination is still the most appropriate method of screening for cardiac disease and will establish many clinical diagnosis. Echocardiography should not replace the cardiovascular physical examination but can be useful in determining the cause and severity of valvular lesions, particularly in older and/or symptomatic patients.”
Funny side note...here is a Twitter conversation prompted recently by my post (@LearnTheHeart) comparing the S3 heart sound to the S4:
What do you think the future holds for the stethoscope?
- by Steven Lome
Topic Reviews: Heart Sounds
Topic Reviews: Heart Murmurs
1. Munt B et al. Physical Examination in Valvular Aortic Stenosis: Correlation with Stenosis Severity and Prediction of Clinical Outcome. Am Heart J, 1999; 137:298-306.
2. Spencer et al. Physician-performed Point-of-care Echocardiography Using a Laptop Platform Compared with Physical Examination in the Cardiovascular Patient. J Am Coll Card. 2001; 37:2013-2018.
3. Kimura BJ et al. Briefly trained physicians can use hand-held ultrasound device to improve detection of LV-dysfunction. Circulation. 2001;104 (suppl II):334. (abstract).
4. DeCara JM et al. The use of small personal ultrasound devices by internests without formal training in echocardiography. Eur J Echocardiog. 2003;4:141-7.
5. Alexander JH et al. Feasibility of point-of-care echo by non-cardiologist physicians to assess left ventricular function, pericardial effusion, mitral regurgitation and aortic valve thickening. Circulation. 2001;104 (suppl II): 334. (abstract).
6. Lemola K et Al. A hand-carried personal ultrasound device for rapid evaluation of left ventricular function: use after limited echotraining. Circulation. 2001;107 (suppl II):496. (abstract).
7. Seward et al. Hand-carried cardiac ultrasound (HCU) device: Recommendations regarding new technology. A report from the Echocardiography Task Force on New Technology of the Nomenclature and Standards Committee of the American Society of Echocardiography. J Am Soc Echocariogr 2002; 15:369-73.
8. Bonow et al. ACC/AHA 2006 Guidelines for the Management of Patients with Valvular Heart Disease: A Report of the American College of Cardiology/American Heart Association Tak Force on Practice Guidelines. J Am Coll Cardiol, 2006;48;e1-e148.